Initial commit

neo/renderer/jpeg-6/jcapimin.cpp

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+/*
+ * jcapimin.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the compression half
+ * of the JPEG library.  These are the "minimum" API routines that may be
+ * needed in either the normal full-compression case or the transcoding-only
+ * case.
+ *
+ * Most of the routines intended to be called directly by an application
+ * are in this file or in jcapistd.c.  But also see jcparam.c for
+ * parameter-setup helper routines, jcomapi.c for routines shared by
+ * compression and decompression, and jctrans.c for the transcoding case.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Initialization of a JPEG compression object.
+ * The error manager must already be set up (in case memory manager fails).
+ */
+
+GLOBAL void
+jpeg_create_compress( j_compress_ptr cinfo ) {
+    int i;
+
+    /* For debugging purposes, zero the whole master structure.
+     * But error manager pointer is already there, so save and restore it.
+     */
+    {
+        struct jpeg_error_mgr * err = cinfo->err;
+        MEMZERO( cinfo, SIZEOF( struct jpeg_compress_struct ) );
+        cinfo->err = err;
+    }
+    cinfo->is_decompressor = FALSE;
+
+    /* Initialize a memory manager instance for this object */
+    jinit_memory_mgr( (j_common_ptr) cinfo );
+
+    /* Zero out pointers to permanent structures. */
+    cinfo->progress = NULL;
+    cinfo->dest = NULL;
+
+    cinfo->comp_info = NULL;
+
+    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
+        cinfo->quant_tbl_ptrs[i] = NULL;
+    }
+
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        cinfo->dc_huff_tbl_ptrs[i] = NULL;
+        cinfo->ac_huff_tbl_ptrs[i] = NULL;
+    }
+
+    cinfo->input_gamma = 1.0;/* in case application forgets */
+
+    /* OK, I'm ready */
+    cinfo->global_state = CSTATE_START;
+}
+
+
+/*
+ * Destruction of a JPEG compression object
+ */
+
+GLOBAL void
+jpeg_destroy_compress( j_compress_ptr cinfo ) {
+    jpeg_destroy( (j_common_ptr) cinfo );/* use common routine */
+}
+
+
+/*
+ * Abort processing of a JPEG compression operation,
+ * but don't destroy the object itself.
+ */
+
+GLOBAL void
+jpeg_abort_compress( j_compress_ptr cinfo ) {
+    jpeg_abort( (j_common_ptr) cinfo );/* use common routine */
+}
+
+
+/*
+ * Forcibly suppress or un-suppress all quantization and Huffman tables.
+ * Marks all currently defined tables as already written (if suppress)
+ * or not written (if !suppress).  This will control whether they get emitted
+ * by a subsequent jpeg_start_compress call.
+ *
+ * This routine is exported for use by applications that want to produce
+ * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
+ * since it is called by jpeg_start_compress, we put it here --- otherwise
+ * jcparam.o would be linked whether the application used it or not.
+ */
+
+GLOBAL void
+jpeg_suppress_tables( j_compress_ptr cinfo, boolean suppress ) {
+    int i;
+    JQUANT_TBL * qtbl;
+    JHUFF_TBL * htbl;
+
+    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
+        if ( ( qtbl = cinfo->quant_tbl_ptrs[i] ) != NULL ) {
+            qtbl->sent_table = suppress;
+        }
+    }
+
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        if ( ( htbl = cinfo->dc_huff_tbl_ptrs[i] ) != NULL ) {
+            htbl->sent_table = suppress;
+        }
+        if ( ( htbl = cinfo->ac_huff_tbl_ptrs[i] ) != NULL ) {
+            htbl->sent_table = suppress;
+        }
+    }
+}
+
+
+/*
+ * Finish JPEG compression.
+ *
+ * If a multipass operating mode was selected, this may do a great deal of
+ * work including most of the actual output.
+ */
+
+GLOBAL void
+jpeg_finish_compress( j_compress_ptr cinfo ) {
+    JDIMENSION iMCU_row;
+
+    if ( ( cinfo->global_state == CSTATE_SCANNING ) ||
+        ( cinfo->global_state == CSTATE_RAW_OK ) ) {
+        /* Terminate first pass */
+        if ( cinfo->next_scanline < cinfo->image_height ) {
+            ERREXIT( cinfo, JERR_TOO_LITTLE_DATA );
+        }
+        ( *cinfo->master->finish_pass )( cinfo );
+    } else if ( cinfo->global_state != CSTATE_WRCOEFS ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Perform any remaining passes */
+    while ( !cinfo->master->is_last_pass ) {
+        ( *cinfo->master->prepare_for_pass )( cinfo );
+        for ( iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++ ) {
+            if ( cinfo->progress != NULL ) {
+                cinfo->progress->pass_counter = (long) iMCU_row;
+                cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
+                ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+            }
+            /* We bypass the main controller and invoke coef controller directly;
+             * all work is being done from the coefficient buffer.
+             */
+            if ( !( *cinfo->coef->compress_data )( cinfo, (JSAMPIMAGE) NULL ) ) {
+                ERREXIT( cinfo, JERR_CANT_SUSPEND );
+            }
+        }
+        ( *cinfo->master->finish_pass )( cinfo );
+    }
+    /* Write EOI, do final cleanup */
+    ( *cinfo->marker->write_file_trailer )( cinfo );
+    ( *cinfo->dest->term_destination )( cinfo );
+    /* We can use jpeg_abort to release memory and reset global_state */
+    jpeg_abort( (j_common_ptr) cinfo );
+}
+
+
+/*
+ * Write a special marker.
+ * This is only recommended for writing COM or APPn markers.
+ * Must be called after jpeg_start_compress() and before
+ * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
+ */
+
+GLOBAL void
+jpeg_write_marker( j_compress_ptr cinfo, int marker,
+                   const JOCTET * dataptr, unsigned int datalen ) {
+    if ( ( cinfo->next_scanline != 0 ) ||
+        ( ( cinfo->global_state != CSTATE_SCANNING ) &&
+         ( cinfo->global_state != CSTATE_RAW_OK ) &&
+         ( cinfo->global_state != CSTATE_WRCOEFS ) ) ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    ( *cinfo->marker->write_any_marker )( cinfo, marker, dataptr, datalen );
+}
+
+
+/*
+ * Alternate compression function: just write an abbreviated table file.
+ * Before calling this, all parameters and a data destination must be set up.
+ *
+ * To produce a pair of files containing abbreviated tables and abbreviated
+ * image data, one would proceed as follows:
+ *
+ *		initialize JPEG object
+ *		set JPEG parameters
+ *		set destination to table file
+ *		jpeg_write_tables(cinfo);
+ *		set destination to image file
+ *		jpeg_start_compress(cinfo, FALSE);
+ *		write data...
+ *		jpeg_finish_compress(cinfo);
+ *
+ * jpeg_write_tables has the side effect of marking all tables written
+ * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
+ * will not re-emit the tables unless it is passed write_all_tables=TRUE.
+ */
+
+GLOBAL void
+jpeg_write_tables( j_compress_ptr cinfo ) {
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    /* (Re)initialize error mgr and destination modules */
+    ( *cinfo->err->reset_error_mgr )( (j_common_ptr) cinfo );
+    ( *cinfo->dest->init_destination )( cinfo );
+    /* Initialize the marker writer ... bit of a crock to do it here. */
+    jinit_marker_writer( cinfo );
+    /* Write them tables! */
+    ( *cinfo->marker->write_tables_only )( cinfo );
+    /* And clean up. */
+    ( *cinfo->dest->term_destination )( cinfo );
+    /* We can use jpeg_abort to release memory. */
+    jpeg_abort( (j_common_ptr) cinfo );
+}

neo/renderer/jpeg-6/jcapistd.cpp

@@ -0,0 +1,167 @@
+/*
+ * jcapistd.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the compression half
+ * of the JPEG library.  These are the "standard" API routines that are
+ * used in the normal full-compression case.  They are not used by a
+ * transcoding-only application.  Note that if an application links in
+ * jpeg_start_compress, it will end up linking in the entire compressor.
+ * We thus must separate this file from jcapimin.c to avoid linking the
+ * whole compression library into a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Compression initialization.
+ * Before calling this, all parameters and a data destination must be set up.
+ *
+ * We require a write_all_tables parameter as a failsafe check when writing
+ * multiple datastreams from the same compression object.  Since prior runs
+ * will have left all the tables marked sent_table=TRUE, a subsequent run
+ * would emit an abbreviated stream (no tables) by default.  This may be what
+ * is wanted, but for safety's sake it should not be the default behavior:
+ * programmers should have to make a deliberate choice to emit abbreviated
+ * images.  Therefore the documentation and examples should encourage people
+ * to pass write_all_tables=TRUE; then it will take active thought to do the
+ * wrong thing.
+ */
+
+GLOBAL void
+jpeg_start_compress( j_compress_ptr cinfo, boolean write_all_tables ) {
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    if ( write_all_tables ) {
+        jpeg_suppress_tables( cinfo, FALSE );
+    }                                   /* mark all tables to be written */
+
+    /* (Re)initialize error mgr and destination modules */
+    ( *cinfo->err->reset_error_mgr )( (j_common_ptr) cinfo );
+    ( *cinfo->dest->init_destination )( cinfo );
+    /* Perform master selection of active modules */
+    jinit_compress_master( cinfo );
+    /* Set up for the first pass */
+    ( *cinfo->master->prepare_for_pass )( cinfo );
+    /* Ready for application to drive first pass through jpeg_write_scanlines
+     * or jpeg_write_raw_data.
+     */
+    cinfo->next_scanline = 0;
+    cinfo->global_state = ( cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING );
+}
+
+
+/*
+ * Write some scanlines of data to the JPEG compressor.
+ *
+ * The return value will be the number of lines actually written.
+ * This should be less than the supplied num_lines only in case that
+ * the data destination module has requested suspension of the compressor,
+ * or if more than image_height scanlines are passed in.
+ *
+ * Note: we warn about excess calls to jpeg_write_scanlines() since
+ * this likely signals an application programmer error.  However,
+ * excess scanlines passed in the last valid call are *silently* ignored,
+ * so that the application need not adjust num_lines for end-of-image
+ * when using a multiple-scanline buffer.
+ */
+
+GLOBAL JDIMENSION
+jpeg_write_scanlines( j_compress_ptr cinfo, JSAMPARRAY scanlines,
+                      JDIMENSION num_lines ) {
+    JDIMENSION row_ctr, rows_left;
+
+    if ( cinfo->global_state != CSTATE_SCANNING ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    if ( cinfo->next_scanline >= cinfo->image_height ) {
+        WARNMS( cinfo, JWRN_TOO_MUCH_DATA );
+    }
+
+    /* Call progress monitor hook if present */
+    if ( cinfo->progress != NULL ) {
+        cinfo->progress->pass_counter = (long) cinfo->next_scanline;
+        cinfo->progress->pass_limit = (long) cinfo->image_height;
+        ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+    }
+
+    /* Give master control module another chance if this is first call to
+     * jpeg_write_scanlines.  This lets output of the frame/scan headers be
+     * delayed so that application can write COM, etc, markers between
+     * jpeg_start_compress and jpeg_write_scanlines.
+     */
+    if ( cinfo->master->call_pass_startup ) {
+        ( *cinfo->master->pass_startup )( cinfo );
+    }
+
+    /* Ignore any extra scanlines at bottom of image. */
+    rows_left = cinfo->image_height - cinfo->next_scanline;
+    if ( num_lines > rows_left ) {
+        num_lines = rows_left;
+    }
+
+    row_ctr = 0;
+    ( *cinfo->main->process_data )( cinfo, scanlines, &row_ctr, num_lines );
+    cinfo->next_scanline += row_ctr;
+    return row_ctr;
+}
+
+
+/*
+ * Alternate entry point to write raw data.
+ * Processes exactly one iMCU row per call, unless suspended.
+ */
+
+GLOBAL JDIMENSION
+jpeg_write_raw_data( j_compress_ptr cinfo, JSAMPIMAGE data,
+                     JDIMENSION num_lines ) {
+    JDIMENSION lines_per_iMCU_row;
+
+    if ( cinfo->global_state != CSTATE_RAW_OK ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    if ( cinfo->next_scanline >= cinfo->image_height ) {
+        WARNMS( cinfo, JWRN_TOO_MUCH_DATA );
+        return 0;
+    }
+
+    /* Call progress monitor hook if present */
+    if ( cinfo->progress != NULL ) {
+        cinfo->progress->pass_counter = (long) cinfo->next_scanline;
+        cinfo->progress->pass_limit = (long) cinfo->image_height;
+        ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+    }
+
+    /* Give master control module another chance if this is first call to
+     * jpeg_write_raw_data.  This lets output of the frame/scan headers be
+     * delayed so that application can write COM, etc, markers between
+     * jpeg_start_compress and jpeg_write_raw_data.
+     */
+    if ( cinfo->master->call_pass_startup ) {
+        ( *cinfo->master->pass_startup )( cinfo );
+    }
+
+    /* Verify that at least one iMCU row has been passed. */
+    lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
+    if ( num_lines < lines_per_iMCU_row ) {
+        ERREXIT( cinfo, JERR_BUFFER_SIZE );
+    }
+
+    /* Directly compress the row. */
+    if ( !( *cinfo->coef->compress_data )( cinfo, data ) ) {
+        /* If compressor did not consume the whole row, suspend processing. */
+        return 0;
+    }
+
+    /* OK, we processed one iMCU row. */
+    cinfo->next_scanline += lines_per_iMCU_row;
+    return lines_per_iMCU_row;
+}

neo/renderer/jpeg-6/jccoefct.cpp

@@ -0,0 +1,449 @@
+/*
+ * jccoefct.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the coefficient buffer controller for compression.
+ * This controller is the top level of the JPEG compressor proper.
+ * The coefficient buffer lies between forward-DCT and entropy encoding steps.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* We use a full-image coefficient buffer when doing Huffman optimization,
+ * and also for writing multiple-scan JPEG files.  In all cases, the DCT
+ * step is run during the first pass, and subsequent passes need only read
+ * the buffered coefficients.
+ */
+#ifdef ENTROPY_OPT_SUPPORTED
+#define FULL_COEF_BUFFER_SUPPORTED
+#else
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+#define FULL_COEF_BUFFER_SUPPORTED
+#endif
+#endif
+
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_c_coef_controller pub;/* public fields */
+
+    JDIMENSION iMCU_row_num;/* iMCU row # within image */
+    JDIMENSION mcu_ctr;     /* counts MCUs processed in current row */
+    int        MCU_vert_offset; /* counts MCU rows within iMCU row */
+    int        MCU_rows_per_iMCU_row; /* number of such rows needed */
+
+    /* For single-pass compression, it's sufficient to buffer just one MCU
+     * (although this may prove a bit slow in practice).  We allocate a
+     * workspace of C_MAX_BLOCKS_IN_MCU coefficient blocks, and reuse it for each
+     * MCU constructed and sent.  (On 80x86, the workspace is FAR even though
+     * it's not really very big; this is to keep the module interfaces unchanged
+     * when a large coefficient buffer is necessary.)
+     * In multi-pass modes, this array points to the current MCU's blocks
+     * within the virtual arrays.
+     */
+    JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
+
+    /* In multi-pass modes, we need a virtual block array for each component. */
+    jvirt_barray_ptr whole_image[MAX_COMPONENTS];
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+
+/* Forward declarations */
+METHODDEF boolean compress_data
+JPP( ( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) );
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+METHODDEF boolean compress_first_pass
+JPP( ( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) );
+METHODDEF boolean compress_output
+JPP( ( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) );
+#endif
+
+
+LOCAL void
+start_iMCU_row( j_compress_ptr cinfo ) {
+/* Reset within-iMCU-row counters for a new row */
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+    /* In an interleaved scan, an MCU row is the same as an iMCU row.
+     * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+     * But at the bottom of the image, process only what's left.
+     */
+    if ( cinfo->comps_in_scan > 1 ) {
+        coef->MCU_rows_per_iMCU_row = 1;
+    } else {
+        if ( coef->iMCU_row_num < ( cinfo->total_iMCU_rows - 1 ) ) {
+            coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+        } else {
+            coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+        }
+    }
+
+    coef->mcu_ctr = 0;
+    coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF void
+start_pass_coef( j_compress_ptr cinfo, J_BUF_MODE pass_mode ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+    coef->iMCU_row_num = 0;
+    start_iMCU_row( cinfo );
+
+    switch ( pass_mode ) {
+        case JBUF_PASS_THRU:
+            if ( coef->whole_image[0] != NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+            coef->pub.compress_data = compress_data;
+            break;
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+        case JBUF_SAVE_AND_PASS:
+            if ( coef->whole_image[0] == NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+            coef->pub.compress_data = compress_first_pass;
+            break;
+        case JBUF_CRANK_DEST:
+            if ( coef->whole_image[0] == NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+            coef->pub.compress_data = compress_output;
+            break;
+#endif
+        default:
+            ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            break;
+    }
+}
+
+
+/*
+ * Process some data in the single-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the image.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf contains a plane for each component in image.
+ * For single pass, this is the same as the components in the scan.
+ */
+
+METHODDEF boolean
+compress_data( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION MCU_col_num; /* index of current MCU within row */
+    JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+    JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+    int blkn, bi, ci, yindex, yoffset, blockcnt;
+    JDIMENSION ypos, xpos;
+    jpeg_component_info * compptr;
+
+    /* Loop to write as much as one whole iMCU row */
+    for ( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+          yoffset++ ) {
+        for ( MCU_col_num = coef->mcu_ctr; MCU_col_num <= last_MCU_col;
+              MCU_col_num++ ) {
+            /* Determine where data comes from in input_buf and do the DCT thing.
+             * Each call on forward_DCT processes a horizontal row of DCT blocks
+             * as wide as an MCU; we rely on having allocated the MCU_buffer[] blocks
+             * sequentially.  Dummy blocks at the right or bottom edge are filled in
+             * specially.  The data in them does not matter for image reconstruction,
+             * so we fill them with values that will encode to the smallest amount of
+             * data, viz: all zeroes in the AC entries, DC entries equal to previous
+             * block's DC value.  (Thanks to Thomas Kinsman for this idea.)
+             */
+            blkn = 0;
+            for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+                compptr = cinfo->cur_comp_info[ci];
+                blockcnt = ( MCU_col_num < last_MCU_col ) ? compptr->MCU_width
+                           : compptr->last_col_width;
+                xpos = MCU_col_num * compptr->MCU_sample_width;
+                ypos = yoffset * DCTSIZE;/* ypos == (yoffset+yindex) * DCTSIZE */
+                for ( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
+                    if ( ( coef->iMCU_row_num < last_iMCU_row ) ||
+                        ( yoffset + yindex < compptr->last_row_height ) ) {
+                        ( *cinfo->fdct->forward_DCT )( cinfo, compptr,
+                                                       input_buf[ci], coef->MCU_buffer[blkn],
+                                                       ypos, xpos, (JDIMENSION) blockcnt );
+                        if ( blockcnt < compptr->MCU_width ) {
+                            /* Create some dummy blocks at the right edge of the image. */
+                            jzero_far( (void FAR *) coef->MCU_buffer[blkn + blockcnt],
+                                      ( compptr->MCU_width - blockcnt ) * SIZEOF( JBLOCK ) );
+                            for ( bi = blockcnt; bi < compptr->MCU_width; bi++ ) {
+                                coef->MCU_buffer[blkn + bi][0][0] = coef->MCU_buffer[blkn + bi - 1][0][0];
+                            }
+                        }
+                    } else {
+                        /* Create a row of dummy blocks at the bottom of the image. */
+                        jzero_far( (void FAR *) coef->MCU_buffer[blkn],
+                                  compptr->MCU_width * SIZEOF( JBLOCK ) );
+                        for ( bi = 0; bi < compptr->MCU_width; bi++ ) {
+                            coef->MCU_buffer[blkn + bi][0][0] = coef->MCU_buffer[blkn - 1][0][0];
+                        }
+                    }
+                    blkn += compptr->MCU_width;
+                    ypos += DCTSIZE;
+                }
+            }
+            /* Try to write the MCU.  In event of a suspension failure, we will
+             * re-DCT the MCU on restart (a bit inefficient, could be fixed...)
+             */
+            if ( !( *cinfo->entropy->encode_mcu )( cinfo, coef->MCU_buffer ) ) {
+                /* Suspension forced; update state counters and exit */
+                coef->MCU_vert_offset = yoffset;
+                coef->mcu_ctr = MCU_col_num;
+                return FALSE;
+            }
+        }
+        /* Completed an MCU row, but perhaps not an iMCU row */
+        coef->mcu_ctr = 0;
+    }
+    /* Completed the iMCU row, advance counters for next one */
+    coef->iMCU_row_num++;
+    start_iMCU_row( cinfo );
+    return TRUE;
+}
+
+
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+
+/*
+ * Process some data in the first pass of a multi-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the image.
+ * This amount of data is read from the source buffer, DCT'd and quantized,
+ * and saved into the virtual arrays.  We also generate suitable dummy blocks
+ * as needed at the right and lower edges.  (The dummy blocks are constructed
+ * in the virtual arrays, which have been padded appropriately.)  This makes
+ * it possible for subsequent passes not to worry about real vs. dummy blocks.
+ *
+ * We must also emit the data to the entropy encoder.  This is conveniently
+ * done by calling compress_output() after we've loaded the current strip
+ * of the virtual arrays.
+ *
+ * NB: input_buf contains a plane for each component in image.  All
+ * components are DCT'd and loaded into the virtual arrays in this pass.
+ * However, it may be that only a subset of the components are emitted to
+ * the entropy encoder during this first pass; be careful about looking
+ * at the scan-dependent variables (MCU dimensions, etc).
+ */
+
+METHODDEF boolean
+compress_first_pass( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+    JDIMENSION blocks_across, MCUs_across, MCUindex;
+    int bi, ci, h_samp_factor, block_row, block_rows, ndummy;
+    JCOEF lastDC;
+    jpeg_component_info * compptr;
+    JBLOCKARRAY buffer;
+    JBLOCKROW thisblockrow, lastblockrow;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Align the virtual buffer for this component. */
+        buffer = ( *cinfo->mem->access_virt_barray )
+                 ( (j_common_ptr) cinfo, coef->whole_image[ci],
+                  coef->iMCU_row_num * compptr->v_samp_factor,
+                  (JDIMENSION) compptr->v_samp_factor, TRUE );
+        /* Count non-dummy DCT block rows in this iMCU row. */
+        if ( coef->iMCU_row_num < last_iMCU_row ) {
+            block_rows = compptr->v_samp_factor;
+        } else {
+            /* NB: can't use last_row_height here, since may not be set! */
+            block_rows = (int) ( compptr->height_in_blocks % compptr->v_samp_factor );
+            if ( block_rows == 0 ) {
+                block_rows = compptr->v_samp_factor;
+            }
+        }
+        blocks_across = compptr->width_in_blocks;
+        h_samp_factor = compptr->h_samp_factor;
+        /* Count number of dummy blocks to be added at the right margin. */
+        ndummy = (int) ( blocks_across % h_samp_factor );
+        if ( ndummy > 0 ) {
+            ndummy = h_samp_factor - ndummy;
+        }
+        /* Perform DCT for all non-dummy blocks in this iMCU row.  Each call
+         * on forward_DCT processes a complete horizontal row of DCT blocks.
+         */
+        for ( block_row = 0; block_row < block_rows; block_row++ ) {
+            thisblockrow = buffer[block_row];
+            ( *cinfo->fdct->forward_DCT )( cinfo, compptr,
+                                           input_buf[ci], thisblockrow,
+                                           (JDIMENSION) ( block_row * DCTSIZE ),
+                                           (JDIMENSION) 0, blocks_across );
+            if ( ndummy > 0 ) {
+                /* Create dummy blocks at the right edge of the image. */
+                thisblockrow += blocks_across;/* => first dummy block */
+                jzero_far( (void FAR *) thisblockrow, ndummy * SIZEOF( JBLOCK ) );
+                lastDC = thisblockrow[-1][0];
+                for ( bi = 0; bi < ndummy; bi++ ) {
+                    thisblockrow[bi][0] = lastDC;
+                }
+            }
+        }
+        /* If at end of image, create dummy block rows as needed.
+         * The tricky part here is that within each MCU, we want the DC values
+         * of the dummy blocks to match the last real block's DC value.
+         * This squeezes a few more bytes out of the resulting file...
+         */
+        if ( coef->iMCU_row_num == last_iMCU_row ) {
+            blocks_across += ndummy;/* include lower right corner */
+            MCUs_across = blocks_across / h_samp_factor;
+            for ( block_row = block_rows; block_row < compptr->v_samp_factor;
+                  block_row++ ) {
+                thisblockrow = buffer[block_row];
+                lastblockrow = buffer[block_row - 1];
+                jzero_far( (void FAR *) thisblockrow,
+                          (size_t) ( blocks_across * SIZEOF( JBLOCK ) ) );
+                for ( MCUindex = 0; MCUindex < MCUs_across; MCUindex++ ) {
+                    lastDC = lastblockrow[h_samp_factor - 1][0];
+                    for ( bi = 0; bi < h_samp_factor; bi++ ) {
+                        thisblockrow[bi][0] = lastDC;
+                    }
+                    thisblockrow += h_samp_factor;/* advance to next MCU in row */
+                    lastblockrow += h_samp_factor;
+                }
+            }
+        }
+    }
+    /* NB: compress_output will increment iMCU_row_num if successful.
+     * A suspension return will result in redoing all the work above next time.
+     */
+
+    /* Emit data to the entropy encoder, sharing code with subsequent passes */
+    return compress_output( cinfo, input_buf );
+}
+
+
+/*
+ * Process some data in subsequent passes of a multi-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the entropy coder.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf is ignored; it is likely to be a NULL pointer.
+ */
+
+METHODDEF boolean
+compress_output( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION MCU_col_num; /* index of current MCU within row */
+    int blkn, ci, xindex, yindex, yoffset;
+    JDIMENSION start_col;
+    JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+    JBLOCKROW buffer_ptr;
+    jpeg_component_info * compptr;
+
+    /* Align the virtual buffers for the components used in this scan.
+     * NB: during first pass, this is safe only because the buffers will
+     * already be aligned properly, so jmemmgr.c won't need to do any I/O.
+     */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        buffer[ci] = ( *cinfo->mem->access_virt_barray )
+                     ( (j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+                      coef->iMCU_row_num * compptr->v_samp_factor,
+                      (JDIMENSION) compptr->v_samp_factor, FALSE );
+    }
+
+    /* Loop to process one whole iMCU row */
+    for ( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+          yoffset++ ) {
+        for ( MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
+              MCU_col_num++ ) {
+            /* Construct list of pointers to DCT blocks belonging to this MCU */
+            blkn = 0;   /* index of current DCT block within MCU */
+            for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+                compptr = cinfo->cur_comp_info[ci];
+                start_col = MCU_col_num * compptr->MCU_width;
+                for ( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
+                    buffer_ptr = buffer[ci][yindex + yoffset] + start_col;
+                    for ( xindex = 0; xindex < compptr->MCU_width; xindex++ ) {
+                        coef->MCU_buffer[blkn++] = buffer_ptr++;
+                    }
+                }
+            }
+            /* Try to write the MCU. */
+            if ( !( *cinfo->entropy->encode_mcu )( cinfo, coef->MCU_buffer ) ) {
+                /* Suspension forced; update state counters and exit */
+                coef->MCU_vert_offset = yoffset;
+                coef->mcu_ctr = MCU_col_num;
+                return FALSE;
+            }
+        }
+        /* Completed an MCU row, but perhaps not an iMCU row */
+        coef->mcu_ctr = 0;
+    }
+    /* Completed the iMCU row, advance counters for next one */
+    coef->iMCU_row_num++;
+    start_iMCU_row( cinfo );
+    return TRUE;
+}
+
+#endif /* FULL_COEF_BUFFER_SUPPORTED */
+
+
+/*
+ * Initialize coefficient buffer controller.
+ */
+
+GLOBAL void
+jinit_c_coef_controller( j_compress_ptr cinfo, boolean need_full_buffer ) {
+    my_coef_ptr coef;
+
+    coef = (my_coef_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_coef_controller ) );
+    cinfo->coef = (struct jpeg_c_coef_controller *) coef;
+    coef->pub.start_pass = start_pass_coef;
+
+    /* Create the coefficient buffer. */
+    if ( need_full_buffer ) {
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+        /* Allocate a full-image virtual array for each component, */
+        /* padded to a multiple of samp_factor DCT blocks in each direction. */
+        int ci;
+        jpeg_component_info * compptr;
+
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            coef->whole_image[ci] = ( *cinfo->mem->request_virt_barray )
+                                    ( (j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+                                     (JDIMENSION) jround_up( (long) compptr->width_in_blocks,
+                                                            (long) compptr->h_samp_factor ),
+                                     (JDIMENSION) jround_up( (long) compptr->height_in_blocks,
+                                                            (long) compptr->v_samp_factor ),
+                                     (JDIMENSION) compptr->v_samp_factor );
+        }
+#else
+        ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+#endif
+    } else {
+        /* We only need a single-MCU buffer. */
+        JBLOCKROW buffer;
+        int i;
+
+        buffer = (JBLOCKROW)
+                 ( *cinfo->mem->alloc_large )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                              C_MAX_BLOCKS_IN_MCU * SIZEOF( JBLOCK ) );
+        for ( i = 0; i < C_MAX_BLOCKS_IN_MCU; i++ ) {
+            coef->MCU_buffer[i] = buffer + i;
+        }
+        coef->whole_image[0] = NULL;/* flag for no virtual arrays */
+    }
+}

neo/renderer/jpeg-6/jccolor.cpp

@@ -0,0 +1,467 @@
+/*
+ * jccolor.c
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains input colorspace conversion routines.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private subobject */
+
+typedef struct {
+    struct jpeg_color_converter pub;/* public fields */
+
+    /* Private state for RGB->YCC conversion */
+    INT32 * rgb_ycc_tab;    /* => table for RGB to YCbCr conversion */
+} my_color_converter;
+
+typedef my_color_converter * my_cconvert_ptr;
+
+
+/**************** RGB -> YCbCr conversion: most common case **************/
+
+/*
+ * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
+ * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
+ * The conversion equations to be implemented are therefore
+ *	Y  =  0.29900 * R + 0.58700 * G + 0.11400 * B
+ *	Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B  + CENTERJSAMPLE
+ *	Cr =  0.50000 * R - 0.41869 * G - 0.08131 * B  + CENTERJSAMPLE
+ * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
+ * Note: older versions of the IJG code used a zero offset of MAXJSAMPLE/2,
+ * rather than CENTERJSAMPLE, for Cb and Cr.  This gave equal positive and
+ * negative swings for Cb/Cr, but meant that grayscale values (Cb=Cr=0)
+ * were not represented exactly.  Now we sacrifice exact representation of
+ * maximum red and maximum blue in order to get exact grayscales.
+ *
+ * To avoid floating-point arithmetic, we represent the fractional constants
+ * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
+ * the products by 2^16, with appropriate rounding, to get the correct answer.
+ *
+ * For even more speed, we avoid doing any multiplications in the inner loop
+ * by precalculating the constants times R,G,B for all possible values.
+ * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
+ * for 12-bit samples it is still acceptable.  It's not very reasonable for
+ * 16-bit samples, but if you want lossless storage you shouldn't be changing
+ * colorspace anyway.
+ * The CENTERJSAMPLE offsets and the rounding fudge-factor of 0.5 are included
+ * in the tables to save adding them separately in the inner loop.
+ */
+
+#define SCALEBITS   16  /* speediest right-shift on some machines */
+#define CBCR_OFFSET ( (INT32) CENTERJSAMPLE << SCALEBITS )
+#define ONE_HALF    ( (INT32) 1 << ( SCALEBITS - 1 ) )
+#define FIX( x )      ( (INT32) ( ( x ) * ( 1L << SCALEBITS ) + 0.5 ) )
+
+/* We allocate one big table and divide it up into eight parts, instead of
+ * doing eight alloc_small requests.  This lets us use a single table base
+ * address, which can be held in a register in the inner loops on many
+ * machines (more than can hold all eight addresses, anyway).
+ */
+
+#define R_Y_OFF     0           /* offset to R => Y section */
+#define G_Y_OFF     ( 1 * ( MAXJSAMPLE + 1 ) )  /* offset to G => Y section */
+#define B_Y_OFF     ( 2 * ( MAXJSAMPLE + 1 ) )  /* etc. */
+#define R_CB_OFF    ( 3 * ( MAXJSAMPLE + 1 ) )
+#define G_CB_OFF    ( 4 * ( MAXJSAMPLE + 1 ) )
+#define B_CB_OFF    ( 5 * ( MAXJSAMPLE + 1 ) )
+#define R_CR_OFF    B_CB_OFF        /* B=>Cb, R=>Cr are the same */
+#define G_CR_OFF    ( 6 * ( MAXJSAMPLE + 1 ) )
+#define B_CR_OFF    ( 7 * ( MAXJSAMPLE + 1 ) )
+#define TABLE_SIZE  ( 8 * ( MAXJSAMPLE + 1 ) )
+
+
+/*
+ * Initialize for RGB->YCC colorspace conversion.
+ */
+
+METHODDEF void
+rgb_ycc_start( j_compress_ptr cinfo ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    INT32 * rgb_ycc_tab;
+    INT32 i;
+
+    /* Allocate and fill in the conversion tables. */
+    cconvert->rgb_ycc_tab = rgb_ycc_tab = (INT32 *)
+                                          ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                       ( TABLE_SIZE * SIZEOF( INT32 ) ) );
+
+    for ( i = 0; i <= MAXJSAMPLE; i++ ) {
+        rgb_ycc_tab[i + R_Y_OFF] = FIX( 0.29900 ) * i;
+        rgb_ycc_tab[i + G_Y_OFF] = FIX( 0.58700 ) * i;
+        rgb_ycc_tab[i + B_Y_OFF] = FIX( 0.11400 ) * i     + ONE_HALF;
+        rgb_ycc_tab[i + R_CB_OFF] = ( -FIX( 0.16874 ) ) * i;
+        rgb_ycc_tab[i + G_CB_OFF] = ( -FIX( 0.33126 ) ) * i;
+        /* We use a rounding fudge-factor of 0.5-epsilon for Cb and Cr.
+         * This ensures that the maximum output will round to MAXJSAMPLE
+         * not MAXJSAMPLE+1, and thus that we don't have to range-limit.
+         */
+        rgb_ycc_tab[i + B_CB_OFF] = FIX( 0.50000 ) * i    + CBCR_OFFSET + ONE_HALF - 1;
+/*  B=>Cb and R=>Cr tables are the same
+    rgb_ycc_tab[i+R_CR_OFF] = FIX(0.50000) * i    + CBCR_OFFSET + ONE_HALF-1;
+ */
+        rgb_ycc_tab[i + G_CR_OFF] = ( -FIX( 0.41869 ) ) * i;
+        rgb_ycc_tab[i + B_CR_OFF] = ( -FIX( 0.08131 ) ) * i;
+    }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ *
+ * Note that we change from the application's interleaved-pixel format
+ * to our internal noninterleaved, one-plane-per-component format.
+ * The input buffer is therefore three times as wide as the output buffer.
+ *
+ * A starting row offset is provided only for the output buffer.  The caller
+ * can easily adjust the passed input_buf value to accommodate any row
+ * offset required on that side.
+ */
+
+METHODDEF void
+rgb_ycc_convert( j_compress_ptr cinfo,
+                 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+                 JDIMENSION output_row, int num_rows ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    register int r, g, b;
+    register INT32 * ctab = cconvert->rgb_ycc_tab;
+    register JSAMPROW inptr;
+    register JSAMPROW outptr0, outptr1, outptr2;
+    register JDIMENSION col;
+    JDIMENSION num_cols = cinfo->image_width;
+
+    while ( --num_rows >= 0 ) {
+        inptr = *input_buf++;
+        outptr0 = output_buf[0][output_row];
+        outptr1 = output_buf[1][output_row];
+        outptr2 = output_buf[2][output_row];
+        output_row++;
+        for ( col = 0; col < num_cols; col++ ) {
+            r = GETJSAMPLE( inptr[RGB_RED] );
+            g = GETJSAMPLE( inptr[RGB_GREEN] );
+            b = GETJSAMPLE( inptr[RGB_BLUE] );
+            inptr += RGB_PIXELSIZE;
+            /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
+             * must be too; we do not need an explicit range-limiting operation.
+             * Hence the value being shifted is never negative, and we don't
+             * need the general RIGHT_SHIFT macro.
+             */
+            /* Y */
+            outptr0[col] = (JSAMPLE)
+                           ( ( ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] + ctab[b + B_Y_OFF] )
+                            >> SCALEBITS );
+            /* Cb */
+            outptr1[col] = (JSAMPLE)
+                           ( ( ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] + ctab[b + B_CB_OFF] )
+                            >> SCALEBITS );
+            /* Cr */
+            outptr2[col] = (JSAMPLE)
+                           ( ( ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] + ctab[b + B_CR_OFF] )
+                            >> SCALEBITS );
+        }
+    }
+}
+
+
+/**************** Cases other than RGB -> YCbCr **************/
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles RGB->grayscale conversion, which is the same
+ * as the RGB->Y portion of RGB->YCbCr.
+ * We assume rgb_ycc_start has been called (we only use the Y tables).
+ */
+
+METHODDEF void
+rgb_gray_convert( j_compress_ptr cinfo,
+                  JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+                  JDIMENSION output_row, int num_rows ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    register int r, g, b;
+    register INT32 * ctab = cconvert->rgb_ycc_tab;
+    register JSAMPROW inptr;
+    register JSAMPROW outptr;
+    register JDIMENSION col;
+    JDIMENSION num_cols = cinfo->image_width;
+
+    while ( --num_rows >= 0 ) {
+        inptr = *input_buf++;
+        outptr = output_buf[0][output_row];
+        output_row++;
+        for ( col = 0; col < num_cols; col++ ) {
+            r = GETJSAMPLE( inptr[RGB_RED] );
+            g = GETJSAMPLE( inptr[RGB_GREEN] );
+            b = GETJSAMPLE( inptr[RGB_BLUE] );
+            inptr += RGB_PIXELSIZE;
+            /* Y */
+            outptr[col] = (JSAMPLE)
+                          ( ( ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] + ctab[b + B_Y_OFF] )
+                           >> SCALEBITS );
+        }
+    }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles Adobe-style CMYK->YCCK conversion,
+ * where we convert R=1-C, G=1-M, and B=1-Y to YCbCr using the same
+ * conversion as above, while passing K (black) unchanged.
+ * We assume rgb_ycc_start has been called.
+ */
+
+METHODDEF void
+cmyk_ycck_convert( j_compress_ptr cinfo,
+                   JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+                   JDIMENSION output_row, int num_rows ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    register int r, g, b;
+    register INT32 * ctab = cconvert->rgb_ycc_tab;
+    register JSAMPROW inptr;
+    register JSAMPROW outptr0, outptr1, outptr2, outptr3;
+    register JDIMENSION col;
+    JDIMENSION num_cols = cinfo->image_width;
+
+    while ( --num_rows >= 0 ) {
+        inptr = *input_buf++;
+        outptr0 = output_buf[0][output_row];
+        outptr1 = output_buf[1][output_row];
+        outptr2 = output_buf[2][output_row];
+        outptr3 = output_buf[3][output_row];
+        output_row++;
+        for ( col = 0; col < num_cols; col++ ) {
+            r = MAXJSAMPLE - GETJSAMPLE( inptr[0] );
+            g = MAXJSAMPLE - GETJSAMPLE( inptr[1] );
+            b = MAXJSAMPLE - GETJSAMPLE( inptr[2] );
+            /* K passes through as-is */
+            outptr3[col] = inptr[3];/* don't need GETJSAMPLE here */
+            inptr += 4;
+            /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
+             * must be too; we do not need an explicit range-limiting operation.
+             * Hence the value being shifted is never negative, and we don't
+             * need the general RIGHT_SHIFT macro.
+             */
+            /* Y */
+            outptr0[col] = (JSAMPLE)
+                           ( ( ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] + ctab[b + B_Y_OFF] )
+                            >> SCALEBITS );
+            /* Cb */
+            outptr1[col] = (JSAMPLE)
+                           ( ( ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] + ctab[b + B_CB_OFF] )
+                            >> SCALEBITS );
+            /* Cr */
+            outptr2[col] = (JSAMPLE)
+                           ( ( ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] + ctab[b + B_CR_OFF] )
+                            >> SCALEBITS );
+        }
+    }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles grayscale output with no conversion.
+ * The source can be either plain grayscale or YCbCr (since Y == gray).
+ */
+
+METHODDEF void
+grayscale_convert( j_compress_ptr cinfo,
+                   JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+                   JDIMENSION output_row, int num_rows ) {
+    register JSAMPROW inptr;
+    register JSAMPROW outptr;
+    register JDIMENSION col;
+    JDIMENSION num_cols = cinfo->image_width;
+    int instride = cinfo->input_components;
+
+    while ( --num_rows >= 0 ) {
+        inptr = *input_buf++;
+        outptr = output_buf[0][output_row];
+        output_row++;
+        for ( col = 0; col < num_cols; col++ ) {
+            outptr[col] = inptr[0];/* don't need GETJSAMPLE() here */
+            inptr += instride;
+        }
+    }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles multi-component colorspaces without conversion.
+ * We assume input_components == num_components.
+ */
+
+METHODDEF void
+null_convert( j_compress_ptr cinfo,
+              JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+              JDIMENSION output_row, int num_rows ) {
+    register JSAMPROW inptr;
+    register JSAMPROW outptr;
+    register JDIMENSION col;
+    register int ci;
+    int nc = cinfo->num_components;
+    JDIMENSION num_cols = cinfo->image_width;
+
+    while ( --num_rows >= 0 ) {
+        /* It seems fastest to make a separate pass for each component. */
+        for ( ci = 0; ci < nc; ci++ ) {
+            inptr = *input_buf;
+            outptr = output_buf[ci][output_row];
+            for ( col = 0; col < num_cols; col++ ) {
+                outptr[col] = inptr[ci];/* don't need GETJSAMPLE() here */
+                inptr += nc;
+            }
+        }
+        input_buf++;
+        output_row++;
+    }
+}
+
+
+/*
+ * Empty method for start_pass.
+ */
+
+METHODDEF void
+null_method( j_compress_ptr cinfo ) {
+    /* no work needed */
+}
+
+
+/*
+ * Module initialization routine for input colorspace conversion.
+ */
+
+GLOBAL void
+jinit_color_converter( j_compress_ptr cinfo ) {
+    my_cconvert_ptr cconvert;
+
+    cconvert = (my_cconvert_ptr)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                            SIZEOF( my_color_converter ) );
+    cinfo->cconvert = (struct jpeg_color_converter *) cconvert;
+    /* set start_pass to null method until we find out differently */
+    cconvert->pub.start_pass = null_method;
+
+    /* Make sure input_components agrees with in_color_space */
+    switch ( cinfo->in_color_space ) {
+        case JCS_GRAYSCALE:
+            if ( cinfo->input_components != 1 ) {
+                ERREXIT( cinfo, JERR_BAD_IN_COLORSPACE );
+            }
+            break;
+
+        case JCS_RGB:
+#if RGB_PIXELSIZE != 3
+            if ( cinfo->input_components != RGB_PIXELSIZE ) {
+                ERREXIT( cinfo, JERR_BAD_IN_COLORSPACE );
+            }
+            break;
+#endif /* else share code with YCbCr */
+
+        case JCS_YCbCr:
+            if ( cinfo->input_components != 3 ) {
+                ERREXIT( cinfo, JERR_BAD_IN_COLORSPACE );
+            }
+            break;
+
+        case JCS_CMYK:
+        case JCS_YCCK:
+            if ( cinfo->input_components != 4 ) {
+                ERREXIT( cinfo, JERR_BAD_IN_COLORSPACE );
+            }
+            break;
+
+        default:    /* JCS_UNKNOWN can be anything */
+            if ( cinfo->input_components < 1 ) {
+                ERREXIT( cinfo, JERR_BAD_IN_COLORSPACE );
+            }
+            break;
+    }
+
+    /* Check num_components, set conversion method based on requested space */
+    switch ( cinfo->jpeg_color_space ) {
+        case JCS_GRAYSCALE:
+            if ( cinfo->num_components != 1 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            if ( cinfo->in_color_space == JCS_GRAYSCALE ) {
+                cconvert->pub.color_convert = grayscale_convert;
+            } else if ( cinfo->in_color_space == JCS_RGB ) {
+                cconvert->pub.start_pass = rgb_ycc_start;
+                cconvert->pub.color_convert = rgb_gray_convert;
+            } else if ( cinfo->in_color_space == JCS_YCbCr ) {
+                cconvert->pub.color_convert = grayscale_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        case JCS_RGB:
+            if ( cinfo->num_components != 3 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            if ( ( cinfo->in_color_space == JCS_RGB ) && ( RGB_PIXELSIZE == 3 ) ) {
+                cconvert->pub.color_convert = null_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        case JCS_YCbCr:
+            if ( cinfo->num_components != 3 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            if ( cinfo->in_color_space == JCS_RGB ) {
+                cconvert->pub.start_pass = rgb_ycc_start;
+                cconvert->pub.color_convert = rgb_ycc_convert;
+            } else if ( cinfo->in_color_space == JCS_YCbCr ) {
+                cconvert->pub.color_convert = null_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        case JCS_CMYK:
+            if ( cinfo->num_components != 4 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            if ( cinfo->in_color_space == JCS_CMYK ) {
+                cconvert->pub.color_convert = null_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        case JCS_YCCK:
+            if ( cinfo->num_components != 4 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            if ( cinfo->in_color_space == JCS_CMYK ) {
+                cconvert->pub.start_pass = rgb_ycc_start;
+                cconvert->pub.color_convert = cmyk_ycck_convert;
+            } else if ( cinfo->in_color_space == JCS_YCCK ) {
+                cconvert->pub.color_convert = null_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        default:    /* allow null conversion of JCS_UNKNOWN */
+            if ( ( cinfo->jpeg_color_space != cinfo->in_color_space ) ||
+                ( cinfo->num_components != cinfo->input_components ) ) {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            cconvert->pub.color_convert = null_convert;
+            break;
+    }
+}

neo/renderer/jpeg-6/jcdctmgr.cpp

@@ -0,0 +1,385 @@
+/*
+ * jcdctmgr.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the forward-DCT management logic.
+ * This code selects a particular DCT implementation to be used,
+ * and it performs related housekeeping chores including coefficient
+ * quantization.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+
+/* Private subobject for this module */
+
+typedef struct {
+    struct jpeg_forward_dct pub;/* public fields */
+
+    /* Pointer to the DCT routine actually in use */
+    forward_DCT_method_ptr do_dct;
+
+    /* The actual post-DCT divisors --- not identical to the quant table
+     * entries, because of scaling (especially for an unnormalized DCT).
+     * Each table is given in normal array order; note that this must
+     * be converted from the zigzag order of the quantization tables.
+     */
+    DCTELEM * divisors[NUM_QUANT_TBLS];
+
+#ifdef DCT_FLOAT_SUPPORTED
+    /* Same as above for the floating-point case. */
+    float_DCT_method_ptr do_float_dct;
+    FAST_FLOAT *         float_divisors[NUM_QUANT_TBLS];
+#endif
+} my_fdct_controller;
+
+typedef my_fdct_controller * my_fdct_ptr;
+
+
+/*
+ * Initialize for a processing pass.
+ * Verify that all referenced Q-tables are present, and set up
+ * the divisor table for each one.
+ * In the current implementation, DCT of all components is done during
+ * the first pass, even if only some components will be output in the
+ * first scan.  Hence all components should be examined here.
+ */
+
+METHODDEF void
+start_pass_fdctmgr( j_compress_ptr cinfo ) {
+    my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+    int ci, qtblno, i;
+    jpeg_component_info * compptr;
+    JQUANT_TBL * qtbl;
+    //DCTELEM * dtbl;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        qtblno = compptr->quant_tbl_no;
+        /* Make sure specified quantization table is present */
+        if ( ( qtblno < 0 ) || ( qtblno >= NUM_QUANT_TBLS ) ||
+            ( cinfo->quant_tbl_ptrs[qtblno] == NULL ) ) {
+            ERREXIT1( cinfo, JERR_NO_QUANT_TABLE, qtblno );
+        }
+        qtbl = cinfo->quant_tbl_ptrs[qtblno];
+        /* Compute divisors for this quant table */
+        /* We may do this more than once for same table, but it's not a big deal */
+        switch ( cinfo->dct_method ) {
+#ifdef DCT_ISLOW_SUPPORTED
+            case JDCT_ISLOW:
+                /* For LL&M IDCT method, divisors are equal to raw quantization
+                 * coefficients multiplied by 8 (to counteract scaling).
+                 */
+                if ( fdct->divisors[qtblno] == NULL ) {
+                    fdct->divisors[qtblno] = (DCTELEM *)
+                                             ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                          DCTSIZE2 * SIZEOF( DCTELEM ) );
+                }
+                dtbl = fdct->divisors[qtblno];
+                for ( i = 0; i < DCTSIZE2; i++ ) {
+                    dtbl[i] = ( (DCTELEM) qtbl->quantval[jpeg_zigzag_order[i]] ) << 3;
+                }
+                break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+            case JDCT_IFAST:
+            {
+                /* For AA&N IDCT method, divisors are equal to quantization
+                 * coefficients scaled by scalefactor[row]*scalefactor[col], where
+                 *   scalefactor[0] = 1
+                 *   scalefactor[k] = cos(k*PI/16) * sqrt(2)    for k=1..7
+                 * We apply a further scale factor of 8.
+                 */
+#define CONST_BITS 14
+                static const INT16 aanscales[DCTSIZE2] = {
+                    /* precomputed values scaled up by 14 bits: in natural order */
+                    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
+                    22725, 31521, 29692, 26722, 22725, 17855, 12299,  6270,
+                    21407, 29692, 27969, 25172, 21407, 16819, 11585,  5906,
+                    19266, 26722, 25172, 22654, 19266, 15137, 10426,  5315,
+                    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
+                    12873, 17855, 16819, 15137, 12873, 10114,  6967,  3552,
+                    8867, 12299, 11585, 10426,  8867,  6967,  4799,  2446,
+                    4520,  6270,  5906,  5315,  4520,  3552,  2446,  1247
+                };
+                SHIFT_TEMPS
+
+                if ( fdct->divisors[qtblno] == NULL ) {
+                    fdct->divisors[qtblno] = (DCTELEM *)
+                                             ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                          DCTSIZE2 * SIZEOF( DCTELEM ) );
+                }
+                dtbl = fdct->divisors[qtblno];
+                for ( i = 0; i < DCTSIZE2; i++ ) {
+                    dtbl[i] = (DCTELEM)
+                              DESCALE( MULTIPLY16V16( (INT32) qtbl->quantval[jpeg_zigzag_order[i]],
+                                                     (INT32) aanscales[i] ),
+                                       CONST_BITS - 3 );
+                }
+            }
+                break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+            case JDCT_FLOAT:
+            {
+                /* For float AA&N IDCT method, divisors are equal to quantization
+                 * coefficients scaled by scalefactor[row]*scalefactor[col], where
+                 *   scalefactor[0] = 1
+                 *   scalefactor[k] = cos(k*PI/16) * sqrt(2)    for k=1..7
+                 * We apply a further scale factor of 8.
+                 * What's actually stored is 1/divisor so that the inner loop can
+                 * use a multiplication rather than a division.
+                 */
+                FAST_FLOAT * fdtbl;
+                int row, col;
+                static const double aanscalefactor[DCTSIZE] = {
+                    1.0, 1.387039845, 1.306562965, 1.175875602,
+                    1.0, 0.785694958, 0.541196100, 0.275899379
+                };
+
+                if ( fdct->float_divisors[qtblno] == NULL ) {
+                    fdct->float_divisors[qtblno] = (FAST_FLOAT *)
+                                                   ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                                DCTSIZE2 * SIZEOF( FAST_FLOAT ) );
+                }
+                fdtbl = fdct->float_divisors[qtblno];
+                i = 0;
+                for ( row = 0; row < DCTSIZE; row++ ) {
+                    for ( col = 0; col < DCTSIZE; col++ ) {
+                        fdtbl[i] = (FAST_FLOAT)
+                                   ( 1.0 / ( ( (double) qtbl->quantval[jpeg_zigzag_order[i]] *
+                                              aanscalefactor[row] * aanscalefactor[col] * 8.0 ) ) );
+                        i++;
+                    }
+                }
+            }
+                break;
+#endif
+            default:
+                ERREXIT( cinfo, JERR_NOT_COMPILED );
+                break;
+        }
+    }
+}
+
+
+/*
+ * Perform forward DCT on one or more blocks of a component.
+ *
+ * The input samples are taken from the sample_data[] array starting at
+ * position start_row/start_col, and moving to the right for any additional
+ * blocks. The quantized coefficients are returned in coef_blocks[].
+ */
+
+METHODDEF void
+forward_DCT( j_compress_ptr cinfo, jpeg_component_info * compptr,
+             JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
+             JDIMENSION start_row, JDIMENSION start_col,
+             JDIMENSION num_blocks ) {
+/* This version is used for integer DCT implementations. */
+/* This routine is heavily used, so it's worth coding it tightly. */
+    my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+    forward_DCT_method_ptr do_dct = fdct->do_dct;
+    DCTELEM * divisors = fdct->divisors[compptr->quant_tbl_no];
+    DCTELEM workspace[DCTSIZE2];/* work area for FDCT subroutine */
+    JDIMENSION bi;
+
+    sample_data += start_row;/* fold in the vertical offset once */
+
+    for ( bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE ) {
+        /* Load data into workspace, applying unsigned->signed conversion */
+        { register DCTELEM * workspaceptr;
+          register JSAMPROW elemptr;
+          register int elemr;
+
+          workspaceptr = workspace;
+          for ( elemr = 0; elemr < DCTSIZE; elemr++ ) {
+              elemptr = sample_data[elemr] + start_col;
+#if DCTSIZE == 8        /* unroll the inner loop */
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+              *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+#else
+              { register int elemc;
+            for ( elemc = DCTSIZE; elemc > 0; elemc-- ) {
+                *workspaceptr++ = GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE;
+            }
+              }
+#endif
+          }
+        }
+
+        /* Perform the DCT */
+        ( *do_dct )( workspace );
+
+        /* Quantize/descale the coefficients, and store into coef_blocks[] */
+        { register DCTELEM temp, qval;
+          register int i;
+          register JCOEFPTR output_ptr = coef_blocks[bi];
+
+          for ( i = 0; i < DCTSIZE2; i++ ) {
+              qval = divisors[i];
+              temp = workspace[i];
+              /* Divide the coefficient value by qval, ensuring proper rounding.
+               * Since C does not specify the direction of rounding for negative
+               * quotients, we have to force the dividend positive for portability.
+               *
+               * In most files, at least half of the output values will be zero
+               * (at default quantization settings, more like three-quarters...)
+               * so we should ensure that this case is fast.  On many machines,
+               * a comparison is enough cheaper than a divide to make a special test
+               * a win.  Since both inputs will be nonnegative, we need only test
+               * for a < b to discover whether a/b is 0.
+               * If your machine's division is fast enough, define FAST_DIVIDE.
+               */
+#ifdef FAST_DIVIDE
+#define DIVIDE_BY( a, b )  a /= b
+#else
+#define DIVIDE_BY(a,b)	if (a >= b) a /= b; else a = 0
+#endif
+              if ( temp < 0 ) {
+                  temp = -temp;
+                  temp += qval >> 1;/* for rounding */
+                  DIVIDE_BY( temp, qval );
+                  temp = -temp;
+              } else {
+                  temp += qval >> 1;/* for rounding */
+                  DIVIDE_BY( temp, qval );
+              }
+              output_ptr[i] = (JCOEF) temp;
+          }
+        }
+    }
+}
+
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+METHODDEF void
+forward_DCT_float( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                   JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
+                   JDIMENSION start_row, JDIMENSION start_col,
+                   JDIMENSION num_blocks ) {
+/* This version is used for floating-point DCT implementations. */
+/* This routine is heavily used, so it's worth coding it tightly. */
+    my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+    float_DCT_method_ptr do_dct = fdct->do_float_dct;
+    FAST_FLOAT * divisors = fdct->float_divisors[compptr->quant_tbl_no];
+    FAST_FLOAT workspace[DCTSIZE2];/* work area for FDCT subroutine */
+    JDIMENSION bi;
+
+    sample_data += start_row;/* fold in the vertical offset once */
+
+    for ( bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE ) {
+        /* Load data into workspace, applying unsigned->signed conversion */
+        { register FAST_FLOAT * workspaceptr;
+          register JSAMPROW elemptr;
+          register int elemr;
+
+          workspaceptr = workspace;
+          for ( elemr = 0; elemr < DCTSIZE; elemr++ ) {
+              elemptr = sample_data[elemr] + start_col;
+#if DCTSIZE == 8        /* unroll the inner loop */
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+              *workspaceptr++ = (FAST_FLOAT)( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+#else
+              { register int elemc;
+            for ( elemc = DCTSIZE; elemc > 0; elemc-- ) {
+                *workspaceptr++ = (FAST_FLOAT)
+                                  ( GETJSAMPLE( *elemptr++ ) - CENTERJSAMPLE );
+            }
+              }
+#endif
+          }
+        }
+
+        /* Perform the DCT */
+        ( *do_dct )( workspace );
+
+        /* Quantize/descale the coefficients, and store into coef_blocks[] */
+        { register FAST_FLOAT temp;
+          register int i;
+          register JCOEFPTR output_ptr = coef_blocks[bi];
+
+          for ( i = 0; i < DCTSIZE2; i++ ) {
+              /* Apply the quantization and scaling factor */
+              temp = workspace[i] * divisors[i];
+              /* Round to nearest integer.
+               * Since C does not specify the direction of rounding for negative
+               * quotients, we have to force the dividend positive for portability.
+               * The maximum coefficient size is +-16K (for 12-bit data), so this
+               * code should work for either 16-bit or 32-bit ints.
+               */
+              output_ptr[i] = (JCOEF) ( (int) ( temp + (FAST_FLOAT) 16384.5 ) - 16384 );
+          }
+        }
+    }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */
+
+
+/*
+ * Initialize FDCT manager.
+ */
+
+GLOBAL void
+jinit_forward_dct( j_compress_ptr cinfo ) {
+    my_fdct_ptr fdct;
+    int i;
+
+    fdct = (my_fdct_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_fdct_controller ) );
+    cinfo->fdct = (struct jpeg_forward_dct *) fdct;
+    fdct->pub.start_pass = start_pass_fdctmgr;
+
+    switch ( cinfo->dct_method ) {
+#ifdef DCT_ISLOW_SUPPORTED
+        case JDCT_ISLOW:
+            fdct->pub.forward_DCT = forward_DCT;
+            fdct->do_dct = jpeg_fdct_islow;
+            break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+        case JDCT_IFAST:
+            fdct->pub.forward_DCT = forward_DCT;
+            fdct->do_dct = jpeg_fdct_ifast;
+            break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+        case JDCT_FLOAT:
+            fdct->pub.forward_DCT = forward_DCT_float;
+            fdct->do_float_dct = jpeg_fdct_float;
+            break;
+#endif
+        default:
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+            break;
+    }
+
+    /* Mark divisor tables unallocated */
+    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
+        fdct->divisors[i] = NULL;
+#ifdef DCT_FLOAT_SUPPORTED
+        fdct->float_divisors[i] = NULL;
+#endif
+    }
+}

neo/renderer/jpeg-6/jchuff.cpp

@@ -0,0 +1,868 @@
+/*
+ * jchuff.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy encoding routines.
+ *
+ * Much of the complexity here has to do with supporting output suspension.
+ * If the data destination module demands suspension, we want to be able to
+ * back up to the start of the current MCU.  To do this, we copy state
+ * variables into local working storage, and update them back to the
+ * permanent JPEG objects only upon successful completion of an MCU.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jchuff.h"      /* Declarations shared with jcphuff.c */
+
+
+/* Expanded entropy encoder object for Huffman encoding.
+ *
+ * The savable_state subrecord contains fields that change within an MCU,
+ * but must not be updated permanently until we complete the MCU.
+ */
+
+typedef struct {
+    INT32 put_buffer;   /* current bit-accumulation buffer */
+    int   put_bits;     /* # of bits now in it */
+    int   last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+} savable_state;
+
+/* This macro is to work around compilers with missing or broken
+ * structure assignment.  You'll need to fix this code if you have
+ * such a compiler and you change MAX_COMPS_IN_SCAN.
+ */
+
+#ifndef NO_STRUCT_ASSIGN
+#define ASSIGN_STATE( dest, src )  ( ( dest ) = ( src ) )
+#else
+#if MAX_COMPS_IN_SCAN == 4
+#define ASSIGN_STATE( dest, src )  \
+    ( ( dest ).put_buffer = ( src ).put_buffer, \
+     ( dest ).put_bits = ( src ).put_bits, \
+     ( dest ).last_dc_val[0] = ( src ).last_dc_val[0], \
+     ( dest ).last_dc_val[1] = ( src ).last_dc_val[1], \
+     ( dest ).last_dc_val[2] = ( src ).last_dc_val[2], \
+     ( dest ).last_dc_val[3] = ( src ).last_dc_val[3] )
+#endif
+#endif
+
+
+typedef struct {
+    struct jpeg_entropy_encoder pub;/* public fields */
+
+    savable_state saved;    /* Bit buffer & DC state at start of MCU */
+
+    /* These fields are NOT loaded into local working state. */
+    unsigned int restarts_to_go;/* MCUs left in this restart interval */
+    int          next_restart_num; /* next restart number to write (0-7) */
+
+    /* Pointers to derived tables (these workspaces have image lifespan) */
+    c_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
+    c_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
+
+#ifdef ENTROPY_OPT_SUPPORTED    /* Statistics tables for optimization */
+    long * dc_count_ptrs[NUM_HUFF_TBLS];
+    long * ac_count_ptrs[NUM_HUFF_TBLS];
+#endif
+} huff_entropy_encoder;
+
+typedef huff_entropy_encoder * huff_entropy_ptr;
+
+/* Working state while writing an MCU.
+ * This struct contains all the fields that are needed by subroutines.
+ */
+
+typedef struct {
+    JOCTET *       next_output_byte; /* => next byte to write in buffer */
+    size_t         free_in_buffer; /* # of byte spaces remaining in buffer */
+    savable_state  cur;     /* Current bit buffer & DC state */
+    j_compress_ptr cinfo;   /* dump_buffer needs access to this */
+} working_state;
+
+
+/* Forward declarations */
+METHODDEF boolean encode_mcu_huff JPP( ( j_compress_ptr cinfo,
+                                         JBLOCKROW * MCU_data ) );
+METHODDEF void finish_pass_huff JPP( (j_compress_ptr cinfo) );
+#ifdef ENTROPY_OPT_SUPPORTED
+METHODDEF boolean encode_mcu_gather JPP( ( j_compress_ptr cinfo,
+                                           JBLOCKROW * MCU_data ) );
+METHODDEF void finish_pass_gather JPP( (j_compress_ptr cinfo) );
+#endif
+
+
+/*
+ * Initialize for a Huffman-compressed scan.
+ * If gather_statistics is TRUE, we do not output anything during the scan,
+ * just count the Huffman symbols used and generate Huffman code tables.
+ */
+
+METHODDEF void
+start_pass_huff( j_compress_ptr cinfo, boolean gather_statistics ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    int ci, dctbl, actbl;
+    jpeg_component_info * compptr;
+
+    if ( gather_statistics ) {
+#ifdef ENTROPY_OPT_SUPPORTED
+        entropy->pub.encode_mcu = encode_mcu_gather;
+        entropy->pub.finish_pass = finish_pass_gather;
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+    } else {
+        entropy->pub.encode_mcu = encode_mcu_huff;
+        entropy->pub.finish_pass = finish_pass_huff;
+    }
+
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        dctbl = compptr->dc_tbl_no;
+        actbl = compptr->ac_tbl_no;
+        /* Make sure requested tables are present */
+        /* (In gather mode, tables need not be allocated yet) */
+        if ( ( dctbl < 0 ) || ( dctbl >= NUM_HUFF_TBLS ) ||
+            ( ( cinfo->dc_huff_tbl_ptrs[dctbl] == NULL ) && ( !gather_statistics ) ) ) {
+            ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, dctbl );
+        }
+        if ( ( actbl < 0 ) || ( actbl >= NUM_HUFF_TBLS ) ||
+            ( ( cinfo->ac_huff_tbl_ptrs[actbl] == NULL ) && ( !gather_statistics ) ) ) {
+            ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, actbl );
+        }
+        if ( gather_statistics ) {
+#ifdef ENTROPY_OPT_SUPPORTED
+            /* Allocate and zero the statistics tables */
+            /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
+            if ( entropy->dc_count_ptrs[dctbl] == NULL ) {
+                entropy->dc_count_ptrs[dctbl] = (long *)
+                                                ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                             257 * SIZEOF( long ) );
+            }
+            MEMZERO( entropy->dc_count_ptrs[dctbl], 257 * SIZEOF( long ) );
+            if ( entropy->ac_count_ptrs[actbl] == NULL ) {
+                entropy->ac_count_ptrs[actbl] = (long *)
+                                                ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                             257 * SIZEOF( long ) );
+            }
+            MEMZERO( entropy->ac_count_ptrs[actbl], 257 * SIZEOF( long ) );
+#endif
+        } else {
+            /* Compute derived values for Huffman tables */
+            /* We may do this more than once for a table, but it's not expensive */
+            jpeg_make_c_derived_tbl( cinfo, cinfo->dc_huff_tbl_ptrs[dctbl],
+                                     &entropy->dc_derived_tbls[dctbl] );
+            jpeg_make_c_derived_tbl( cinfo, cinfo->ac_huff_tbl_ptrs[actbl],
+                                     &entropy->ac_derived_tbls[actbl] );
+        }
+        /* Initialize DC predictions to 0 */
+        entropy->saved.last_dc_val[ci] = 0;
+    }
+
+    /* Initialize bit buffer to empty */
+    entropy->saved.put_buffer = 0;
+    entropy->saved.put_bits = 0;
+
+    /* Initialize restart stuff */
+    entropy->restarts_to_go = cinfo->restart_interval;
+    entropy->next_restart_num = 0;
+}
+
+
+/*
+ * Compute the derived values for a Huffman table.
+ * Note this is also used by jcphuff.c.
+ */
+
+GLOBAL void
+jpeg_make_c_derived_tbl( j_compress_ptr cinfo, JHUFF_TBL * htbl,
+                         c_derived_tbl ** pdtbl ) {
+    c_derived_tbl * dtbl;
+    int p, i, l, lastp, si;
+    char huffsize[257];
+    unsigned int huffcode[257];
+    unsigned int code;
+
+    /* Allocate a workspace if we haven't already done so. */
+    if ( *pdtbl == NULL ) {
+        *pdtbl = (c_derived_tbl *)
+                 ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                              SIZEOF( c_derived_tbl ) );
+    }
+    dtbl = *pdtbl;
+
+    /* Figure C.1: make table of Huffman code length for each symbol */
+    /* Note that this is in code-length order. */
+
+    p = 0;
+    for ( l = 1; l <= 16; l++ ) {
+        for ( i = 1; i <= (int) htbl->bits[l]; i++ ) {
+            huffsize[p++] = (char) l;
+        }
+    }
+    huffsize[p] = 0;
+    lastp = p;
+
+    /* Figure C.2: generate the codes themselves */
+    /* Note that this is in code-length order. */
+
+    code = 0;
+    si = huffsize[0];
+    p = 0;
+    while ( huffsize[p] ) {
+        while ( ( (int) huffsize[p] ) == si ) {
+            huffcode[p++] = code;
+            code++;
+        }
+        code <<= 1;
+        si++;
+    }
+
+    /* Figure C.3: generate encoding tables */
+    /* These are code and size indexed by symbol value */
+
+    /* Set any codeless symbols to have code length 0;
+     * this allows emit_bits to detect any attempt to emit such symbols.
+     */
+    MEMZERO( dtbl->ehufsi, SIZEOF( dtbl->ehufsi ) );
+
+    for ( p = 0; p < lastp; p++ ) {
+        dtbl->ehufco[htbl->huffval[p]] = huffcode[p];
+        dtbl->ehufsi[htbl->huffval[p]] = huffsize[p];
+    }
+}
+
+
+/* Outputting bytes to the file */
+
+/* Emit a byte, taking 'action' if must suspend. */
+#define emit_byte( state, val, action )  \
+    { *( state )->next_output_byte++ = (JOCTET) ( val );  \
+      if ( -- ( state )->free_in_buffer == 0 ) { \
+          if ( !dump_buffer( state ) )  \
+          { action; } } }
+
+
+LOCAL boolean
+dump_buffer( working_state * state ) {
+/* Empty the output buffer; return TRUE if successful, FALSE if must suspend */
+    struct jpeg_destination_mgr * dest = state->cinfo->dest;
+
+    if ( !( *dest->empty_output_buffer )( state->cinfo ) ) {
+        return FALSE;
+    }
+    /* After a successful buffer dump, must reset buffer pointers */
+    state->next_output_byte = dest->next_output_byte;
+    state->free_in_buffer = dest->free_in_buffer;
+    return TRUE;
+}
+
+
+/* Outputting bits to the file */
+
+/* Only the right 24 bits of put_buffer are used; the valid bits are
+ * left-justified in this part.  At most 16 bits can be passed to emit_bits
+ * in one call, and we never retain more than 7 bits in put_buffer
+ * between calls, so 24 bits are sufficient.
+ */
+
+INLINE
+LOCAL boolean
+emit_bits( working_state * state, unsigned int code, int size ) {
+/* Emit some bits; return TRUE if successful, FALSE if must suspend */
+/* This routine is heavily used, so it's worth coding tightly. */
+    register INT32 put_buffer = (INT32) code;
+    register int put_bits = state->cur.put_bits;
+
+    /* if size is 0, caller used an invalid Huffman table entry */
+    if ( size == 0 ) {
+        ERREXIT( state->cinfo, JERR_HUFF_MISSING_CODE );
+    }
+
+    put_buffer &= ( ( (INT32) 1 ) << size ) - 1;/* mask off any extra bits in code */
+
+    put_bits += size;   /* new number of bits in buffer */
+
+    put_buffer <<= 24 - put_bits;/* align incoming bits */
+
+    put_buffer |= state->cur.put_buffer;/* and merge with old buffer contents */
+
+    while ( put_bits >= 8 ) {
+        int c = (int) ( ( put_buffer >> 16 ) & 0xFF );
+
+        emit_byte( state, c, return FALSE );
+        if ( c == 0xFF ) {  /* need to stuff a zero byte? */
+            emit_byte( state, 0, return FALSE );
+        }
+        put_buffer <<= 8;
+        put_bits -= 8;
+    }
+
+    state->cur.put_buffer = put_buffer;/* update state variables */
+    state->cur.put_bits = put_bits;
+
+    return TRUE;
+}
+
+
+LOCAL boolean
+flush_bits( working_state * state ) {
+    if ( !emit_bits( state, 0x7F, 7 ) ) {/* fill any partial byte with ones */
+        return FALSE;
+    }
+    state->cur.put_buffer = 0;  /* and reset bit-buffer to empty */
+    state->cur.put_bits = 0;
+    return TRUE;
+}
+
+
+/* Encode a single block's worth of coefficients */
+
+LOCAL boolean
+encode_one_block( working_state * state, JCOEFPTR block, int last_dc_val,
+                  c_derived_tbl * dctbl, c_derived_tbl * actbl ) {
+    register int temp, temp2;
+    register int nbits;
+    register int k, r, i;
+
+    /* Encode the DC coefficient difference per section F.1.2.1 */
+
+    temp = temp2 = block[0] - last_dc_val;
+
+    if ( temp < 0 ) {
+        temp = -temp;   /* temp is abs value of input */
+        /* For a negative input, want temp2 = bitwise complement of abs(input) */
+        /* This code assumes we are on a two's complement machine */
+        temp2--;
+    }
+
+    /* Find the number of bits needed for the magnitude of the coefficient */
+    nbits = 0;
+    while ( temp ) {
+        nbits++;
+        temp >>= 1;
+    }
+
+    /* Emit the Huffman-coded symbol for the number of bits */
+    if ( !emit_bits( state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits] ) ) {
+        return FALSE;
+    }
+
+    /* Emit that number of bits of the value, if positive, */
+    /* or the complement of its magnitude, if negative. */
+    if ( nbits ) {      /* emit_bits rejects calls with size 0 */
+        if ( !emit_bits( state, (unsigned int) temp2, nbits ) ) {
+            return FALSE;
+        }
+    }
+
+    /* Encode the AC coefficients per section F.1.2.2 */
+
+    r = 0;          /* r = run length of zeros */
+
+    for ( k = 1; k < DCTSIZE2; k++ ) {
+        if ( ( temp = block[jpeg_natural_order[k]] ) == 0 ) {
+            r++;
+        } else {
+            /* if run length > 15, must emit special run-length-16 codes (0xF0) */
+            while ( r > 15 ) {
+                if ( !emit_bits( state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0] ) ) {
+                    return FALSE;
+                }
+                r -= 16;
+            }
+
+            temp2 = temp;
+            if ( temp < 0 ) {
+                temp = -temp;/* temp is abs value of input */
+                /* This code assumes we are on a two's complement machine */
+                temp2--;
+            }
+
+            /* Find the number of bits needed for the magnitude of the coefficient */
+            nbits = 1;  /* there must be at least one 1 bit */
+            while ( ( temp >>= 1 ) ) {
+                nbits++;
+            }
+
+            /* Emit Huffman symbol for run length / number of bits */
+            i = ( r << 4 ) + nbits;
+            if ( !emit_bits( state, actbl->ehufco[i], actbl->ehufsi[i] ) ) {
+                return FALSE;
+            }
+
+            /* Emit that number of bits of the value, if positive, */
+            /* or the complement of its magnitude, if negative. */
+            if ( !emit_bits( state, (unsigned int) temp2, nbits ) ) {
+                return FALSE;
+            }
+
+            r = 0;
+        }
+    }
+
+    /* If the last coef(s) were zero, emit an end-of-block code */
+    if ( r > 0 ) {
+        if ( !emit_bits( state, actbl->ehufco[0], actbl->ehufsi[0] ) ) {
+            return FALSE;
+        }
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * Emit a restart marker & resynchronize predictions.
+ */
+
+LOCAL boolean
+emit_restart( working_state * state, int restart_num ) {
+    int ci;
+
+    if ( !flush_bits( state ) ) {
+        return FALSE;
+    }
+
+    emit_byte( state, 0xFF, return FALSE );
+    emit_byte( state, JPEG_RST0 + restart_num, return FALSE );
+
+    /* Re-initialize DC predictions to 0 */
+    for ( ci = 0; ci < state->cinfo->comps_in_scan; ci++ ) {
+        state->cur.last_dc_val[ci] = 0;
+    }
+
+    /* The restart counter is not updated until we successfully write the MCU. */
+
+    return TRUE;
+}
+
+
+/*
+ * Encode and output one MCU's worth of Huffman-compressed coefficients.
+ */
+
+METHODDEF boolean
+encode_mcu_huff( j_compress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    working_state state;
+    int blkn, ci;
+    jpeg_component_info * compptr;
+
+    /* Load up working state */
+    state.next_output_byte = cinfo->dest->next_output_byte;
+    state.free_in_buffer = cinfo->dest->free_in_buffer;
+    ASSIGN_STATE( state.cur, entropy->saved );
+    state.cinfo = cinfo;
+
+    /* Emit restart marker if needed */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            if ( !emit_restart( &state, entropy->next_restart_num ) ) {
+                return FALSE;
+            }
+        }
+    }
+
+    /* Encode the MCU data blocks */
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        ci = cinfo->MCU_membership[blkn];
+        compptr = cinfo->cur_comp_info[ci];
+        if ( !encode_one_block( &state,
+                                MCU_data[blkn][0], state.cur.last_dc_val[ci],
+                                entropy->dc_derived_tbls[compptr->dc_tbl_no],
+                                entropy->ac_derived_tbls[compptr->ac_tbl_no] ) ) {
+            return FALSE;
+        }
+        /* Update last_dc_val */
+        state.cur.last_dc_val[ci] = MCU_data[blkn][0][0];
+    }
+
+    /* Completed MCU, so update state */
+    cinfo->dest->next_output_byte = state.next_output_byte;
+    cinfo->dest->free_in_buffer = state.free_in_buffer;
+    ASSIGN_STATE( entropy->saved, state.cur );
+
+    /* Update restart-interval state too */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            entropy->restarts_to_go = cinfo->restart_interval;
+            entropy->next_restart_num++;
+            entropy->next_restart_num &= 7;
+        }
+        entropy->restarts_to_go--;
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * Finish up at the end of a Huffman-compressed scan.
+ */
+
+METHODDEF void
+finish_pass_huff( j_compress_ptr cinfo ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    working_state state;
+
+    /* Load up working state ... flush_bits needs it */
+    state.next_output_byte = cinfo->dest->next_output_byte;
+    state.free_in_buffer = cinfo->dest->free_in_buffer;
+    ASSIGN_STATE( state.cur, entropy->saved );
+    state.cinfo = cinfo;
+
+    /* Flush out the last data */
+    if ( !flush_bits( &state ) ) {
+        ERREXIT( cinfo, JERR_CANT_SUSPEND );
+    }
+
+    /* Update state */
+    cinfo->dest->next_output_byte = state.next_output_byte;
+    cinfo->dest->free_in_buffer = state.free_in_buffer;
+    ASSIGN_STATE( entropy->saved, state.cur );
+}
+
+
+/*
+ * Huffman coding optimization.
+ *
+ * This actually is optimization, in the sense that we find the best possible
+ * Huffman table(s) for the given data.  We first scan the supplied data and
+ * count the number of uses of each symbol that is to be Huffman-coded.
+ * (This process must agree with the code above.)  Then we build an
+ * optimal Huffman coding tree for the observed counts.
+ *
+ * The JPEG standard requires Huffman codes to be no more than 16 bits long.
+ * If some symbols have a very small but nonzero probability, the Huffman tree
+ * must be adjusted to meet the code length restriction.  We currently use
+ * the adjustment method suggested in the JPEG spec.  This method is *not*
+ * optimal; it may not choose the best possible limited-length code.  But
+ * since the symbols involved are infrequently used, it's not clear that
+ * going to extra trouble is worthwhile.
+ */
+
+#ifdef ENTROPY_OPT_SUPPORTED
+
+
+/* Process a single block's worth of coefficients */
+
+LOCAL void
+htest_one_block( JCOEFPTR block, int last_dc_val,
+                 long dc_counts[], long ac_counts[] ) {
+    register int temp;
+    register int nbits;
+    register int k, r;
+
+    /* Encode the DC coefficient difference per section F.1.2.1 */
+
+    temp = block[0] - last_dc_val;
+    if ( temp < 0 ) {
+        temp = -temp;
+    }
+
+    /* Find the number of bits needed for the magnitude of the coefficient */
+    nbits = 0;
+    while ( temp ) {
+        nbits++;
+        temp >>= 1;
+    }
+
+    /* Count the Huffman symbol for the number of bits */
+    dc_counts[nbits]++;
+
+    /* Encode the AC coefficients per section F.1.2.2 */
+
+    r = 0;          /* r = run length of zeros */
+
+    for ( k = 1; k < DCTSIZE2; k++ ) {
+        if ( ( temp = block[jpeg_natural_order[k]] ) == 0 ) {
+            r++;
+        } else {
+            /* if run length > 15, must emit special run-length-16 codes (0xF0) */
+            while ( r > 15 ) {
+                ac_counts[0xF0]++;
+                r -= 16;
+            }
+
+            /* Find the number of bits needed for the magnitude of the coefficient */
+            if ( temp < 0 ) {
+                temp = -temp;
+            }
+
+            /* Find the number of bits needed for the magnitude of the coefficient */
+            nbits = 1;  /* there must be at least one 1 bit */
+            while ( ( temp >>= 1 ) ) {
+                nbits++;
+            }
+
+            /* Count Huffman symbol for run length / number of bits */
+            ac_counts[( r << 4 ) + nbits]++;
+
+            r = 0;
+        }
+    }
+
+    /* If the last coef(s) were zero, emit an end-of-block code */
+    if ( r > 0 ) {
+        ac_counts[0]++;
+    }
+}
+
+
+/*
+ * Trial-encode one MCU's worth of Huffman-compressed coefficients.
+ * No data is actually output, so no suspension return is possible.
+ */
+
+METHODDEF boolean
+encode_mcu_gather( j_compress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    int blkn, ci;
+    jpeg_component_info * compptr;
+
+    /* Take care of restart intervals if needed */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            /* Re-initialize DC predictions to 0 */
+            for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+                entropy->saved.last_dc_val[ci] = 0;
+            }
+            /* Update restart state */
+            entropy->restarts_to_go = cinfo->restart_interval;
+        }
+        entropy->restarts_to_go--;
+    }
+
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        ci = cinfo->MCU_membership[blkn];
+        compptr = cinfo->cur_comp_info[ci];
+        htest_one_block( MCU_data[blkn][0], entropy->saved.last_dc_val[ci],
+                         entropy->dc_count_ptrs[compptr->dc_tbl_no],
+                         entropy->ac_count_ptrs[compptr->ac_tbl_no] );
+        entropy->saved.last_dc_val[ci] = MCU_data[blkn][0][0];
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * Generate the optimal coding for the given counts, fill htbl.
+ * Note this is also used by jcphuff.c.
+ */
+
+GLOBAL void
+jpeg_gen_optimal_table( j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[] ) {
+#define MAX_CLEN 32     /* assumed maximum initial code length */
+    UINT8 bits[MAX_CLEN + 1];/* bits[k] = # of symbols with code length k */
+    int codesize[257];      /* codesize[k] = code length of symbol k */
+    int others[257];    /* next symbol in current branch of tree */
+    int c1, c2;
+    int p, i, j;
+    long v;
+
+    /* This algorithm is explained in section K.2 of the JPEG standard */
+
+    MEMZERO( bits, SIZEOF( bits ) );
+    MEMZERO( codesize, SIZEOF( codesize ) );
+    for ( i = 0; i < 257; i++ ) {
+        others[i] = -1;
+    }                   /* init links to empty */
+
+    freq[256] = 1;      /* make sure there is a nonzero count */
+    /* Including the pseudo-symbol 256 in the Huffman procedure guarantees
+     * that no real symbol is given code-value of all ones, because 256
+     * will be placed in the largest codeword category.
+     */
+
+    /* Huffman's basic algorithm to assign optimal code lengths to symbols */
+
+    for (;; ) {
+        /* Find the smallest nonzero frequency, set c1 = its symbol */
+        /* In case of ties, take the larger symbol number */
+        c1 = -1;
+        v = 1000000000L;
+        for ( i = 0; i <= 256; i++ ) {
+            if ( ( freq[i] ) && ( freq[i] <= v ) ) {
+                v = freq[i];
+                c1 = i;
+            }
+        }
+
+        /* Find the next smallest nonzero frequency, set c2 = its symbol */
+        /* In case of ties, take the larger symbol number */
+        c2 = -1;
+        v = 1000000000L;
+        for ( i = 0; i <= 256; i++ ) {
+            if ( ( freq[i] ) && ( freq[i] <= v ) && ( i != c1 ) ) {
+                v = freq[i];
+                c2 = i;
+            }
+        }
+
+        /* Done if we've merged everything into one frequency */
+        if ( c2 < 0 ) {
+            break;
+        }
+
+        /* Else merge the two counts/trees */
+        freq[c1] += freq[c2];
+        freq[c2] = 0;
+
+        /* Increment the codesize of everything in c1's tree branch */
+        codesize[c1]++;
+        while ( others[c1] >= 0 ) {
+            c1 = others[c1];
+            codesize[c1]++;
+        }
+
+        others[c1] = c2;    /* chain c2 onto c1's tree branch */
+
+        /* Increment the codesize of everything in c2's tree branch */
+        codesize[c2]++;
+        while ( others[c2] >= 0 ) {
+            c2 = others[c2];
+            codesize[c2]++;
+        }
+    }
+
+    /* Now count the number of symbols of each code length */
+    for ( i = 0; i <= 256; i++ ) {
+        if ( codesize[i] ) {
+            /* The JPEG standard seems to think that this can't happen, */
+            /* but I'm paranoid... */
+            if ( codesize[i] > MAX_CLEN ) {
+                ERREXIT( cinfo, JERR_HUFF_CLEN_OVERFLOW );
+            }
+
+            bits[codesize[i]]++;
+        }
+    }
+
+    /* JPEG doesn't allow symbols with code lengths over 16 bits, so if the pure
+     * Huffman procedure assigned any such lengths, we must adjust the coding.
+     * Here is what the JPEG spec says about how this next bit works:
+     * Since symbols are paired for the longest Huffman code, the symbols are
+     * removed from this length category two at a time.  The prefix for the pair
+     * (which is one bit shorter) is allocated to one of the pair; then,
+     * skipping the BITS entry for that prefix length, a code word from the next
+     * shortest nonzero BITS entry is converted into a prefix for two code words
+     * one bit longer.
+     */
+
+    for ( i = MAX_CLEN; i > 16; i-- ) {
+        while ( bits[i] > 0 ) {
+            j = i - 2;  /* find length of new prefix to be used */
+            while ( bits[j] == 0 ) {
+                j--;
+            }
+
+            bits[i] -= 2;/* remove two symbols */
+            bits[i - 1]++;/* one goes in this length */
+            bits[j + 1] += 2;/* two new symbols in this length */
+            bits[j]--;  /* symbol of this length is now a prefix */
+        }
+    }
+
+    /* Remove the count for the pseudo-symbol 256 from the largest codelength */
+    while ( bits[i] == 0 ) {/* find largest codelength still in use */
+        i--;
+    }
+    bits[i]--;
+
+    /* Return final symbol counts (only for lengths 0..16) */
+    MEMCOPY( htbl->bits, bits, SIZEOF( htbl->bits ) );
+
+    /* Return a list of the symbols sorted by code length */
+    /* It's not real clear to me why we don't need to consider the codelength
+     * changes made above, but the JPEG spec seems to think this works.
+     */
+    p = 0;
+    for ( i = 1; i <= MAX_CLEN; i++ ) {
+        for ( j = 0; j <= 255; j++ ) {
+            if ( codesize[j] == i ) {
+                htbl->huffval[p] = (UINT8) j;
+                p++;
+            }
+        }
+    }
+
+    /* Set sent_table FALSE so updated table will be written to JPEG file. */
+    htbl->sent_table = FALSE;
+}
+
+
+/*
+ * Finish up a statistics-gathering pass and create the new Huffman tables.
+ */
+
+METHODDEF void
+finish_pass_gather( j_compress_ptr cinfo ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    int ci, dctbl, actbl;
+    jpeg_component_info * compptr;
+    JHUFF_TBL ** htblptr;
+    boolean did_dc[NUM_HUFF_TBLS];
+    boolean did_ac[NUM_HUFF_TBLS];
+
+    /* It's important not to apply jpeg_gen_optimal_table more than once
+     * per table, because it clobbers the input frequency counts!
+     */
+    MEMZERO( did_dc, SIZEOF( did_dc ) );
+    MEMZERO( did_ac, SIZEOF( did_ac ) );
+
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        dctbl = compptr->dc_tbl_no;
+        actbl = compptr->ac_tbl_no;
+        if ( !did_dc[dctbl] ) {
+            htblptr = &cinfo->dc_huff_tbl_ptrs[dctbl];
+            if ( *htblptr == NULL ) {
+                *htblptr = jpeg_alloc_huff_table( (j_common_ptr) cinfo );
+            }
+            jpeg_gen_optimal_table( cinfo, *htblptr, entropy->dc_count_ptrs[dctbl] );
+            did_dc[dctbl] = TRUE;
+        }
+        if ( !did_ac[actbl] ) {
+            htblptr = &cinfo->ac_huff_tbl_ptrs[actbl];
+            if ( *htblptr == NULL ) {
+                *htblptr = jpeg_alloc_huff_table( (j_common_ptr) cinfo );
+            }
+            jpeg_gen_optimal_table( cinfo, *htblptr, entropy->ac_count_ptrs[actbl] );
+            did_ac[actbl] = TRUE;
+        }
+    }
+}
+
+
+#endif /* ENTROPY_OPT_SUPPORTED */
+
+
+/*
+ * Module initialization routine for Huffman entropy encoding.
+ */
+
+GLOBAL void
+jinit_huff_encoder( j_compress_ptr cinfo ) {
+    huff_entropy_ptr entropy;
+    int i;
+
+    entropy = (huff_entropy_ptr)
+              ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                           SIZEOF( huff_entropy_encoder ) );
+    cinfo->entropy = (struct jpeg_entropy_encoder *) entropy;
+    entropy->pub.start_pass = start_pass_huff;
+
+    /* Mark tables unallocated */
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
+#ifdef ENTROPY_OPT_SUPPORTED
+        entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL;
+#endif
+    }
+}

neo/renderer/jpeg-6/jchuff.h

@@ -0,0 +1,34 @@
+/*
+ * jchuff.h
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains declarations for Huffman entropy encoding routines
+ * that are shared between the sequential encoder (jchuff.c) and the
+ * progressive encoder (jcphuff.c).  No other modules need to see these.
+ */
+
+/* Derived data constructed for each Huffman table */
+
+typedef struct {
+  unsigned int ehufco[256];	/* code for each symbol */
+  char ehufsi[256];		/* length of code for each symbol */
+  /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */
+} c_derived_tbl;
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_make_c_derived_tbl	jMkCDerived
+#define jpeg_gen_optimal_table	jGenOptTbl
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+/* Expand a Huffman table definition into the derived format */
+EXTERN void jpeg_make_c_derived_tbl JPP((j_compress_ptr cinfo,
+				JHUFF_TBL * htbl, c_derived_tbl ** pdtbl));
+
+/* Generate an optimal table definition given the specified counts */
+EXTERN void jpeg_gen_optimal_table JPP((j_compress_ptr cinfo,
+					JHUFF_TBL * htbl, long freq[]));

neo/renderer/jpeg-6/jcinit.cpp

@@ -0,0 +1,72 @@
+/*
+ * jcinit.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains initialization logic for the JPEG compressor.
+ * This routine is in charge of selecting the modules to be executed and
+ * making an initialization call to each one.
+ *
+ * Logically, this code belongs in jcmaster.c.  It's split out because
+ * linking this routine implies linking the entire compression library.
+ * For a transcoding-only application, we want to be able to use jcmaster.c
+ * without linking in the whole library.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Master selection of compression modules.
+ * This is done once at the start of processing an image.  We determine
+ * which modules will be used and give them appropriate initialization calls.
+ */
+
+GLOBAL void
+jinit_compress_master( j_compress_ptr cinfo ) {
+    /* Initialize master control (includes parameter checking/processing) */
+    jinit_c_master_control( cinfo, FALSE /* full compression */ );
+
+    /* Preprocessing */
+    if ( !cinfo->raw_data_in ) {
+        jinit_color_converter( cinfo );
+        jinit_downsampler( cinfo );
+        jinit_c_prep_controller( cinfo, FALSE /* never need full buffer here */ );
+    }
+    /* Forward DCT */
+    jinit_forward_dct( cinfo );
+    /* Entropy encoding: either Huffman or arithmetic coding. */
+    if ( cinfo->arith_code ) {
+        ERREXIT( cinfo, JERR_ARITH_NOTIMPL );
+    } else {
+        if ( cinfo->progressive_mode ) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+            jinit_phuff_encoder( cinfo );
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        } else {
+            jinit_huff_encoder( cinfo );
+        }
+    }
+
+    /* Need a full-image coefficient buffer in any multi-pass mode. */
+    jinit_c_coef_controller( cinfo,
+                            ( cinfo->num_scans > 1 || cinfo->optimize_coding ) );
+    jinit_c_main_controller( cinfo, FALSE /* never need full buffer here */ );
+
+    jinit_marker_writer( cinfo );
+
+    /* We can now tell the memory manager to allocate virtual arrays. */
+    ( *cinfo->mem->realize_virt_arrays )( (j_common_ptr) cinfo );
+
+    /* Write the datastream header (SOI) immediately.
+     * Frame and scan headers are postponed till later.
+     * This lets application insert special markers after the SOI.
+     */
+    ( *cinfo->marker->write_file_header )( cinfo );
+}

neo/renderer/jpeg-6/jcmainct.cpp

@@ -0,0 +1,296 @@
+/*
+ * jcmainct.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the main buffer controller for compression.
+ * The main buffer lies between the pre-processor and the JPEG
+ * compressor proper; it holds downsampled data in the JPEG colorspace.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Note: currently, there is no operating mode in which a full-image buffer
+ * is needed at this step.  If there were, that mode could not be used with
+ * "raw data" input, since this module is bypassed in that case.  However,
+ * we've left the code here for possible use in special applications.
+ */
+#undef FULL_MAIN_BUFFER_SUPPORTED
+
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_c_main_controller pub;/* public fields */
+
+    JDIMENSION cur_iMCU_row;/* number of current iMCU row */
+    JDIMENSION rowgroup_ctr;/* counts row groups received in iMCU row */
+    boolean    suspended;   /* remember if we suspended output */
+    J_BUF_MODE pass_mode;   /* current operating mode */
+
+    /* If using just a strip buffer, this points to the entire set of buffers
+     * (we allocate one for each component).  In the full-image case, this
+     * points to the currently accessible strips of the virtual arrays.
+     */
+    JSAMPARRAY buffer[MAX_COMPONENTS];
+
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+    /* If using full-image storage, this array holds pointers to virtual-array
+     * control blocks for each component.  Unused if not full-image storage.
+     */
+    jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
+#endif
+} my_main_controller;
+
+typedef my_main_controller * my_main_ptr;
+
+
+/* Forward declarations */
+METHODDEF void process_data_simple_main
+JPP( ( j_compress_ptr cinfo, JSAMPARRAY input_buf,
+       JDIMENSION * in_row_ctr, JDIMENSION in_rows_avail ) );
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+METHODDEF void process_data_buffer_main
+JPP( ( j_compress_ptr cinfo, JSAMPARRAY input_buf,
+       JDIMENSION * in_row_ctr, JDIMENSION in_rows_avail ) );
+#endif
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF void
+start_pass_main( j_compress_ptr cinfo, J_BUF_MODE pass_mode ) {
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+
+    /* Do nothing in raw-data mode. */
+    if ( cinfo->raw_data_in ) {
+        return;
+    }
+
+    main->cur_iMCU_row = 0; /* initialize counters */
+    main->rowgroup_ctr = 0;
+    main->suspended = FALSE;
+    main->pass_mode = pass_mode;/* save mode for use by process_data */
+
+    switch ( pass_mode ) {
+        case JBUF_PASS_THRU:
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+            if ( main->whole_image[0] != NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+#endif
+            main->pub.process_data = process_data_simple_main;
+            break;
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+        case JBUF_SAVE_SOURCE:
+        case JBUF_CRANK_DEST:
+        case JBUF_SAVE_AND_PASS:
+            if ( main->whole_image[0] == NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+            main->pub.process_data = process_data_buffer_main;
+            break;
+#endif
+        default:
+            ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            break;
+    }
+}
+
+
+/*
+ * Process some data.
+ * This routine handles the simple pass-through mode,
+ * where we have only a strip buffer.
+ */
+
+METHODDEF void
+process_data_simple_main( j_compress_ptr cinfo,
+                          JSAMPARRAY input_buf, JDIMENSION * in_row_ctr,
+                          JDIMENSION in_rows_avail ) {
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+
+    while ( main->cur_iMCU_row < cinfo->total_iMCU_rows ) {
+        /* Read input data if we haven't filled the main buffer yet */
+        if ( main->rowgroup_ctr < DCTSIZE ) {
+            ( *cinfo->prep->pre_process_data )( cinfo,
+                                                input_buf, in_row_ctr, in_rows_avail,
+                                                main->buffer, &main->rowgroup_ctr,
+                                                (JDIMENSION) DCTSIZE );
+        }
+
+        /* If we don't have a full iMCU row buffered, return to application for
+         * more data.  Note that preprocessor will always pad to fill the iMCU row
+         * at the bottom of the image.
+         */
+        if ( main->rowgroup_ctr != DCTSIZE ) {
+            return;
+        }
+
+        /* Send the completed row to the compressor */
+        if ( !( *cinfo->coef->compress_data )( cinfo, main->buffer ) ) {
+            /* If compressor did not consume the whole row, then we must need to
+             * suspend processing and return to the application.  In this situation
+             * we pretend we didn't yet consume the last input row; otherwise, if
+             * it happened to be the last row of the image, the application would
+             * think we were done.
+             */
+            if ( !main->suspended ) {
+                ( *in_row_ctr )--;
+                main->suspended = TRUE;
+            }
+            return;
+        }
+        /* We did finish the row.  Undo our little suspension hack if a previous
+         * call suspended; then mark the main buffer empty.
+         */
+        if ( main->suspended ) {
+            ( *in_row_ctr )++;
+            main->suspended = FALSE;
+        }
+        main->rowgroup_ctr = 0;
+        main->cur_iMCU_row++;
+    }
+}
+
+
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+
+/*
+ * Process some data.
+ * This routine handles all of the modes that use a full-size buffer.
+ */
+
+METHODDEF void
+process_data_buffer_main( j_compress_ptr cinfo,
+                          JSAMPARRAY input_buf, JDIMENSION * in_row_ctr,
+                          JDIMENSION in_rows_avail ) {
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+    int ci;
+    jpeg_component_info * compptr;
+    boolean writing = ( main->pass_mode != JBUF_CRANK_DEST );
+
+    while ( main->cur_iMCU_row < cinfo->total_iMCU_rows ) {
+        /* Realign the virtual buffers if at the start of an iMCU row. */
+        if ( main->rowgroup_ctr == 0 ) {
+            for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+                  ci++, compptr++ ) {
+                main->buffer[ci] = ( *cinfo->mem->access_virt_sarray )
+                                   ( (j_common_ptr) cinfo, main->whole_image[ci],
+                                    main->cur_iMCU_row * ( compptr->v_samp_factor * DCTSIZE ),
+                                    (JDIMENSION) ( compptr->v_samp_factor * DCTSIZE ), writing );
+            }
+            /* In a read pass, pretend we just read some source data. */
+            if ( !writing ) {
+                *in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
+                main->rowgroup_ctr = DCTSIZE;
+            }
+        }
+
+        /* If a write pass, read input data until the current iMCU row is full. */
+        /* Note: preprocessor will pad if necessary to fill the last iMCU row. */
+        if ( writing ) {
+            ( *cinfo->prep->pre_process_data )( cinfo,
+                                                input_buf, in_row_ctr, in_rows_avail,
+                                                main->buffer, &main->rowgroup_ctr,
+                                                (JDIMENSION) DCTSIZE );
+            /* Return to application if we need more data to fill the iMCU row. */
+            if ( main->rowgroup_ctr < DCTSIZE ) {
+                return;
+            }
+        }
+
+        /* Emit data, unless this is a sink-only pass. */
+        if ( main->pass_mode != JBUF_SAVE_SOURCE ) {
+            if ( !( *cinfo->coef->compress_data )( cinfo, main->buffer ) ) {
+                /* If compressor did not consume the whole row, then we must need to
+                 * suspend processing and return to the application.  In this situation
+                 * we pretend we didn't yet consume the last input row; otherwise, if
+                 * it happened to be the last row of the image, the application would
+                 * think we were done.
+                 */
+                if ( !main->suspended ) {
+                    ( *in_row_ctr )--;
+                    main->suspended = TRUE;
+                }
+                return;
+            }
+            /* We did finish the row.  Undo our little suspension hack if a previous
+             * call suspended; then mark the main buffer empty.
+             */
+            if ( main->suspended ) {
+                ( *in_row_ctr )++;
+                main->suspended = FALSE;
+            }
+        }
+
+        /* If get here, we are done with this iMCU row.  Mark buffer empty. */
+        main->rowgroup_ctr = 0;
+        main->cur_iMCU_row++;
+    }
+}
+
+#endif /* FULL_MAIN_BUFFER_SUPPORTED */
+
+
+/*
+ * Initialize main buffer controller.
+ */
+
+GLOBAL void
+jinit_c_main_controller( j_compress_ptr cinfo, boolean need_full_buffer ) {
+    my_main_ptr main;
+    int ci;
+    jpeg_component_info * compptr;
+
+    main = (my_main_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_main_controller ) );
+    cinfo->main = (struct jpeg_c_main_controller *) main;
+    main->pub.start_pass = start_pass_main;
+
+    /* We don't need to create a buffer in raw-data mode. */
+    if ( cinfo->raw_data_in ) {
+        return;
+    }
+
+    /* Create the buffer.  It holds downsampled data, so each component
+     * may be of a different size.
+     */
+    if ( need_full_buffer ) {
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+        /* Allocate a full-image virtual array for each component */
+        /* Note we pad the bottom to a multiple of the iMCU height */
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            main->whole_image[ci] = ( *cinfo->mem->request_virt_sarray )
+                                    ( (j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+                                     compptr->width_in_blocks * DCTSIZE,
+                                     (JDIMENSION) jround_up( (long) compptr->height_in_blocks,
+                                                            (long) compptr->v_samp_factor ) * DCTSIZE,
+                                     (JDIMENSION) ( compptr->v_samp_factor * DCTSIZE ) );
+        }
+#else
+        ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+#endif
+    } else {
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+        main->whole_image[0] = NULL;/* flag for no virtual arrays */
+#endif
+        /* Allocate a strip buffer for each component */
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            main->buffer[ci] = ( *cinfo->mem->alloc_sarray )
+                               ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                compptr->width_in_blocks * DCTSIZE,
+                                (JDIMENSION) ( compptr->v_samp_factor * DCTSIZE ) );
+        }
+    }
+}

neo/renderer/jpeg-6/jcmarker.cpp

@@ -0,0 +1,644 @@
+/*
+ * jcmarker.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to write JPEG datastream markers.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+typedef enum {          /* JPEG marker codes */
+    M_SOF0  = 0xc0,
+    M_SOF1  = 0xc1,
+    M_SOF2  = 0xc2,
+    M_SOF3  = 0xc3,
+
+    M_SOF5  = 0xc5,
+    M_SOF6  = 0xc6,
+    M_SOF7  = 0xc7,
+
+    M_JPG   = 0xc8,
+    M_SOF9  = 0xc9,
+    M_SOF10 = 0xca,
+    M_SOF11 = 0xcb,
+
+    M_SOF13 = 0xcd,
+    M_SOF14 = 0xce,
+    M_SOF15 = 0xcf,
+
+    M_DHT   = 0xc4,
+
+    M_DAC   = 0xcc,
+
+    M_RST0  = 0xd0,
+    M_RST1  = 0xd1,
+    M_RST2  = 0xd2,
+    M_RST3  = 0xd3,
+    M_RST4  = 0xd4,
+    M_RST5  = 0xd5,
+    M_RST6  = 0xd6,
+    M_RST7  = 0xd7,
+
+    M_SOI   = 0xd8,
+    M_EOI   = 0xd9,
+    M_SOS   = 0xda,
+    M_DQT   = 0xdb,
+    M_DNL   = 0xdc,
+    M_DRI   = 0xdd,
+    M_DHP   = 0xde,
+    M_EXP   = 0xdf,
+
+    M_APP0  = 0xe0,
+    M_APP1  = 0xe1,
+    M_APP2  = 0xe2,
+    M_APP3  = 0xe3,
+    M_APP4  = 0xe4,
+    M_APP5  = 0xe5,
+    M_APP6  = 0xe6,
+    M_APP7  = 0xe7,
+    M_APP8  = 0xe8,
+    M_APP9  = 0xe9,
+    M_APP10 = 0xea,
+    M_APP11 = 0xeb,
+    M_APP12 = 0xec,
+    M_APP13 = 0xed,
+    M_APP14 = 0xee,
+    M_APP15 = 0xef,
+
+    M_JPG0  = 0xf0,
+    M_JPG13 = 0xfd,
+    M_COM   = 0xfe,
+
+    M_TEM   = 0x01,
+
+    M_ERROR = 0x100
+} JPEG_MARKER;
+
+
+/*
+ * Basic output routines.
+ *
+ * Note that we do not support suspension while writing a marker.
+ * Therefore, an application using suspension must ensure that there is
+ * enough buffer space for the initial markers (typ. 600-700 bytes) before
+ * calling jpeg_start_compress, and enough space to write the trailing EOI
+ * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
+ * modes are not supported at all with suspension, so those two are the only
+ * points where markers will be written.
+ */
+
+LOCAL void
+emit_byte( j_compress_ptr cinfo, int val ) {
+/* Emit a byte */
+    struct jpeg_destination_mgr * dest = cinfo->dest;
+
+    *( dest->next_output_byte )++ = (JOCTET) val;
+    if ( --dest->free_in_buffer == 0 ) {
+        if ( !( *dest->empty_output_buffer )( cinfo ) ) {
+            ERREXIT( cinfo, JERR_CANT_SUSPEND );
+        }
+    }
+}
+
+
+LOCAL void
+emit_marker( j_compress_ptr cinfo, JPEG_MARKER mark ) {
+/* Emit a marker code */
+    emit_byte( cinfo, 0xFF );
+    emit_byte( cinfo, (int) mark );
+}
+
+
+LOCAL void
+emit_2bytes( j_compress_ptr cinfo, int value ) {
+/* Emit a 2-byte integer; these are always MSB first in JPEG files */
+    emit_byte( cinfo, ( value >> 8 ) & 0xFF );
+    emit_byte( cinfo, value & 0xFF );
+}
+
+
+/*
+ * Routines to write specific marker types.
+ */
+
+LOCAL int
+emit_dqt( j_compress_ptr cinfo, int index ) {
+/* Emit a DQT marker */
+/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
+    JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
+    int prec;
+    int i;
+
+    if ( qtbl == NULL ) {
+        ERREXIT1( cinfo, JERR_NO_QUANT_TABLE, index );
+    }
+
+    prec = 0;
+    for ( i = 0; i < DCTSIZE2; i++ ) {
+        if ( qtbl->quantval[i] > 255 ) {
+            prec = 1;
+        }
+    }
+
+    if ( !qtbl->sent_table ) {
+        emit_marker( cinfo, M_DQT );
+
+        emit_2bytes( cinfo, prec ? DCTSIZE2 * 2 + 1 + 2 : DCTSIZE2 + 1 + 2 );
+
+        emit_byte( cinfo, index + ( prec << 4 ) );
+
+        for ( i = 0; i < DCTSIZE2; i++ ) {
+            if ( prec ) {
+                emit_byte( cinfo, qtbl->quantval[i] >> 8 );
+            }
+            emit_byte( cinfo, qtbl->quantval[i] & 0xFF );
+        }
+
+        qtbl->sent_table = TRUE;
+    }
+
+    return prec;
+}
+
+
+LOCAL void
+emit_dht( j_compress_ptr cinfo, int index, boolean is_ac ) {
+/* Emit a DHT marker */
+    JHUFF_TBL * htbl;
+    int length, i;
+
+    if ( is_ac ) {
+        htbl = cinfo->ac_huff_tbl_ptrs[index];
+        index += 0x10;  /* output index has AC bit set */
+    } else {
+        htbl = cinfo->dc_huff_tbl_ptrs[index];
+    }
+
+    if ( htbl == NULL ) {
+        ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, index );
+    }
+
+    if ( !htbl->sent_table ) {
+        emit_marker( cinfo, M_DHT );
+
+        length = 0;
+        for ( i = 1; i <= 16; i++ ) {
+            length += htbl->bits[i];
+        }
+
+        emit_2bytes( cinfo, length + 2 + 1 + 16 );
+        emit_byte( cinfo, index );
+
+        for ( i = 1; i <= 16; i++ ) {
+            emit_byte( cinfo, htbl->bits[i] );
+        }
+
+        for ( i = 0; i < length; i++ ) {
+            emit_byte( cinfo, htbl->huffval[i] );
+        }
+
+        htbl->sent_table = TRUE;
+    }
+}
+
+
+LOCAL void
+emit_dac( j_compress_ptr cinfo ) {
+/* Emit a DAC marker */
+/* Since the useful info is so small, we want to emit all the tables in */
+/* one DAC marker.  Therefore this routine does its own scan of the table. */
+#ifdef C_ARITH_CODING_SUPPORTED
+    char dc_in_use[NUM_ARITH_TBLS];
+    char ac_in_use[NUM_ARITH_TBLS];
+    int length, i;
+    jpeg_component_info * compptr;
+
+    for ( i = 0; i < NUM_ARITH_TBLS; i++ ) {
+        dc_in_use[i] = ac_in_use[i] = 0;
+    }
+
+    for ( i = 0; i < cinfo->comps_in_scan; i++ ) {
+        compptr = cinfo->cur_comp_info[i];
+        dc_in_use[compptr->dc_tbl_no] = 1;
+        ac_in_use[compptr->ac_tbl_no] = 1;
+    }
+
+    length = 0;
+    for ( i = 0; i < NUM_ARITH_TBLS; i++ ) {
+        length += dc_in_use[i] + ac_in_use[i];
+    }
+
+    emit_marker( cinfo, M_DAC );
+
+    emit_2bytes( cinfo, length * 2 + 2 );
+
+    for ( i = 0; i < NUM_ARITH_TBLS; i++ ) {
+        if ( dc_in_use[i] ) {
+            emit_byte( cinfo, i );
+            emit_byte( cinfo, cinfo->arith_dc_L[i] + ( cinfo->arith_dc_U[i] << 4 ) );
+        }
+        if ( ac_in_use[i] ) {
+            emit_byte( cinfo, i + 0x10 );
+            emit_byte( cinfo, cinfo->arith_ac_K[i] );
+        }
+    }
+#endif /* C_ARITH_CODING_SUPPORTED */
+}
+
+
+LOCAL void
+emit_dri( j_compress_ptr cinfo ) {
+/* Emit a DRI marker */
+    emit_marker( cinfo, M_DRI );
+
+    emit_2bytes( cinfo, 4 );/* fixed length */
+
+    emit_2bytes( cinfo, (int) cinfo->restart_interval );
+}
+
+
+LOCAL void
+emit_sof( j_compress_ptr cinfo, JPEG_MARKER code ) {
+/* Emit a SOF marker */
+    int ci;
+    jpeg_component_info * compptr;
+
+    emit_marker( cinfo, code );
+
+    emit_2bytes( cinfo, 3 * cinfo->num_components + 2 + 5 + 1 );/* length */
+
+    /* Make sure image isn't bigger than SOF field can handle */
+    if ( ( (long) cinfo->image_height > 65535L ) ||
+        ( (long) cinfo->image_width > 65535L ) ) {
+        ERREXIT1( cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535 );
+    }
+
+    emit_byte( cinfo, cinfo->data_precision );
+    emit_2bytes( cinfo, (int) cinfo->image_height );
+    emit_2bytes( cinfo, (int) cinfo->image_width );
+
+    emit_byte( cinfo, cinfo->num_components );
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        emit_byte( cinfo, compptr->component_id );
+        emit_byte( cinfo, ( compptr->h_samp_factor << 4 ) + compptr->v_samp_factor );
+        emit_byte( cinfo, compptr->quant_tbl_no );
+    }
+}
+
+
+LOCAL void
+emit_sos( j_compress_ptr cinfo ) {
+/* Emit a SOS marker */
+    int i, td, ta;
+    jpeg_component_info * compptr;
+
+    emit_marker( cinfo, M_SOS );
+
+    emit_2bytes( cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3 );/* length */
+
+    emit_byte( cinfo, cinfo->comps_in_scan );
+
+    for ( i = 0; i < cinfo->comps_in_scan; i++ ) {
+        compptr = cinfo->cur_comp_info[i];
+        emit_byte( cinfo, compptr->component_id );
+        td = compptr->dc_tbl_no;
+        ta = compptr->ac_tbl_no;
+        if ( cinfo->progressive_mode ) {
+            /* Progressive mode: only DC or only AC tables are used in one scan;
+             * furthermore, Huffman coding of DC refinement uses no table at all.
+             * We emit 0 for unused field(s); this is recommended by the P&M text
+             * but does not seem to be specified in the standard.
+             */
+            if ( cinfo->Ss == 0 ) {
+                ta = 0;/* DC scan */
+                if ( ( cinfo->Ah != 0 ) && ( !cinfo->arith_code ) ) {
+                    td = 0;
+                }   /* no DC table either */
+            } else {
+                td = 0;/* AC scan */
+            }
+        }
+        emit_byte( cinfo, ( td << 4 ) + ta );
+    }
+
+    emit_byte( cinfo, cinfo->Ss );
+    emit_byte( cinfo, cinfo->Se );
+    emit_byte( cinfo, ( cinfo->Ah << 4 ) + cinfo->Al );
+}
+
+
+LOCAL void
+emit_jfif_app0( j_compress_ptr cinfo ) {
+/* Emit a JFIF-compliant APP0 marker */
+/*
+ * Length of APP0 block	(2 bytes)
+ * Block ID			(4 bytes - ASCII "JFIF")
+ * Zero byte			(1 byte to terminate the ID string)
+ * Version Major, Minor	(2 bytes - 0x01, 0x01)
+ * Units			(1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
+ * Xdpu			(2 bytes - dots per unit horizontal)
+ * Ydpu			(2 bytes - dots per unit vertical)
+ * Thumbnail X size		(1 byte)
+ * Thumbnail Y size		(1 byte)
+ */
+
+    emit_marker( cinfo, M_APP0 );
+
+    emit_2bytes( cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1 );/* length */
+
+    emit_byte( cinfo, 0x4A );/* Identifier: ASCII "JFIF" */
+    emit_byte( cinfo, 0x46 );
+    emit_byte( cinfo, 0x49 );
+    emit_byte( cinfo, 0x46 );
+    emit_byte( cinfo, 0 );
+    /* We currently emit version code 1.01 since we use no 1.02 features.
+     * This may avoid complaints from some older decoders.
+     */
+    emit_byte( cinfo, 1 );  /* Major version */
+    emit_byte( cinfo, 1 );  /* Minor version */
+    emit_byte( cinfo, cinfo->density_unit );/* Pixel size information */
+    emit_2bytes( cinfo, (int) cinfo->X_density );
+    emit_2bytes( cinfo, (int) cinfo->Y_density );
+    emit_byte( cinfo, 0 );  /* No thumbnail image */
+    emit_byte( cinfo, 0 );
+}
+
+
+LOCAL void
+emit_adobe_app14( j_compress_ptr cinfo ) {
+/* Emit an Adobe APP14 marker */
+/*
+ * Length of APP14 block	(2 bytes)
+ * Block ID			(5 bytes - ASCII "Adobe")
+ * Version Number		(2 bytes - currently 100)
+ * Flags0			(2 bytes - currently 0)
+ * Flags1			(2 bytes - currently 0)
+ * Color transform		(1 byte)
+ *
+ * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
+ * now in circulation seem to use Version = 100, so that's what we write.
+ *
+ * We write the color transform byte as 1 if the JPEG color space is
+ * YCbCr, 2 if it's YCCK, 0 otherwise.  Adobe's definition has to do with
+ * whether the encoder performed a transformation, which is pretty useless.
+ */
+
+    emit_marker( cinfo, M_APP14 );
+
+    emit_2bytes( cinfo, 2 + 5 + 2 + 2 + 2 + 1 );/* length */
+
+    emit_byte( cinfo, 0x41 );/* Identifier: ASCII "Adobe" */
+    emit_byte( cinfo, 0x64 );
+    emit_byte( cinfo, 0x6F );
+    emit_byte( cinfo, 0x62 );
+    emit_byte( cinfo, 0x65 );
+    emit_2bytes( cinfo, 100 );/* Version */
+    emit_2bytes( cinfo, 0 );/* Flags0 */
+    emit_2bytes( cinfo, 0 );/* Flags1 */
+    switch ( cinfo->jpeg_color_space ) {
+        case JCS_YCbCr:
+            emit_byte( cinfo, 1 );/* Color transform = 1 */
+            break;
+        case JCS_YCCK:
+            emit_byte( cinfo, 2 );/* Color transform = 2 */
+            break;
+        default:
+            emit_byte( cinfo, 0 );/* Color transform = 0 */
+            break;
+    }
+}
+
+
+/*
+ * This routine is exported for possible use by applications.
+ * The intended use is to emit COM or APPn markers after calling
+ * jpeg_start_compress() and before the first jpeg_write_scanlines() call
+ * (hence, after write_file_header but before write_frame_header).
+ * Other uses are not guaranteed to produce desirable results.
+ */
+
+METHODDEF void
+write_any_marker( j_compress_ptr cinfo, int marker,
+                  const JOCTET * dataptr, unsigned int datalen ) {
+/* Emit an arbitrary marker with parameters */
+    if ( datalen <= (unsigned int) 65533 ) {/* safety check */
+        emit_marker( cinfo, (JPEG_MARKER) marker );
+
+        emit_2bytes( cinfo, (int) ( datalen + 2 ) );/* total length */
+
+        while ( datalen-- ) {
+            emit_byte( cinfo, *dataptr );
+            dataptr++;
+        }
+    }
+}
+
+
+/*
+ * Write datastream header.
+ * This consists of an SOI and optional APPn markers.
+ * We recommend use of the JFIF marker, but not the Adobe marker,
+ * when using YCbCr or grayscale data.  The JFIF marker should NOT
+ * be used for any other JPEG colorspace.  The Adobe marker is helpful
+ * to distinguish RGB, CMYK, and YCCK colorspaces.
+ * Note that an application can write additional header markers after
+ * jpeg_start_compress returns.
+ */
+
+METHODDEF void
+write_file_header( j_compress_ptr cinfo ) {
+    emit_marker( cinfo, M_SOI );/* first the SOI */
+
+    if ( cinfo->write_JFIF_header ) {/* next an optional JFIF APP0 */
+        emit_jfif_app0( cinfo );
+    }
+    if ( cinfo->write_Adobe_marker ) {/* next an optional Adobe APP14 */
+        emit_adobe_app14( cinfo );
+    }
+}
+
+
+/*
+ * Write frame header.
+ * This consists of DQT and SOFn markers.
+ * Note that we do not emit the SOF until we have emitted the DQT(s).
+ * This avoids compatibility problems with incorrect implementations that
+ * try to error-check the quant table numbers as soon as they see the SOF.
+ */
+
+METHODDEF void
+write_frame_header( j_compress_ptr cinfo ) {
+    int ci, prec;
+    boolean is_baseline;
+    jpeg_component_info * compptr;
+
+    /* Emit DQT for each quantization table.
+     * Note that emit_dqt() suppresses any duplicate tables.
+     */
+    prec = 0;
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        prec += emit_dqt( cinfo, compptr->quant_tbl_no );
+    }
+    /* now prec is nonzero iff there are any 16-bit quant tables. */
+
+    /* Check for a non-baseline specification.
+     * Note we assume that Huffman table numbers won't be changed later.
+     */
+    if ( ( cinfo->arith_code ) || ( cinfo->progressive_mode ) ||
+        ( cinfo->data_precision != 8 ) ) {
+        is_baseline = FALSE;
+    } else {
+        is_baseline = TRUE;
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            if ( ( compptr->dc_tbl_no > 1 ) || ( compptr->ac_tbl_no > 1 ) ) {
+                is_baseline = FALSE;
+            }
+        }
+        if ( ( prec ) && ( is_baseline ) ) {
+            is_baseline = FALSE;
+            /* If it's baseline except for quantizer size, warn the user */
+            TRACEMS( cinfo, 0, JTRC_16BIT_TABLES );
+        }
+    }
+
+    /* Emit the proper SOF marker */
+    if ( cinfo->arith_code ) {
+        emit_sof( cinfo, M_SOF9 );/* SOF code for arithmetic coding */
+    } else {
+        if ( cinfo->progressive_mode ) {
+            emit_sof( cinfo, M_SOF2 );
+        }                       /* SOF code for progressive Huffman */
+        else if ( is_baseline ) {
+            emit_sof( cinfo, M_SOF0 );
+        }                       /* SOF code for baseline implementation */
+        else {
+            emit_sof( cinfo, M_SOF1 );
+        }                       /* SOF code for non-baseline Huffman file */
+    }
+}
+
+
+/*
+ * Write scan header.
+ * This consists of DHT or DAC markers, optional DRI, and SOS.
+ * Compressed data will be written following the SOS.
+ */
+
+METHODDEF void
+write_scan_header( j_compress_ptr cinfo ) {
+    int i;
+    jpeg_component_info * compptr;
+
+    if ( cinfo->arith_code ) {
+        /* Emit arith conditioning info.  We may have some duplication
+         * if the file has multiple scans, but it's so small it's hardly
+         * worth worrying about.
+         */
+        emit_dac( cinfo );
+    } else {
+        /* Emit Huffman tables.
+         * Note that emit_dht() suppresses any duplicate tables.
+         */
+        for ( i = 0; i < cinfo->comps_in_scan; i++ ) {
+            compptr = cinfo->cur_comp_info[i];
+            if ( cinfo->progressive_mode ) {
+                /* Progressive mode: only DC or only AC tables are used in one scan */
+                if ( cinfo->Ss == 0 ) {
+                    if ( cinfo->Ah == 0 ) {/* DC needs no table for refinement scan */
+                        emit_dht( cinfo, compptr->dc_tbl_no, FALSE );
+                    }
+                } else {
+                    emit_dht( cinfo, compptr->ac_tbl_no, TRUE );
+                }
+            } else {
+                /* Sequential mode: need both DC and AC tables */
+                emit_dht( cinfo, compptr->dc_tbl_no, FALSE );
+                emit_dht( cinfo, compptr->ac_tbl_no, TRUE );
+            }
+        }
+    }
+
+    /* Emit DRI if required --- note that DRI value could change for each scan.
+     * If it doesn't, a tiny amount of space is wasted in multiple-scan files.
+     * We assume DRI will never be nonzero for one scan and zero for a later one.
+     */
+    if ( cinfo->restart_interval ) {
+        emit_dri( cinfo );
+    }
+
+    emit_sos( cinfo );
+}
+
+
+/*
+ * Write datastream trailer.
+ */
+
+METHODDEF void
+write_file_trailer( j_compress_ptr cinfo ) {
+    emit_marker( cinfo, M_EOI );
+}
+
+
+/*
+ * Write an abbreviated table-specification datastream.
+ * This consists of SOI, DQT and DHT tables, and EOI.
+ * Any table that is defined and not marked sent_table = TRUE will be
+ * emitted.  Note that all tables will be marked sent_table = TRUE at exit.
+ */
+
+METHODDEF void
+write_tables_only( j_compress_ptr cinfo ) {
+    int i;
+
+    emit_marker( cinfo, M_SOI );
+
+    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
+        if ( cinfo->quant_tbl_ptrs[i] != NULL ) {
+            (void) emit_dqt( cinfo, i );
+        }
+    }
+
+    if ( !cinfo->arith_code ) {
+        for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+            if ( cinfo->dc_huff_tbl_ptrs[i] != NULL ) {
+                emit_dht( cinfo, i, FALSE );
+            }
+            if ( cinfo->ac_huff_tbl_ptrs[i] != NULL ) {
+                emit_dht( cinfo, i, TRUE );
+            }
+        }
+    }
+
+    emit_marker( cinfo, M_EOI );
+}
+
+
+/*
+ * Initialize the marker writer module.
+ */
+
+GLOBAL void
+jinit_marker_writer( j_compress_ptr cinfo ) {
+    /* Create the subobject */
+    cinfo->marker = (struct jpeg_marker_writer *)
+                    ( * cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                  SIZEOF( struct jpeg_marker_writer ) );
+    /* Initialize method pointers */
+    cinfo->marker->write_any_marker = write_any_marker;
+    cinfo->marker->write_file_header = write_file_header;
+    cinfo->marker->write_frame_header = write_frame_header;
+    cinfo->marker->write_scan_header = write_scan_header;
+    cinfo->marker->write_file_trailer = write_file_trailer;
+    cinfo->marker->write_tables_only = write_tables_only;
+}

neo/renderer/jpeg-6/jcmaster.cpp

@@ -0,0 +1,607 @@
+/*
+ * jcmaster.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains master control logic for the JPEG compressor.
+ * These routines are concerned with parameter validation, initial setup,
+ * and inter-pass control (determining the number of passes and the work
+ * to be done in each pass).
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private state */
+
+typedef enum {
+    main_pass,      /* input data, also do first output step */
+    huff_opt_pass,      /* Huffman code optimization pass */
+    output_pass     /* data output pass */
+} c_pass_type;
+
+typedef struct {
+    struct jpeg_comp_master pub;/* public fields */
+
+    c_pass_type pass_type;  /* the type of the current pass */
+
+    int pass_number;    /* # of passes completed */
+    int total_passes;   /* total # of passes needed */
+
+    int scan_number;    /* current index in scan_info[] */
+} my_comp_master;
+
+typedef my_comp_master * my_master_ptr;
+
+
+/*
+ * Support routines that do various essential calculations.
+ */
+
+LOCAL void
+initial_setup( j_compress_ptr cinfo ) {
+/* Do computations that are needed before master selection phase */
+    int ci;
+    jpeg_component_info * compptr;
+    long samplesperrow;
+    JDIMENSION jd_samplesperrow;
+
+    /* Sanity check on image dimensions */
+    if ( ( cinfo->image_height <= 0 ) || ( cinfo->image_width <= 0 )
+        || ( cinfo->num_components <= 0 ) || ( cinfo->input_components <= 0 ) ) {
+        ERREXIT( cinfo, JERR_EMPTY_IMAGE );
+    }
+
+    /* Make sure image isn't bigger than I can handle */
+    if ( ( (long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ) ||
+        ( (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION ) ) {
+        ERREXIT1( cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION );
+    }
+
+    /* Width of an input scanline must be representable as JDIMENSION. */
+    samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
+    jd_samplesperrow = (JDIMENSION) samplesperrow;
+    if ( (long) jd_samplesperrow != samplesperrow ) {
+        ERREXIT( cinfo, JERR_WIDTH_OVERFLOW );
+    }
+
+    /* For now, precision must match compiled-in value... */
+    if ( cinfo->data_precision != BITS_IN_JSAMPLE ) {
+        ERREXIT1( cinfo, JERR_BAD_PRECISION, cinfo->data_precision );
+    }
+
+    /* Check that number of components won't exceed internal array sizes */
+    if ( cinfo->num_components > MAX_COMPONENTS ) {
+        ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+                  MAX_COMPONENTS );
+    }
+
+    /* Compute maximum sampling factors; check factor validity */
+    cinfo->max_h_samp_factor = 1;
+    cinfo->max_v_samp_factor = 1;
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        if ( ( compptr->h_samp_factor <= 0 ) || ( compptr->h_samp_factor > MAX_SAMP_FACTOR ) ||
+            ( compptr->v_samp_factor <= 0 ) || ( compptr->v_samp_factor > MAX_SAMP_FACTOR ) ) {
+            ERREXIT( cinfo, JERR_BAD_SAMPLING );
+        }
+        cinfo->max_h_samp_factor = MAX( cinfo->max_h_samp_factor,
+                                        compptr->h_samp_factor );
+        cinfo->max_v_samp_factor = MAX( cinfo->max_v_samp_factor,
+                                        compptr->v_samp_factor );
+    }
+
+    /* Compute dimensions of components */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Fill in the correct component_index value; don't rely on application */
+        compptr->component_index = ci;
+        /* For compression, we never do DCT scaling. */
+        compptr->DCT_scaled_size = DCTSIZE;
+        /* Size in DCT blocks */
+        compptr->width_in_blocks = (JDIMENSION)
+                                   jdiv_round_up( (long) cinfo->image_width * (long) compptr->h_samp_factor,
+                                                 (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
+        compptr->height_in_blocks = (JDIMENSION)
+                                    jdiv_round_up( (long) cinfo->image_height * (long) compptr->v_samp_factor,
+                                                  (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+        /* Size in samples */
+        compptr->downsampled_width = (JDIMENSION)
+                                     jdiv_round_up( (long) cinfo->image_width * (long) compptr->h_samp_factor,
+                                                   (long) cinfo->max_h_samp_factor );
+        compptr->downsampled_height = (JDIMENSION)
+                                      jdiv_round_up( (long) cinfo->image_height * (long) compptr->v_samp_factor,
+                                                    (long) cinfo->max_v_samp_factor );
+        /* Mark component needed (this flag isn't actually used for compression) */
+        compptr->component_needed = TRUE;
+    }
+
+    /* Compute number of fully interleaved MCU rows (number of times that
+     * main controller will call coefficient controller).
+     */
+    cinfo->total_iMCU_rows = (JDIMENSION)
+                             jdiv_round_up( (long) cinfo->image_height,
+                                           (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+}
+
+
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+
+LOCAL void
+validate_script( j_compress_ptr cinfo ) {
+/* Verify that the scan script in cinfo->scan_info[] is valid; also
+ * determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
+ */
+    const jpeg_scan_info * scanptr;
+    int scanno, ncomps, ci, coefi, thisi;
+    int Ss, Se, Ah, Al;
+    boolean component_sent[MAX_COMPONENTS];
+#ifdef C_PROGRESSIVE_SUPPORTED
+    int * last_bitpos_ptr;
+    int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
+    /* -1 until that coefficient has been seen; then last Al for it */
+#endif
+
+    if ( cinfo->num_scans <= 0 ) {
+        ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, 0 );
+    }
+
+    /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
+     * for progressive JPEG, no scan can have this.
+     */
+    scanptr = cinfo->scan_info;
+    if ( ( scanptr->Ss != 0 ) || ( scanptr->Se != DCTSIZE2 - 1 ) ) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+        cinfo->progressive_mode = TRUE;
+        last_bitpos_ptr = &last_bitpos[0][0];
+        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+            for ( coefi = 0; coefi < DCTSIZE2; coefi++ ) {
+                *last_bitpos_ptr++ = -1;
+            }
+        }
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+    } else {
+        cinfo->progressive_mode = FALSE;
+        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+            component_sent[ci] = FALSE;
+        }
+    }
+
+    for ( scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++ ) {
+        /* Validate component indexes */
+        ncomps = scanptr->comps_in_scan;
+        if ( ( ncomps <= 0 ) || ( ncomps > MAX_COMPS_IN_SCAN ) ) {
+            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN );
+        }
+        for ( ci = 0; ci < ncomps; ci++ ) {
+            thisi = scanptr->component_index[ci];
+            if ( ( thisi < 0 ) || ( thisi >= cinfo->num_components ) ) {
+                ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, scanno );
+            }
+            /* Components must appear in SOF order within each scan */
+            if ( ( ci > 0 ) && ( thisi <= scanptr->component_index[ci - 1] ) ) {
+                ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, scanno );
+            }
+        }
+        /* Validate progression parameters */
+        Ss = scanptr->Ss;
+        Se = scanptr->Se;
+        Ah = scanptr->Ah;
+        Al = scanptr->Al;
+        if ( cinfo->progressive_mode ) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+            if ( ( Ss < 0 ) || ( Ss >= DCTSIZE2 ) || ( Se < Ss ) || ( Se >= DCTSIZE2 ) ||
+                ( Ah < 0 ) || ( Ah > 13 ) || ( Al < 0 ) || ( Al > 13 ) ) {
+                ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+            }
+            if ( Ss == 0 ) {
+                if ( Se != 0 ) {/* DC and AC together not OK */
+                    ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+                }
+            } else {
+                if ( ncomps != 1 ) {/* AC scans must be for only one component */
+                    ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+                }
+            }
+            for ( ci = 0; ci < ncomps; ci++ ) {
+                last_bitpos_ptr = &last_bitpos[scanptr->component_index[ci]][0];
+                if ( ( Ss != 0 ) && ( last_bitpos_ptr[0] < 0 ) ) {/* AC without prior DC scan */
+                    ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+                }
+                for ( coefi = Ss; coefi <= Se; coefi++ ) {
+                    if ( last_bitpos_ptr[coefi] < 0 ) {
+                        /* first scan of this coefficient */
+                        if ( Ah != 0 ) {
+                            ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+                        }
+                    } else {
+                        /* not first scan */
+                        if ( ( Ah != last_bitpos_ptr[coefi] ) || ( Al != Ah - 1 ) ) {
+                            ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+                        }
+                    }
+                    last_bitpos_ptr[coefi] = Al;
+                }
+            }
+#endif
+        } else {
+            /* For sequential JPEG, all progression parameters must be these: */
+            if ( ( Ss != 0 ) || ( Se != DCTSIZE2 - 1 ) || ( Ah != 0 ) || ( Al != 0 ) ) {
+                ERREXIT1( cinfo, JERR_BAD_PROG_SCRIPT, scanno );
+            }
+            /* Make sure components are not sent twice */
+            for ( ci = 0; ci < ncomps; ci++ ) {
+                thisi = scanptr->component_index[ci];
+                if ( component_sent[thisi] ) {
+                    ERREXIT1( cinfo, JERR_BAD_SCAN_SCRIPT, scanno );
+                }
+                component_sent[thisi] = TRUE;
+            }
+        }
+    }
+
+    /* Now verify that everything got sent. */
+    if ( cinfo->progressive_mode ) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+        /* For progressive mode, we only check that at least some DC data
+         * got sent for each component; the spec does not require that all bits
+         * of all coefficients be transmitted.  Would it be wiser to enforce
+         * transmission of all coefficient bits??
+         */
+        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+            if ( last_bitpos[ci][0] < 0 ) {
+                ERREXIT( cinfo, JERR_MISSING_DATA );
+            }
+        }
+#endif
+    } else {
+        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+            if ( !component_sent[ci] ) {
+                ERREXIT( cinfo, JERR_MISSING_DATA );
+            }
+        }
+    }
+}
+
+#endif /* C_MULTISCAN_FILES_SUPPORTED */
+
+
+LOCAL void
+select_scan_parameters( j_compress_ptr cinfo ) {
+/* Set up the scan parameters for the current scan */
+    int ci;
+
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+    if ( cinfo->scan_info != NULL ) {
+        /* Prepare for current scan --- the script is already validated */
+        my_master_ptr master = (my_master_ptr) cinfo->master;
+        const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;
+
+        cinfo->comps_in_scan = scanptr->comps_in_scan;
+        for ( ci = 0; ci < scanptr->comps_in_scan; ci++ ) {
+            cinfo->cur_comp_info[ci] =
+                &cinfo->comp_info[scanptr->component_index[ci]];
+        }
+        cinfo->Ss = scanptr->Ss;
+        cinfo->Se = scanptr->Se;
+        cinfo->Ah = scanptr->Ah;
+        cinfo->Al = scanptr->Al;
+    } else
+#endif
+    {
+        /* Prepare for single sequential-JPEG scan containing all components */
+        if ( cinfo->num_components > MAX_COMPS_IN_SCAN ) {
+            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+                      MAX_COMPS_IN_SCAN );
+        }
+        cinfo->comps_in_scan = cinfo->num_components;
+        for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+            cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
+        }
+        cinfo->Ss = 0;
+        cinfo->Se = DCTSIZE2 - 1;
+        cinfo->Ah = 0;
+        cinfo->Al = 0;
+    }
+}
+
+
+LOCAL void
+per_scan_setup( j_compress_ptr cinfo ) {
+/* Do computations that are needed before processing a JPEG scan */
+/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
+    int ci, mcublks, tmp;
+    jpeg_component_info * compptr;
+
+    if ( cinfo->comps_in_scan == 1 ) {
+
+        /* Noninterleaved (single-component) scan */
+        compptr = cinfo->cur_comp_info[0];
+
+        /* Overall image size in MCUs */
+        cinfo->MCUs_per_row = compptr->width_in_blocks;
+        cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
+
+        /* For noninterleaved scan, always one block per MCU */
+        compptr->MCU_width = 1;
+        compptr->MCU_height = 1;
+        compptr->MCU_blocks = 1;
+        compptr->MCU_sample_width = DCTSIZE;
+        compptr->last_col_width = 1;
+        /* For noninterleaved scans, it is convenient to define last_row_height
+         * as the number of block rows present in the last iMCU row.
+         */
+        tmp = (int) ( compptr->height_in_blocks % compptr->v_samp_factor );
+        if ( tmp == 0 ) {
+            tmp = compptr->v_samp_factor;
+        }
+        compptr->last_row_height = tmp;
+
+        /* Prepare array describing MCU composition */
+        cinfo->blocks_in_MCU = 1;
+        cinfo->MCU_membership[0] = 0;
+
+    } else {
+
+        /* Interleaved (multi-component) scan */
+        if ( ( cinfo->comps_in_scan <= 0 ) || ( cinfo->comps_in_scan > MAX_COMPS_IN_SCAN ) ) {
+            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
+                      MAX_COMPS_IN_SCAN );
+        }
+
+        /* Overall image size in MCUs */
+        cinfo->MCUs_per_row = (JDIMENSION)
+                              jdiv_round_up( (long) cinfo->image_width,
+                                            (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
+        cinfo->MCU_rows_in_scan = (JDIMENSION)
+                                  jdiv_round_up( (long) cinfo->image_height,
+                                                (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+
+        cinfo->blocks_in_MCU = 0;
+
+        for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+            compptr = cinfo->cur_comp_info[ci];
+            /* Sampling factors give # of blocks of component in each MCU */
+            compptr->MCU_width = compptr->h_samp_factor;
+            compptr->MCU_height = compptr->v_samp_factor;
+            compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
+            compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
+            /* Figure number of non-dummy blocks in last MCU column & row */
+            tmp = (int) ( compptr->width_in_blocks % compptr->MCU_width );
+            if ( tmp == 0 ) {
+                tmp = compptr->MCU_width;
+            }
+            compptr->last_col_width = tmp;
+            tmp = (int) ( compptr->height_in_blocks % compptr->MCU_height );
+            if ( tmp == 0 ) {
+                tmp = compptr->MCU_height;
+            }
+            compptr->last_row_height = tmp;
+            /* Prepare array describing MCU composition */
+            mcublks = compptr->MCU_blocks;
+            if ( cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU ) {
+                ERREXIT( cinfo, JERR_BAD_MCU_SIZE );
+            }
+            while ( mcublks-- > 0 ) {
+                cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
+            }
+        }
+
+    }
+
+    /* Convert restart specified in rows to actual MCU count. */
+    /* Note that count must fit in 16 bits, so we provide limiting. */
+    if ( cinfo->restart_in_rows > 0 ) {
+        long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
+        cinfo->restart_interval = (unsigned int) MIN( nominal, 65535L );
+    }
+}
+
+
+/*
+ * Per-pass setup.
+ * This is called at the beginning of each pass.  We determine which modules
+ * will be active during this pass and give them appropriate start_pass calls.
+ * We also set is_last_pass to indicate whether any more passes will be
+ * required.
+ */
+
+METHODDEF void
+prepare_for_pass( j_compress_ptr cinfo ) {
+    my_master_ptr master = (my_master_ptr) cinfo->master;
+
+    switch ( master->pass_type ) {
+        case main_pass:
+            /* Initial pass: will collect input data, and do either Huffman
+             * optimization or data output for the first scan.
+             */
+            select_scan_parameters( cinfo );
+            per_scan_setup( cinfo );
+            if ( !cinfo->raw_data_in ) {
+                ( *cinfo->cconvert->start_pass )( cinfo );
+                ( *cinfo->downsample->start_pass )( cinfo );
+                ( *cinfo->prep->start_pass )( cinfo, JBUF_PASS_THRU );
+            }
+            ( *cinfo->fdct->start_pass )( cinfo );
+            ( *cinfo->entropy->start_pass )( cinfo, cinfo->optimize_coding );
+            ( *cinfo->coef->start_pass )( cinfo,
+                                         ( master->total_passes > 1 ?
+                                           JBUF_SAVE_AND_PASS : JBUF_PASS_THRU ) );
+            ( *cinfo->main->start_pass )( cinfo, JBUF_PASS_THRU );
+            if ( cinfo->optimize_coding ) {
+                /* No immediate data output; postpone writing frame/scan headers */
+                master->pub.call_pass_startup = FALSE;
+            } else {
+                /* Will write frame/scan headers at first jpeg_write_scanlines call */
+                master->pub.call_pass_startup = TRUE;
+            }
+            break;
+#ifdef ENTROPY_OPT_SUPPORTED
+        case huff_opt_pass:
+            /* Do Huffman optimization for a scan after the first one. */
+            select_scan_parameters( cinfo );
+            per_scan_setup( cinfo );
+            if ( ( cinfo->Ss != 0 ) || ( cinfo->Ah == 0 ) || ( cinfo->arith_code ) ) {
+                ( *cinfo->entropy->start_pass )( cinfo, TRUE );
+                ( *cinfo->coef->start_pass )( cinfo, JBUF_CRANK_DEST );
+                master->pub.call_pass_startup = FALSE;
+                break;
+            }
+            /* Special case: Huffman DC refinement scans need no Huffman table
+             * and therefore we can skip the optimization pass for them.
+             */
+            master->pass_type = output_pass;
+            master->pass_number++;
+            /*FALLTHROUGH*/
+#endif
+        case output_pass:
+            /* Do a data-output pass. */
+            /* We need not repeat per-scan setup if prior optimization pass did it. */
+            if ( !cinfo->optimize_coding ) {
+                select_scan_parameters( cinfo );
+                per_scan_setup( cinfo );
+            }
+            ( *cinfo->entropy->start_pass )( cinfo, FALSE );
+            ( *cinfo->coef->start_pass )( cinfo, JBUF_CRANK_DEST );
+            /* We emit frame/scan headers now */
+            if ( master->scan_number == 0 ) {
+                ( *cinfo->marker->write_frame_header )( cinfo );
+            }
+            ( *cinfo->marker->write_scan_header )( cinfo );
+            master->pub.call_pass_startup = FALSE;
+            break;
+        default:
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+    }
+
+    master->pub.is_last_pass = ( master->pass_number == master->total_passes - 1 );
+
+    /* Set up progress monitor's pass info if present */
+    if ( cinfo->progress != NULL ) {
+        cinfo->progress->completed_passes = master->pass_number;
+        cinfo->progress->total_passes = master->total_passes;
+    }
+}
+
+
+/*
+ * Special start-of-pass hook.
+ * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
+ * In single-pass processing, we need this hook because we don't want to
+ * write frame/scan headers during jpeg_start_compress; we want to let the
+ * application write COM markers etc. between jpeg_start_compress and the
+ * jpeg_write_scanlines loop.
+ * In multi-pass processing, this routine is not used.
+ */
+
+METHODDEF void
+pass_startup( j_compress_ptr cinfo ) {
+    cinfo->master->call_pass_startup = FALSE;/* reset flag so call only once */
+
+    ( *cinfo->marker->write_frame_header )( cinfo );
+    ( *cinfo->marker->write_scan_header )( cinfo );
+}
+
+
+/*
+ * Finish up at end of pass.
+ */
+
+METHODDEF void
+finish_pass_master( j_compress_ptr cinfo ) {
+    my_master_ptr master = (my_master_ptr) cinfo->master;
+
+    /* The entropy coder always needs an end-of-pass call,
+     * either to analyze statistics or to flush its output buffer.
+     */
+    ( *cinfo->entropy->finish_pass )( cinfo );
+
+    /* Update state for next pass */
+    switch ( master->pass_type ) {
+        case main_pass:
+            /* next pass is either output of scan 0 (after optimization)
+             * or output of scan 1 (if no optimization).
+             */
+            master->pass_type = output_pass;
+            if ( !cinfo->optimize_coding ) {
+                master->scan_number++;
+            }
+            break;
+        case huff_opt_pass:
+            /* next pass is always output of current scan */
+            master->pass_type = output_pass;
+            break;
+        case output_pass:
+            /* next pass is either optimization or output of next scan */
+            if ( cinfo->optimize_coding ) {
+                master->pass_type = huff_opt_pass;
+            }
+            master->scan_number++;
+            break;
+    }
+
+    master->pass_number++;
+}
+
+
+/*
+ * Initialize master compression control.
+ */
+
+GLOBAL void
+jinit_c_master_control( j_compress_ptr cinfo, boolean transcode_only ) {
+    my_master_ptr master;
+
+    master = (my_master_ptr)
+             ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                          SIZEOF( my_comp_master ) );
+    cinfo->master = (struct jpeg_comp_master *) master;
+    master->pub.prepare_for_pass = prepare_for_pass;
+    master->pub.pass_startup = pass_startup;
+    master->pub.finish_pass = finish_pass_master;
+    master->pub.is_last_pass = FALSE;
+
+    /* Validate parameters, determine derived values */
+    initial_setup( cinfo );
+
+    if ( cinfo->scan_info != NULL ) {
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+        validate_script( cinfo );
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+    } else {
+        cinfo->progressive_mode = FALSE;
+        cinfo->num_scans = 1;
+    }
+
+    if ( cinfo->progressive_mode ) {/*  TEMPORARY HACK ??? */
+        cinfo->optimize_coding = TRUE;
+    }                              /* assume default tables no good for progressive mode */
+
+    /* Initialize my private state */
+    if ( transcode_only ) {
+        /* no main pass in transcoding */
+        if ( cinfo->optimize_coding ) {
+            master->pass_type = huff_opt_pass;
+        } else {
+            master->pass_type = output_pass;
+        }
+    } else {
+        /* for normal compression, first pass is always this type: */
+        master->pass_type = main_pass;
+    }
+    master->scan_number = 0;
+    master->pass_number = 0;
+    if ( cinfo->optimize_coding ) {
+        master->total_passes = cinfo->num_scans * 2;
+    } else {
+        master->total_passes = cinfo->num_scans;
+    }
+}

neo/renderer/jpeg-6/jcomapi.cpp

@@ -0,0 +1,91 @@
+/*
+ * jcomapi.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface routines that are used for both
+ * compression and decompression.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Abort processing of a JPEG compression or decompression operation,
+ * but don't destroy the object itself.
+ *
+ * For this, we merely clean up all the nonpermanent memory pools.
+ * Note that temp files (virtual arrays) are not allowed to belong to
+ * the permanent pool, so we will be able to close all temp files here.
+ * Closing a data source or destination, if necessary, is the application's
+ * responsibility.
+ */
+
+GLOBAL void
+jpeg_abort( j_common_ptr cinfo ) {
+    int pool;
+
+    /* Releasing pools in reverse order might help avoid fragmentation
+     * with some (brain-damaged) malloc libraries.
+     */
+    for ( pool = JPOOL_NUMPOOLS - 1; pool > JPOOL_PERMANENT; pool-- ) {
+        ( *cinfo->mem->free_pool )( cinfo, pool );
+    }
+
+    /* Reset overall state for possible reuse of object */
+    cinfo->global_state = ( cinfo->is_decompressor ? DSTATE_START : CSTATE_START );
+}
+
+
+/*
+ * Destruction of a JPEG object.
+ *
+ * Everything gets deallocated except the master jpeg_compress_struct itself
+ * and the error manager struct.  Both of these are supplied by the application
+ * and must be freed, if necessary, by the application.  (Often they are on
+ * the stack and so don't need to be freed anyway.)
+ * Closing a data source or destination, if necessary, is the application's
+ * responsibility.
+ */
+
+GLOBAL void
+jpeg_destroy( j_common_ptr cinfo ) {
+    /* We need only tell the memory manager to release everything. */
+    /* NB: mem pointer is NULL if memory mgr failed to initialize. */
+    if ( cinfo->mem != NULL ) {
+        ( *cinfo->mem->self_destruct )( cinfo );
+    }
+    cinfo->mem = NULL;      /* be safe if jpeg_destroy is called twice */
+    cinfo->global_state = 0;/* mark it destroyed */
+}
+
+
+/*
+ * Convenience routines for allocating quantization and Huffman tables.
+ * (Would jutils.c be a more reasonable place to put these?)
+ */
+
+GLOBAL JQUANT_TBL *
+jpeg_alloc_quant_table( j_common_ptr cinfo ) {
+    JQUANT_TBL * tbl;
+
+    tbl = (JQUANT_TBL *)
+          ( *cinfo->mem->alloc_small )( cinfo, JPOOL_PERMANENT, SIZEOF( JQUANT_TBL ) );
+    tbl->sent_table = FALSE;/* make sure this is false in any new table */
+    return tbl;
+}
+
+
+GLOBAL JHUFF_TBL *
+jpeg_alloc_huff_table( j_common_ptr cinfo ) {
+    JHUFF_TBL * tbl;
+
+    tbl = (JHUFF_TBL *)
+          ( *cinfo->mem->alloc_small )( cinfo, JPOOL_PERMANENT, SIZEOF( JHUFF_TBL ) );
+    tbl->sent_table = FALSE;/* make sure this is false in any new table */
+    return tbl;
+}

neo/renderer/jpeg-6/jconfig.h

@@ -0,0 +1,41 @@
+/* jconfig.wat --- jconfig.h for Watcom C/C++ on MS-DOS or OS/2. */
+/* see jconfig.doc for explanations */
+
+#define HAVE_PROTOTYPES
+#define HAVE_UNSIGNED_CHAR
+#define HAVE_UNSIGNED_SHORT
+/* #define void char */
+/* #define const */
+#define CHAR_IS_UNSIGNED
+#define HAVE_STDDEF_H
+#define HAVE_STDLIB_H
+#undef NEED_BSD_STRINGS
+#undef NEED_SYS_TYPES_H
+#undef NEED_FAR_POINTERS	/* Watcom uses flat 32-bit addressing */
+#undef NEED_SHORT_EXTERNAL_NAMES
+#undef INCOMPLETE_TYPES_BROKEN
+
+#define JDCT_DEFAULT  JDCT_FLOAT
+#define JDCT_FASTEST  JDCT_FLOAT
+
+#ifdef JPEG_INTERNALS
+
+#undef RIGHT_SHIFT_IS_UNSIGNED
+
+#endif /* JPEG_INTERNALS */
+
+#ifdef JPEG_CJPEG_DJPEG
+
+#define BMP_SUPPORTED		/* BMP image file format */
+#define GIF_SUPPORTED		/* GIF image file format */
+#define PPM_SUPPORTED		/* PBMPLUS PPM/PGM image file format */
+#undef RLE_SUPPORTED		/* Utah RLE image file format */
+#define TARGA_SUPPORTED		/* Targa image file format */
+
+#undef TWO_FILE_COMMANDLINE	/* optional */
+#define USE_SETMODE		/* Needed to make one-file style work in Watcom */
+#undef NEED_SIGNAL_CATCHER	/* Define this if you use jmemname.c */
+#undef DONT_USE_B_MODE
+#undef PROGRESS_REPORT		/* optional */
+
+#endif /* JPEG_CJPEG_DJPEG */

neo/renderer/jpeg-6/jcparam.cpp

@@ -0,0 +1,584 @@
+/*
+ * jcparam.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains optional default-setting code for the JPEG compressor.
+ * Applications do not have to use this file, but those that don't use it
+ * must know a lot more about the innards of the JPEG code.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Quantization table setup routines
+ */
+
+GLOBAL void
+jpeg_add_quant_table( j_compress_ptr cinfo, int which_tbl,
+                      const unsigned int * basic_table,
+                      int scale_factor, boolean force_baseline ) {
+/* Define a quantization table equal to the basic_table times
+ * a scale factor (given as a percentage).
+ * If force_baseline is TRUE, the computed quantization table entries
+ * are limited to 1..255 for JPEG baseline compatibility.
+ */
+    JQUANT_TBL ** qtblptr = &cinfo->quant_tbl_ptrs[which_tbl];
+    int i;
+    long temp;
+
+    /* Safety check to ensure start_compress not called yet. */
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    if ( *qtblptr == NULL ) {
+        *qtblptr = jpeg_alloc_quant_table( (j_common_ptr) cinfo );
+    }
+
+    for ( i = 0; i < DCTSIZE2; i++ ) {
+        temp = ( (long) basic_table[i] * scale_factor + 50L ) / 100L;
+        /* limit the values to the valid range */
+        if ( temp <= 0L ) {
+            temp = 1L;
+        }
+        if ( temp > 32767L ) {
+            temp = 32767L;
+        }                             /* max quantizer needed for 12 bits */
+        if ( ( force_baseline ) && ( temp > 255L ) ) {
+            temp = 255L;
+        }               /* limit to baseline range if requested */
+        ( *qtblptr )->quantval[i] = (UINT16) temp;
+    }
+
+    /* Initialize sent_table FALSE so table will be written to JPEG file. */
+    ( *qtblptr )->sent_table = FALSE;
+}
+
+
+GLOBAL void
+jpeg_set_linear_quality( j_compress_ptr cinfo, int scale_factor,
+                         boolean force_baseline ) {
+/* Set or change the 'quality' (quantization) setting, using default tables
+ * and a straight percentage-scaling quality scale.  In most cases it's better
+ * to use jpeg_set_quality (below); this entry point is provided for
+ * applications that insist on a linear percentage scaling.
+ */
+/* This is the sample quantization table given in the JPEG spec section K.1,
+ * but expressed in zigzag order (as are all of our quant. tables).
+ * The spec says that the values given produce "good" quality, and
+ * when divided by 2, "very good" quality.
+ */
+    static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
+        16,  11,  12,  14,  12,  10,  16,  14,
+        13,  14,  18,  17,  16,  19,  24,  40,
+        26,  24,  22,  22,  24,  49,  35,  37,
+        29,  40,  58,  51,  61,  60,  57,  51,
+        56,  55,  64,  72,  92,  78,  64,  68,
+        87,  69,  55,  56,  80, 109,  81,  87,
+        95,  98, 103, 104, 103,  62,  77, 113,
+        121, 112, 100, 120,  92, 101, 103,  99
+    };
+    static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
+        17,  18,  18,  24,  21,  24,  47,  26,
+        26,  47,  99,  66,  56,  66,  99,  99,
+        99,  99,  99,  99,  99,  99,  99,  99,
+        99,  99,  99,  99,  99,  99,  99,  99,
+        99,  99,  99,  99,  99,  99,  99,  99,
+        99,  99,  99,  99,  99,  99,  99,  99,
+        99,  99,  99,  99,  99,  99,  99,  99,
+        99,  99,  99,  99,  99,  99,  99,  99
+    };
+
+    /* Set up two quantization tables using the specified scaling */
+    jpeg_add_quant_table( cinfo, 0, std_luminance_quant_tbl,
+                          scale_factor, force_baseline );
+    jpeg_add_quant_table( cinfo, 1, std_chrominance_quant_tbl,
+                          scale_factor, force_baseline );
+}
+
+
+GLOBAL int
+jpeg_quality_scaling( int quality ) {
+/* Convert a user-specified quality rating to a percentage scaling factor
+ * for an underlying quantization table, using our recommended scaling curve.
+ * The input 'quality' factor should be 0 (terrible) to 100 (very good).
+ */
+/* Safety limit on quality factor.  Convert 0 to 1 to avoid zero divide. */
+    if ( quality <= 0 ) {
+        quality = 1;
+    }
+    if ( quality > 100 ) {
+        quality = 100;
+    }
+
+    /* The basic table is used as-is (scaling 100) for a quality of 50.
+     * Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
+     * note that at Q=100 the scaling is 0, which will cause j_add_quant_table
+     * to make all the table entries 1 (hence, no quantization loss).
+     * Qualities 1..50 are converted to scaling percentage 5000/Q.
+     */
+    if ( quality < 50 ) {
+        quality = 5000 / quality;
+    } else {
+        quality = 200 - quality * 2;
+    }
+
+    return quality;
+}
+
+
+GLOBAL void
+jpeg_set_quality( j_compress_ptr cinfo, int quality, boolean force_baseline ) {
+/* Set or change the 'quality' (quantization) setting, using default tables.
+ * This is the standard quality-adjusting entry point for typical user
+ * interfaces; only those who want detailed control over quantization tables
+ * would use the preceding three routines directly.
+ */
+/* Convert user 0-100 rating to percentage scaling */
+    quality = jpeg_quality_scaling( quality );
+
+    /* Set up standard quality tables */
+    jpeg_set_linear_quality( cinfo, quality, force_baseline );
+}
+
+
+/*
+ * Huffman table setup routines
+ */
+
+LOCAL void
+add_huff_table( j_compress_ptr cinfo,
+                JHUFF_TBL ** htblptr, const UINT8 * bits, const UINT8 * val ) {
+/* Define a Huffman table */
+    if ( *htblptr == NULL ) {
+        *htblptr = jpeg_alloc_huff_table( (j_common_ptr) cinfo );
+    }
+
+    MEMCOPY( ( *htblptr )->bits, bits, SIZEOF( ( *htblptr )->bits ) );
+    MEMCOPY( ( *htblptr )->huffval, val, SIZEOF( ( *htblptr )->huffval ) );
+
+    /* Initialize sent_table FALSE so table will be written to JPEG file. */
+    ( *htblptr )->sent_table = FALSE;
+}
+
+
+LOCAL void
+std_huff_tables( j_compress_ptr cinfo ) {
+/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
+/* IMPORTANT: these are only valid for 8-bit data precision! */
+    static const UINT8 bits_dc_luminance[17] =
+    { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
+    static const UINT8 val_dc_luminance[] =
+    { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
+
+    static const UINT8 bits_dc_chrominance[17] =
+    { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
+    static const UINT8 val_dc_chrominance[] =
+    { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
+
+    static const UINT8 bits_ac_luminance[17] =
+    { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
+    static const UINT8 val_ac_luminance[] =
+    { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
+      0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
+      0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
+      0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
+      0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
+      0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
+      0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+      0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
+      0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+      0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
+      0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
+      0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
+      0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
+      0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+      0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
+      0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
+      0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
+      0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
+      0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
+      0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
+      0xf9, 0xfa };
+
+    static const UINT8 bits_ac_chrominance[17] =
+    { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
+    static const UINT8 val_ac_chrominance[] =
+    { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
+      0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
+      0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
+      0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
+      0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
+      0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
+      0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
+      0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
+      0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+      0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+      0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+      0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+      0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
+      0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
+      0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
+      0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
+      0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
+      0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
+      0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
+      0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
+      0xf9, 0xfa };
+
+    add_huff_table( cinfo, &cinfo->dc_huff_tbl_ptrs[0],
+                    bits_dc_luminance, val_dc_luminance );
+    add_huff_table( cinfo, &cinfo->ac_huff_tbl_ptrs[0],
+                    bits_ac_luminance, val_ac_luminance );
+    add_huff_table( cinfo, &cinfo->dc_huff_tbl_ptrs[1],
+                    bits_dc_chrominance, val_dc_chrominance );
+    add_huff_table( cinfo, &cinfo->ac_huff_tbl_ptrs[1],
+                    bits_ac_chrominance, val_ac_chrominance );
+}
+
+
+/*
+ * Default parameter setup for compression.
+ *
+ * Applications that don't choose to use this routine must do their
+ * own setup of all these parameters.  Alternately, you can call this
+ * to establish defaults and then alter parameters selectively.  This
+ * is the recommended approach since, if we add any new parameters,
+ * your code will still work (they'll be set to reasonable defaults).
+ */
+
+GLOBAL void
+jpeg_set_defaults( j_compress_ptr cinfo ) {
+    int i;
+
+    /* Safety check to ensure start_compress not called yet. */
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    /* Allocate comp_info array large enough for maximum component count.
+     * Array is made permanent in case application wants to compress
+     * multiple images at same param settings.
+     */
+    if ( cinfo->comp_info == NULL ) {
+        cinfo->comp_info = (jpeg_component_info *)
+                           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
+                                                        MAX_COMPONENTS * SIZEOF( jpeg_component_info ) );
+    }
+
+    /* Initialize everything not dependent on the color space */
+
+    cinfo->data_precision = BITS_IN_JSAMPLE;
+    /* Set up two quantization tables using default quality of 75 */
+    jpeg_set_quality( cinfo, 75, TRUE );
+    /* Set up two Huffman tables */
+    std_huff_tables( cinfo );
+
+    /* Initialize default arithmetic coding conditioning */
+    for ( i = 0; i < NUM_ARITH_TBLS; i++ ) {
+        cinfo->arith_dc_L[i] = 0;
+        cinfo->arith_dc_U[i] = 1;
+        cinfo->arith_ac_K[i] = 5;
+    }
+
+    /* Default is no multiple-scan output */
+    cinfo->scan_info = NULL;
+    cinfo->num_scans = 0;
+
+    /* Expect normal source image, not raw downsampled data */
+    cinfo->raw_data_in = FALSE;
+
+    /* Use Huffman coding, not arithmetic coding, by default */
+    cinfo->arith_code = FALSE;
+
+    /* By default, don't do extra passes to optimize entropy coding */
+    cinfo->optimize_coding = FALSE;
+    /* The standard Huffman tables are only valid for 8-bit data precision.
+     * If the precision is higher, force optimization on so that usable
+     * tables will be computed.  This test can be removed if default tables
+     * are supplied that are valid for the desired precision.
+     */
+    if ( cinfo->data_precision > 8 ) {
+        cinfo->optimize_coding = TRUE;
+    }
+
+    /* By default, use the simpler non-cosited sampling alignment */
+    cinfo->CCIR601_sampling = FALSE;
+
+    /* No input smoothing */
+    cinfo->smoothing_factor = 0;
+
+    /* DCT algorithm preference */
+    cinfo->dct_method = JDCT_DEFAULT;
+
+    /* No restart markers */
+    cinfo->restart_interval = 0;
+    cinfo->restart_in_rows = 0;
+
+    /* Fill in default JFIF marker parameters.  Note that whether the marker
+     * will actually be written is determined by jpeg_set_colorspace.
+     */
+    cinfo->density_unit = 0;/* Pixel size is unknown by default */
+    cinfo->X_density = 1;   /* Pixel aspect ratio is square by default */
+    cinfo->Y_density = 1;
+
+    /* Choose JPEG colorspace based on input space, set defaults accordingly */
+
+    jpeg_default_colorspace( cinfo );
+}
+
+
+/*
+ * Select an appropriate JPEG colorspace for in_color_space.
+ */
+
+GLOBAL void
+jpeg_default_colorspace( j_compress_ptr cinfo ) {
+    switch ( cinfo->in_color_space ) {
+        case JCS_GRAYSCALE:
+            jpeg_set_colorspace( cinfo, JCS_GRAYSCALE );
+            break;
+        case JCS_RGB:
+            jpeg_set_colorspace( cinfo, JCS_YCbCr );
+            break;
+        case JCS_YCbCr:
+            jpeg_set_colorspace( cinfo, JCS_YCbCr );
+            break;
+        case JCS_CMYK:
+            jpeg_set_colorspace( cinfo, JCS_CMYK );/* By default, no translation */
+            break;
+        case JCS_YCCK:
+            jpeg_set_colorspace( cinfo, JCS_YCCK );
+            break;
+        case JCS_UNKNOWN:
+            jpeg_set_colorspace( cinfo, JCS_UNKNOWN );
+            break;
+        default:
+            ERREXIT( cinfo, JERR_BAD_IN_COLORSPACE );
+    }
+}
+
+
+/*
+ * Set the JPEG colorspace, and choose colorspace-dependent default values.
+ */
+
+GLOBAL void
+jpeg_set_colorspace( j_compress_ptr cinfo, J_COLOR_SPACE colorspace ) {
+    jpeg_component_info * compptr;
+    int ci;
+
+#define SET_COMP( index, id, hsamp, vsamp, quant, dctbl, actbl )  \
+    ( compptr = &cinfo->comp_info[index], \
+     compptr->component_id = ( id ), \
+     compptr->h_samp_factor = ( hsamp ), \
+     compptr->v_samp_factor = ( vsamp ), \
+     compptr->quant_tbl_no = ( quant ), \
+     compptr->dc_tbl_no = ( dctbl ), \
+     compptr->ac_tbl_no = ( actbl ) )
+
+    /* Safety check to ensure start_compress not called yet. */
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    /* For all colorspaces, we use Q and Huff tables 0 for luminance components,
+     * tables 1 for chrominance components.
+     */
+
+    cinfo->jpeg_color_space = colorspace;
+
+    cinfo->write_JFIF_header = FALSE;/* No marker for non-JFIF colorspaces */
+    cinfo->write_Adobe_marker = FALSE;/* write no Adobe marker by default */
+
+    switch ( colorspace ) {
+        case JCS_GRAYSCALE:
+            cinfo->write_JFIF_header = TRUE;/* Write a JFIF marker */
+            cinfo->num_components = 1;
+            /* JFIF specifies component ID 1 */
+            SET_COMP( 0, 1, 1, 1, 0, 0, 0 );
+            break;
+        case JCS_RGB:
+            cinfo->write_Adobe_marker = TRUE;/* write Adobe marker to flag RGB */
+            cinfo->num_components = 3;
+            SET_COMP( 0, 0x52 /* 'R' */, 1, 1, 0, 0, 0 );
+            SET_COMP( 1, 0x47 /* 'G' */, 1, 1, 0, 0, 0 );
+            SET_COMP( 2, 0x42 /* 'B' */, 1, 1, 0, 0, 0 );
+            break;
+        case JCS_YCbCr:
+            cinfo->write_JFIF_header = TRUE;/* Write a JFIF marker */
+            cinfo->num_components = 3;
+            /* JFIF specifies component IDs 1,2,3 */
+            /* We default to 2x2 subsamples of chrominance */
+            SET_COMP( 0, 1, 2, 2, 0, 0, 0 );
+            SET_COMP( 1, 2, 1, 1, 1, 1, 1 );
+            SET_COMP( 2, 3, 1, 1, 1, 1, 1 );
+            break;
+        case JCS_CMYK:
+            cinfo->write_Adobe_marker = TRUE;/* write Adobe marker to flag CMYK */
+            cinfo->num_components = 4;
+            SET_COMP( 0, 0x43 /* 'C' */, 1, 1, 0, 0, 0 );
+            SET_COMP( 1, 0x4D /* 'M' */, 1, 1, 0, 0, 0 );
+            SET_COMP( 2, 0x59 /* 'Y' */, 1, 1, 0, 0, 0 );
+            SET_COMP( 3, 0x4B /* 'K' */, 1, 1, 0, 0, 0 );
+            break;
+        case JCS_YCCK:
+            cinfo->write_Adobe_marker = TRUE;/* write Adobe marker to flag YCCK */
+            cinfo->num_components = 4;
+            SET_COMP( 0, 1, 2, 2, 0, 0, 0 );
+            SET_COMP( 1, 2, 1, 1, 1, 1, 1 );
+            SET_COMP( 2, 3, 1, 1, 1, 1, 1 );
+            SET_COMP( 3, 4, 2, 2, 0, 0, 0 );
+            break;
+        case JCS_UNKNOWN:
+            cinfo->num_components = cinfo->input_components;
+            if ( ( cinfo->num_components < 1 ) || ( cinfo->num_components > MAX_COMPONENTS ) ) {
+                ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+                          MAX_COMPONENTS );
+            }
+            for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+                SET_COMP( ci, ci, 1, 1, 0, 0, 0 );
+            }
+            break;
+        default:
+            ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+    }
+}
+
+
+#ifdef C_PROGRESSIVE_SUPPORTED
+
+LOCAL jpeg_scan_info *
+fill_a_scan( jpeg_scan_info * scanptr, int ci,
+             int Ss, int Se, int Ah, int Al ) {
+/* Support routine: generate one scan for specified component */
+    scanptr->comps_in_scan = 1;
+    scanptr->component_index[0] = ci;
+    scanptr->Ss = Ss;
+    scanptr->Se = Se;
+    scanptr->Ah = Ah;
+    scanptr->Al = Al;
+    scanptr++;
+    return scanptr;
+}
+
+LOCAL jpeg_scan_info *
+fill_scans( jpeg_scan_info * scanptr, int ncomps,
+            int Ss, int Se, int Ah, int Al ) {
+/* Support routine: generate one scan for each component */
+    int ci;
+
+    for ( ci = 0; ci < ncomps; ci++ ) {
+        scanptr->comps_in_scan = 1;
+        scanptr->component_index[0] = ci;
+        scanptr->Ss = Ss;
+        scanptr->Se = Se;
+        scanptr->Ah = Ah;
+        scanptr->Al = Al;
+        scanptr++;
+    }
+    return scanptr;
+}
+
+LOCAL jpeg_scan_info *
+fill_dc_scans( jpeg_scan_info * scanptr, int ncomps, int Ah, int Al ) {
+/* Support routine: generate interleaved DC scan if possible, else N scans */
+    int ci;
+
+    if ( ncomps <= MAX_COMPS_IN_SCAN ) {
+        /* Single interleaved DC scan */
+        scanptr->comps_in_scan = ncomps;
+        for ( ci = 0; ci < ncomps; ci++ ) {
+            scanptr->component_index[ci] = ci;
+        }
+        scanptr->Ss = scanptr->Se = 0;
+        scanptr->Ah = Ah;
+        scanptr->Al = Al;
+        scanptr++;
+    } else {
+        /* Noninterleaved DC scan for each component */
+        scanptr = fill_scans( scanptr, ncomps, 0, 0, Ah, Al );
+    }
+    return scanptr;
+}
+
+
+/*
+ * Create a recommended progressive-JPEG script.
+ * cinfo->num_components and cinfo->jpeg_color_space must be correct.
+ */
+
+GLOBAL void
+jpeg_simple_progression( j_compress_ptr cinfo ) {
+    int ncomps = cinfo->num_components;
+    int nscans;
+    jpeg_scan_info * scanptr;
+
+    /* Safety check to ensure start_compress not called yet. */
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    /* Figure space needed for script.  Calculation must match code below! */
+    if ( ( ncomps == 3 ) && ( cinfo->jpeg_color_space == JCS_YCbCr ) ) {
+        /* Custom script for YCbCr color images. */
+        nscans = 10;
+    } else {
+        /* All-purpose script for other color spaces. */
+        if ( ncomps > MAX_COMPS_IN_SCAN ) {
+            nscans = 6 * ncomps;
+        }                   /* 2 DC + 4 AC scans per component */
+        else {
+            nscans = 2 + 4 * ncomps;
+        }                       /* 2 DC scans; 4 AC scans per component */
+    }
+
+    /* Allocate space for script. */
+    /* We use permanent pool just in case application re-uses script. */
+    scanptr = (jpeg_scan_info *)
+              ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
+                                           nscans * SIZEOF( jpeg_scan_info ) );
+    cinfo->scan_info = scanptr;
+    cinfo->num_scans = nscans;
+
+    if ( ( ncomps == 3 ) && ( cinfo->jpeg_color_space == JCS_YCbCr ) ) {
+        /* Custom script for YCbCr color images. */
+        /* Initial DC scan */
+        scanptr = fill_dc_scans( scanptr, ncomps, 0, 1 );
+        /* Initial AC scan: get some luma data out in a hurry */
+        scanptr = fill_a_scan( scanptr, 0, 1, 5, 0, 2 );
+        /* Chroma data is too small to be worth expending many scans on */
+        scanptr = fill_a_scan( scanptr, 2, 1, 63, 0, 1 );
+        scanptr = fill_a_scan( scanptr, 1, 1, 63, 0, 1 );
+        /* Complete spectral selection for luma AC */
+        scanptr = fill_a_scan( scanptr, 0, 6, 63, 0, 2 );
+        /* Refine next bit of luma AC */
+        scanptr = fill_a_scan( scanptr, 0, 1, 63, 2, 1 );
+        /* Finish DC successive approximation */
+        scanptr = fill_dc_scans( scanptr, ncomps, 1, 0 );
+        /* Finish AC successive approximation */
+        scanptr = fill_a_scan( scanptr, 2, 1, 63, 1, 0 );
+        scanptr = fill_a_scan( scanptr, 1, 1, 63, 1, 0 );
+        /* Luma bottom bit comes last since it's usually largest scan */
+        scanptr = fill_a_scan( scanptr, 0, 1, 63, 1, 0 );
+    } else {
+        /* All-purpose script for other color spaces. */
+        /* Successive approximation first pass */
+        scanptr = fill_dc_scans( scanptr, ncomps, 0, 1 );
+        scanptr = fill_scans( scanptr, ncomps, 1, 5, 0, 2 );
+        scanptr = fill_scans( scanptr, ncomps, 6, 63, 0, 2 );
+        /* Successive approximation second pass */
+        scanptr = fill_scans( scanptr, ncomps, 1, 63, 2, 1 );
+        /* Successive approximation final pass */
+        scanptr = fill_dc_scans( scanptr, ncomps, 1, 0 );
+        scanptr = fill_scans( scanptr, ncomps, 1, 63, 1, 0 );
+    }
+}
+
+#endif /* C_PROGRESSIVE_SUPPORTED */

neo/renderer/jpeg-6/jcphuff.cpp

@@ -0,0 +1,847 @@
+/*
+ * jcphuff.c
+ *
+ * Copyright (C) 1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy encoding routines for progressive JPEG.
+ *
+ * We do not support output suspension in this module, since the library
+ * currently does not allow multiple-scan files to be written with output
+ * suspension.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jchuff.h"      /* Declarations shared with jchuff.c */
+
+#ifdef C_PROGRESSIVE_SUPPORTED
+
+/* Expanded entropy encoder object for progressive Huffman encoding. */
+
+typedef struct {
+    struct jpeg_entropy_encoder pub;/* public fields */
+
+    /* Mode flag: TRUE for optimization, FALSE for actual data output */
+    boolean gather_statistics;
+
+    /* Bit-level coding status.
+     * next_output_byte/free_in_buffer are local copies of cinfo->dest fields.
+     */
+    JOCTET *       next_output_byte; /* => next byte to write in buffer */
+    size_t         free_in_buffer; /* # of byte spaces remaining in buffer */
+    INT32          put_buffer; /* current bit-accumulation buffer */
+    int            put_bits; /* # of bits now in it */
+    j_compress_ptr cinfo;   /* link to cinfo (needed for dump_buffer) */
+
+    /* Coding status for DC components */
+    int last_dc_val[MAX_COMPS_IN_SCAN];/* last DC coef for each component */
+
+    /* Coding status for AC components */
+    int          ac_tbl_no; /* the table number of the single component */
+    unsigned int EOBRUN;    /* run length of EOBs */
+    unsigned int BE;    /* # of buffered correction bits before MCU */
+    char *       bit_buffer;/* buffer for correction bits (1 per char) */
+    /* packing correction bits tightly would save some space but cost time... */
+
+    unsigned int restarts_to_go;/* MCUs left in this restart interval */
+    int          next_restart_num; /* next restart number to write (0-7) */
+
+    /* Pointers to derived tables (these workspaces have image lifespan).
+     * Since any one scan codes only DC or only AC, we only need one set
+     * of tables, not one for DC and one for AC.
+     */
+    c_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
+
+    /* Statistics tables for optimization; again, one set is enough */
+    long * count_ptrs[NUM_HUFF_TBLS];
+} phuff_entropy_encoder;
+
+typedef phuff_entropy_encoder * phuff_entropy_ptr;
+
+/* MAX_CORR_BITS is the number of bits the AC refinement correction-bit
+ * buffer can hold.  Larger sizes may slightly improve compression, but
+ * 1000 is already well into the realm of overkill.
+ * The minimum safe size is 64 bits.
+ */
+
+#define MAX_CORR_BITS  1000 /* Max # of correction bits I can buffer */
+
+/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32.
+ * We assume that int right shift is unsigned if INT32 right shift is,
+ * which should be safe.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define ISHIFT_TEMPS    int ishift_temp;
+#define IRIGHT_SHIFT( x, shft )  \
+    ( ( ishift_temp = ( x ) ) < 0 ? \
+                      ( ishift_temp >> ( shft ) ) | ( ( ~0 ) << ( 16 - ( shft ) ) ) : \
+                      ( ishift_temp >> ( shft ) ) )
+#else
+#define ISHIFT_TEMPS
+#define IRIGHT_SHIFT( x, shft )    ( ( x ) >> ( shft ) )
+#endif
+
+/* Forward declarations */
+METHODDEF boolean encode_mcu_DC_first JPP( ( j_compress_ptr cinfo,
+                                             JBLOCKROW * MCU_data ) );
+METHODDEF boolean encode_mcu_AC_first JPP( ( j_compress_ptr cinfo,
+                                             JBLOCKROW * MCU_data ) );
+METHODDEF boolean encode_mcu_DC_refine JPP( ( j_compress_ptr cinfo,
+                                              JBLOCKROW * MCU_data ) );
+METHODDEF boolean encode_mcu_AC_refine JPP( ( j_compress_ptr cinfo,
+                                              JBLOCKROW * MCU_data ) );
+METHODDEF void finish_pass_phuff JPP( (j_compress_ptr cinfo) );
+METHODDEF void finish_pass_gather_phuff JPP( (j_compress_ptr cinfo) );
+
+
+/*
+ * Initialize for a Huffman-compressed scan using progressive JPEG.
+ */
+
+METHODDEF void
+start_pass_phuff( j_compress_ptr cinfo, boolean gather_statistics ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    boolean is_DC_band;
+    int ci, tbl;
+    jpeg_component_info * compptr;
+
+    entropy->cinfo = cinfo;
+    entropy->gather_statistics = gather_statistics;
+
+    is_DC_band = ( cinfo->Ss == 0 );
+
+    /* We assume jcmaster.c already validated the scan parameters. */
+
+    /* Select execution routines */
+    if ( cinfo->Ah == 0 ) {
+        if ( is_DC_band ) {
+            entropy->pub.encode_mcu = encode_mcu_DC_first;
+        } else {
+            entropy->pub.encode_mcu = encode_mcu_AC_first;
+        }
+    } else {
+        if ( is_DC_band ) {
+            entropy->pub.encode_mcu = encode_mcu_DC_refine;
+        } else {
+            entropy->pub.encode_mcu = encode_mcu_AC_refine;
+            /* AC refinement needs a correction bit buffer */
+            if ( entropy->bit_buffer == NULL ) {
+                entropy->bit_buffer = (char *)
+                                      ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                   MAX_CORR_BITS * SIZEOF( char ) );
+            }
+        }
+    }
+    if ( gather_statistics ) {
+        entropy->pub.finish_pass = finish_pass_gather_phuff;
+    } else {
+        entropy->pub.finish_pass = finish_pass_phuff;
+    }
+
+    /* Only DC coefficients may be interleaved, so cinfo->comps_in_scan = 1
+     * for AC coefficients.
+     */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        /* Initialize DC predictions to 0 */
+        entropy->last_dc_val[ci] = 0;
+        /* Make sure requested tables are present */
+        /* (In gather mode, tables need not be allocated yet) */
+        if ( is_DC_band ) {
+            if ( cinfo->Ah != 0 ) {/* DC refinement needs no table */
+                continue;
+            }
+            tbl = compptr->dc_tbl_no;
+            if ( ( tbl < 0 ) || ( tbl >= NUM_HUFF_TBLS ) ||
+                ( ( cinfo->dc_huff_tbl_ptrs[tbl] == NULL ) && ( !gather_statistics ) ) ) {
+                ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, tbl );
+            }
+        } else {
+            entropy->ac_tbl_no = tbl = compptr->ac_tbl_no;
+            if ( ( tbl < 0 ) || ( tbl >= NUM_HUFF_TBLS ) ||
+                ( ( cinfo->ac_huff_tbl_ptrs[tbl] == NULL ) && ( !gather_statistics ) ) ) {
+                ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, tbl );
+            }
+        }
+        if ( gather_statistics ) {
+            /* Allocate and zero the statistics tables */
+            /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
+            if ( entropy->count_ptrs[tbl] == NULL ) {
+                entropy->count_ptrs[tbl] = (long *)
+                                           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                                        257 * SIZEOF( long ) );
+            }
+            MEMZERO( entropy->count_ptrs[tbl], 257 * SIZEOF( long ) );
+        } else {
+            /* Compute derived values for Huffman tables */
+            /* We may do this more than once for a table, but it's not expensive */
+            if ( is_DC_band ) {
+                jpeg_make_c_derived_tbl( cinfo, cinfo->dc_huff_tbl_ptrs[tbl],
+                                         &entropy->derived_tbls[tbl] );
+            } else {
+                jpeg_make_c_derived_tbl( cinfo, cinfo->ac_huff_tbl_ptrs[tbl],
+                                         &entropy->derived_tbls[tbl] );
+            }
+        }
+    }
+
+    /* Initialize AC stuff */
+    entropy->EOBRUN = 0;
+    entropy->BE = 0;
+
+    /* Initialize bit buffer to empty */
+    entropy->put_buffer = 0;
+    entropy->put_bits = 0;
+
+    /* Initialize restart stuff */
+    entropy->restarts_to_go = cinfo->restart_interval;
+    entropy->next_restart_num = 0;
+}
+
+
+/* Outputting bytes to the file.
+ * NB: these must be called only when actually outputting,
+ * that is, entropy->gather_statistics == FALSE.
+ */
+
+/* Emit a byte */
+#define emit_byte( entropy, val )  \
+    { *( entropy )->next_output_byte++ = (JOCTET) ( val );  \
+      if ( -- ( entropy )->free_in_buffer == 0 ) { \
+          dump_buffer( entropy ); } }
+
+
+LOCAL void
+dump_buffer( phuff_entropy_ptr entropy ) {
+/* Empty the output buffer; we do not support suspension in this module. */
+    struct jpeg_destination_mgr * dest = entropy->cinfo->dest;
+
+    if ( !( *dest->empty_output_buffer )( entropy->cinfo ) ) {
+        ERREXIT( entropy->cinfo, JERR_CANT_SUSPEND );
+    }
+    /* After a successful buffer dump, must reset buffer pointers */
+    entropy->next_output_byte = dest->next_output_byte;
+    entropy->free_in_buffer = dest->free_in_buffer;
+}
+
+
+/* Outputting bits to the file */
+
+/* Only the right 24 bits of put_buffer are used; the valid bits are
+ * left-justified in this part.  At most 16 bits can be passed to emit_bits
+ * in one call, and we never retain more than 7 bits in put_buffer
+ * between calls, so 24 bits are sufficient.
+ */
+
+INLINE
+LOCAL void
+emit_bits( phuff_entropy_ptr entropy, unsigned int code, int size ) {
+/* Emit some bits, unless we are in gather mode */
+/* This routine is heavily used, so it's worth coding tightly. */
+    register INT32 put_buffer = (INT32) code;
+    register int put_bits = entropy->put_bits;
+
+    /* if size is 0, caller used an invalid Huffman table entry */
+    if ( size == 0 ) {
+        ERREXIT( entropy->cinfo, JERR_HUFF_MISSING_CODE );
+    }
+
+    if ( entropy->gather_statistics ) {
+        return;
+    }               /* do nothing if we're only getting stats */
+
+    put_buffer &= ( ( (INT32) 1 ) << size ) - 1;/* mask off any extra bits in code */
+
+    put_bits += size;   /* new number of bits in buffer */
+
+    put_buffer <<= 24 - put_bits;/* align incoming bits */
+
+    put_buffer |= entropy->put_buffer;/* and merge with old buffer contents */
+
+    while ( put_bits >= 8 ) {
+        int c = (int) ( ( put_buffer >> 16 ) & 0xFF );
+
+        emit_byte( entropy, c );
+        if ( c == 0xFF ) {  /* need to stuff a zero byte? */
+            emit_byte( entropy, 0 );
+        }
+        put_buffer <<= 8;
+        put_bits -= 8;
+    }
+
+    entropy->put_buffer = put_buffer;/* update variables */
+    entropy->put_bits = put_bits;
+}
+
+
+LOCAL void
+flush_bits( phuff_entropy_ptr entropy ) {
+    emit_bits( entropy, 0x7F, 7 );/* fill any partial byte with ones */
+    entropy->put_buffer = 0;   /* and reset bit-buffer to empty */
+    entropy->put_bits = 0;
+}
+
+
+/*
+ * Emit (or just count) a Huffman symbol.
+ */
+
+INLINE
+LOCAL void
+emit_symbol( phuff_entropy_ptr entropy, int tbl_no, int symbol ) {
+    if ( entropy->gather_statistics ) {
+        entropy->count_ptrs[tbl_no][symbol]++;
+    } else {
+        c_derived_tbl * tbl = entropy->derived_tbls[tbl_no];
+        emit_bits( entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol] );
+    }
+}
+
+
+/*
+ * Emit bits from a correction bit buffer.
+ */
+
+LOCAL void
+emit_buffered_bits( phuff_entropy_ptr entropy, char * bufstart,
+                    unsigned int nbits ) {
+    if ( entropy->gather_statistics ) {
+        return;
+    }               /* no real work */
+
+    while ( nbits > 0 ) {
+        emit_bits( entropy, (unsigned int) ( *bufstart ), 1 );
+        bufstart++;
+        nbits--;
+    }
+}
+
+
+/*
+ * Emit any pending EOBRUN symbol.
+ */
+
+LOCAL void
+emit_eobrun( phuff_entropy_ptr entropy ) {
+    register int temp, nbits;
+
+    if ( entropy->EOBRUN > 0 ) {/* if there is any pending EOBRUN */
+        temp = entropy->EOBRUN;
+        nbits = 0;
+        while ( ( temp >>= 1 ) ) {
+            nbits++;
+        }
+
+        emit_symbol( entropy, entropy->ac_tbl_no, nbits << 4 );
+        if ( nbits ) {
+            emit_bits( entropy, entropy->EOBRUN, nbits );
+        }
+
+        entropy->EOBRUN = 0;
+
+        /* Emit any buffered correction bits */
+        emit_buffered_bits( entropy, entropy->bit_buffer, entropy->BE );
+        entropy->BE = 0;
+    }
+}
+
+
+/*
+ * Emit a restart marker & resynchronize predictions.
+ */
+
+LOCAL void
+emit_restart( phuff_entropy_ptr entropy, int restart_num ) {
+    int ci;
+
+    emit_eobrun( entropy );
+
+    if ( !entropy->gather_statistics ) {
+        flush_bits( entropy );
+        emit_byte( entropy, 0xFF );
+        emit_byte( entropy, JPEG_RST0 + restart_num );
+    }
+
+    if ( entropy->cinfo->Ss == 0 ) {
+        /* Re-initialize DC predictions to 0 */
+        for ( ci = 0; ci < entropy->cinfo->comps_in_scan; ci++ ) {
+            entropy->last_dc_val[ci] = 0;
+        }
+    } else {
+        /* Re-initialize all AC-related fields to 0 */
+        entropy->EOBRUN = 0;
+        entropy->BE = 0;
+    }
+}
+
+
+/*
+ * MCU encoding for DC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF boolean
+encode_mcu_DC_first( j_compress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    register int temp, temp2;
+    register int nbits;
+    int blkn, ci;
+    int Al = cinfo->Al;
+    JBLOCKROW block;
+    jpeg_component_info * compptr;
+    ISHIFT_TEMPS
+
+    entropy->next_output_byte = cinfo->dest->next_output_byte;
+    entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+    /* Emit restart marker if needed */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            emit_restart( entropy, entropy->next_restart_num );
+        }
+    }
+
+    /* Encode the MCU data blocks */
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        block = MCU_data[blkn];
+        ci = cinfo->MCU_membership[blkn];
+        compptr = cinfo->cur_comp_info[ci];
+
+        /* Compute the DC value after the required point transform by Al.
+         * This is simply an arithmetic right shift.
+         */
+        temp2 = IRIGHT_SHIFT( (int) ( ( *block )[0] ), Al );
+
+        /* DC differences are figured on the point-transformed values. */
+        temp = temp2 - entropy->last_dc_val[ci];
+        entropy->last_dc_val[ci] = temp2;
+
+        /* Encode the DC coefficient difference per section G.1.2.1 */
+        temp2 = temp;
+        if ( temp < 0 ) {
+            temp = -temp;/* temp is abs value of input */
+            /* For a negative input, want temp2 = bitwise complement of abs(input) */
+            /* This code assumes we are on a two's complement machine */
+            temp2--;
+        }
+
+        /* Find the number of bits needed for the magnitude of the coefficient */
+        nbits = 0;
+        while ( temp ) {
+            nbits++;
+            temp >>= 1;
+        }
+
+        /* Count/emit the Huffman-coded symbol for the number of bits */
+        emit_symbol( entropy, compptr->dc_tbl_no, nbits );
+
+        /* Emit that number of bits of the value, if positive, */
+        /* or the complement of its magnitude, if negative. */
+        if ( nbits ) {  /* emit_bits rejects calls with size 0 */
+            emit_bits( entropy, (unsigned int) temp2, nbits );
+        }
+    }
+
+    cinfo->dest->next_output_byte = entropy->next_output_byte;
+    cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+    /* Update restart-interval state too */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            entropy->restarts_to_go = cinfo->restart_interval;
+            entropy->next_restart_num++;
+            entropy->next_restart_num &= 7;
+        }
+        entropy->restarts_to_go--;
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * MCU encoding for AC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF boolean
+encode_mcu_AC_first( j_compress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    register int temp, temp2;
+    register int nbits;
+    register int r, k;
+    int Se = cinfo->Se;
+    int Al = cinfo->Al;
+    JBLOCKROW block;
+
+    entropy->next_output_byte = cinfo->dest->next_output_byte;
+    entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+    /* Emit restart marker if needed */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            emit_restart( entropy, entropy->next_restart_num );
+        }
+    }
+
+    /* Encode the MCU data block */
+    block = MCU_data[0];
+
+    /* Encode the AC coefficients per section G.1.2.2, fig. G.3 */
+
+    r = 0;          /* r = run length of zeros */
+
+    for ( k = cinfo->Ss; k <= Se; k++ ) {
+        if ( ( temp = ( *block )[jpeg_natural_order[k]] ) == 0 ) {
+            r++;
+            continue;
+        }
+        /* We must apply the point transform by Al.  For AC coefficients this
+         * is an integer division with rounding towards 0.  To do this portably
+         * in C, we shift after obtaining the absolute value; so the code is
+         * interwoven with finding the abs value (temp) and output bits (temp2).
+         */
+        if ( temp < 0 ) {
+            temp = -temp;/* temp is abs value of input */
+            temp >>= Al;/* apply the point transform */
+            /* For a negative coef, want temp2 = bitwise complement of abs(coef) */
+            temp2 = ~temp;
+        } else {
+            temp >>= Al;/* apply the point transform */
+            temp2 = temp;
+        }
+        /* Watch out for case that nonzero coef is zero after point transform */
+        if ( temp == 0 ) {
+            r++;
+            continue;
+        }
+
+        /* Emit any pending EOBRUN */
+        if ( entropy->EOBRUN > 0 ) {
+            emit_eobrun( entropy );
+        }
+        /* if run length > 15, must emit special run-length-16 codes (0xF0) */
+        while ( r > 15 ) {
+            emit_symbol( entropy, entropy->ac_tbl_no, 0xF0 );
+            r -= 16;
+        }
+
+        /* Find the number of bits needed for the magnitude of the coefficient */
+        nbits = 1;      /* there must be at least one 1 bit */
+        while ( ( temp >>= 1 ) ) {
+            nbits++;
+        }
+
+        /* Count/emit Huffman symbol for run length / number of bits */
+        emit_symbol( entropy, entropy->ac_tbl_no, ( r << 4 ) + nbits );
+
+        /* Emit that number of bits of the value, if positive, */
+        /* or the complement of its magnitude, if negative. */
+        emit_bits( entropy, (unsigned int) temp2, nbits );
+
+        r = 0;      /* reset zero run length */
+    }
+
+    if ( r > 0 ) {      /* If there are trailing zeroes, */
+        entropy->EOBRUN++;  /* count an EOB */
+        if ( entropy->EOBRUN == 0x7FFF ) {
+            emit_eobrun( entropy );
+        }                   /* force it out to avoid overflow */
+    }
+
+    cinfo->dest->next_output_byte = entropy->next_output_byte;
+    cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+    /* Update restart-interval state too */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            entropy->restarts_to_go = cinfo->restart_interval;
+            entropy->next_restart_num++;
+            entropy->next_restart_num &= 7;
+        }
+        entropy->restarts_to_go--;
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * MCU encoding for DC successive approximation refinement scan.
+ * Note: we assume such scans can be multi-component, although the spec
+ * is not very clear on the point.
+ */
+
+METHODDEF boolean
+encode_mcu_DC_refine( j_compress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    register int temp;
+    int blkn;
+    int Al = cinfo->Al;
+    JBLOCKROW block;
+
+    entropy->next_output_byte = cinfo->dest->next_output_byte;
+    entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+    /* Emit restart marker if needed */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            emit_restart( entropy, entropy->next_restart_num );
+        }
+    }
+
+    /* Encode the MCU data blocks */
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        block = MCU_data[blkn];
+
+        /* We simply emit the Al'th bit of the DC coefficient value. */
+        temp = ( *block )[0];
+        emit_bits( entropy, (unsigned int) ( temp >> Al ), 1 );
+    }
+
+    cinfo->dest->next_output_byte = entropy->next_output_byte;
+    cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+    /* Update restart-interval state too */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            entropy->restarts_to_go = cinfo->restart_interval;
+            entropy->next_restart_num++;
+            entropy->next_restart_num &= 7;
+        }
+        entropy->restarts_to_go--;
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * MCU encoding for AC successive approximation refinement scan.
+ */
+
+METHODDEF boolean
+encode_mcu_AC_refine( j_compress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    register int temp;
+    register int r, k;
+    int EOB;
+    char * BR_buffer;
+    unsigned int BR;
+    int Se = cinfo->Se;
+    int Al = cinfo->Al;
+    JBLOCKROW block;
+    int absvalues[DCTSIZE2];
+
+    entropy->next_output_byte = cinfo->dest->next_output_byte;
+    entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+    /* Emit restart marker if needed */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            emit_restart( entropy, entropy->next_restart_num );
+        }
+    }
+
+    /* Encode the MCU data block */
+    block = MCU_data[0];
+
+    /* It is convenient to make a pre-pass to determine the transformed
+     * coefficients' absolute values and the EOB position.
+     */
+    EOB = 0;
+    for ( k = cinfo->Ss; k <= Se; k++ ) {
+        temp = ( *block )[jpeg_natural_order[k]];
+        /* We must apply the point transform by Al.  For AC coefficients this
+         * is an integer division with rounding towards 0.  To do this portably
+         * in C, we shift after obtaining the absolute value.
+         */
+        if ( temp < 0 ) {
+            temp = -temp;
+        }               /* temp is abs value of input */
+        temp >>= Al;    /* apply the point transform */
+        absvalues[k] = temp;/* save abs value for main pass */
+        if ( temp == 1 ) {
+            EOB = k;
+        }               /* EOB = index of last newly-nonzero coef */
+    }
+
+    /* Encode the AC coefficients per section G.1.2.3, fig. G.7 */
+
+    r = 0;          /* r = run length of zeros */
+    BR = 0;         /* BR = count of buffered bits added now */
+    BR_buffer = entropy->bit_buffer + entropy->BE;/* Append bits to buffer */
+
+    for ( k = cinfo->Ss; k <= Se; k++ ) {
+        if ( ( temp = absvalues[k] ) == 0 ) {
+            r++;
+            continue;
+        }
+
+        /* Emit any required ZRLs, but not if they can be folded into EOB */
+        while ( r > 15 && k <= EOB ) {
+            /* emit any pending EOBRUN and the BE correction bits */
+            emit_eobrun( entropy );
+            /* Emit ZRL */
+            emit_symbol( entropy, entropy->ac_tbl_no, 0xF0 );
+            r -= 16;
+            /* Emit buffered correction bits that must be associated with ZRL */
+            emit_buffered_bits( entropy, BR_buffer, BR );
+            BR_buffer = entropy->bit_buffer;/* BE bits are gone now */
+            BR = 0;
+        }
+
+        /* If the coef was previously nonzero, it only needs a correction bit.
+         * NOTE: a straight translation of the spec's figure G.7 would suggest
+         * that we also need to test r > 15.  But if r > 15, we can only get here
+         * if k > EOB, which implies that this coefficient is not 1.
+         */
+        if ( temp > 1 ) {
+            /* The correction bit is the next bit of the absolute value. */
+            BR_buffer[BR++] = (char) ( temp & 1 );
+            continue;
+        }
+
+        /* Emit any pending EOBRUN and the BE correction bits */
+        emit_eobrun( entropy );
+
+        /* Count/emit Huffman symbol for run length / number of bits */
+        emit_symbol( entropy, entropy->ac_tbl_no, ( r << 4 ) + 1 );
+
+        /* Emit output bit for newly-nonzero coef */
+        temp = ( ( *block )[jpeg_natural_order[k]] < 0 ) ? 0 : 1;
+        emit_bits( entropy, (unsigned int) temp, 1 );
+
+        /* Emit buffered correction bits that must be associated with this code */
+        emit_buffered_bits( entropy, BR_buffer, BR );
+        BR_buffer = entropy->bit_buffer;/* BE bits are gone now */
+        BR = 0;
+        r = 0;      /* reset zero run length */
+    }
+
+    if ( ( r > 0 ) || ( BR > 0 ) ) {/* If there are trailing zeroes, */
+        entropy->EOBRUN++;  /* count an EOB */
+        entropy->BE += BR;  /* concat my correction bits to older ones */
+        /* We force out the EOB if we risk either:
+         * 1. overflow of the EOB counter;
+         * 2. overflow of the correction bit buffer during the next MCU.
+         */
+        if ( ( entropy->EOBRUN == 0x7FFF ) || ( entropy->BE > ( MAX_CORR_BITS - DCTSIZE2 + 1 ) ) ) {
+            emit_eobrun( entropy );
+        }
+    }
+
+    cinfo->dest->next_output_byte = entropy->next_output_byte;
+    cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+    /* Update restart-interval state too */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            entropy->restarts_to_go = cinfo->restart_interval;
+            entropy->next_restart_num++;
+            entropy->next_restart_num &= 7;
+        }
+        entropy->restarts_to_go--;
+    }
+
+    return TRUE;
+}
+
+
+/*
+ * Finish up at the end of a Huffman-compressed progressive scan.
+ */
+
+METHODDEF void
+finish_pass_phuff( j_compress_ptr cinfo ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+
+    entropy->next_output_byte = cinfo->dest->next_output_byte;
+    entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+    /* Flush out any buffered data */
+    emit_eobrun( entropy );
+    flush_bits( entropy );
+
+    cinfo->dest->next_output_byte = entropy->next_output_byte;
+    cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+}
+
+
+/*
+ * Finish up a statistics-gathering pass and create the new Huffman tables.
+ */
+
+METHODDEF void
+finish_pass_gather_phuff( j_compress_ptr cinfo ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    boolean is_DC_band;
+    int ci, tbl;
+    jpeg_component_info * compptr;
+    JHUFF_TBL ** htblptr;
+    boolean did[NUM_HUFF_TBLS];
+
+    /* Flush out buffered data (all we care about is counting the EOB symbol) */
+    emit_eobrun( entropy );
+
+    is_DC_band = ( cinfo->Ss == 0 );
+
+    /* It's important not to apply jpeg_gen_optimal_table more than once
+     * per table, because it clobbers the input frequency counts!
+     */
+    MEMZERO( did, SIZEOF( did ) );
+
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        if ( is_DC_band ) {
+            if ( cinfo->Ah != 0 ) {/* DC refinement needs no table */
+                continue;
+            }
+            tbl = compptr->dc_tbl_no;
+        } else {
+            tbl = compptr->ac_tbl_no;
+        }
+        if ( !did[tbl] ) {
+            if ( is_DC_band ) {
+                htblptr = &cinfo->dc_huff_tbl_ptrs[tbl];
+            } else {
+                htblptr = &cinfo->ac_huff_tbl_ptrs[tbl];
+            }
+            if ( *htblptr == NULL ) {
+                *htblptr = jpeg_alloc_huff_table( (j_common_ptr) cinfo );
+            }
+            jpeg_gen_optimal_table( cinfo, *htblptr, entropy->count_ptrs[tbl] );
+            did[tbl] = TRUE;
+        }
+    }
+}
+
+
+/*
+ * Module initialization routine for progressive Huffman entropy encoding.
+ */
+
+GLOBAL void
+jinit_phuff_encoder( j_compress_ptr cinfo ) {
+    phuff_entropy_ptr entropy;
+    int i;
+
+    entropy = (phuff_entropy_ptr)
+              ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                           SIZEOF( phuff_entropy_encoder ) );
+    cinfo->entropy = (struct jpeg_entropy_encoder *) entropy;
+    entropy->pub.start_pass = start_pass_phuff;
+
+    /* Mark tables unallocated */
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        entropy->derived_tbls[i] = NULL;
+        entropy->count_ptrs[i] = NULL;
+    }
+    entropy->bit_buffer = NULL; /* needed only in AC refinement scan */
+}
+
+#endif /* C_PROGRESSIVE_SUPPORTED */

neo/renderer/jpeg-6/jcprepct.cpp

@@ -0,0 +1,370 @@
+/*
+ * jcprepct.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the compression preprocessing controller.
+ * This controller manages the color conversion, downsampling,
+ * and edge expansion steps.
+ *
+ * Most of the complexity here is associated with buffering input rows
+ * as required by the downsampler.  See the comments at the head of
+ * jcsample.c for the downsampler's needs.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* At present, jcsample.c can request context rows only for smoothing.
+ * In the future, we might also need context rows for CCIR601 sampling
+ * or other more-complex downsampling procedures.  The code to support
+ * context rows should be compiled only if needed.
+ */
+#ifdef INPUT_SMOOTHING_SUPPORTED
+#define CONTEXT_ROWS_SUPPORTED
+#endif
+
+
+/*
+ * For the simple (no-context-row) case, we just need to buffer one
+ * row group's worth of pixels for the downsampling step.  At the bottom of
+ * the image, we pad to a full row group by replicating the last pixel row.
+ * The downsampler's last output row is then replicated if needed to pad
+ * out to a full iMCU row.
+ *
+ * When providing context rows, we must buffer three row groups' worth of
+ * pixels.  Three row groups are physically allocated, but the row pointer
+ * arrays are made five row groups high, with the extra pointers above and
+ * below "wrapping around" to point to the last and first real row groups.
+ * This allows the downsampler to access the proper context rows.
+ * At the top and bottom of the image, we create dummy context rows by
+ * copying the first or last real pixel row.  This copying could be avoided
+ * by pointer hacking as is done in jdmainct.c, but it doesn't seem worth the
+ * trouble on the compression side.
+ */
+
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_c_prep_controller pub;/* public fields */
+
+    /* Downsampling input buffer.  This buffer holds color-converted data
+     * until we have enough to do a downsample step.
+     */
+    JSAMPARRAY color_buf[MAX_COMPONENTS];
+
+    JDIMENSION rows_to_go;  /* counts rows remaining in source image */
+    int        next_buf_row; /* index of next row to store in color_buf */
+
+#ifdef CONTEXT_ROWS_SUPPORTED   /* only needed for context case */
+    int this_row_group;     /* starting row index of group to process */
+    int next_buf_stop;      /* downsample when we reach this index */
+#endif
+} my_prep_controller;
+
+typedef my_prep_controller * my_prep_ptr;
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF void
+start_pass_prep( j_compress_ptr cinfo, J_BUF_MODE pass_mode ) {
+    my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+
+    if ( pass_mode != JBUF_PASS_THRU ) {
+        ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+    }
+
+    /* Initialize total-height counter for detecting bottom of image */
+    prep->rows_to_go = cinfo->image_height;
+    /* Mark the conversion buffer empty */
+    prep->next_buf_row = 0;
+#ifdef CONTEXT_ROWS_SUPPORTED
+    /* Preset additional state variables for context mode.
+     * These aren't used in non-context mode, so we needn't test which mode.
+     */
+    prep->this_row_group = 0;
+    /* Set next_buf_stop to stop after two row groups have been read in. */
+    prep->next_buf_stop = 2 * cinfo->max_v_samp_factor;
+#endif
+}
+
+
+/*
+ * Expand an image vertically from height input_rows to height output_rows,
+ * by duplicating the bottom row.
+ */
+
+LOCAL void
+expand_bottom_edge( JSAMPARRAY image_data, JDIMENSION num_cols,
+                    int input_rows, int output_rows ) {
+    register int row;
+
+    for ( row = input_rows; row < output_rows; row++ ) {
+        jcopy_sample_rows( image_data, input_rows - 1, image_data, row,
+                           1, num_cols );
+    }
+}
+
+
+/*
+ * Process some data in the simple no-context case.
+ *
+ * Preprocessor output data is counted in "row groups".  A row group
+ * is defined to be v_samp_factor sample rows of each component.
+ * Downsampling will produce this much data from each max_v_samp_factor
+ * input rows.
+ */
+
+METHODDEF void
+pre_process_data( j_compress_ptr cinfo,
+                  JSAMPARRAY input_buf, JDIMENSION * in_row_ctr,
+                  JDIMENSION in_rows_avail,
+                  JSAMPIMAGE output_buf, JDIMENSION * out_row_group_ctr,
+                  JDIMENSION out_row_groups_avail ) {
+    my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+    int numrows, ci;
+    JDIMENSION inrows;
+    jpeg_component_info * compptr;
+
+    while ( *in_row_ctr < in_rows_avail &&
+            *out_row_group_ctr < out_row_groups_avail ) {
+        /* Do color conversion to fill the conversion buffer. */
+        inrows = in_rows_avail - *in_row_ctr;
+        numrows = cinfo->max_v_samp_factor - prep->next_buf_row;
+        numrows = (int) MIN( (JDIMENSION) numrows, inrows );
+        ( *cinfo->cconvert->color_convert )( cinfo, input_buf + *in_row_ctr,
+                                             prep->color_buf,
+                                             (JDIMENSION) prep->next_buf_row,
+                                             numrows );
+        *in_row_ctr += numrows;
+        prep->next_buf_row += numrows;
+        prep->rows_to_go -= numrows;
+        /* If at bottom of image, pad to fill the conversion buffer. */
+        if ( ( prep->rows_to_go == 0 ) &&
+            ( prep->next_buf_row < cinfo->max_v_samp_factor ) ) {
+            for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+                expand_bottom_edge( prep->color_buf[ci], cinfo->image_width,
+                                    prep->next_buf_row, cinfo->max_v_samp_factor );
+            }
+            prep->next_buf_row = cinfo->max_v_samp_factor;
+        }
+        /* If we've filled the conversion buffer, empty it. */
+        if ( prep->next_buf_row == cinfo->max_v_samp_factor ) {
+            ( *cinfo->downsample->downsample )( cinfo,
+                                                prep->color_buf, (JDIMENSION) 0,
+                                                output_buf, *out_row_group_ctr );
+            prep->next_buf_row = 0;
+            ( *out_row_group_ctr )++;
+        }
+        /* If at bottom of image, pad the output to a full iMCU height.
+         * Note we assume the caller is providing a one-iMCU-height output buffer!
+         */
+        if ( ( prep->rows_to_go == 0 ) &&
+            ( *out_row_group_ctr < out_row_groups_avail ) ) {
+            for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+                  ci++, compptr++ ) {
+                expand_bottom_edge( output_buf[ci],
+                                   compptr->width_in_blocks * DCTSIZE,
+                                   (int) ( *out_row_group_ctr * compptr->v_samp_factor ),
+                                   (int) ( out_row_groups_avail * compptr->v_samp_factor ) );
+            }
+            *out_row_group_ctr = out_row_groups_avail;
+            break;      /* can exit outer loop without test */
+        }
+    }
+}
+
+
+#ifdef CONTEXT_ROWS_SUPPORTED
+
+/*
+ * Process some data in the context case.
+ */
+
+METHODDEF void
+pre_process_context( j_compress_ptr cinfo,
+                     JSAMPARRAY input_buf, JDIMENSION * in_row_ctr,
+                     JDIMENSION in_rows_avail,
+                     JSAMPIMAGE output_buf, JDIMENSION * out_row_group_ctr,
+                     JDIMENSION out_row_groups_avail ) {
+    my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+    int numrows, ci;
+    int buf_height = cinfo->max_v_samp_factor * 3;
+    JDIMENSION inrows;
+    jpeg_component_info * compptr;
+
+    while ( *out_row_group_ctr < out_row_groups_avail ) {
+        if ( *in_row_ctr < in_rows_avail ) {
+            /* Do color conversion to fill the conversion buffer. */
+            inrows = in_rows_avail - *in_row_ctr;
+            numrows = prep->next_buf_stop - prep->next_buf_row;
+            numrows = (int) MIN( (JDIMENSION) numrows, inrows );
+            ( *cinfo->cconvert->color_convert )( cinfo, input_buf + *in_row_ctr,
+                                                 prep->color_buf,
+                                                 (JDIMENSION) prep->next_buf_row,
+                                                 numrows );
+            /* Pad at top of image, if first time through */
+            if ( prep->rows_to_go == cinfo->image_height ) {
+                for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+                    int row;
+                    for ( row = 1; row <= cinfo->max_v_samp_factor; row++ ) {
+                        jcopy_sample_rows( prep->color_buf[ci], 0,
+                                           prep->color_buf[ci], -row,
+                                           1, cinfo->image_width );
+                    }
+                }
+            }
+            *in_row_ctr += numrows;
+            prep->next_buf_row += numrows;
+            prep->rows_to_go -= numrows;
+        } else {
+            /* Return for more data, unless we are at the bottom of the image. */
+            if ( prep->rows_to_go != 0 ) {
+                break;
+            }
+        }
+        /* If at bottom of image, pad to fill the conversion buffer. */
+        if ( ( prep->rows_to_go == 0 ) &&
+            ( prep->next_buf_row < prep->next_buf_stop ) ) {
+            for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+                expand_bottom_edge( prep->color_buf[ci], cinfo->image_width,
+                                    prep->next_buf_row, prep->next_buf_stop );
+            }
+            prep->next_buf_row = prep->next_buf_stop;
+        }
+        /* If we've gotten enough data, downsample a row group. */
+        if ( prep->next_buf_row == prep->next_buf_stop ) {
+            ( *cinfo->downsample->downsample )( cinfo,
+                                                prep->color_buf,
+                                                (JDIMENSION) prep->this_row_group,
+                                                output_buf, *out_row_group_ctr );
+            ( *out_row_group_ctr )++;
+            /* Advance pointers with wraparound as necessary. */
+            prep->this_row_group += cinfo->max_v_samp_factor;
+            if ( prep->this_row_group >= buf_height ) {
+                prep->this_row_group = 0;
+            }
+            if ( prep->next_buf_row >= buf_height ) {
+                prep->next_buf_row = 0;
+            }
+            prep->next_buf_stop = prep->next_buf_row + cinfo->max_v_samp_factor;
+        }
+        /* If at bottom of image, pad the output to a full iMCU height.
+         * Note we assume the caller is providing a one-iMCU-height output buffer!
+         */
+        if ( ( prep->rows_to_go == 0 ) &&
+            ( *out_row_group_ctr < out_row_groups_avail ) ) {
+            for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+                  ci++, compptr++ ) {
+                expand_bottom_edge( output_buf[ci],
+                                   compptr->width_in_blocks * DCTSIZE,
+                                   (int) ( *out_row_group_ctr * compptr->v_samp_factor ),
+                                   (int) ( out_row_groups_avail * compptr->v_samp_factor ) );
+            }
+            *out_row_group_ctr = out_row_groups_avail;
+            break;      /* can exit outer loop without test */
+        }
+    }
+}
+
+
+/*
+ * Create the wrapped-around downsampling input buffer needed for context mode.
+ */
+
+LOCAL void
+create_context_buffer( j_compress_ptr cinfo ) {
+    my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+    int rgroup_height = cinfo->max_v_samp_factor;
+    int ci, i;
+    jpeg_component_info * compptr;
+    JSAMPARRAY true_buffer, fake_buffer;
+
+    /* Grab enough space for fake row pointers for all the components;
+     * we need five row groups' worth of pointers for each component.
+     */
+    fake_buffer = (JSAMPARRAY)
+                  ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                               ( cinfo->num_components * 5 * rgroup_height ) *
+                                               SIZEOF( JSAMPROW ) );
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Allocate the actual buffer space (3 row groups) for this component.
+         * We make the buffer wide enough to allow the downsampler to edge-expand
+         * horizontally within the buffer, if it so chooses.
+         */
+        true_buffer = ( *cinfo->mem->alloc_sarray )
+                      ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                       (JDIMENSION) ( ( (long) compptr->width_in_blocks * DCTSIZE *
+                                       cinfo->max_h_samp_factor ) / compptr->h_samp_factor ),
+                       (JDIMENSION) ( 3 * rgroup_height ) );
+        /* Copy true buffer row pointers into the middle of the fake row array */
+        MEMCOPY( fake_buffer + rgroup_height, true_buffer,
+                3 * rgroup_height * SIZEOF( JSAMPROW ) );
+        /* Fill in the above and below wraparound pointers */
+        for ( i = 0; i < rgroup_height; i++ ) {
+            fake_buffer[i] = true_buffer[2 * rgroup_height + i];
+            fake_buffer[4 * rgroup_height + i] = true_buffer[i];
+        }
+        prep->color_buf[ci] = fake_buffer + rgroup_height;
+        fake_buffer += 5 * rgroup_height;/* point to space for next component */
+    }
+}
+
+#endif /* CONTEXT_ROWS_SUPPORTED */
+
+
+/*
+ * Initialize preprocessing controller.
+ */
+
+GLOBAL void
+jinit_c_prep_controller( j_compress_ptr cinfo, boolean need_full_buffer ) {
+    my_prep_ptr prep;
+    int ci;
+    jpeg_component_info * compptr;
+
+    if ( need_full_buffer ) {/* safety check */
+        ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+    }
+
+    prep = (my_prep_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_prep_controller ) );
+    cinfo->prep = (struct jpeg_c_prep_controller *) prep;
+    prep->pub.start_pass = start_pass_prep;
+
+    /* Allocate the color conversion buffer.
+     * We make the buffer wide enough to allow the downsampler to edge-expand
+     * horizontally within the buffer, if it so chooses.
+     */
+    if ( cinfo->downsample->need_context_rows ) {
+        /* Set up to provide context rows */
+#ifdef CONTEXT_ROWS_SUPPORTED
+        prep->pub.pre_process_data = pre_process_context;
+        create_context_buffer( cinfo );
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+    } else {
+        /* No context, just make it tall enough for one row group */
+        prep->pub.pre_process_data = pre_process_data;
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            prep->color_buf[ci] = ( *cinfo->mem->alloc_sarray )
+                                  ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                   (JDIMENSION) ( ( (long) compptr->width_in_blocks * DCTSIZE *
+                                                   cinfo->max_h_samp_factor ) / compptr->h_samp_factor ),
+                                   (JDIMENSION) cinfo->max_v_samp_factor );
+        }
+    }
+}

neo/renderer/jpeg-6/jcsample.cpp

@@ -0,0 +1,523 @@
+/*
+ * jcsample.c
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains downsampling routines.
+ *
+ * Downsampling input data is counted in "row groups".  A row group
+ * is defined to be max_v_samp_factor pixel rows of each component,
+ * from which the downsampler produces v_samp_factor sample rows.
+ * A single row group is processed in each call to the downsampler module.
+ *
+ * The downsampler is responsible for edge-expansion of its output data
+ * to fill an integral number of DCT blocks horizontally.  The source buffer
+ * may be modified if it is helpful for this purpose (the source buffer is
+ * allocated wide enough to correspond to the desired output width).
+ * The caller (the prep controller) is responsible for vertical padding.
+ *
+ * The downsampler may request "context rows" by setting need_context_rows
+ * during startup.  In this case, the input arrays will contain at least
+ * one row group's worth of pixels above and below the passed-in data;
+ * the caller will create dummy rows at image top and bottom by replicating
+ * the first or last real pixel row.
+ *
+ * An excellent reference for image resampling is
+ *   Digital Image Warping, George Wolberg, 1990.
+ *   Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
+ *
+ * The downsampling algorithm used here is a simple average of the source
+ * pixels covered by the output pixel.  The hi-falutin sampling literature
+ * refers to this as a "box filter".  In general the characteristics of a box
+ * filter are not very good, but for the specific cases we normally use (1:1
+ * and 2:1 ratios) the box is equivalent to a "triangle filter" which is not
+ * nearly so bad.  If you intend to use other sampling ratios, you'd be well
+ * advised to improve this code.
+ *
+ * A simple input-smoothing capability is provided.  This is mainly intended
+ * for cleaning up color-dithered GIF input files (if you find it inadequate,
+ * we suggest using an external filtering program such as pnmconvol).  When
+ * enabled, each input pixel P is replaced by a weighted sum of itself and its
+ * eight neighbors.  P's weight is 1-8*SF and each neighbor's weight is SF,
+ * where SF = (smoothing_factor / 1024).
+ * Currently, smoothing is only supported for 2h2v sampling factors.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Pointer to routine to downsample a single component */
+typedef JMETHOD ( void, downsample1_ptr,
+                 ( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                   JSAMPARRAY input_data, JSAMPARRAY output_data ) );
+
+/* Private subobject */
+
+typedef struct {
+    struct jpeg_downsampler pub;/* public fields */
+
+    /* Downsampling method pointers, one per component */
+    downsample1_ptr methods[MAX_COMPONENTS];
+} my_downsampler;
+
+typedef my_downsampler * my_downsample_ptr;
+
+
+/*
+ * Initialize for a downsampling pass.
+ */
+
+METHODDEF void
+start_pass_downsample( j_compress_ptr cinfo ) {
+    /* no work for now */
+}
+
+
+/*
+ * Expand a component horizontally from width input_cols to width output_cols,
+ * by duplicating the rightmost samples.
+ */
+
+LOCAL void
+expand_right_edge( JSAMPARRAY image_data, int num_rows,
+                   JDIMENSION input_cols, JDIMENSION output_cols ) {
+    register JSAMPROW ptr;
+    register JSAMPLE pixval;
+    register int count;
+    int row;
+    int numcols = (int) ( output_cols - input_cols );
+
+    if ( numcols > 0 ) {
+        for ( row = 0; row < num_rows; row++ ) {
+            ptr = image_data[row] + input_cols;
+            pixval = ptr[-1];/* don't need GETJSAMPLE() here */
+            for ( count = numcols; count > 0; count-- ) {
+                *ptr++ = pixval;
+            }
+        }
+    }
+}
+
+
+/*
+ * Do downsampling for a whole row group (all components).
+ *
+ * In this version we simply downsample each component independently.
+ */
+
+METHODDEF void
+sep_downsample( j_compress_ptr cinfo,
+                JSAMPIMAGE input_buf, JDIMENSION in_row_index,
+                JSAMPIMAGE output_buf, JDIMENSION out_row_group_index ) {
+    my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample;
+    int ci;
+    jpeg_component_info * compptr;
+    JSAMPARRAY in_ptr, out_ptr;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        in_ptr = input_buf[ci] + in_row_index;
+        out_ptr = output_buf[ci] + ( out_row_group_index * compptr->v_samp_factor );
+        ( *downsample->methods[ci] )( cinfo, compptr, in_ptr, out_ptr );
+    }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * One row group is processed per call.
+ * This version handles arbitrary integral sampling ratios, without smoothing.
+ * Note that this version is not actually used for customary sampling ratios.
+ */
+
+METHODDEF void
+int_downsample( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                JSAMPARRAY input_data, JSAMPARRAY output_data ) {
+    int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v;
+    JDIMENSION outcol, outcol_h;/* outcol_h == outcol*h_expand */
+    JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+    JSAMPROW inptr, outptr;
+    INT32 outvalue;
+
+    h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor;
+    v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor;
+    numpix = h_expand * v_expand;
+    numpix2 = numpix / 2;
+
+    /* Expand input data enough to let all the output samples be generated
+     * by the standard loop.  Special-casing padded output would be more
+     * efficient.
+     */
+    expand_right_edge( input_data, cinfo->max_v_samp_factor,
+                       cinfo->image_width, output_cols * h_expand );
+
+    inrow = 0;
+    for ( outrow = 0; outrow < compptr->v_samp_factor; outrow++ ) {
+        outptr = output_data[outrow];
+        for ( outcol = 0, outcol_h = 0; outcol < output_cols;
+              outcol++, outcol_h += h_expand ) {
+            outvalue = 0;
+            for ( v = 0; v < v_expand; v++ ) {
+                inptr = input_data[inrow + v] + outcol_h;
+                for ( h = 0; h < h_expand; h++ ) {
+                    outvalue += (INT32) GETJSAMPLE( *inptr++ );
+                }
+            }
+            *outptr++ = (JSAMPLE) ( ( outvalue + numpix2 ) / numpix );
+        }
+        inrow += v_expand;
+    }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the special case of a full-size component,
+ * without smoothing.
+ */
+
+METHODDEF void
+fullsize_downsample( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                     JSAMPARRAY input_data, JSAMPARRAY output_data ) {
+    /* Copy the data */
+    jcopy_sample_rows( input_data, 0, output_data, 0,
+                       cinfo->max_v_samp_factor, cinfo->image_width );
+    /* Edge-expand */
+    expand_right_edge( output_data, cinfo->max_v_samp_factor,
+                       cinfo->image_width, compptr->width_in_blocks * DCTSIZE );
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the common case of 2:1 horizontal and 1:1 vertical,
+ * without smoothing.
+ *
+ * A note about the "bias" calculations: when rounding fractional values to
+ * integer, we do not want to always round 0.5 up to the next integer.
+ * If we did that, we'd introduce a noticeable bias towards larger values.
+ * Instead, this code is arranged so that 0.5 will be rounded up or down at
+ * alternate pixel locations (a simple ordered dither pattern).
+ */
+
+METHODDEF void
+h2v1_downsample( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                 JSAMPARRAY input_data, JSAMPARRAY output_data ) {
+    int outrow;
+    JDIMENSION outcol;
+    JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+    register JSAMPROW inptr, outptr;
+    register int bias;
+
+    /* Expand input data enough to let all the output samples be generated
+     * by the standard loop.  Special-casing padded output would be more
+     * efficient.
+     */
+    expand_right_edge( input_data, cinfo->max_v_samp_factor,
+                       cinfo->image_width, output_cols * 2 );
+
+    for ( outrow = 0; outrow < compptr->v_samp_factor; outrow++ ) {
+        outptr = output_data[outrow];
+        inptr = input_data[outrow];
+        bias = 0;       /* bias = 0,1,0,1,... for successive samples */
+        for ( outcol = 0; outcol < output_cols; outcol++ ) {
+            *outptr++ = (JSAMPLE) ( ( GETJSAMPLE( *inptr ) + GETJSAMPLE( inptr[1] )
+                                      + bias ) >> 1 );
+            bias ^= 1;  /* 0=>1, 1=>0 */
+            inptr += 2;
+        }
+    }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
+ * without smoothing.
+ */
+
+METHODDEF void
+h2v2_downsample( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                 JSAMPARRAY input_data, JSAMPARRAY output_data ) {
+    int inrow, outrow;
+    JDIMENSION outcol;
+    JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+    register JSAMPROW inptr0, inptr1, outptr;
+    register int bias;
+
+    /* Expand input data enough to let all the output samples be generated
+     * by the standard loop.  Special-casing padded output would be more
+     * efficient.
+     */
+    expand_right_edge( input_data, cinfo->max_v_samp_factor,
+                       cinfo->image_width, output_cols * 2 );
+
+    inrow = 0;
+    for ( outrow = 0; outrow < compptr->v_samp_factor; outrow++ ) {
+        outptr = output_data[outrow];
+        inptr0 = input_data[inrow];
+        inptr1 = input_data[inrow + 1];
+        bias = 1;       /* bias = 1,2,1,2,... for successive samples */
+        for ( outcol = 0; outcol < output_cols; outcol++ ) {
+            *outptr++ = (JSAMPLE) ( ( GETJSAMPLE( *inptr0 ) + GETJSAMPLE( inptr0[1] ) +
+                                      GETJSAMPLE( *inptr1 ) + GETJSAMPLE( inptr1[1] )
+                                      + bias ) >> 2 );
+            bias ^= 3;  /* 1=>2, 2=>1 */
+            inptr0 += 2;
+            inptr1 += 2;
+        }
+        inrow += 2;
+    }
+}
+
+
+#ifdef INPUT_SMOOTHING_SUPPORTED
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
+ * with smoothing.  One row of context is required.
+ */
+
+METHODDEF void
+h2v2_smooth_downsample( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                        JSAMPARRAY input_data, JSAMPARRAY output_data ) {
+    int inrow, outrow;
+    JDIMENSION colctr;
+    JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+    register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
+    INT32 membersum, neighsum, memberscale, neighscale;
+
+    /* Expand input data enough to let all the output samples be generated
+     * by the standard loop.  Special-casing padded output would be more
+     * efficient.
+     */
+    expand_right_edge( input_data - 1, cinfo->max_v_samp_factor + 2,
+                       cinfo->image_width, output_cols * 2 );
+
+    /* We don't bother to form the individual "smoothed" input pixel values;
+     * we can directly compute the output which is the average of the four
+     * smoothed values.  Each of the four member pixels contributes a fraction
+     * (1-8*SF) to its own smoothed image and a fraction SF to each of the three
+     * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final
+     * output.  The four corner-adjacent neighbor pixels contribute a fraction
+     * SF to just one smoothed pixel, or SF/4 to the final output; while the
+     * eight edge-adjacent neighbors contribute SF to each of two smoothed
+     * pixels, or SF/2 overall.  In order to use integer arithmetic, these
+     * factors are scaled by 2^16 = 65536.
+     * Also recall that SF = smoothing_factor / 1024.
+     */
+
+    memberscale = 16384 - cinfo->smoothing_factor * 80;/* scaled (1-5*SF)/4 */
+    neighscale = cinfo->smoothing_factor * 16;/* scaled SF/4 */
+
+    inrow = 0;
+    for ( outrow = 0; outrow < compptr->v_samp_factor; outrow++ ) {
+        outptr = output_data[outrow];
+        inptr0 = input_data[inrow];
+        inptr1 = input_data[inrow + 1];
+        above_ptr = input_data[inrow - 1];
+        below_ptr = input_data[inrow + 2];
+
+        /* Special case for first column: pretend column -1 is same as column 0 */
+        membersum = GETJSAMPLE( *inptr0 ) + GETJSAMPLE( inptr0[1] ) +
+                    GETJSAMPLE( *inptr1 ) + GETJSAMPLE( inptr1[1] );
+        neighsum = GETJSAMPLE( *above_ptr ) + GETJSAMPLE( above_ptr[1] ) +
+                   GETJSAMPLE( *below_ptr ) + GETJSAMPLE( below_ptr[1] ) +
+                   GETJSAMPLE( *inptr0 ) + GETJSAMPLE( inptr0[2] ) +
+                   GETJSAMPLE( *inptr1 ) + GETJSAMPLE( inptr1[2] );
+        neighsum += neighsum;
+        neighsum += GETJSAMPLE( *above_ptr ) + GETJSAMPLE( above_ptr[2] ) +
+                    GETJSAMPLE( *below_ptr ) + GETJSAMPLE( below_ptr[2] );
+        membersum = membersum * memberscale + neighsum * neighscale;
+        *outptr++ = (JSAMPLE) ( ( membersum + 32768 ) >> 16 );
+        inptr0 += 2;
+        inptr1 += 2;
+        above_ptr += 2;
+        below_ptr += 2;
+
+        for ( colctr = output_cols - 2; colctr > 0; colctr-- ) {
+            /* sum of pixels directly mapped to this output element */
+            membersum = GETJSAMPLE( *inptr0 ) + GETJSAMPLE( inptr0[1] ) +
+                        GETJSAMPLE( *inptr1 ) + GETJSAMPLE( inptr1[1] );
+            /* sum of edge-neighbor pixels */
+            neighsum = GETJSAMPLE( *above_ptr ) + GETJSAMPLE( above_ptr[1] ) +
+                       GETJSAMPLE( *below_ptr ) + GETJSAMPLE( below_ptr[1] ) +
+                       GETJSAMPLE( inptr0[-1] ) + GETJSAMPLE( inptr0[2] ) +
+                       GETJSAMPLE( inptr1[-1] ) + GETJSAMPLE( inptr1[2] );
+            /* The edge-neighbors count twice as much as corner-neighbors */
+            neighsum += neighsum;
+            /* Add in the corner-neighbors */
+            neighsum += GETJSAMPLE( above_ptr[-1] ) + GETJSAMPLE( above_ptr[2] ) +
+                        GETJSAMPLE( below_ptr[-1] ) + GETJSAMPLE( below_ptr[2] );
+            /* form final output scaled up by 2^16 */
+            membersum = membersum * memberscale + neighsum * neighscale;
+            /* round, descale and output it */
+            *outptr++ = (JSAMPLE) ( ( membersum + 32768 ) >> 16 );
+            inptr0 += 2;
+            inptr1 += 2;
+            above_ptr += 2;
+            below_ptr += 2;
+        }
+
+        /* Special case for last column */
+        membersum = GETJSAMPLE( *inptr0 ) + GETJSAMPLE( inptr0[1] ) +
+                    GETJSAMPLE( *inptr1 ) + GETJSAMPLE( inptr1[1] );
+        neighsum = GETJSAMPLE( *above_ptr ) + GETJSAMPLE( above_ptr[1] ) +
+                   GETJSAMPLE( *below_ptr ) + GETJSAMPLE( below_ptr[1] ) +
+                   GETJSAMPLE( inptr0[-1] ) + GETJSAMPLE( inptr0[1] ) +
+                   GETJSAMPLE( inptr1[-1] ) + GETJSAMPLE( inptr1[1] );
+        neighsum += neighsum;
+        neighsum += GETJSAMPLE( above_ptr[-1] ) + GETJSAMPLE( above_ptr[1] ) +
+                    GETJSAMPLE( below_ptr[-1] ) + GETJSAMPLE( below_ptr[1] );
+        membersum = membersum * memberscale + neighsum * neighscale;
+        *outptr = (JSAMPLE) ( ( membersum + 32768 ) >> 16 );
+
+        inrow += 2;
+    }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the special case of a full-size component,
+ * with smoothing.  One row of context is required.
+ */
+
+METHODDEF void
+fullsize_smooth_downsample( j_compress_ptr cinfo, jpeg_component_info * compptr,
+                            JSAMPARRAY input_data, JSAMPARRAY output_data ) {
+    int outrow;
+    JDIMENSION colctr;
+    JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+    register JSAMPROW inptr, above_ptr, below_ptr, outptr;
+    INT32 membersum, neighsum, memberscale, neighscale;
+    int colsum, lastcolsum, nextcolsum;
+
+    /* Expand input data enough to let all the output samples be generated
+     * by the standard loop.  Special-casing padded output would be more
+     * efficient.
+     */
+    expand_right_edge( input_data - 1, cinfo->max_v_samp_factor + 2,
+                       cinfo->image_width, output_cols );
+
+    /* Each of the eight neighbor pixels contributes a fraction SF to the
+     * smoothed pixel, while the main pixel contributes (1-8*SF).  In order
+     * to use integer arithmetic, these factors are multiplied by 2^16 = 65536.
+     * Also recall that SF = smoothing_factor / 1024.
+     */
+
+    memberscale = 65536L - cinfo->smoothing_factor * 512L;/* scaled 1-8*SF */
+    neighscale = cinfo->smoothing_factor * 64;/* scaled SF */
+
+    for ( outrow = 0; outrow < compptr->v_samp_factor; outrow++ ) {
+        outptr = output_data[outrow];
+        inptr = input_data[outrow];
+        above_ptr = input_data[outrow - 1];
+        below_ptr = input_data[outrow + 1];
+
+        /* Special case for first column */
+        colsum = GETJSAMPLE( *above_ptr++ ) + GETJSAMPLE( *below_ptr++ ) +
+                 GETJSAMPLE( *inptr );
+        membersum = GETJSAMPLE( *inptr++ );
+        nextcolsum = GETJSAMPLE( *above_ptr ) + GETJSAMPLE( *below_ptr ) +
+                     GETJSAMPLE( *inptr );
+        neighsum = colsum + ( colsum - membersum ) + nextcolsum;
+        membersum = membersum * memberscale + neighsum * neighscale;
+        *outptr++ = (JSAMPLE) ( ( membersum + 32768 ) >> 16 );
+        lastcolsum = colsum;
+        colsum = nextcolsum;
+
+        for ( colctr = output_cols - 2; colctr > 0; colctr-- ) {
+            membersum = GETJSAMPLE( *inptr++ );
+            above_ptr++;
+            below_ptr++;
+            nextcolsum = GETJSAMPLE( *above_ptr ) + GETJSAMPLE( *below_ptr ) +
+                         GETJSAMPLE( *inptr );
+            neighsum = lastcolsum + ( colsum - membersum ) + nextcolsum;
+            membersum = membersum * memberscale + neighsum * neighscale;
+            *outptr++ = (JSAMPLE) ( ( membersum + 32768 ) >> 16 );
+            lastcolsum = colsum;
+            colsum = nextcolsum;
+        }
+
+        /* Special case for last column */
+        membersum = GETJSAMPLE( *inptr );
+        neighsum = lastcolsum + ( colsum - membersum ) + colsum;
+        membersum = membersum * memberscale + neighsum * neighscale;
+        *outptr = (JSAMPLE) ( ( membersum + 32768 ) >> 16 );
+
+    }
+}
+
+#endif /* INPUT_SMOOTHING_SUPPORTED */
+
+
+/*
+ * Module initialization routine for downsampling.
+ * Note that we must select a routine for each component.
+ */
+
+GLOBAL void
+jinit_downsampler( j_compress_ptr cinfo ) {
+    my_downsample_ptr downsample;
+    int ci;
+    jpeg_component_info * compptr;
+    boolean smoothok = TRUE;
+
+    downsample = (my_downsample_ptr)
+                 ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                              SIZEOF( my_downsampler ) );
+    cinfo->downsample = (struct jpeg_downsampler *) downsample;
+    downsample->pub.start_pass = start_pass_downsample;
+    downsample->pub.downsample = sep_downsample;
+    downsample->pub.need_context_rows = FALSE;
+
+    if ( cinfo->CCIR601_sampling ) {
+        ERREXIT( cinfo, JERR_CCIR601_NOTIMPL );
+    }
+
+    /* Verify we can handle the sampling factors, and set up method pointers */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        if ( ( compptr->h_samp_factor == cinfo->max_h_samp_factor ) &&
+            ( compptr->v_samp_factor == cinfo->max_v_samp_factor ) ) {
+#ifdef INPUT_SMOOTHING_SUPPORTED
+            if ( cinfo->smoothing_factor ) {
+                downsample->methods[ci] = fullsize_smooth_downsample;
+                downsample->pub.need_context_rows = TRUE;
+            } else
+#endif
+            downsample->methods[ci] = fullsize_downsample;
+        } else if ( compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
+                    compptr->v_samp_factor == cinfo->max_v_samp_factor ) {
+            smoothok = FALSE;
+            downsample->methods[ci] = h2v1_downsample;
+        } else if ( compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
+                    compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor ) {
+#ifdef INPUT_SMOOTHING_SUPPORTED
+            if ( cinfo->smoothing_factor ) {
+                downsample->methods[ci] = h2v2_smooth_downsample;
+                downsample->pub.need_context_rows = TRUE;
+            } else
+#endif
+            downsample->methods[ci] = h2v2_downsample;
+        } else if ( ( cinfo->max_h_samp_factor % compptr->h_samp_factor ) == 0 &&
+                   ( cinfo->max_v_samp_factor % compptr->v_samp_factor ) == 0 ) {
+            smoothok = FALSE;
+            downsample->methods[ci] = int_downsample;
+        } else {
+            ERREXIT( cinfo, JERR_FRACT_SAMPLE_NOTIMPL );
+        }
+    }
+
+#ifdef INPUT_SMOOTHING_SUPPORTED
+    if ( ( cinfo->smoothing_factor ) && ( !smoothok ) ) {
+        TRACEMS( cinfo, 0, JTRC_SMOOTH_NOTIMPL );
+    }
+#endif
+}

neo/renderer/jpeg-6/jctrans.cpp

@@ -0,0 +1,374 @@
+/*
+ * jctrans.c
+ *
+ * Copyright (C) 1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains library routines for transcoding compression,
+ * that is, writing raw DCT coefficient arrays to an output JPEG file.
+ * The routines in jcapimin.c will also be needed by a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Forward declarations */
+LOCAL void transencode_master_selection
+JPP( ( j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays ) );
+LOCAL void transencode_coef_controller
+JPP( ( j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays ) );
+
+
+/*
+ * Compression initialization for writing raw-coefficient data.
+ * Before calling this, all parameters and a data destination must be set up.
+ * Call jpeg_finish_compress() to actually write the data.
+ *
+ * The number of passed virtual arrays must match cinfo->num_components.
+ * Note that the virtual arrays need not be filled or even realized at
+ * the time write_coefficients is called; indeed, if the virtual arrays
+ * were requested from this compression object's memory manager, they
+ * typically will be realized during this routine and filled afterwards.
+ */
+
+GLOBAL void
+jpeg_write_coefficients( j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays ) {
+    if ( cinfo->global_state != CSTATE_START ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Mark all tables to be written */
+    jpeg_suppress_tables( cinfo, FALSE );
+    /* (Re)initialize error mgr and destination modules */
+    ( *cinfo->err->reset_error_mgr )( (j_common_ptr) cinfo );
+    ( *cinfo->dest->init_destination )( cinfo );
+    /* Perform master selection of active modules */
+    transencode_master_selection( cinfo, coef_arrays );
+    /* Wait for jpeg_finish_compress() call */
+    cinfo->next_scanline = 0;/* so jpeg_write_marker works */
+    cinfo->global_state = CSTATE_WRCOEFS;
+}
+
+
+/*
+ * Initialize the compression object with default parameters,
+ * then copy from the source object all parameters needed for lossless
+ * transcoding.  Parameters that can be varied without loss (such as
+ * scan script and Huffman optimization) are left in their default states.
+ */
+
+GLOBAL void
+jpeg_copy_critical_parameters( j_decompress_ptr srcinfo,
+                               j_compress_ptr dstinfo ) {
+    JQUANT_TBL ** qtblptr;
+    jpeg_component_info * incomp, * outcomp;
+    JQUANT_TBL * c_quant, * slot_quant;
+    int tblno, ci, coefi;
+
+    /* Safety check to ensure start_compress not called yet. */
+    if ( dstinfo->global_state != CSTATE_START ) {
+        ERREXIT1( dstinfo, JERR_BAD_STATE, dstinfo->global_state );
+    }
+    /* Copy fundamental image dimensions */
+    dstinfo->image_width = srcinfo->image_width;
+    dstinfo->image_height = srcinfo->image_height;
+    dstinfo->input_components = srcinfo->num_components;
+    dstinfo->in_color_space = srcinfo->jpeg_color_space;
+    /* Initialize all parameters to default values */
+    jpeg_set_defaults( dstinfo );
+    /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
+     * Fix it to get the right header markers for the image colorspace.
+     */
+    jpeg_set_colorspace( dstinfo, srcinfo->jpeg_color_space );
+    dstinfo->data_precision = srcinfo->data_precision;
+    dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
+    /* Copy the source's quantization tables. */
+    for ( tblno = 0; tblno < NUM_QUANT_TBLS; tblno++ ) {
+        if ( srcinfo->quant_tbl_ptrs[tblno] != NULL ) {
+            qtblptr = &dstinfo->quant_tbl_ptrs[tblno];
+            if ( *qtblptr == NULL ) {
+                *qtblptr = jpeg_alloc_quant_table( (j_common_ptr) dstinfo );
+            }
+            MEMCOPY( ( *qtblptr )->quantval,
+                    srcinfo->quant_tbl_ptrs[tblno]->quantval,
+                    SIZEOF( ( *qtblptr )->quantval ) );
+            ( *qtblptr )->sent_table = FALSE;
+        }
+    }
+    /* Copy the source's per-component info.
+     * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
+     */
+    dstinfo->num_components = srcinfo->num_components;
+    if ( ( dstinfo->num_components < 1 ) || ( dstinfo->num_components > MAX_COMPONENTS ) ) {
+        ERREXIT2( dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
+                  MAX_COMPONENTS );
+    }
+    for ( ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
+          ci < dstinfo->num_components; ci++, incomp++, outcomp++ ) {
+        outcomp->component_id = incomp->component_id;
+        outcomp->h_samp_factor = incomp->h_samp_factor;
+        outcomp->v_samp_factor = incomp->v_samp_factor;
+        outcomp->quant_tbl_no = incomp->quant_tbl_no;
+        /* Make sure saved quantization table for component matches the qtable
+         * slot.  If not, the input file re-used this qtable slot.
+         * IJG encoder currently cannot duplicate this.
+         */
+        tblno = outcomp->quant_tbl_no;
+        if ( ( tblno < 0 ) || ( tblno >= NUM_QUANT_TBLS ) ||
+            ( srcinfo->quant_tbl_ptrs[tblno] == NULL ) ) {
+            ERREXIT1( dstinfo, JERR_NO_QUANT_TABLE, tblno );
+        }
+        slot_quant = srcinfo->quant_tbl_ptrs[tblno];
+        c_quant = incomp->quant_table;
+        if ( c_quant != NULL ) {
+            for ( coefi = 0; coefi < DCTSIZE2; coefi++ ) {
+                if ( c_quant->quantval[coefi] != slot_quant->quantval[coefi] ) {
+                    ERREXIT1( dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno );
+                }
+            }
+        }
+        /* Note: we do not copy the source's Huffman table assignments;
+         * instead we rely on jpeg_set_colorspace to have made a suitable choice.
+         */
+    }
+}
+
+
+/*
+ * Master selection of compression modules for transcoding.
+ * This substitutes for jcinit.c's initialization of the full compressor.
+ */
+
+LOCAL void
+transencode_master_selection( j_compress_ptr cinfo,
+                              jvirt_barray_ptr * coef_arrays ) {
+    /* Although we don't actually use input_components for transcoding,
+     * jcmaster.c's initial_setup will complain if input_components is 0.
+     */
+    cinfo->input_components = 1;
+    /* Initialize master control (includes parameter checking/processing) */
+    jinit_c_master_control( cinfo, TRUE /* transcode only */ );
+
+    /* Entropy encoding: either Huffman or arithmetic coding. */
+    if ( cinfo->arith_code ) {
+        ERREXIT( cinfo, JERR_ARITH_NOTIMPL );
+    } else {
+        if ( cinfo->progressive_mode ) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+            jinit_phuff_encoder( cinfo );
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        } else {
+            jinit_huff_encoder( cinfo );
+        }
+    }
+
+    /* We need a special coefficient buffer controller. */
+    transencode_coef_controller( cinfo, coef_arrays );
+
+    jinit_marker_writer( cinfo );
+
+    /* We can now tell the memory manager to allocate virtual arrays. */
+    ( *cinfo->mem->realize_virt_arrays )( (j_common_ptr) cinfo );
+
+    /* Write the datastream header (SOI) immediately.
+     * Frame and scan headers are postponed till later.
+     * This lets application insert special markers after the SOI.
+     */
+    ( *cinfo->marker->write_file_header )( cinfo );
+}
+
+
+/*
+ * The rest of this file is a special implementation of the coefficient
+ * buffer controller.  This is similar to jccoefct.c, but it handles only
+ * output from presupplied virtual arrays.  Furthermore, we generate any
+ * dummy padding blocks on-the-fly rather than expecting them to be present
+ * in the arrays.
+ */
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_c_coef_controller pub;/* public fields */
+
+    JDIMENSION iMCU_row_num;/* iMCU row # within image */
+    JDIMENSION mcu_ctr;     /* counts MCUs processed in current row */
+    int        MCU_vert_offset; /* counts MCU rows within iMCU row */
+    int        MCU_rows_per_iMCU_row; /* number of such rows needed */
+
+    /* Virtual block array for each component. */
+    jvirt_barray_ptr * whole_image;
+
+    /* Workspace for constructing dummy blocks at right/bottom edges. */
+    JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU];
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+
+LOCAL void
+start_iMCU_row( j_compress_ptr cinfo ) {
+/* Reset within-iMCU-row counters for a new row */
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+    /* In an interleaved scan, an MCU row is the same as an iMCU row.
+     * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+     * But at the bottom of the image, process only what's left.
+     */
+    if ( cinfo->comps_in_scan > 1 ) {
+        coef->MCU_rows_per_iMCU_row = 1;
+    } else {
+        if ( coef->iMCU_row_num < ( cinfo->total_iMCU_rows - 1 ) ) {
+            coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+        } else {
+            coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+        }
+    }
+
+    coef->mcu_ctr = 0;
+    coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF void
+start_pass_coef( j_compress_ptr cinfo, J_BUF_MODE pass_mode ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+    if ( pass_mode != JBUF_CRANK_DEST ) {
+        ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+    }
+
+    coef->iMCU_row_num = 0;
+    start_iMCU_row( cinfo );
+}
+
+
+/*
+ * Process some data.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the entropy coder.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf is ignored; it is likely to be a NULL pointer.
+ */
+
+METHODDEF boolean
+compress_output( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION MCU_col_num; /* index of current MCU within row */
+    JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+    JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+    int blkn, ci, xindex, yindex, yoffset, blockcnt;
+    JDIMENSION start_col;
+    JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+    JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
+    JBLOCKROW buffer_ptr;
+    jpeg_component_info * compptr;
+
+    /* Align the virtual buffers for the components used in this scan. */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        buffer[ci] = ( *cinfo->mem->access_virt_barray )
+                     ( (j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+                      coef->iMCU_row_num * compptr->v_samp_factor,
+                      (JDIMENSION) compptr->v_samp_factor, FALSE );
+    }
+
+    /* Loop to process one whole iMCU row */
+    for ( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+          yoffset++ ) {
+        for ( MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
+              MCU_col_num++ ) {
+            /* Construct list of pointers to DCT blocks belonging to this MCU */
+            blkn = 0;   /* index of current DCT block within MCU */
+            for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+                compptr = cinfo->cur_comp_info[ci];
+                start_col = MCU_col_num * compptr->MCU_width;
+                blockcnt = ( MCU_col_num < last_MCU_col ) ? compptr->MCU_width
+                           : compptr->last_col_width;
+                for ( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
+                    if ( ( coef->iMCU_row_num < last_iMCU_row ) ||
+                        ( yindex + yoffset < compptr->last_row_height ) ) {
+                        /* Fill in pointers to real blocks in this row */
+                        buffer_ptr = buffer[ci][yindex + yoffset] + start_col;
+                        for ( xindex = 0; xindex < blockcnt; xindex++ ) {
+                            MCU_buffer[blkn++] = buffer_ptr++;
+                        }
+                    } else {
+                        /* At bottom of image, need a whole row of dummy blocks */
+                        xindex = 0;
+                    }
+                    /* Fill in any dummy blocks needed in this row.
+                     * Dummy blocks are filled in the same way as in jccoefct.c:
+                     * all zeroes in the AC entries, DC entries equal to previous
+                     * block's DC value.  The init routine has already zeroed the
+                     * AC entries, so we need only set the DC entries correctly.
+                     */
+                    for (; xindex < compptr->MCU_width; xindex++ ) {
+                        MCU_buffer[blkn] = coef->dummy_buffer[blkn];
+                        MCU_buffer[blkn][0][0] = MCU_buffer[blkn - 1][0][0];
+                        blkn++;
+                    }
+                }
+            }
+            /* Try to write the MCU. */
+            if ( !( *cinfo->entropy->encode_mcu )( cinfo, MCU_buffer ) ) {
+                /* Suspension forced; update state counters and exit */
+                coef->MCU_vert_offset = yoffset;
+                coef->mcu_ctr = MCU_col_num;
+                return FALSE;
+            }
+        }
+        /* Completed an MCU row, but perhaps not an iMCU row */
+        coef->mcu_ctr = 0;
+    }
+    /* Completed the iMCU row, advance counters for next one */
+    coef->iMCU_row_num++;
+    start_iMCU_row( cinfo );
+    return TRUE;
+}
+
+
+/*
+ * Initialize coefficient buffer controller.
+ *
+ * Each passed coefficient array must be the right size for that
+ * coefficient: width_in_blocks wide and height_in_blocks high,
+ * with unitheight at least v_samp_factor.
+ */
+
+LOCAL void
+transencode_coef_controller( j_compress_ptr cinfo,
+                             jvirt_barray_ptr * coef_arrays ) {
+    my_coef_ptr coef;
+    JBLOCKROW buffer;
+    int i;
+
+    coef = (my_coef_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_coef_controller ) );
+    cinfo->coef = (struct jpeg_c_coef_controller *) coef;
+    coef->pub.start_pass = start_pass_coef;
+    coef->pub.compress_data = compress_output;
+
+    /* Save pointer to virtual arrays */
+    coef->whole_image = coef_arrays;
+
+    /* Allocate and pre-zero space for dummy DCT blocks. */
+    buffer = (JBLOCKROW)
+             ( *cinfo->mem->alloc_large )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                          C_MAX_BLOCKS_IN_MCU * SIZEOF( JBLOCK ) );
+    jzero_far( (void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF( JBLOCK ) );
+    for ( i = 0; i < C_MAX_BLOCKS_IN_MCU; i++ ) {
+        coef->dummy_buffer[i] = buffer + i;
+    }
+}

neo/renderer/jpeg-6/jdapimin.cpp

@@ -0,0 +1,398 @@
+/*
+ * jdapimin.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the decompression half
+ * of the JPEG library.  These are the "minimum" API routines that may be
+ * needed in either the normal full-decompression case or the
+ * transcoding-only case.
+ *
+ * Most of the routines intended to be called directly by an application
+ * are in this file or in jdapistd.c.  But also see jcomapi.c for routines
+ * shared by compression and decompression, and jdtrans.c for the transcoding
+ * case.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Initialization of a JPEG decompression object.
+ * The error manager must already be set up (in case memory manager fails).
+ */
+
+GLOBAL void
+jpeg_create_decompress( j_decompress_ptr cinfo ) {
+    int i;
+
+    /* For debugging purposes, zero the whole master structure.
+     * But error manager pointer is already there, so save and restore it.
+     */
+    {
+        struct jpeg_error_mgr * err = cinfo->err;
+        MEMZERO( cinfo, SIZEOF( struct jpeg_decompress_struct ) );
+        cinfo->err = err;
+    }
+    cinfo->is_decompressor = TRUE;
+
+    /* Initialize a memory manager instance for this object */
+    jinit_memory_mgr( (j_common_ptr) cinfo );
+
+    /* Zero out pointers to permanent structures. */
+    cinfo->progress = NULL;
+    cinfo->src = NULL;
+
+    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
+        cinfo->quant_tbl_ptrs[i] = NULL;
+    }
+
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        cinfo->dc_huff_tbl_ptrs[i] = NULL;
+        cinfo->ac_huff_tbl_ptrs[i] = NULL;
+    }
+
+    /* Initialize marker processor so application can override methods
+     * for COM, APPn markers before calling jpeg_read_header.
+     */
+    jinit_marker_reader( cinfo );
+
+    /* And initialize the overall input controller. */
+    jinit_input_controller( cinfo );
+
+    /* OK, I'm ready */
+    cinfo->global_state = DSTATE_START;
+}
+
+
+/*
+ * Destruction of a JPEG decompression object
+ */
+
+GLOBAL void
+jpeg_destroy_decompress( j_decompress_ptr cinfo ) {
+    jpeg_destroy( (j_common_ptr) cinfo );/* use common routine */
+}
+
+
+/*
+ * Abort processing of a JPEG decompression operation,
+ * but don't destroy the object itself.
+ */
+
+GLOBAL void
+jpeg_abort_decompress( j_decompress_ptr cinfo ) {
+    jpeg_abort( (j_common_ptr) cinfo );/* use common routine */
+}
+
+
+/*
+ * Install a special processing method for COM or APPn markers.
+ */
+
+GLOBAL void
+jpeg_set_marker_processor( j_decompress_ptr cinfo, int marker_code,
+                           jpeg_marker_parser_method routine ) {
+    if ( marker_code == JPEG_COM ) {
+        cinfo->marker->process_COM = routine;
+    } else if ( marker_code >= JPEG_APP0 && marker_code <= JPEG_APP0 + 15 ) {
+        cinfo->marker->process_APPn[marker_code - JPEG_APP0] = routine;
+    } else {
+        ERREXIT1( cinfo, JERR_UNKNOWN_MARKER, marker_code );
+    }
+}
+
+
+/*
+ * Set default decompression parameters.
+ */
+
+LOCAL void
+default_decompress_parms( j_decompress_ptr cinfo ) {
+    /* Guess the input colorspace, and set output colorspace accordingly. */
+    /* (Wish JPEG committee had provided a real way to specify this...) */
+    /* Note application may override our guesses. */
+    switch ( cinfo->num_components ) {
+        case 1:
+            cinfo->jpeg_color_space = JCS_GRAYSCALE;
+            cinfo->out_color_space = JCS_GRAYSCALE;
+            break;
+
+        case 3:
+            if ( cinfo->saw_JFIF_marker ) {
+                cinfo->jpeg_color_space = JCS_YCbCr;/* JFIF implies YCbCr */
+            } else if ( cinfo->saw_Adobe_marker ) {
+                switch ( cinfo->Adobe_transform ) {
+                    case 0:
+                        cinfo->jpeg_color_space = JCS_RGB;
+                        break;
+                    case 1:
+                        cinfo->jpeg_color_space = JCS_YCbCr;
+                        break;
+                    default:
+                        WARNMS1( cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform );
+                        cinfo->jpeg_color_space = JCS_YCbCr;/* assume it's YCbCr */
+                        break;
+                }
+            } else {
+                /* Saw no special markers, try to guess from the component IDs */
+                int cid0 = cinfo->comp_info[0].component_id;
+                int cid1 = cinfo->comp_info[1].component_id;
+                int cid2 = cinfo->comp_info[2].component_id;
+
+                if ( ( cid0 == 1 ) && ( cid1 == 2 ) && ( cid2 == 3 ) ) {
+                    cinfo->jpeg_color_space = JCS_YCbCr;
+                }                        /* assume JFIF w/out marker */
+                else if ( cid0 == 82 && cid1 == 71 && cid2 == 66 ) {
+                    cinfo->jpeg_color_space = JCS_RGB;
+                }                      /* ASCII 'R', 'G', 'B' */
+                else {
+                    TRACEMS3( cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2 );
+                    cinfo->jpeg_color_space = JCS_YCbCr;/* assume it's YCbCr */
+                }
+            }
+            /* Always guess RGB is proper output colorspace. */
+            cinfo->out_color_space = JCS_RGB;
+            break;
+
+        case 4:
+            if ( cinfo->saw_Adobe_marker ) {
+                switch ( cinfo->Adobe_transform ) {
+                    case 0:
+                        cinfo->jpeg_color_space = JCS_CMYK;
+                        break;
+                    case 2:
+                        cinfo->jpeg_color_space = JCS_YCCK;
+                        break;
+                    default:
+                        WARNMS1( cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform );
+                        cinfo->jpeg_color_space = JCS_YCCK;/* assume it's YCCK */
+                        break;
+                }
+            } else {
+                /* No special markers, assume straight CMYK. */
+                cinfo->jpeg_color_space = JCS_CMYK;
+            }
+            cinfo->out_color_space = JCS_CMYK;
+            break;
+
+        default:
+            cinfo->jpeg_color_space = JCS_UNKNOWN;
+            cinfo->out_color_space = JCS_UNKNOWN;
+            break;
+    }
+
+    /* Set defaults for other decompression parameters. */
+    cinfo->scale_num = 1;   /* 1:1 scaling */
+    cinfo->scale_denom = 1;
+    cinfo->output_gamma = 1.0;
+    cinfo->buffered_image = FALSE;
+    cinfo->raw_data_out = FALSE;
+    cinfo->dct_method = JDCT_DEFAULT;
+    cinfo->do_fancy_upsampling = TRUE;
+    cinfo->do_block_smoothing = TRUE;
+    cinfo->quantize_colors = FALSE;
+    /* We set these in case application only sets quantize_colors. */
+    cinfo->dither_mode = JDITHER_FS;
+#ifdef QUANT_2PASS_SUPPORTED
+    cinfo->two_pass_quantize = TRUE;
+#else
+    cinfo->two_pass_quantize = FALSE;
+#endif
+    cinfo->desired_number_of_colors = 256;
+    cinfo->colormap = NULL;
+    /* Initialize for no mode change in buffered-image mode. */
+    cinfo->enable_1pass_quant = FALSE;
+    cinfo->enable_external_quant = FALSE;
+    cinfo->enable_2pass_quant = FALSE;
+}
+
+
+/*
+ * Decompression startup: read start of JPEG datastream to see what's there.
+ * Need only initialize JPEG object and supply a data source before calling.
+ *
+ * This routine will read as far as the first SOS marker (ie, actual start of
+ * compressed data), and will save all tables and parameters in the JPEG
+ * object.  It will also initialize the decompression parameters to default
+ * values, and finally return JPEG_HEADER_OK.  On return, the application may
+ * adjust the decompression parameters and then call jpeg_start_decompress.
+ * (Or, if the application only wanted to determine the image parameters,
+ * the data need not be decompressed.  In that case, call jpeg_abort or
+ * jpeg_destroy to release any temporary space.)
+ * If an abbreviated (tables only) datastream is presented, the routine will
+ * return JPEG_HEADER_TABLES_ONLY upon reaching EOI.  The application may then
+ * re-use the JPEG object to read the abbreviated image datastream(s).
+ * It is unnecessary (but OK) to call jpeg_abort in this case.
+ * The JPEG_SUSPENDED return code only occurs if the data source module
+ * requests suspension of the decompressor.  In this case the application
+ * should load more source data and then re-call jpeg_read_header to resume
+ * processing.
+ * If a non-suspending data source is used and require_image is TRUE, then the
+ * return code need not be inspected since only JPEG_HEADER_OK is possible.
+ *
+ * This routine is now just a front end to jpeg_consume_input, with some
+ * extra error checking.
+ */
+
+GLOBAL int
+jpeg_read_header( j_decompress_ptr cinfo, boolean require_image ) {
+    int retcode;
+
+    if ( ( cinfo->global_state != DSTATE_START ) &&
+        ( cinfo->global_state != DSTATE_INHEADER ) ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    retcode = jpeg_consume_input( cinfo );
+
+    switch ( retcode ) {
+        case JPEG_REACHED_SOS:
+            retcode = JPEG_HEADER_OK;
+            break;
+        case JPEG_REACHED_EOI:
+            if ( require_image ) {/* Complain if application wanted an image */
+                ERREXIT( cinfo, JERR_NO_IMAGE );
+            }
+            /* Reset to start state; it would be safer to require the application to
+             * call jpeg_abort, but we can't change it now for compatibility reasons.
+             * A side effect is to free any temporary memory (there shouldn't be any).
+             */
+            jpeg_abort( (j_common_ptr) cinfo );/* sets state = DSTATE_START */
+            retcode = JPEG_HEADER_TABLES_ONLY;
+            break;
+        case JPEG_SUSPENDED:
+            /* no work */
+            break;
+    }
+
+    return retcode;
+}
+
+
+/*
+ * Consume data in advance of what the decompressor requires.
+ * This can be called at any time once the decompressor object has
+ * been created and a data source has been set up.
+ *
+ * This routine is essentially a state machine that handles a couple
+ * of critical state-transition actions, namely initial setup and
+ * transition from header scanning to ready-for-start_decompress.
+ * All the actual input is done via the input controller's consume_input
+ * method.
+ */
+
+GLOBAL int
+jpeg_consume_input( j_decompress_ptr cinfo ) {
+    int retcode = JPEG_SUSPENDED;
+
+    /* NB: every possible DSTATE value should be listed in this switch */
+    switch ( cinfo->global_state ) {
+        case DSTATE_START:
+            /* Start-of-datastream actions: reset appropriate modules */
+            ( *cinfo->inputctl->reset_input_controller )( cinfo );
+            /* Initialize application's data source module */
+            ( *cinfo->src->init_source )( cinfo );
+            cinfo->global_state = DSTATE_INHEADER;
+            /*FALLTHROUGH*/
+        case DSTATE_INHEADER:
+            retcode = ( *cinfo->inputctl->consume_input )( cinfo );
+            if ( retcode == JPEG_REACHED_SOS ) {/* Found SOS, prepare to decompress */
+                /* Set up default parameters based on header data */
+                default_decompress_parms( cinfo );
+                /* Set global state: ready for start_decompress */
+                cinfo->global_state = DSTATE_READY;
+            }
+            break;
+        case DSTATE_READY:
+            /* Can't advance past first SOS until start_decompress is called */
+            retcode = JPEG_REACHED_SOS;
+            break;
+        case DSTATE_PRELOAD:
+        case DSTATE_PRESCAN:
+        case DSTATE_SCANNING:
+        case DSTATE_RAW_OK:
+        case DSTATE_BUFIMAGE:
+        case DSTATE_BUFPOST:
+        case DSTATE_STOPPING:
+            retcode = ( *cinfo->inputctl->consume_input )( cinfo );
+            break;
+        default:
+            ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    return retcode;
+}
+
+
+/*
+ * Have we finished reading the input file?
+ */
+
+GLOBAL boolean
+jpeg_input_complete( j_decompress_ptr cinfo ) {
+    /* Check for valid jpeg object */
+    if ( ( cinfo->global_state < DSTATE_START ) ||
+        ( cinfo->global_state > DSTATE_STOPPING ) ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    return cinfo->inputctl->eoi_reached;
+}
+
+
+/*
+ * Is there more than one scan?
+ */
+
+GLOBAL boolean
+jpeg_has_multiple_scans( j_decompress_ptr cinfo ) {
+    /* Only valid after jpeg_read_header completes */
+    if ( ( cinfo->global_state < DSTATE_READY ) ||
+        ( cinfo->global_state > DSTATE_STOPPING ) ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    return cinfo->inputctl->has_multiple_scans;
+}
+
+
+/*
+ * Finish JPEG decompression.
+ *
+ * This will normally just verify the file trailer and release temp storage.
+ *
+ * Returns FALSE if suspended.  The return value need be inspected only if
+ * a suspending data source is used.
+ */
+
+GLOBAL boolean
+jpeg_finish_decompress( j_decompress_ptr cinfo ) {
+    if ( ( ( cinfo->global_state == DSTATE_SCANNING ) ||
+          ( cinfo->global_state == DSTATE_RAW_OK ) && !cinfo->buffered_image ) ) {
+        /* Terminate final pass of non-buffered mode */
+        if ( cinfo->output_scanline < cinfo->output_height ) {
+            ERREXIT( cinfo, JERR_TOO_LITTLE_DATA );
+        }
+        ( *cinfo->master->finish_output_pass )( cinfo );
+        cinfo->global_state = DSTATE_STOPPING;
+    } else if ( cinfo->global_state == DSTATE_BUFIMAGE ) {
+        /* Finishing after a buffered-image operation */
+        cinfo->global_state = DSTATE_STOPPING;
+    } else if ( cinfo->global_state != DSTATE_STOPPING ) {
+        /* STOPPING = repeat call after a suspension, anything else is error */
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Read until EOI */
+    while ( !cinfo->inputctl->eoi_reached ) {
+        if ( ( *cinfo->inputctl->consume_input )( cinfo ) == JPEG_SUSPENDED ) {
+            return FALSE;
+        }               /* Suspend, come back later */
+    }
+    /* Do final cleanup */
+    ( *cinfo->src->term_source )( cinfo );
+    /* We can use jpeg_abort to release memory and reset global_state */
+    jpeg_abort( (j_common_ptr) cinfo );
+    return TRUE;
+}

neo/renderer/jpeg-6/jdapistd.cpp

@@ -0,0 +1,282 @@
+/*
+ * jdapistd.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the decompression half
+ * of the JPEG library.  These are the "standard" API routines that are
+ * used in the normal full-decompression case.  They are not used by a
+ * transcoding-only application.  Note that if an application links in
+ * jpeg_start_decompress, it will end up linking in the entire decompressor.
+ * We thus must separate this file from jdapimin.c to avoid linking the
+ * whole decompression library into a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Forward declarations */
+LOCAL boolean output_pass_setup JPP( (j_decompress_ptr cinfo) );
+
+
+/*
+ * Decompression initialization.
+ * jpeg_read_header must be completed before calling this.
+ *
+ * If a multipass operating mode was selected, this will do all but the
+ * last pass, and thus may take a great deal of time.
+ *
+ * Returns FALSE if suspended.  The return value need be inspected only if
+ * a suspending data source is used.
+ */
+
+GLOBAL boolean
+jpeg_start_decompress( j_decompress_ptr cinfo ) {
+    if ( cinfo->global_state == DSTATE_READY ) {
+        /* First call: initialize master control, select active modules */
+        jinit_master_decompress( cinfo );
+        if ( cinfo->buffered_image ) {
+            /* No more work here; expecting jpeg_start_output next */
+            cinfo->global_state = DSTATE_BUFIMAGE;
+            return TRUE;
+        }
+        cinfo->global_state = DSTATE_PRELOAD;
+    }
+    if ( cinfo->global_state == DSTATE_PRELOAD ) {
+        /* If file has multiple scans, absorb them all into the coef buffer */
+        if ( cinfo->inputctl->has_multiple_scans ) {
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+            for (;; ) {
+                int retcode;
+                /* Call progress monitor hook if present */
+                if ( cinfo->progress != NULL ) {
+                    ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+                }
+                /* Absorb some more input */
+                retcode = ( *cinfo->inputctl->consume_input )( cinfo );
+                if ( retcode == JPEG_SUSPENDED ) {
+                    return FALSE;
+                }
+                if ( retcode == JPEG_REACHED_EOI ) {
+                    break;
+                }
+                /* Advance progress counter if appropriate */
+                if ( ( cinfo->progress != NULL ) &&
+                    ( ( retcode == JPEG_ROW_COMPLETED ) || ( retcode == JPEG_REACHED_SOS ) ) ) {
+                    if ( ++cinfo->progress->pass_counter >= cinfo->progress->pass_limit ) {
+                        /* jdmaster underestimated number of scans; ratchet up one scan */
+                        cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
+                    }
+                }
+            }
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+        }
+        cinfo->output_scan_number = cinfo->input_scan_number;
+    } else if ( cinfo->global_state != DSTATE_PRESCAN ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Perform any dummy output passes, and set up for the final pass */
+    return output_pass_setup( cinfo );
+}
+
+
+/*
+ * Set up for an output pass, and perform any dummy pass(es) needed.
+ * Common subroutine for jpeg_start_decompress and jpeg_start_output.
+ * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
+ * Exit: If done, returns TRUE and sets global_state for proper output mode.
+ *       If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
+ */
+
+LOCAL boolean
+output_pass_setup( j_decompress_ptr cinfo ) {
+    if ( cinfo->global_state != DSTATE_PRESCAN ) {
+        /* First call: do pass setup */
+        ( *cinfo->master->prepare_for_output_pass )( cinfo );
+        cinfo->output_scanline = 0;
+        cinfo->global_state = DSTATE_PRESCAN;
+    }
+    /* Loop over any required dummy passes */
+    while ( cinfo->master->is_dummy_pass ) {
+#ifdef QUANT_2PASS_SUPPORTED
+        /* Crank through the dummy pass */
+        while ( cinfo->output_scanline < cinfo->output_height ) {
+            JDIMENSION last_scanline;
+            /* Call progress monitor hook if present */
+            if ( cinfo->progress != NULL ) {
+                cinfo->progress->pass_counter = (long) cinfo->output_scanline;
+                cinfo->progress->pass_limit = (long) cinfo->output_height;
+                ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+            }
+            /* Process some data */
+            last_scanline = cinfo->output_scanline;
+            ( *cinfo->main->process_data )( cinfo, (JSAMPARRAY) NULL,
+                                            &cinfo->output_scanline, (JDIMENSION) 0 );
+            if ( cinfo->output_scanline == last_scanline ) {
+                return FALSE;
+            }           /* No progress made, must suspend */
+        }
+        /* Finish up dummy pass, and set up for another one */
+        ( *cinfo->master->finish_output_pass )( cinfo );
+        ( *cinfo->master->prepare_for_output_pass )( cinfo );
+        cinfo->output_scanline = 0;
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif /* QUANT_2PASS_SUPPORTED */
+    }
+    /* Ready for application to drive output pass through
+     * jpeg_read_scanlines or jpeg_read_raw_data.
+     */
+    cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
+    return TRUE;
+}
+
+
+/*
+ * Read some scanlines of data from the JPEG decompressor.
+ *
+ * The return value will be the number of lines actually read.
+ * This may be less than the number requested in several cases,
+ * including bottom of image, data source suspension, and operating
+ * modes that emit multiple scanlines at a time.
+ *
+ * Note: we warn about excess calls to jpeg_read_scanlines() since
+ * this likely signals an application programmer error.  However,
+ * an oversize buffer (max_lines > scanlines remaining) is not an error.
+ */
+
+GLOBAL JDIMENSION
+jpeg_read_scanlines( j_decompress_ptr cinfo, JSAMPARRAY scanlines,
+                     JDIMENSION max_lines ) {
+    JDIMENSION row_ctr;
+
+    if ( cinfo->global_state != DSTATE_SCANNING ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    if ( cinfo->output_scanline >= cinfo->output_height ) {
+        WARNMS( cinfo, JWRN_TOO_MUCH_DATA );
+        return 0;
+    }
+
+    /* Call progress monitor hook if present */
+    if ( cinfo->progress != NULL ) {
+        cinfo->progress->pass_counter = (long) cinfo->output_scanline;
+        cinfo->progress->pass_limit = (long) cinfo->output_height;
+        ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+    }
+
+    /* Process some data */
+    row_ctr = 0;
+    ( *cinfo->main->process_data )( cinfo, scanlines, &row_ctr, max_lines );
+    cinfo->output_scanline += row_ctr;
+    return row_ctr;
+}
+
+
+/*
+ * Alternate entry point to read raw data.
+ * Processes exactly one iMCU row per call, unless suspended.
+ */
+
+GLOBAL JDIMENSION
+jpeg_read_raw_data( j_decompress_ptr cinfo, JSAMPIMAGE data,
+                    JDIMENSION max_lines ) {
+    JDIMENSION lines_per_iMCU_row;
+
+    if ( cinfo->global_state != DSTATE_RAW_OK ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    if ( cinfo->output_scanline >= cinfo->output_height ) {
+        WARNMS( cinfo, JWRN_TOO_MUCH_DATA );
+        return 0;
+    }
+
+    /* Call progress monitor hook if present */
+    if ( cinfo->progress != NULL ) {
+        cinfo->progress->pass_counter = (long) cinfo->output_scanline;
+        cinfo->progress->pass_limit = (long) cinfo->output_height;
+        ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+    }
+
+    /* Verify that at least one iMCU row can be returned. */
+    lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size;
+    if ( max_lines < lines_per_iMCU_row ) {
+        ERREXIT( cinfo, JERR_BUFFER_SIZE );
+    }
+
+    /* Decompress directly into user's buffer. */
+    if ( !( *cinfo->coef->decompress_data )( cinfo, data ) ) {
+        return 0;
+    }                   /* suspension forced, can do nothing more */
+
+    /* OK, we processed one iMCU row. */
+    cinfo->output_scanline += lines_per_iMCU_row;
+    return lines_per_iMCU_row;
+}
+
+
+/* Additional entry points for buffered-image mode. */
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+
+/*
+ * Initialize for an output pass in buffered-image mode.
+ */
+
+GLOBAL boolean
+jpeg_start_output( j_decompress_ptr cinfo, int scan_number ) {
+    if ( ( cinfo->global_state != DSTATE_BUFIMAGE ) &&
+        ( cinfo->global_state != DSTATE_PRESCAN ) ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Limit scan number to valid range */
+    if ( scan_number <= 0 ) {
+        scan_number = 1;
+    }
+    if ( ( cinfo->inputctl->eoi_reached ) &&
+        ( scan_number > cinfo->input_scan_number ) ) {
+        scan_number = cinfo->input_scan_number;
+    }
+    cinfo->output_scan_number = scan_number;
+    /* Perform any dummy output passes, and set up for the real pass */
+    return output_pass_setup( cinfo );
+}
+
+
+/*
+ * Finish up after an output pass in buffered-image mode.
+ *
+ * Returns FALSE if suspended.  The return value need be inspected only if
+ * a suspending data source is used.
+ */
+
+GLOBAL boolean
+jpeg_finish_output( j_decompress_ptr cinfo ) {
+    if ( ( ( cinfo->global_state == DSTATE_SCANNING ) ||
+          ( cinfo->global_state == DSTATE_RAW_OK ) && cinfo->buffered_image ) ) {
+        /* Terminate this pass. */
+        /* We do not require the whole pass to have been completed. */
+        ( *cinfo->master->finish_output_pass )( cinfo );
+        cinfo->global_state = DSTATE_BUFPOST;
+    } else if ( cinfo->global_state != DSTATE_BUFPOST ) {
+        /* BUFPOST = repeat call after a suspension, anything else is error */
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Read markers looking for SOS or EOI */
+    while ( cinfo->input_scan_number <= cinfo->output_scan_number &&
+            !cinfo->inputctl->eoi_reached ) {
+        if ( ( *cinfo->inputctl->consume_input )( cinfo ) == JPEG_SUSPENDED ) {
+            return FALSE;
+        }               /* Suspend, come back later */
+    }
+    cinfo->global_state = DSTATE_BUFIMAGE;
+    return TRUE;
+}
+
+#endif /* D_MULTISCAN_FILES_SUPPORTED */

neo/renderer/jpeg-6/jdatadst.cpp

@@ -0,0 +1,150 @@
+/*
+ * jdatadst.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains compression data destination routines for the case of
+ * emitting JPEG data to a file (or any stdio stream).  While these routines
+ * are sufficient for most applications, some will want to use a different
+ * destination manager.
+ * IMPORTANT: we assume that fwrite() will correctly transcribe an array of
+ * JOCTETs into 8-bit-wide elements on external storage.  If char is wider
+ * than 8 bits on your machine, you may need to do some tweaking.
+ */
+
+/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jerror.h"
+
+
+/* Expanded data destination object for stdio output */
+
+typedef struct {
+    struct jpeg_destination_mgr pub;/* public fields */
+
+    FILE *   outfile;   /* target stream */
+    JOCTET * buffer;    /* start of buffer */
+} my_destination_mgr;
+
+typedef my_destination_mgr * my_dest_ptr;
+
+#define OUTPUT_BUF_SIZE  4096   /* choose an efficiently fwrite'able size */
+
+
+/*
+ * Initialize destination --- called by jpeg_start_compress
+ * before any data is actually written.
+ */
+
+METHODDEF void
+init_destination( j_compress_ptr cinfo ) {
+    my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
+
+    /* Allocate the output buffer --- it will be released when done with image */
+    dest->buffer = (JOCTET *)
+                   ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                OUTPUT_BUF_SIZE * SIZEOF( JOCTET ) );
+
+    dest->pub.next_output_byte = dest->buffer;
+    dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
+}
+
+
+/*
+ * Empty the output buffer --- called whenever buffer fills up.
+ *
+ * In typical applications, this should write the entire output buffer
+ * (ignoring the current state of next_output_byte & free_in_buffer),
+ * reset the pointer & count to the start of the buffer, and return TRUE
+ * indicating that the buffer has been dumped.
+ *
+ * In applications that need to be able to suspend compression due to output
+ * overrun, a FALSE return indicates that the buffer cannot be emptied now.
+ * In this situation, the compressor will return to its caller (possibly with
+ * an indication that it has not accepted all the supplied scanlines).  The
+ * application should resume compression after it has made more room in the
+ * output buffer.  Note that there are substantial restrictions on the use of
+ * suspension --- see the documentation.
+ *
+ * When suspending, the compressor will back up to a convenient restart point
+ * (typically the start of the current MCU). next_output_byte & free_in_buffer
+ * indicate where the restart point will be if the current call returns FALSE.
+ * Data beyond this point will be regenerated after resumption, so do not
+ * write it out when emptying the buffer externally.
+ */
+
+METHODDEF boolean
+empty_output_buffer( j_compress_ptr cinfo ) {
+    my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
+
+    if ( JFWRITE( dest->outfile, dest->buffer, OUTPUT_BUF_SIZE ) !=
+         (size_t) OUTPUT_BUF_SIZE ) {
+        ERREXIT( cinfo, JERR_FILE_WRITE );
+    }
+
+    dest->pub.next_output_byte = dest->buffer;
+    dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
+
+    return TRUE;
+}
+
+
+/*
+ * Terminate destination --- called by jpeg_finish_compress
+ * after all data has been written.  Usually needs to flush buffer.
+ *
+ * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
+ * application must deal with any cleanup that should happen even
+ * for error exit.
+ */
+
+METHODDEF void
+term_destination( j_compress_ptr cinfo ) {
+    my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
+    size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
+
+    /* Write any data remaining in the buffer */
+    if ( datacount > 0 ) {
+        if ( JFWRITE( dest->outfile, dest->buffer, datacount ) != datacount ) {
+            ERREXIT( cinfo, JERR_FILE_WRITE );
+        }
+    }
+    fflush( dest->outfile );
+    /* Make sure we wrote the output file OK */
+    if ( ferror( dest->outfile ) ) {
+        ERREXIT( cinfo, JERR_FILE_WRITE );
+    }
+}
+
+
+/*
+ * Prepare for output to a stdio stream.
+ * The caller must have already opened the stream, and is responsible
+ * for closing it after finishing compression.
+ */
+
+GLOBAL void
+jpeg_stdio_dest( j_compress_ptr cinfo, FILE * outfile ) {
+    my_dest_ptr dest;
+
+    /* The destination object is made permanent so that multiple JPEG images
+     * can be written to the same file without re-executing jpeg_stdio_dest.
+     * This makes it dangerous to use this manager and a different destination
+     * manager serially with the same JPEG object, because their private object
+     * sizes may be different.  Caveat programmer.
+     */
+    if ( cinfo->dest == NULL ) {/* first time for this JPEG object? */
+        cinfo->dest = (struct jpeg_destination_mgr *)
+                      ( * cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
+                                                    SIZEOF( my_destination_mgr ) );
+    }
+
+    dest = (my_dest_ptr) cinfo->dest;
+    dest->pub.init_destination = init_destination;
+    dest->pub.empty_output_buffer = empty_output_buffer;
+    dest->pub.term_destination = term_destination;
+    dest->outfile = outfile;
+}

neo/renderer/jpeg-6/jdatasrc.cpp

@@ -0,0 +1,199 @@
+/*
+ * jdatasrc.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains decompression data source routines for the case of
+ * reading JPEG data from a file (or any stdio stream).  While these routines
+ * are sufficient for most applications, some will want to use a different
+ * source manager.
+ * IMPORTANT: we assume that fread() will correctly transcribe an array of
+ * JOCTETs from 8-bit-wide elements on external storage.  If char is wider
+ * than 8 bits on your machine, you may need to do some tweaking.
+ */
+
+
+/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jerror.h"
+
+
+/* Expanded data source object for stdio input */
+
+typedef struct {
+    struct jpeg_source_mgr pub; /* public fields */
+
+    unsigned char * infile;     /* source stream */
+    JOCTET *        buffer; /* start of buffer */
+    boolean         start_of_file; /* have we gotten any data yet? */
+} my_source_mgr;
+
+typedef my_source_mgr * my_src_ptr;
+
+#define INPUT_BUF_SIZE  4096    /* choose an efficiently fread'able size */
+
+
+/*
+ * Initialize source --- called by jpeg_read_header
+ * before any data is actually read.
+ */
+
+METHODDEF void
+init_source( j_decompress_ptr cinfo ) {
+    my_src_ptr src = (my_src_ptr) cinfo->src;
+
+    /* We reset the empty-input-file flag for each image,
+     * but we don't clear the input buffer.
+     * This is correct behavior for reading a series of images from one source.
+     */
+    src->start_of_file = TRUE;
+}
+
+
+/*
+ * Fill the input buffer --- called whenever buffer is emptied.
+ *
+ * In typical applications, this should read fresh data into the buffer
+ * (ignoring the current state of next_input_byte & bytes_in_buffer),
+ * reset the pointer & count to the start of the buffer, and return TRUE
+ * indicating that the buffer has been reloaded.  It is not necessary to
+ * fill the buffer entirely, only to obtain at least one more byte.
+ *
+ * There is no such thing as an EOF return.  If the end of the file has been
+ * reached, the routine has a choice of ERREXIT() or inserting fake data into
+ * the buffer.  In most cases, generating a warning message and inserting a
+ * fake EOI marker is the best course of action --- this will allow the
+ * decompressor to output however much of the image is there.  However,
+ * the resulting error message is misleading if the real problem is an empty
+ * input file, so we handle that case specially.
+ *
+ * In applications that need to be able to suspend compression due to input
+ * not being available yet, a FALSE return indicates that no more data can be
+ * obtained right now, but more may be forthcoming later.  In this situation,
+ * the decompressor will return to its caller (with an indication of the
+ * number of scanlines it has read, if any).  The application should resume
+ * decompression after it has loaded more data into the input buffer.  Note
+ * that there are substantial restrictions on the use of suspension --- see
+ * the documentation.
+ *
+ * When suspending, the decompressor will back up to a convenient restart point
+ * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
+ * indicate where the restart point will be if the current call returns FALSE.
+ * Data beyond this point must be rescanned after resumption, so move it to
+ * the front of the buffer rather than discarding it.
+ */
+
+METHODDEF boolean
+fill_input_buffer( j_decompress_ptr cinfo ) {
+    my_src_ptr src = (my_src_ptr) cinfo->src;
+
+    memcpy( src->buffer, src->infile, INPUT_BUF_SIZE );
+
+    src->infile += INPUT_BUF_SIZE;
+
+    src->pub.next_input_byte = src->buffer;
+    src->pub.bytes_in_buffer = INPUT_BUF_SIZE;
+    src->start_of_file = FALSE;
+
+    return TRUE;
+}
+
+
+/*
+ * Skip data --- used to skip over a potentially large amount of
+ * uninteresting data (such as an APPn marker).
+ *
+ * Writers of suspendable-input applications must note that skip_input_data
+ * is not granted the right to give a suspension return.  If the skip extends
+ * beyond the data currently in the buffer, the buffer can be marked empty so
+ * that the next read will cause a fill_input_buffer call that can suspend.
+ * Arranging for additional bytes to be discarded before reloading the input
+ * buffer is the application writer's problem.
+ */
+
+METHODDEF void
+skip_input_data( j_decompress_ptr cinfo, long num_bytes ) {
+    my_src_ptr src = (my_src_ptr) cinfo->src;
+
+    /* Just a dumb implementation for now.  Could use fseek() except
+     * it doesn't work on pipes.  Not clear that being smart is worth
+     * any trouble anyway --- large skips are infrequent.
+     */
+    if ( num_bytes > 0 ) {
+        while ( num_bytes > (long) src->pub.bytes_in_buffer ) {
+            num_bytes -= (long) src->pub.bytes_in_buffer;
+            (void) fill_input_buffer( cinfo );
+            /* note we assume that fill_input_buffer will never return FALSE,
+             * so suspension need not be handled.
+             */
+        }
+        src->pub.next_input_byte += (size_t) num_bytes;
+        src->pub.bytes_in_buffer -= (size_t) num_bytes;
+    }
+}
+
+
+/*
+ * An additional method that can be provided by data source modules is the
+ * resync_to_restart method for error recovery in the presence of RST markers.
+ * For the moment, this source module just uses the default resync method
+ * provided by the JPEG library.  That method assumes that no backtracking
+ * is possible.
+ */
+
+
+/*
+ * Terminate source --- called by jpeg_finish_decompress
+ * after all data has been read.  Often a no-op.
+ *
+ * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
+ * application must deal with any cleanup that should happen even
+ * for error exit.
+ */
+
+METHODDEF void
+term_source( j_decompress_ptr cinfo ) {
+    /* no work necessary here */
+}
+
+
+/*
+ * Prepare for input from a stdio stream.
+ * The caller must have already opened the stream, and is responsible
+ * for closing it after finishing decompression.
+ */
+
+GLOBAL void
+jpeg_stdio_src( j_decompress_ptr cinfo, unsigned char * infile ) {
+    my_src_ptr src;
+
+    /* The source object and input buffer are made permanent so that a series
+     * of JPEG images can be read from the same file by calling jpeg_stdio_src
+     * only before the first one.  (If we discarded the buffer at the end of
+     * one image, we'd likely lose the start of the next one.)
+     * This makes it unsafe to use this manager and a different source
+     * manager serially with the same JPEG object.  Caveat programmer.
+     */
+    if ( cinfo->src == NULL ) {/* first time for this JPEG object? */
+        cinfo->src = (struct jpeg_source_mgr *)
+                     ( * cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
+                                                   SIZEOF( my_source_mgr ) );
+        src = (my_src_ptr) cinfo->src;
+        src->buffer = (JOCTET *)
+                      ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
+                                                   INPUT_BUF_SIZE * SIZEOF( JOCTET ) );
+    }
+
+    src = (my_src_ptr) cinfo->src;
+    src->pub.init_source = init_source;
+    src->pub.fill_input_buffer = fill_input_buffer;
+    src->pub.skip_input_data = skip_input_data;
+    src->pub.resync_to_restart = jpeg_resync_to_restart;/* use default method */
+    src->pub.term_source = term_source;
+    src->infile = infile;
+    src->pub.bytes_in_buffer = 0;/* forces fill_input_buffer on first read */
+    src->pub.next_input_byte = NULL;/* until buffer loaded */
+}

neo/renderer/jpeg-6/jdcoefct.cpp

@@ -0,0 +1,750 @@
+/*
+ * jdcoefct.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the coefficient buffer controller for decompression.
+ * This controller is the top level of the JPEG decompressor proper.
+ * The coefficient buffer lies between entropy decoding and inverse-DCT steps.
+ *
+ * In buffered-image mode, this controller is the interface between
+ * input-oriented processing and output-oriented processing.
+ * Also, the input side (only) is used when reading a file for transcoding.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+/* Block smoothing is only applicable for progressive JPEG, so: */
+#ifndef D_PROGRESSIVE_SUPPORTED
+#undef BLOCK_SMOOTHING_SUPPORTED
+#endif
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_d_coef_controller pub;/* public fields */
+
+    /* These variables keep track of the current location of the input side. */
+    /* cinfo->input_iMCU_row is also used for this. */
+    JDIMENSION MCU_ctr;     /* counts MCUs processed in current row */
+    int        MCU_vert_offset; /* counts MCU rows within iMCU row */
+    int        MCU_rows_per_iMCU_row; /* number of such rows needed */
+
+    /* The output side's location is represented by cinfo->output_iMCU_row. */
+
+    /* In single-pass modes, it's sufficient to buffer just one MCU.
+     * We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
+     * and let the entropy decoder write into that workspace each time.
+     * (On 80x86, the workspace is FAR even though it's not really very big;
+     * this is to keep the module interfaces unchanged when a large coefficient
+     * buffer is necessary.)
+     * In multi-pass modes, this array points to the current MCU's blocks
+     * within the virtual arrays; it is used only by the input side.
+     */
+    JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+    /* In multi-pass modes, we need a virtual block array for each component. */
+    jvirt_barray_ptr whole_image[MAX_COMPONENTS];
+#endif
+
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+    /* When doing block smoothing, we latch coefficient Al values here */
+    int * coef_bits_latch;
+#define SAVED_COEFS  6      /* we save coef_bits[0..5] */
+#endif
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+/* Forward declarations */
+METHODDEF int decompress_onepass
+JPP( ( j_decompress_ptr cinfo, JSAMPIMAGE output_buf ) );
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+METHODDEF int decompress_data
+JPP( ( j_decompress_ptr cinfo, JSAMPIMAGE output_buf ) );
+#endif
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+LOCAL boolean smoothing_ok JPP( (j_decompress_ptr cinfo) );
+METHODDEF int decompress_smooth_data
+JPP( ( j_decompress_ptr cinfo, JSAMPIMAGE output_buf ) );
+#endif
+
+
+LOCAL void
+start_iMCU_row( j_decompress_ptr cinfo ) {
+/* Reset within-iMCU-row counters for a new row (input side) */
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+    /* In an interleaved scan, an MCU row is the same as an iMCU row.
+     * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+     * But at the bottom of the image, process only what's left.
+     */
+    if ( cinfo->comps_in_scan > 1 ) {
+        coef->MCU_rows_per_iMCU_row = 1;
+    } else {
+        if ( cinfo->input_iMCU_row < ( cinfo->total_iMCU_rows - 1 ) ) {
+            coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+        } else {
+            coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+        }
+    }
+
+    coef->MCU_ctr = 0;
+    coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for an input processing pass.
+ */
+
+METHODDEF void
+start_input_pass( j_decompress_ptr cinfo ) {
+    cinfo->input_iMCU_row = 0;
+    start_iMCU_row( cinfo );
+}
+
+
+/*
+ * Initialize for an output processing pass.
+ */
+
+METHODDEF void
+start_output_pass( j_decompress_ptr cinfo ) {
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+    /* If multipass, check to see whether to use block smoothing on this pass */
+    if ( coef->pub.coef_arrays != NULL ) {
+        if ( ( cinfo->do_block_smoothing ) && ( smoothing_ok( cinfo ) ) ) {
+            coef->pub.decompress_data = decompress_smooth_data;
+        } else {
+            coef->pub.decompress_data = decompress_data;
+        }
+    }
+#endif
+    cinfo->output_iMCU_row = 0;
+}
+
+
+/*
+ * Decompress and return some data in the single-pass case.
+ * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
+ * Input and output must run in lockstep since we have only a one-MCU buffer.
+ * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
+ *
+ * NB: output_buf contains a plane for each component in image.
+ * For single pass, this is the same as the components in the scan.
+ */
+
+METHODDEF int
+decompress_onepass( j_decompress_ptr cinfo, JSAMPIMAGE output_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION MCU_col_num; /* index of current MCU within row */
+    JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+    JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+    int blkn, ci, xindex, yindex, yoffset, useful_width;
+    JSAMPARRAY output_ptr;
+    JDIMENSION start_col, output_col;
+    jpeg_component_info * compptr;
+    inverse_DCT_method_ptr inverse_DCT;
+
+    /* Loop to process as much as one whole iMCU row */
+    for ( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+          yoffset++ ) {
+        for ( MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
+              MCU_col_num++ ) {
+            /* Try to fetch an MCU.  Entropy decoder expects buffer to be zeroed. */
+            jzero_far( (void FAR *) coef->MCU_buffer[0],
+                      (size_t) ( cinfo->blocks_in_MCU * SIZEOF( JBLOCK ) ) );
+            if ( !( *cinfo->entropy->decode_mcu )( cinfo, coef->MCU_buffer ) ) {
+                /* Suspension forced; update state counters and exit */
+                coef->MCU_vert_offset = yoffset;
+                coef->MCU_ctr = MCU_col_num;
+                return JPEG_SUSPENDED;
+            }
+            /* Determine where data should go in output_buf and do the IDCT thing.
+             * We skip dummy blocks at the right and bottom edges (but blkn gets
+             * incremented past them!).  Note the inner loop relies on having
+             * allocated the MCU_buffer[] blocks sequentially.
+             */
+            blkn = 0;   /* index of current DCT block within MCU */
+            for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+                compptr = cinfo->cur_comp_info[ci];
+                /* Don't bother to IDCT an uninteresting component. */
+                if ( !compptr->component_needed ) {
+                    blkn += compptr->MCU_blocks;
+                    continue;
+                }
+                inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
+                useful_width = ( MCU_col_num < last_MCU_col ) ? compptr->MCU_width
+                               : compptr->last_col_width;
+                output_ptr = output_buf[ci] + yoffset * compptr->DCT_scaled_size;
+                start_col = MCU_col_num * compptr->MCU_sample_width;
+                for ( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
+                    if ( ( cinfo->input_iMCU_row < last_iMCU_row ) ||
+                        ( yoffset + yindex < compptr->last_row_height ) ) {
+                        output_col = start_col;
+                        for ( xindex = 0; xindex < useful_width; xindex++ ) {
+                            ( *inverse_DCT )( cinfo, compptr,
+                                              (JCOEFPTR) coef->MCU_buffer[blkn + xindex],
+                                              output_ptr, output_col );
+                            output_col += compptr->DCT_scaled_size;
+                        }
+                    }
+                    blkn += compptr->MCU_width;
+                    output_ptr += compptr->DCT_scaled_size;
+                }
+            }
+        }
+        /* Completed an MCU row, but perhaps not an iMCU row */
+        coef->MCU_ctr = 0;
+    }
+    /* Completed the iMCU row, advance counters for next one */
+    cinfo->output_iMCU_row++;
+    if ( ++ ( cinfo->input_iMCU_row ) < cinfo->total_iMCU_rows ) {
+        start_iMCU_row( cinfo );
+        return JPEG_ROW_COMPLETED;
+    }
+    /* Completed the scan */
+    ( *cinfo->inputctl->finish_input_pass )( cinfo );
+    return JPEG_SCAN_COMPLETED;
+}
+
+
+/*
+ * Dummy consume-input routine for single-pass operation.
+ */
+
+METHODDEF int
+dummy_consume_data( j_decompress_ptr cinfo ) {
+    return JPEG_SUSPENDED;  /* Always indicate nothing was done */
+}
+
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+
+/*
+ * Consume input data and store it in the full-image coefficient buffer.
+ * We read as much as one fully interleaved MCU row ("iMCU" row) per call,
+ * ie, v_samp_factor block rows for each component in the scan.
+ * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
+ */
+
+METHODDEF int
+consume_data( j_decompress_ptr cinfo ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION MCU_col_num; /* index of current MCU within row */
+    int blkn, ci, xindex, yindex, yoffset;
+    JDIMENSION start_col;
+    JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+    JBLOCKROW buffer_ptr;
+    jpeg_component_info * compptr;
+
+    /* Align the virtual buffers for the components used in this scan. */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        buffer[ci] = ( *cinfo->mem->access_virt_barray )
+                     ( (j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+                      cinfo->input_iMCU_row * compptr->v_samp_factor,
+                      (JDIMENSION) compptr->v_samp_factor, TRUE );
+        /* Note: entropy decoder expects buffer to be zeroed,
+         * but this is handled automatically by the memory manager
+         * because we requested a pre-zeroed array.
+         */
+    }
+
+    /* Loop to process one whole iMCU row */
+    for ( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+          yoffset++ ) {
+        for ( MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
+              MCU_col_num++ ) {
+            /* Construct list of pointers to DCT blocks belonging to this MCU */
+            blkn = 0;   /* index of current DCT block within MCU */
+            for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+                compptr = cinfo->cur_comp_info[ci];
+                start_col = MCU_col_num * compptr->MCU_width;
+                for ( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
+                    buffer_ptr = buffer[ci][yindex + yoffset] + start_col;
+                    for ( xindex = 0; xindex < compptr->MCU_width; xindex++ ) {
+                        coef->MCU_buffer[blkn++] = buffer_ptr++;
+                    }
+                }
+            }
+            /* Try to fetch the MCU. */
+            if ( !( *cinfo->entropy->decode_mcu )( cinfo, coef->MCU_buffer ) ) {
+                /* Suspension forced; update state counters and exit */
+                coef->MCU_vert_offset = yoffset;
+                coef->MCU_ctr = MCU_col_num;
+                return JPEG_SUSPENDED;
+            }
+        }
+        /* Completed an MCU row, but perhaps not an iMCU row */
+        coef->MCU_ctr = 0;
+    }
+    /* Completed the iMCU row, advance counters for next one */
+    if ( ++ ( cinfo->input_iMCU_row ) < cinfo->total_iMCU_rows ) {
+        start_iMCU_row( cinfo );
+        return JPEG_ROW_COMPLETED;
+    }
+    /* Completed the scan */
+    ( *cinfo->inputctl->finish_input_pass )( cinfo );
+    return JPEG_SCAN_COMPLETED;
+}
+
+
+/*
+ * Decompress and return some data in the multi-pass case.
+ * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
+ * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
+ *
+ * NB: output_buf contains a plane for each component in image.
+ */
+
+METHODDEF int
+decompress_data( j_decompress_ptr cinfo, JSAMPIMAGE output_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+    JDIMENSION block_num;
+    int ci, block_row, block_rows;
+    JBLOCKARRAY buffer;
+    JBLOCKROW buffer_ptr;
+    JSAMPARRAY output_ptr;
+    JDIMENSION output_col;
+    jpeg_component_info * compptr;
+    inverse_DCT_method_ptr inverse_DCT;
+
+    /* Force some input to be done if we are getting ahead of the input. */
+    while ( cinfo->input_scan_number < cinfo->output_scan_number ||
+           ( cinfo->input_scan_number == cinfo->output_scan_number &&
+             cinfo->input_iMCU_row <= cinfo->output_iMCU_row ) ) {
+        if ( ( *cinfo->inputctl->consume_input )( cinfo ) == JPEG_SUSPENDED ) {
+            return JPEG_SUSPENDED;
+        }
+    }
+
+    /* OK, output from the virtual arrays. */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Don't bother to IDCT an uninteresting component. */
+        if ( !compptr->component_needed ) {
+            continue;
+        }
+        /* Align the virtual buffer for this component. */
+        buffer = ( *cinfo->mem->access_virt_barray )
+                 ( (j_common_ptr) cinfo, coef->whole_image[ci],
+                  cinfo->output_iMCU_row * compptr->v_samp_factor,
+                  (JDIMENSION) compptr->v_samp_factor, FALSE );
+        /* Count non-dummy DCT block rows in this iMCU row. */
+        if ( cinfo->output_iMCU_row < last_iMCU_row ) {
+            block_rows = compptr->v_samp_factor;
+        } else {
+            /* NB: can't use last_row_height here; it is input-side-dependent! */
+            block_rows = (int) ( compptr->height_in_blocks % compptr->v_samp_factor );
+            if ( block_rows == 0 ) {
+                block_rows = compptr->v_samp_factor;
+            }
+        }
+        inverse_DCT = cinfo->idct->inverse_DCT[ci];
+        output_ptr = output_buf[ci];
+        /* Loop over all DCT blocks to be processed. */
+        for ( block_row = 0; block_row < block_rows; block_row++ ) {
+            buffer_ptr = buffer[block_row];
+            output_col = 0;
+            for ( block_num = 0; block_num < compptr->width_in_blocks; block_num++ ) {
+                ( *inverse_DCT )( cinfo, compptr, (JCOEFPTR) buffer_ptr,
+                                  output_ptr, output_col );
+                buffer_ptr++;
+                output_col += compptr->DCT_scaled_size;
+            }
+            output_ptr += compptr->DCT_scaled_size;
+        }
+    }
+
+    if ( ++ ( cinfo->output_iMCU_row ) < cinfo->total_iMCU_rows ) {
+        return JPEG_ROW_COMPLETED;
+    }
+    return JPEG_SCAN_COMPLETED;
+}
+
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+
+
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+
+/*
+ * This code applies interblock smoothing as described by section K.8
+ * of the JPEG standard: the first 5 AC coefficients are estimated from
+ * the DC values of a DCT block and its 8 neighboring blocks.
+ * We apply smoothing only for progressive JPEG decoding, and only if
+ * the coefficients it can estimate are not yet known to full precision.
+ */
+
+/*
+ * Determine whether block smoothing is applicable and safe.
+ * We also latch the current states of the coef_bits[] entries for the
+ * AC coefficients; otherwise, if the input side of the decompressor
+ * advances into a new scan, we might think the coefficients are known
+ * more accurately than they really are.
+ */
+
+LOCAL boolean
+smoothing_ok( j_decompress_ptr cinfo ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    boolean smoothing_useful = FALSE;
+    int ci, coefi;
+    jpeg_component_info * compptr;
+    JQUANT_TBL * qtable;
+    int * coef_bits;
+    int * coef_bits_latch;
+
+    if ( ( !cinfo->progressive_mode ) || ( cinfo->coef_bits == NULL ) ) {
+        return FALSE;
+    }
+
+    /* Allocate latch area if not already done */
+    if ( coef->coef_bits_latch == NULL ) {
+        coef->coef_bits_latch = (int *)
+                                ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                             cinfo->num_components *
+                                                             ( SAVED_COEFS * SIZEOF( int ) ) );
+    }
+    coef_bits_latch = coef->coef_bits_latch;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* All components' quantization values must already be latched. */
+        if ( ( qtable = compptr->quant_table ) == NULL ) {
+            return FALSE;
+        }
+        /* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */
+        for ( coefi = 0; coefi <= 5; coefi++ ) {
+            if ( qtable->quantval[coefi] == 0 ) {
+                return FALSE;
+            }
+        }
+        /* DC values must be at least partly known for all components. */
+        coef_bits = cinfo->coef_bits[ci];
+        if ( coef_bits[0] < 0 ) {
+            return FALSE;
+        }
+        /* Block smoothing is helpful if some AC coefficients remain inaccurate. */
+        for ( coefi = 1; coefi <= 5; coefi++ ) {
+            coef_bits_latch[coefi] = coef_bits[coefi];
+            if ( coef_bits[coefi] != 0 ) {
+                smoothing_useful = TRUE;
+            }
+        }
+        coef_bits_latch += SAVED_COEFS;
+    }
+
+    return smoothing_useful;
+}
+
+
+/*
+ * Variant of decompress_data for use when doing block smoothing.
+ */
+
+METHODDEF int
+decompress_smooth_data( j_decompress_ptr cinfo, JSAMPIMAGE output_buf ) {
+    my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+    JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+    JDIMENSION block_num, last_block_column;
+    int ci, block_row, block_rows, access_rows;
+    JBLOCKARRAY buffer;
+    JBLOCKROW buffer_ptr, prev_block_row, next_block_row;
+    JSAMPARRAY output_ptr;
+    JDIMENSION output_col;
+    jpeg_component_info * compptr;
+    inverse_DCT_method_ptr inverse_DCT;
+    boolean first_row, last_row;
+    JBLOCK workspace;
+    int * coef_bits;
+    JQUANT_TBL * quanttbl;
+    INT32 Q00, Q01, Q02, Q10, Q11, Q20, num;
+    int DC1, DC2, DC3, DC4, DC5, DC6, DC7, DC8, DC9;
+    int Al, pred;
+
+    /* Force some input to be done if we are getting ahead of the input. */
+    while ( cinfo->input_scan_number <= cinfo->output_scan_number &&
+            !cinfo->inputctl->eoi_reached ) {
+        if ( cinfo->input_scan_number == cinfo->output_scan_number ) {
+            /* If input is working on current scan, we ordinarily want it to
+             * have completed the current row.  But if input scan is DC,
+             * we want it to keep one row ahead so that next block row's DC
+             * values are up to date.
+             */
+            JDIMENSION delta = ( cinfo->Ss == 0 ) ? 1 : 0;
+            if ( cinfo->input_iMCU_row > cinfo->output_iMCU_row + delta ) {
+                break;
+            }
+        }
+        if ( ( *cinfo->inputctl->consume_input )( cinfo ) == JPEG_SUSPENDED ) {
+            return JPEG_SUSPENDED;
+        }
+    }
+
+    /* OK, output from the virtual arrays. */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Don't bother to IDCT an uninteresting component. */
+        if ( !compptr->component_needed ) {
+            continue;
+        }
+        /* Count non-dummy DCT block rows in this iMCU row. */
+        if ( cinfo->output_iMCU_row < last_iMCU_row ) {
+            block_rows = compptr->v_samp_factor;
+            access_rows = block_rows * 2;/* this and next iMCU row */
+            last_row = FALSE;
+        } else {
+            /* NB: can't use last_row_height here; it is input-side-dependent! */
+            block_rows = (int) ( compptr->height_in_blocks % compptr->v_samp_factor );
+            if ( block_rows == 0 ) {
+                block_rows = compptr->v_samp_factor;
+            }
+            access_rows = block_rows;/* this iMCU row only */
+            last_row = TRUE;
+        }
+        /* Align the virtual buffer for this component. */
+        if ( cinfo->output_iMCU_row > 0 ) {
+            access_rows += compptr->v_samp_factor;/* prior iMCU row too */
+            buffer = ( *cinfo->mem->access_virt_barray )
+                     ( (j_common_ptr) cinfo, coef->whole_image[ci],
+                      ( cinfo->output_iMCU_row - 1 ) * compptr->v_samp_factor,
+                      (JDIMENSION) access_rows, FALSE );
+            buffer += compptr->v_samp_factor;/* point to current iMCU row */
+            first_row = FALSE;
+        } else {
+            buffer = ( *cinfo->mem->access_virt_barray )
+                     ( (j_common_ptr) cinfo, coef->whole_image[ci],
+                      (JDIMENSION) 0, (JDIMENSION) access_rows, FALSE );
+            first_row = TRUE;
+        }
+        /* Fetch component-dependent info */
+        coef_bits = coef->coef_bits_latch + ( ci * SAVED_COEFS );
+        quanttbl = compptr->quant_table;
+        Q00 = quanttbl->quantval[0];
+        Q01 = quanttbl->quantval[1];
+        Q10 = quanttbl->quantval[2];
+        Q20 = quanttbl->quantval[3];
+        Q11 = quanttbl->quantval[4];
+        Q02 = quanttbl->quantval[5];
+        inverse_DCT = cinfo->idct->inverse_DCT[ci];
+        output_ptr = output_buf[ci];
+        /* Loop over all DCT blocks to be processed. */
+        for ( block_row = 0; block_row < block_rows; block_row++ ) {
+            buffer_ptr = buffer[block_row];
+            if ( ( first_row ) && ( block_row == 0 ) ) {
+                prev_block_row = buffer_ptr;
+            } else {
+                prev_block_row = buffer[block_row - 1];
+            }
+            if ( ( last_row ) && ( block_row == block_rows - 1 ) ) {
+                next_block_row = buffer_ptr;
+            } else {
+                next_block_row = buffer[block_row + 1];
+            }
+            /* We fetch the surrounding DC values using a sliding-register approach.
+             * Initialize all nine here so as to do the right thing on narrow pics.
+             */
+            DC1 = DC2 = DC3 = (int) prev_block_row[0][0];
+            DC4 = DC5 = DC6 = (int) buffer_ptr[0][0];
+            DC7 = DC8 = DC9 = (int) next_block_row[0][0];
+            output_col = 0;
+            last_block_column = compptr->width_in_blocks - 1;
+            for ( block_num = 0; block_num <= last_block_column; block_num++ ) {
+                /* Fetch current DCT block into workspace so we can modify it. */
+                jcopy_block_row( buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1 );
+                /* Update DC values */
+                if ( block_num < last_block_column ) {
+                    DC3 = (int) prev_block_row[1][0];
+                    DC6 = (int) buffer_ptr[1][0];
+                    DC9 = (int) next_block_row[1][0];
+                }
+                /* Compute coefficient estimates per K.8.
+                 * An estimate is applied only if coefficient is still zero,
+                 * and is not known to be fully accurate.
+                 */
+                /* AC01 */
+                if ( ( ( Al = coef_bits[1] ) != 0 ) && ( workspace[1] == 0 ) ) {
+                    num = 36 * Q00 * ( DC4 - DC6 );
+                    if ( num >= 0 ) {
+                        pred = (int) ( ( ( Q01 << 7 ) + num ) / ( Q01 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                    } else {
+                        pred = (int) ( ( ( Q01 << 7 ) - num ) / ( Q01 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                        pred = -pred;
+                    }
+                    workspace[1] = (JCOEF) pred;
+                }
+                /* AC10 */
+                if ( ( ( Al = coef_bits[2] ) != 0 ) && ( workspace[8] == 0 ) ) {
+                    num = 36 * Q00 * ( DC2 - DC8 );
+                    if ( num >= 0 ) {
+                        pred = (int) ( ( ( Q10 << 7 ) + num ) / ( Q10 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                    } else {
+                        pred = (int) ( ( ( Q10 << 7 ) - num ) / ( Q10 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                        pred = -pred;
+                    }
+                    workspace[8] = (JCOEF) pred;
+                }
+                /* AC20 */
+                if ( ( ( Al = coef_bits[3] ) != 0 ) && ( workspace[16] == 0 ) ) {
+                    num = 9 * Q00 * ( DC2 + DC8 - 2 * DC5 );
+                    if ( num >= 0 ) {
+                        pred = (int) ( ( ( Q20 << 7 ) + num ) / ( Q20 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                    } else {
+                        pred = (int) ( ( ( Q20 << 7 ) - num ) / ( Q20 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                        pred = -pred;
+                    }
+                    workspace[16] = (JCOEF) pred;
+                }
+                /* AC11 */
+                if ( ( ( Al = coef_bits[4] ) != 0 ) && ( workspace[9] == 0 ) ) {
+                    num = 5 * Q00 * ( DC1 - DC3 - DC7 + DC9 );
+                    if ( num >= 0 ) {
+                        pred = (int) ( ( ( Q11 << 7 ) + num ) / ( Q11 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                    } else {
+                        pred = (int) ( ( ( Q11 << 7 ) - num ) / ( Q11 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                        pred = -pred;
+                    }
+                    workspace[9] = (JCOEF) pred;
+                }
+                /* AC02 */
+                if ( ( ( Al = coef_bits[5] ) != 0 ) && ( workspace[2] == 0 ) ) {
+                    num = 9 * Q00 * ( DC4 + DC6 - 2 * DC5 );
+                    if ( num >= 0 ) {
+                        pred = (int) ( ( ( Q02 << 7 ) + num ) / ( Q02 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                    } else {
+                        pred = (int) ( ( ( Q02 << 7 ) - num ) / ( Q02 << 8 ) );
+                        if ( ( Al > 0 ) && ( pred >= ( 1 << Al ) ) ) {
+                            pred = ( 1 << Al ) - 1;
+                        }
+                        pred = -pred;
+                    }
+                    workspace[2] = (JCOEF) pred;
+                }
+                /* OK, do the IDCT */
+                ( *inverse_DCT )( cinfo, compptr, (JCOEFPTR) workspace,
+                                  output_ptr, output_col );
+                /* Advance for next column */
+                DC1 = DC2;
+                DC2 = DC3;
+                DC4 = DC5;
+                DC5 = DC6;
+                DC7 = DC8;
+                DC8 = DC9;
+                buffer_ptr++, prev_block_row++, next_block_row++;
+                output_col += compptr->DCT_scaled_size;
+            }
+            output_ptr += compptr->DCT_scaled_size;
+        }
+    }
+
+    if ( ++ ( cinfo->output_iMCU_row ) < cinfo->total_iMCU_rows ) {
+        return JPEG_ROW_COMPLETED;
+    }
+    return JPEG_SCAN_COMPLETED;
+}
+
+#endif /* BLOCK_SMOOTHING_SUPPORTED */
+
+
+/*
+ * Initialize coefficient buffer controller.
+ */
+
+GLOBAL void
+jinit_d_coef_controller( j_decompress_ptr cinfo, boolean need_full_buffer ) {
+    my_coef_ptr coef;
+
+    coef = (my_coef_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_coef_controller ) );
+    cinfo->coef = (struct jpeg_d_coef_controller *) coef;
+    coef->pub.start_input_pass = start_input_pass;
+    coef->pub.start_output_pass = start_output_pass;
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+    coef->coef_bits_latch = NULL;
+#endif
+
+    /* Create the coefficient buffer. */
+    if ( need_full_buffer ) {
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+        /* Allocate a full-image virtual array for each component, */
+        /* padded to a multiple of samp_factor DCT blocks in each direction. */
+        /* Note we ask for a pre-zeroed array. */
+        int ci, access_rows;
+        jpeg_component_info * compptr;
+
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            access_rows = compptr->v_samp_factor;
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+            /* If block smoothing could be used, need a bigger window */
+            if ( cinfo->progressive_mode ) {
+                access_rows *= 3;
+            }
+#endif
+            coef->whole_image[ci] = ( *cinfo->mem->request_virt_barray )
+                                    ( (j_common_ptr) cinfo, JPOOL_IMAGE, TRUE,
+                                     (JDIMENSION) jround_up( (long) compptr->width_in_blocks,
+                                                            (long) compptr->h_samp_factor ),
+                                     (JDIMENSION) jround_up( (long) compptr->height_in_blocks,
+                                                            (long) compptr->v_samp_factor ),
+                                     (JDIMENSION) access_rows );
+        }
+        coef->pub.consume_data = consume_data;
+        coef->pub.decompress_data = decompress_data;
+        coef->pub.coef_arrays = coef->whole_image;/* link to virtual arrays */
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+    } else {
+        /* We only need a single-MCU buffer. */
+        JBLOCKROW buffer;
+        int i;
+
+        buffer = (JBLOCKROW)
+                 ( *cinfo->mem->alloc_large )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                              D_MAX_BLOCKS_IN_MCU * SIZEOF( JBLOCK ) );
+        for ( i = 0; i < D_MAX_BLOCKS_IN_MCU; i++ ) {
+            coef->MCU_buffer[i] = buffer + i;
+        }
+        coef->pub.consume_data = dummy_consume_data;
+        coef->pub.decompress_data = decompress_onepass;
+        coef->pub.coef_arrays = NULL;/* flag for no virtual arrays */
+    }
+}

neo/renderer/jpeg-6/jdcolor.cpp

@@ -0,0 +1,371 @@
+/*
+ * jdcolor.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains output colorspace conversion routines.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private subobject */
+
+typedef struct {
+    struct jpeg_color_deconverter pub;/* public fields */
+
+    /* Private state for YCC->RGB conversion */
+    int *   Cr_r_tab;   /* => table for Cr to R conversion */
+    int *   Cb_b_tab;   /* => table for Cb to B conversion */
+    INT32 * Cr_g_tab;   /* => table for Cr to G conversion */
+    INT32 * Cb_g_tab;   /* => table for Cb to G conversion */
+} my_color_deconverter;
+
+typedef my_color_deconverter * my_cconvert_ptr;
+
+
+/**************** YCbCr -> RGB conversion: most common case **************/
+
+/*
+ * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
+ * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
+ * The conversion equations to be implemented are therefore
+ *	R = Y                + 1.40200 * Cr
+ *	G = Y - 0.34414 * Cb - 0.71414 * Cr
+ *	B = Y + 1.77200 * Cb
+ * where Cb and Cr represent the incoming values less CENTERJSAMPLE.
+ * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
+ *
+ * To avoid floating-point arithmetic, we represent the fractional constants
+ * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
+ * the products by 2^16, with appropriate rounding, to get the correct answer.
+ * Notice that Y, being an integral input, does not contribute any fraction
+ * so it need not participate in the rounding.
+ *
+ * For even more speed, we avoid doing any multiplications in the inner loop
+ * by precalculating the constants times Cb and Cr for all possible values.
+ * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
+ * for 12-bit samples it is still acceptable.  It's not very reasonable for
+ * 16-bit samples, but if you want lossless storage you shouldn't be changing
+ * colorspace anyway.
+ * The Cr=>R and Cb=>B values can be rounded to integers in advance; the
+ * values for the G calculation are left scaled up, since we must add them
+ * together before rounding.
+ */
+
+#define SCALEBITS   16  /* speediest right-shift on some machines */
+#define ONE_HALF    ( (INT32) 1 << ( SCALEBITS - 1 ) )
+#define FIX( x )      ( (INT32) ( ( x ) * ( 1L << SCALEBITS ) + 0.5 ) )
+
+
+/*
+ * Initialize tables for YCC->RGB colorspace conversion.
+ */
+
+LOCAL void
+build_ycc_rgb_table( j_decompress_ptr cinfo ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    int i;
+    INT32 x;
+    SHIFT_TEMPS
+
+    cconvert->Cr_r_tab = (int *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( int ) );
+    cconvert->Cb_b_tab = (int *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( int ) );
+    cconvert->Cr_g_tab = (INT32 *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( INT32 ) );
+    cconvert->Cb_g_tab = (INT32 *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( INT32 ) );
+
+    for ( i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++ ) {
+        /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
+        /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
+        /* Cr=>R value is nearest int to 1.40200 * x */
+        cconvert->Cr_r_tab[i] = (int)
+                                RIGHT_SHIFT( FIX( 1.40200 ) * x + ONE_HALF, SCALEBITS );
+        /* Cb=>B value is nearest int to 1.77200 * x */
+        cconvert->Cb_b_tab[i] = (int)
+                                RIGHT_SHIFT( FIX( 1.77200 ) * x + ONE_HALF, SCALEBITS );
+        /* Cr=>G value is scaled-up -0.71414 * x */
+        cconvert->Cr_g_tab[i] = ( -FIX( 0.71414 ) ) * x;
+        /* Cb=>G value is scaled-up -0.34414 * x */
+        /* We also add in ONE_HALF so that need not do it in inner loop */
+        cconvert->Cb_g_tab[i] = ( -FIX( 0.34414 ) ) * x + ONE_HALF;
+    }
+}
+
+
+/*
+ * Convert some rows of samples to the output colorspace.
+ *
+ * Note that we change from noninterleaved, one-plane-per-component format
+ * to interleaved-pixel format.  The output buffer is therefore three times
+ * as wide as the input buffer.
+ * A starting row offset is provided only for the input buffer.  The caller
+ * can easily adjust the passed output_buf value to accommodate any row
+ * offset required on that side.
+ */
+
+METHODDEF void
+ycc_rgb_convert( j_decompress_ptr cinfo,
+                 JSAMPIMAGE input_buf, JDIMENSION input_row,
+                 JSAMPARRAY output_buf, int num_rows ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    register int y, cb, cr;
+    register JSAMPROW outptr;
+    register JSAMPROW inptr0, inptr1, inptr2;
+    register JDIMENSION col;
+    JDIMENSION num_cols = cinfo->output_width;
+    /* copy these pointers into registers if possible */
+    register JSAMPLE * range_limit = cinfo->sample_range_limit;
+    register int * Crrtab = cconvert->Cr_r_tab;
+    register int * Cbbtab = cconvert->Cb_b_tab;
+    register INT32 * Crgtab = cconvert->Cr_g_tab;
+    register INT32 * Cbgtab = cconvert->Cb_g_tab;
+    SHIFT_TEMPS
+
+    while ( --num_rows >= 0 ) {
+        inptr0 = input_buf[0][input_row];
+        inptr1 = input_buf[1][input_row];
+        inptr2 = input_buf[2][input_row];
+        input_row++;
+        outptr = *output_buf++;
+        for ( col = 0; col < num_cols; col++ ) {
+            y  = GETJSAMPLE( inptr0[col] );
+            cb = GETJSAMPLE( inptr1[col] );
+            cr = GETJSAMPLE( inptr2[col] );
+            /* Range-limiting is essential due to noise introduced by DCT losses. */
+            outptr[RGB_RED] =   range_limit[y + Crrtab[cr]];
+            outptr[RGB_GREEN] = range_limit[y +
+                                            ( (int) RIGHT_SHIFT( Cbgtab[cb] + Crgtab[cr],
+                                                                 SCALEBITS ) )];
+            outptr[RGB_BLUE] =  range_limit[y + Cbbtab[cb]];
+            outptr += RGB_PIXELSIZE;
+        }
+    }
+}
+
+
+/**************** Cases other than YCbCr -> RGB **************/
+
+
+/*
+ * Color conversion for no colorspace change: just copy the data,
+ * converting from separate-planes to interleaved representation.
+ */
+
+METHODDEF void
+null_convert( j_decompress_ptr cinfo,
+              JSAMPIMAGE input_buf, JDIMENSION input_row,
+              JSAMPARRAY output_buf, int num_rows ) {
+    register JSAMPROW inptr, outptr;
+    register JDIMENSION count;
+    register int num_components = cinfo->num_components;
+    JDIMENSION num_cols = cinfo->output_width;
+    int ci;
+
+    while ( --num_rows >= 0 ) {
+        for ( ci = 0; ci < num_components; ci++ ) {
+            inptr = input_buf[ci][input_row];
+            outptr = output_buf[0] + ci;
+            for ( count = num_cols; count > 0; count-- ) {
+                *outptr = *inptr++;/* needn't bother with GETJSAMPLE() here */
+                outptr += num_components;
+            }
+        }
+        input_row++;
+        output_buf++;
+    }
+}
+
+
+/*
+ * Color conversion for grayscale: just copy the data.
+ * This also works for YCbCr -> grayscale conversion, in which
+ * we just copy the Y (luminance) component and ignore chrominance.
+ */
+
+METHODDEF void
+grayscale_convert( j_decompress_ptr cinfo,
+                   JSAMPIMAGE input_buf, JDIMENSION input_row,
+                   JSAMPARRAY output_buf, int num_rows ) {
+    jcopy_sample_rows( input_buf[0], (int) input_row, output_buf, 0,
+                       num_rows, cinfo->output_width );
+}
+
+
+/*
+ * Adobe-style YCCK->CMYK conversion.
+ * We convert YCbCr to R=1-C, G=1-M, and B=1-Y using the same
+ * conversion as above, while passing K (black) unchanged.
+ * We assume build_ycc_rgb_table has been called.
+ */
+
+METHODDEF void
+ycck_cmyk_convert( j_decompress_ptr cinfo,
+                   JSAMPIMAGE input_buf, JDIMENSION input_row,
+                   JSAMPARRAY output_buf, int num_rows ) {
+    my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+    register int y, cb, cr;
+    register JSAMPROW outptr;
+    register JSAMPROW inptr0, inptr1, inptr2, inptr3;
+    register JDIMENSION col;
+    JDIMENSION num_cols = cinfo->output_width;
+    /* copy these pointers into registers if possible */
+    register JSAMPLE * range_limit = cinfo->sample_range_limit;
+    register int * Crrtab = cconvert->Cr_r_tab;
+    register int * Cbbtab = cconvert->Cb_b_tab;
+    register INT32 * Crgtab = cconvert->Cr_g_tab;
+    register INT32 * Cbgtab = cconvert->Cb_g_tab;
+    SHIFT_TEMPS
+
+    while ( --num_rows >= 0 ) {
+        inptr0 = input_buf[0][input_row];
+        inptr1 = input_buf[1][input_row];
+        inptr2 = input_buf[2][input_row];
+        inptr3 = input_buf[3][input_row];
+        input_row++;
+        outptr = *output_buf++;
+        for ( col = 0; col < num_cols; col++ ) {
+            y  = GETJSAMPLE( inptr0[col] );
+            cb = GETJSAMPLE( inptr1[col] );
+            cr = GETJSAMPLE( inptr2[col] );
+            /* Range-limiting is essential due to noise introduced by DCT losses. */
+            outptr[0] = range_limit[MAXJSAMPLE - ( y + Crrtab[cr] )];/* red */
+            outptr[1] = range_limit[MAXJSAMPLE - ( y +  /* green */
+                                                  ( (int) RIGHT_SHIFT( Cbgtab[cb] + Crgtab[cr],
+                                                                       SCALEBITS ) ) )];
+            outptr[2] = range_limit[MAXJSAMPLE - ( y + Cbbtab[cb] )];/* blue */
+            /* K passes through unchanged */
+            outptr[3] = inptr3[col];/* don't need GETJSAMPLE here */
+            outptr += 4;
+        }
+    }
+}
+
+
+/*
+ * Empty method for start_pass.
+ */
+
+METHODDEF void
+start_pass_dcolor( j_decompress_ptr cinfo ) {
+    /* no work needed */
+}
+
+
+/*
+ * Module initialization routine for output colorspace conversion.
+ */
+
+GLOBAL void
+jinit_color_deconverter( j_decompress_ptr cinfo ) {
+    my_cconvert_ptr cconvert;
+    int ci;
+
+    cconvert = (my_cconvert_ptr)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                            SIZEOF( my_color_deconverter ) );
+    cinfo->cconvert = (struct jpeg_color_deconverter *) cconvert;
+    cconvert->pub.start_pass = start_pass_dcolor;
+
+    /* Make sure num_components agrees with jpeg_color_space */
+    switch ( cinfo->jpeg_color_space ) {
+        case JCS_GRAYSCALE:
+            if ( cinfo->num_components != 1 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            break;
+
+        case JCS_RGB:
+        case JCS_YCbCr:
+            if ( cinfo->num_components != 3 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            break;
+
+        case JCS_CMYK:
+        case JCS_YCCK:
+            if ( cinfo->num_components != 4 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            break;
+
+        default:    /* JCS_UNKNOWN can be anything */
+            if ( cinfo->num_components < 1 ) {
+                ERREXIT( cinfo, JERR_BAD_J_COLORSPACE );
+            }
+            break;
+    }
+
+    /* Set out_color_components and conversion method based on requested space.
+     * Also clear the component_needed flags for any unused components,
+     * so that earlier pipeline stages can avoid useless computation.
+     */
+
+    switch ( cinfo->out_color_space ) {
+        case JCS_GRAYSCALE:
+            cinfo->out_color_components = 1;
+            if ( ( cinfo->jpeg_color_space == JCS_GRAYSCALE ) ||
+                ( cinfo->jpeg_color_space == JCS_YCbCr ) ) {
+                cconvert->pub.color_convert = grayscale_convert;
+                /* For color->grayscale conversion, only the Y (0) component is needed */
+                for ( ci = 1; ci < cinfo->num_components; ci++ ) {
+                    cinfo->comp_info[ci].component_needed = FALSE;
+                }
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        case JCS_RGB:
+            cinfo->out_color_components = RGB_PIXELSIZE;
+            if ( cinfo->jpeg_color_space == JCS_YCbCr ) {
+                cconvert->pub.color_convert = ycc_rgb_convert;
+                build_ycc_rgb_table( cinfo );
+            } else if ( cinfo->jpeg_color_space == JCS_RGB && RGB_PIXELSIZE == 3 ) {
+                cconvert->pub.color_convert = null_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        case JCS_CMYK:
+            cinfo->out_color_components = 4;
+            if ( cinfo->jpeg_color_space == JCS_YCCK ) {
+                cconvert->pub.color_convert = ycck_cmyk_convert;
+                build_ycc_rgb_table( cinfo );
+            } else if ( cinfo->jpeg_color_space == JCS_CMYK ) {
+                cconvert->pub.color_convert = null_convert;
+            } else {
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+
+        default:
+            /* Permit null conversion to same output space */
+            if ( cinfo->out_color_space == cinfo->jpeg_color_space ) {
+                cinfo->out_color_components = cinfo->num_components;
+                cconvert->pub.color_convert = null_convert;
+            } else {/* unsupported non-null conversion */
+                ERREXIT( cinfo, JERR_CONVERSION_NOTIMPL );
+            }
+            break;
+    }
+
+    if ( cinfo->quantize_colors ) {
+        cinfo->output_components = 1;
+    }                             /* single colormapped output component */
+    else {
+        cinfo->output_components = cinfo->out_color_components;
+    }
+}

neo/renderer/jpeg-6/jdct.h

@@ -0,0 +1,176 @@
+/*
+ * jdct.h
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This include file contains common declarations for the forward and
+ * inverse DCT modules.  These declarations are private to the DCT managers
+ * (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
+ * The individual DCT algorithms are kept in separate files to ease 
+ * machine-dependent tuning (e.g., assembly coding).
+ */
+
+
+/*
+ * A forward DCT routine is given a pointer to a work area of type DCTELEM[];
+ * the DCT is to be performed in-place in that buffer.  Type DCTELEM is int
+ * for 8-bit samples, INT32 for 12-bit samples.  (NOTE: Floating-point DCT
+ * implementations use an array of type FAST_FLOAT, instead.)
+ * The DCT inputs are expected to be signed (range +-CENTERJSAMPLE).
+ * The DCT outputs are returned scaled up by a factor of 8; they therefore
+ * have a range of +-8K for 8-bit data, +-128K for 12-bit data.  This
+ * convention improves accuracy in integer implementations and saves some
+ * work in floating-point ones.
+ * Quantization of the output coefficients is done by jcdctmgr.c.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+typedef int DCTELEM;		/* 16 or 32 bits is fine */
+#else
+typedef INT32 DCTELEM;		/* must have 32 bits */
+#endif
+
+typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data));
+typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data));
+
+
+/*
+ * An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
+ * to an output sample array.  The routine must dequantize the input data as
+ * well as perform the IDCT; for dequantization, it uses the multiplier table
+ * pointed to by compptr->dct_table.  The output data is to be placed into the
+ * sample array starting at a specified column.  (Any row offset needed will
+ * be applied to the array pointer before it is passed to the IDCT code.)
+ * Note that the number of samples emitted by the IDCT routine is
+ * DCT_scaled_size * DCT_scaled_size.
+ */
+
+/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
+
+/*
+ * Each IDCT routine has its own ideas about the best dct_table element type.
+ */
+
+typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
+#if BITS_IN_JSAMPLE == 8
+typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
+#define IFAST_SCALE_BITS  2	/* fractional bits in scale factors */
+#else
+typedef INT32 IFAST_MULT_TYPE;	/* need 32 bits for scaled quantizers */
+#define IFAST_SCALE_BITS  13	/* fractional bits in scale factors */
+#endif
+typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
+
+
+/*
+ * Each IDCT routine is responsible for range-limiting its results and
+ * converting them to unsigned form (0..MAXJSAMPLE).  The raw outputs could
+ * be quite far out of range if the input data is corrupt, so a bulletproof
+ * range-limiting step is required.  We use a mask-and-table-lookup method
+ * to do the combined operations quickly.  See the comments with
+ * prepare_range_limit_table (in jdmaster.c) for more info.
+ */
+
+#define IDCT_range_limit(cinfo)  ((cinfo)->sample_range_limit + CENTERJSAMPLE)
+
+#define RANGE_MASK  (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */
+
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_fdct_islow		jFDislow
+#define jpeg_fdct_ifast		jFDifast
+#define jpeg_fdct_float		jFDfloat
+#define jpeg_idct_islow		jRDislow
+#define jpeg_idct_ifast		jRDifast
+#define jpeg_idct_float		jRDfloat
+#define jpeg_idct_4x4		jRD4x4
+#define jpeg_idct_2x2		jRD2x2
+#define jpeg_idct_1x1		jRD1x1
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+/* Extern declarations for the forward and inverse DCT routines. */
+
+EXTERN void jpeg_fdct_islow JPP((DCTELEM * data));
+EXTERN void jpeg_fdct_ifast JPP((DCTELEM * data));
+EXTERN void jpeg_fdct_float JPP((FAST_FLOAT * data));
+
+EXTERN void jpeg_idct_islow
+    JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
+	 JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
+EXTERN void jpeg_idct_ifast
+    JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
+	 JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
+EXTERN void jpeg_idct_float
+    JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
+	 JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
+EXTERN void jpeg_idct_4x4
+    JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
+	 JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
+EXTERN void jpeg_idct_2x2
+    JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
+	 JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
+EXTERN void jpeg_idct_1x1
+    JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
+	 JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
+
+
+/*
+ * Macros for handling fixed-point arithmetic; these are used by many
+ * but not all of the DCT/IDCT modules.
+ *
+ * All values are expected to be of type INT32.
+ * Fractional constants are scaled left by CONST_BITS bits.
+ * CONST_BITS is defined within each module using these macros,
+ * and may differ from one module to the next.
+ */
+
+#define ONE	((INT32) 1)
+#define CONST_SCALE (ONE << CONST_BITS)
+
+/* Convert a positive real constant to an integer scaled by CONST_SCALE.
+ * Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
+ * thus causing a lot of useless floating-point operations at run time.
+ */
+
+#define FIX(x)	((INT32) ((x) * CONST_SCALE + 0.5))
+
+/* Descale and correctly round an INT32 value that's scaled by N bits.
+ * We assume RIGHT_SHIFT rounds towards minus infinity, so adding
+ * the fudge factor is correct for either sign of X.
+ */
+
+#define DESCALE(x,n)  RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * This macro is used only when the two inputs will actually be no more than
+ * 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
+ * full 32x32 multiply.  This provides a useful speedup on many machines.
+ * Unfortunately there is no way to specify a 16x16->32 multiply portably
+ * in C, but some C compilers will do the right thing if you provide the
+ * correct combination of casts.
+ */
+
+#ifdef SHORTxSHORT_32		/* may work if 'int' is 32 bits */
+#define MULTIPLY16C16(var,const)  (((INT16) (var)) * ((INT16) (const)))
+#endif
+#ifdef SHORTxLCONST_32		/* known to work with Microsoft C 6.0 */
+#define MULTIPLY16C16(var,const)  (((INT16) (var)) * ((INT32) (const)))
+#endif
+
+#ifndef MULTIPLY16C16		/* default definition */
+#define MULTIPLY16C16(var,const)  ((var) * (const))
+#endif
+
+/* Same except both inputs are variables. */
+
+#ifdef SHORTxSHORT_32		/* may work if 'int' is 32 bits */
+#define MULTIPLY16V16(var1,var2)  (((INT16) (var1)) * ((INT16) (var2)))
+#endif
+
+#ifndef MULTIPLY16V16		/* default definition */
+#define MULTIPLY16V16(var1,var2)  ((var1) * (var2))
+#endif

neo/renderer/jpeg-6/jddctmgr.cpp

@@ -0,0 +1,270 @@
+/*
+ * jddctmgr.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the inverse-DCT management logic.
+ * This code selects a particular IDCT implementation to be used,
+ * and it performs related housekeeping chores.  No code in this file
+ * is executed per IDCT step, only during output pass setup.
+ *
+ * Note that the IDCT routines are responsible for performing coefficient
+ * dequantization as well as the IDCT proper.  This module sets up the
+ * dequantization multiplier table needed by the IDCT routine.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+
+/*
+ * The decompressor input side (jdinput.c) saves away the appropriate
+ * quantization table for each component at the start of the first scan
+ * involving that component.  (This is necessary in order to correctly
+ * decode files that reuse Q-table slots.)
+ * When we are ready to make an output pass, the saved Q-table is converted
+ * to a multiplier table that will actually be used by the IDCT routine.
+ * The multiplier table contents are IDCT-method-dependent.  To support
+ * application changes in IDCT method between scans, we can remake the
+ * multiplier tables if necessary.
+ * In buffered-image mode, the first output pass may occur before any data
+ * has been seen for some components, and thus before their Q-tables have
+ * been saved away.  To handle this case, multiplier tables are preset
+ * to zeroes; the result of the IDCT will be a neutral gray level.
+ */
+
+
+/* Private subobject for this module */
+
+typedef struct {
+    struct jpeg_inverse_dct pub;/* public fields */
+
+    /* This array contains the IDCT method code that each multiplier table
+     * is currently set up for, or -1 if it's not yet set up.
+     * The actual multiplier tables are pointed to by dct_table in the
+     * per-component comp_info structures.
+     */
+    int cur_method[MAX_COMPONENTS];
+} my_idct_controller;
+
+typedef my_idct_controller * my_idct_ptr;
+
+
+/* Allocated multiplier tables: big enough for any supported variant */
+
+typedef union {
+    ISLOW_MULT_TYPE islow_array[DCTSIZE2];
+#ifdef DCT_IFAST_SUPPORTED
+    IFAST_MULT_TYPE ifast_array[DCTSIZE2];
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+    FLOAT_MULT_TYPE float_array[DCTSIZE2];
+#endif
+} multiplier_table;
+
+
+/* The current scaled-IDCT routines require ISLOW-style multiplier tables,
+ * so be sure to compile that code if either ISLOW or SCALING is requested.
+ */
+#ifdef DCT_ISLOW_SUPPORTED
+#define PROVIDE_ISLOW_TABLES
+#else
+#ifdef IDCT_SCALING_SUPPORTED
+#define PROVIDE_ISLOW_TABLES
+#endif
+#endif
+
+
+/*
+ * Prepare for an output pass.
+ * Here we select the proper IDCT routine for each component and build
+ * a matching multiplier table.
+ */
+
+METHODDEF void
+start_pass( j_decompress_ptr cinfo ) {
+    my_idct_ptr idct = (my_idct_ptr) cinfo->idct;
+    int ci, i;
+    jpeg_component_info * compptr;
+    int method = 0;
+    inverse_DCT_method_ptr method_ptr = NULL;
+    JQUANT_TBL * qtbl;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Select the proper IDCT routine for this component's scaling */
+        switch ( compptr->DCT_scaled_size ) {
+#ifdef IDCT_SCALING_SUPPORTED
+            case 1:
+                method_ptr = jpeg_idct_1x1;
+                method = JDCT_ISLOW;/* jidctred uses islow-style table */
+                break;
+            case 2:
+                method_ptr = jpeg_idct_2x2;
+                method = JDCT_ISLOW;/* jidctred uses islow-style table */
+                break;
+            case 4:
+                method_ptr = jpeg_idct_4x4;
+                method = JDCT_ISLOW;/* jidctred uses islow-style table */
+                break;
+#endif
+            case DCTSIZE:
+                switch ( cinfo->dct_method ) {
+#ifdef DCT_ISLOW_SUPPORTED
+                    case JDCT_ISLOW:
+                        method_ptr = jpeg_idct_islow;
+                        method = JDCT_ISLOW;
+                        break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+                    case JDCT_IFAST:
+                        method_ptr = jpeg_idct_ifast;
+                        method = JDCT_IFAST;
+                        break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+                    case JDCT_FLOAT:
+                        method_ptr = jpeg_idct_float;
+                        method = JDCT_FLOAT;
+                        break;
+#endif
+                    default:
+                        ERREXIT( cinfo, JERR_NOT_COMPILED );
+                        break;
+                }
+                break;
+            default:
+                ERREXIT1( cinfo, JERR_BAD_DCTSIZE, compptr->DCT_scaled_size );
+                break;
+        }
+        idct->pub.inverse_DCT[ci] = method_ptr;
+        /* Create multiplier table from quant table.
+         * However, we can skip this if the component is uninteresting
+         * or if we already built the table.  Also, if no quant table
+         * has yet been saved for the component, we leave the
+         * multiplier table all-zero; we'll be reading zeroes from the
+         * coefficient controller's buffer anyway.
+         */
+        if ( ( !compptr->component_needed ) || ( idct->cur_method[ci] == method ) ) {
+            continue;
+        }
+        qtbl = compptr->quant_table;
+        if ( qtbl == NULL ) {/* happens if no data yet for component */
+            continue;
+        }
+        idct->cur_method[ci] = method;
+        switch ( method ) {
+#ifdef PROVIDE_ISLOW_TABLES
+            case JDCT_ISLOW:
+            {
+                /* For LL&M IDCT method, multipliers are equal to raw quantization
+                 * coefficients, but are stored in natural order as ints.
+                 */
+                ISLOW_MULT_TYPE * ismtbl = (ISLOW_MULT_TYPE *) compptr->dct_table;
+                for ( i = 0; i < DCTSIZE2; i++ ) {
+                    ismtbl[i] = (ISLOW_MULT_TYPE) qtbl->quantval[jpeg_zigzag_order[i]];
+                }
+            }
+                break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+            case JDCT_IFAST:
+            {
+                /* For AA&N IDCT method, multipliers are equal to quantization
+                 * coefficients scaled by scalefactor[row]*scalefactor[col], where
+                 *   scalefactor[0] = 1
+                 *   scalefactor[k] = cos(k*PI/16) * sqrt(2)    for k=1..7
+                 * For integer operation, the multiplier table is to be scaled by
+                 * IFAST_SCALE_BITS.  The multipliers are stored in natural order.
+                 */
+                IFAST_MULT_TYPE * ifmtbl = (IFAST_MULT_TYPE *) compptr->dct_table;
+#define CONST_BITS 14
+                static const INT16 aanscales[DCTSIZE2] = {
+                    /* precomputed values scaled up by 14 bits */
+                    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
+                    22725, 31521, 29692, 26722, 22725, 17855, 12299,  6270,
+                    21407, 29692, 27969, 25172, 21407, 16819, 11585,  5906,
+                    19266, 26722, 25172, 22654, 19266, 15137, 10426,  5315,
+                    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
+                    12873, 17855, 16819, 15137, 12873, 10114,  6967,  3552,
+                    8867, 12299, 11585, 10426,  8867,  6967,  4799,  2446,
+                    4520,  6270,  5906,  5315,  4520,  3552,  2446,  1247
+                };
+                SHIFT_TEMPS
+
+                for ( i = 0; i < DCTSIZE2; i++ ) {
+                    ifmtbl[i] = (IFAST_MULT_TYPE)
+                                DESCALE( MULTIPLY16V16( (INT32) qtbl->quantval[jpeg_zigzag_order[i]],
+                                                       (INT32) aanscales[i] ),
+                                         CONST_BITS - IFAST_SCALE_BITS );
+                }
+            }
+                break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+            case JDCT_FLOAT:
+            {
+                /* For float AA&N IDCT method, multipliers are equal to quantization
+                 * coefficients scaled by scalefactor[row]*scalefactor[col], where
+                 *   scalefactor[0] = 1
+                 *   scalefactor[k] = cos(k*PI/16) * sqrt(2)    for k=1..7
+                 * The multipliers are stored in natural order.
+                 */
+                FLOAT_MULT_TYPE * fmtbl = (FLOAT_MULT_TYPE *) compptr->dct_table;
+                int row, col;
+                static const double aanscalefactor[DCTSIZE] = {
+                    1.0, 1.387039845, 1.306562965, 1.175875602,
+                    1.0, 0.785694958, 0.541196100, 0.275899379
+                };
+
+                i = 0;
+                for ( row = 0; row < DCTSIZE; row++ ) {
+                    for ( col = 0; col < DCTSIZE; col++ ) {
+                        fmtbl[i] = (FLOAT_MULT_TYPE)
+                                   ( (double) qtbl->quantval[jpeg_zigzag_order[i]] *
+                                    aanscalefactor[row] * aanscalefactor[col] );
+                        i++;
+                    }
+                }
+            }
+                break;
+#endif
+            default:
+                ERREXIT( cinfo, JERR_NOT_COMPILED );
+                break;
+        }
+    }
+}
+
+
+/*
+ * Initialize IDCT manager.
+ */
+
+GLOBAL void
+jinit_inverse_dct( j_decompress_ptr cinfo ) {
+    my_idct_ptr idct;
+    int ci;
+    jpeg_component_info * compptr;
+
+    idct = (my_idct_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_idct_controller ) );
+    cinfo->idct = (struct jpeg_inverse_dct *) idct;
+    idct->pub.start_pass = start_pass;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Allocate and pre-zero a multiplier table for each component */
+        compptr->dct_table =
+            ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                         SIZEOF( multiplier_table ) );
+        MEMZERO( compptr->dct_table, SIZEOF( multiplier_table ) );
+        /* Mark multiplier table not yet set up for any method */
+        idct->cur_method[ci] = -1;
+    }
+}

neo/renderer/jpeg-6/jdhuff.cpp

@@ -0,0 +1,587 @@
+/*
+ * jdhuff.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy decoding routines.
+ *
+ * Much of the complexity here has to do with supporting input suspension.
+ * If the data source module demands suspension, we want to be able to back
+ * up to the start of the current MCU.  To do this, we copy state variables
+ * into local working storage, and update them back to the permanent
+ * storage only upon successful completion of an MCU.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdhuff.h"      /* Declarations shared with jdphuff.c */
+
+
+/*
+ * Expanded entropy decoder object for Huffman decoding.
+ *
+ * The savable_state subrecord contains fields that change within an MCU,
+ * but must not be updated permanently until we complete the MCU.
+ */
+
+typedef struct {
+    int last_dc_val[MAX_COMPS_IN_SCAN];/* last DC coef for each component */
+} savable_state;
+
+/* This macro is to work around compilers with missing or broken
+ * structure assignment.  You'll need to fix this code if you have
+ * such a compiler and you change MAX_COMPS_IN_SCAN.
+ */
+
+#ifndef NO_STRUCT_ASSIGN
+#define ASSIGN_STATE( dest, src )  ( ( dest ) = ( src ) )
+#else
+#if MAX_COMPS_IN_SCAN == 4
+#define ASSIGN_STATE( dest, src )  \
+    ( ( dest ).last_dc_val[0] = ( src ).last_dc_val[0], \
+     ( dest ).last_dc_val[1] = ( src ).last_dc_val[1], \
+     ( dest ).last_dc_val[2] = ( src ).last_dc_val[2], \
+     ( dest ).last_dc_val[3] = ( src ).last_dc_val[3] )
+#endif
+#endif
+
+
+typedef struct {
+    struct jpeg_entropy_decoder pub;/* public fields */
+
+    /* These fields are loaded into local variables at start of each MCU.
+     * In case of suspension, we exit WITHOUT updating them.
+     */
+    bitread_perm_state bitstate;/* Bit buffer at start of MCU */
+    savable_state      saved; /* Other state at start of MCU */
+
+    /* These fields are NOT loaded into local working state. */
+    unsigned int restarts_to_go;/* MCUs left in this restart interval */
+
+    /* Pointers to derived tables (these workspaces have image lifespan) */
+    d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
+    d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
+} huff_entropy_decoder;
+
+typedef huff_entropy_decoder * huff_entropy_ptr;
+
+
+/*
+ * Initialize for a Huffman-compressed scan.
+ */
+
+METHODDEF void
+start_pass_huff_decoder( j_decompress_ptr cinfo ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    int ci, dctbl, actbl;
+    jpeg_component_info * compptr;
+
+    /* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG.
+     * This ought to be an error condition, but we make it a warning because
+     * there are some baseline files out there with all zeroes in these bytes.
+     */
+    if ( ( cinfo->Ss != 0 ) || ( cinfo->Se != DCTSIZE2 - 1 ) ||
+        ( cinfo->Ah != 0 ) || ( cinfo->Al != 0 ) ) {
+        WARNMS( cinfo, JWRN_NOT_SEQUENTIAL );
+    }
+
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        dctbl = compptr->dc_tbl_no;
+        actbl = compptr->ac_tbl_no;
+        /* Make sure requested tables are present */
+        if ( ( dctbl < 0 ) || ( dctbl >= NUM_HUFF_TBLS ) ||
+            ( cinfo->dc_huff_tbl_ptrs[dctbl] == NULL ) ) {
+            ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, dctbl );
+        }
+        if ( ( actbl < 0 ) || ( actbl >= NUM_HUFF_TBLS ) ||
+            ( cinfo->ac_huff_tbl_ptrs[actbl] == NULL ) ) {
+            ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, actbl );
+        }
+        /* Compute derived values for Huffman tables */
+        /* We may do this more than once for a table, but it's not expensive */
+        jpeg_make_d_derived_tbl( cinfo, cinfo->dc_huff_tbl_ptrs[dctbl],
+                                 &entropy->dc_derived_tbls[dctbl] );
+        jpeg_make_d_derived_tbl( cinfo, cinfo->ac_huff_tbl_ptrs[actbl],
+                                 &entropy->ac_derived_tbls[actbl] );
+        /* Initialize DC predictions to 0 */
+        entropy->saved.last_dc_val[ci] = 0;
+    }
+
+    /* Initialize bitread state variables */
+    entropy->bitstate.bits_left = 0;
+    entropy->bitstate.get_buffer = 0;/* unnecessary, but keeps Purify quiet */
+    entropy->bitstate.printed_eod = FALSE;
+
+    /* Initialize restart counter */
+    entropy->restarts_to_go = cinfo->restart_interval;
+}
+
+
+/*
+ * Compute the derived values for a Huffman table.
+ * Note this is also used by jdphuff.c.
+ */
+
+GLOBAL void
+jpeg_make_d_derived_tbl( j_decompress_ptr cinfo, JHUFF_TBL * htbl,
+                         d_derived_tbl ** pdtbl ) {
+    d_derived_tbl * dtbl;
+    int p, i, l, si;
+    int lookbits, ctr;
+    char huffsize[257];
+    unsigned int huffcode[257];
+    unsigned int code;
+
+    /* Allocate a workspace if we haven't already done so. */
+    if ( *pdtbl == NULL ) {
+        *pdtbl = (d_derived_tbl *)
+                 ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                              SIZEOF( d_derived_tbl ) );
+    }
+    dtbl = *pdtbl;
+    dtbl->pub = htbl;   /* fill in back link */
+
+    /* Figure C.1: make table of Huffman code length for each symbol */
+    /* Note that this is in code-length order. */
+
+    p = 0;
+    for ( l = 1; l <= 16; l++ ) {
+        for ( i = 1; i <= (int) htbl->bits[l]; i++ ) {
+            huffsize[p++] = (char) l;
+        }
+    }
+    huffsize[p] = 0;
+
+    /* Figure C.2: generate the codes themselves */
+    /* Note that this is in code-length order. */
+
+    code = 0;
+    si = huffsize[0];
+    p = 0;
+    while ( huffsize[p] ) {
+        while ( ( (int) huffsize[p] ) == si ) {
+            huffcode[p++] = code;
+            code++;
+        }
+        code <<= 1;
+        si++;
+    }
+
+    /* Figure F.15: generate decoding tables for bit-sequential decoding */
+
+    p = 0;
+    for ( l = 1; l <= 16; l++ ) {
+        if ( htbl->bits[l] ) {
+            dtbl->valptr[l] = p;/* huffval[] index of 1st symbol of code length l */
+            dtbl->mincode[l] = huffcode[p];/* minimum code of length l */
+            p += htbl->bits[l];
+            dtbl->maxcode[l] = huffcode[p - 1];/* maximum code of length l */
+        } else {
+            dtbl->maxcode[l] = -1;/* -1 if no codes of this length */
+        }
+    }
+    dtbl->maxcode[17] = 0xFFFFFL;/* ensures jpeg_huff_decode terminates */
+
+    /* Compute lookahead tables to speed up decoding.
+     * First we set all the table entries to 0, indicating "too long";
+     * then we iterate through the Huffman codes that are short enough and
+     * fill in all the entries that correspond to bit sequences starting
+     * with that code.
+     */
+
+    MEMZERO( dtbl->look_nbits, SIZEOF( dtbl->look_nbits ) );
+
+    p = 0;
+    for ( l = 1; l <= HUFF_LOOKAHEAD; l++ ) {
+        for ( i = 1; i <= (int) htbl->bits[l]; i++, p++ ) {
+            /* l = current code's length, p = its index in huffcode[] & huffval[]. */
+            /* Generate left-justified code followed by all possible bit sequences */
+            lookbits = huffcode[p] << ( HUFF_LOOKAHEAD - l );
+            for ( ctr = 1 << ( HUFF_LOOKAHEAD - l ); ctr > 0; ctr-- ) {
+                dtbl->look_nbits[lookbits] = l;
+                dtbl->look_sym[lookbits] = htbl->huffval[p];
+                lookbits++;
+            }
+        }
+    }
+}
+
+
+/*
+ * Out-of-line code for bit fetching (shared with jdphuff.c).
+ * See jdhuff.h for info about usage.
+ * Note: current values of get_buffer and bits_left are passed as parameters,
+ * but are returned in the corresponding fields of the state struct.
+ *
+ * On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width
+ * of get_buffer to be used.  (On machines with wider words, an even larger
+ * buffer could be used.)  However, on some machines 32-bit shifts are
+ * quite slow and take time proportional to the number of places shifted.
+ * (This is true with most PC compilers, for instance.)  In this case it may
+ * be a win to set MIN_GET_BITS to the minimum value of 15.  This reduces the
+ * average shift distance at the cost of more calls to jpeg_fill_bit_buffer.
+ */
+
+#ifdef SLOW_SHIFT_32
+#define MIN_GET_BITS  15    /* minimum allowable value */
+#else
+#define MIN_GET_BITS  ( BIT_BUF_SIZE - 7 )
+#endif
+
+
+GLOBAL boolean
+jpeg_fill_bit_buffer( bitread_working_state * state,
+                      register bit_buf_type get_buffer, register int bits_left,
+                      int nbits ) {
+/* Load up the bit buffer to a depth of at least nbits */
+/* Copy heavily used state fields into locals (hopefully registers) */
+    register const JOCTET * next_input_byte = state->next_input_byte;
+    register size_t bytes_in_buffer = state->bytes_in_buffer;
+    register int c;
+
+    /* Attempt to load at least MIN_GET_BITS bits into get_buffer. */
+    /* (It is assumed that no request will be for more than that many bits.) */
+
+    while ( bits_left < MIN_GET_BITS ) {
+        /* Attempt to read a byte */
+        if ( state->unread_marker != 0 ) {
+            goto no_more_data;
+        }                   /* can't advance past a marker */
+
+        if ( bytes_in_buffer == 0 ) {
+            if ( !( *state->cinfo->src->fill_input_buffer )( state->cinfo ) ) {
+                return FALSE;
+            }
+            next_input_byte = state->cinfo->src->next_input_byte;
+            bytes_in_buffer = state->cinfo->src->bytes_in_buffer;
+        }
+        bytes_in_buffer--;
+        c = GETJOCTET( *next_input_byte++ );
+
+        /* If it's 0xFF, check and discard stuffed zero byte */
+        if ( c == 0xFF ) {
+            do {
+                if ( bytes_in_buffer == 0 ) {
+                    if ( !( *state->cinfo->src->fill_input_buffer )( state->cinfo ) ) {
+                        return FALSE;
+                    }
+                    next_input_byte = state->cinfo->src->next_input_byte;
+                    bytes_in_buffer = state->cinfo->src->bytes_in_buffer;
+                }
+                bytes_in_buffer--;
+                c = GETJOCTET( *next_input_byte++ );
+            } while ( c == 0xFF );
+
+            if ( c == 0 ) {
+                /* Found FF/00, which represents an FF data byte */
+                c = 0xFF;
+            } else {
+                /* Oops, it's actually a marker indicating end of compressed data. */
+                /* Better put it back for use later */
+                state->unread_marker = c;
+
+no_more_data:
+                /* There should be enough bits still left in the data segment; */
+                /* if so, just break out of the outer while loop. */
+                if ( bits_left >= nbits ) {
+                    break;
+                }
+                /* Uh-oh.  Report corrupted data to user and stuff zeroes into
+                 * the data stream, so that we can produce some kind of image.
+                 * Note that this code will be repeated for each byte demanded
+                 * for the rest of the segment.  We use a nonvolatile flag to ensure
+                 * that only one warning message appears.
+                 */
+                if ( ! * ( state->printed_eod_ptr ) ) {
+                    WARNMS( state->cinfo, JWRN_HIT_MARKER );
+                    *( state->printed_eod_ptr ) = TRUE;
+                }
+                c = 0;/* insert a zero byte into bit buffer */
+            }
+        }
+
+        /* OK, load c into get_buffer */
+        get_buffer = ( get_buffer << 8 ) | c;
+        bits_left += 8;
+    }
+
+    /* Unload the local registers */
+    state->next_input_byte = next_input_byte;
+    state->bytes_in_buffer = bytes_in_buffer;
+    state->get_buffer = get_buffer;
+    state->bits_left = bits_left;
+
+    return TRUE;
+}
+
+
+/*
+ * Out-of-line code for Huffman code decoding.
+ * See jdhuff.h for info about usage.
+ */
+
+GLOBAL int
+jpeg_huff_decode( bitread_working_state * state,
+                  register bit_buf_type get_buffer, register int bits_left,
+                  d_derived_tbl * htbl, int min_bits ) {
+    register int l = min_bits;
+    register INT32 code;
+
+    /* HUFF_DECODE has determined that the code is at least min_bits */
+    /* bits long, so fetch that many bits in one swoop. */
+
+    CHECK_BIT_BUFFER( *state, l, return -1 );
+    code = GET_BITS( l );
+
+    /* Collect the rest of the Huffman code one bit at a time. */
+    /* This is per Figure F.16 in the JPEG spec. */
+
+    while ( code > htbl->maxcode[l] ) {
+        code <<= 1;
+
+        CHECK_BIT_BUFFER( *state, 1, return -1 );
+        code |= GET_BITS( 1 );
+        l++;
+    }
+
+    /* Unload the local registers */
+    state->get_buffer = get_buffer;
+    state->bits_left = bits_left;
+
+    /* With garbage input we may reach the sentinel value l = 17. */
+
+    if ( l > 16 ) {
+        WARNMS( state->cinfo, JWRN_HUFF_BAD_CODE );
+        return 0;       /* fake a zero as the safest result */
+    }
+
+    return htbl->pub->huffval[ htbl->valptr[l] +
+                               ( (int) ( code - htbl->mincode[l] ) ) ];
+}
+
+
+/*
+ * Figure F.12: extend sign bit.
+ * On some machines, a shift and add will be faster than a table lookup.
+ */
+
+#ifdef AVOID_TABLES
+
+#define HUFF_EXTEND( x, s )  ( ( x ) < ( 1 << ( ( s ) - 1 ) ) ? ( x ) + ( ( ( -1 ) << ( s ) ) + 1 ) : ( x ) )
+
+#else
+
+#define HUFF_EXTEND( x, s )  ( ( x ) < extend_test[s] ? ( x ) + extend_offset[s] : ( x ) )
+
+static const int extend_test[16] =   /* entry n is 2**(n-1) */
+{ 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
+  0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
+
+static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
+{ 0, ( ( -1 ) << 1 ) + 1, ( ( -1 ) << 2 ) + 1, ( ( -1 ) << 3 ) + 1, ( ( -1 ) << 4 ) + 1,
+  ( ( -1 ) << 5 ) + 1, ( ( -1 ) << 6 ) + 1, ( ( -1 ) << 7 ) + 1, ( ( -1 ) << 8 ) + 1,
+  ( ( -1 ) << 9 ) + 1, ( ( -1 ) << 10 ) + 1, ( ( -1 ) << 11 ) + 1, ( ( -1 ) << 12 ) + 1,
+  ( ( -1 ) << 13 ) + 1, ( ( -1 ) << 14 ) + 1, ( ( -1 ) << 15 ) + 1 };
+
+#endif /* AVOID_TABLES */
+
+
+/*
+ * Check for a restart marker & resynchronize decoder.
+ * Returns FALSE if must suspend.
+ */
+
+LOCAL boolean
+process_restart( j_decompress_ptr cinfo ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    int ci;
+
+    /* Throw away any unused bits remaining in bit buffer; */
+    /* include any full bytes in next_marker's count of discarded bytes */
+    cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
+    entropy->bitstate.bits_left = 0;
+
+    /* Advance past the RSTn marker */
+    if ( !( *cinfo->marker->read_restart_marker )( cinfo ) ) {
+        return FALSE;
+    }
+
+    /* Re-initialize DC predictions to 0 */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        entropy->saved.last_dc_val[ci] = 0;
+    }
+
+    /* Reset restart counter */
+    entropy->restarts_to_go = cinfo->restart_interval;
+
+    /* Next segment can get another out-of-data warning */
+    entropy->bitstate.printed_eod = FALSE;
+
+    return TRUE;
+}
+
+
+/*
+ * Decode and return one MCU's worth of Huffman-compressed coefficients.
+ * The coefficients are reordered from zigzag order into natural array order,
+ * but are not dequantized.
+ *
+ * The i'th block of the MCU is stored into the block pointed to by
+ * MCU_data[i].  WE ASSUME THIS AREA HAS BEEN ZEROED BY THE CALLER.
+ * (Wholesale zeroing is usually a little faster than retail...)
+ *
+ * Returns FALSE if data source requested suspension.  In that case no
+ * changes have been made to permanent state.  (Exception: some output
+ * coefficients may already have been assigned.  This is harmless for
+ * this module, since we'll just re-assign them on the next call.)
+ */
+
+METHODDEF boolean
+decode_mcu( j_decompress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+    register int s, k, r;
+    int blkn, ci;
+    JBLOCKROW block;
+    BITREAD_STATE_VARS;
+    savable_state state;
+    d_derived_tbl * dctbl;
+    d_derived_tbl * actbl;
+    jpeg_component_info * compptr;
+
+    /* Process restart marker if needed; may have to suspend */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            if ( !process_restart( cinfo ) ) {
+                return FALSE;
+            }
+        }
+    }
+
+    /* Load up working state */
+    BITREAD_LOAD_STATE( cinfo, entropy->bitstate );
+    ASSIGN_STATE( state, entropy->saved );
+
+    /* Outer loop handles each block in the MCU */
+
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        block = MCU_data[blkn];
+        ci = cinfo->MCU_membership[blkn];
+        compptr = cinfo->cur_comp_info[ci];
+        dctbl = entropy->dc_derived_tbls[compptr->dc_tbl_no];
+        actbl = entropy->ac_derived_tbls[compptr->ac_tbl_no];
+
+        /* Decode a single block's worth of coefficients */
+
+        /* Section F.2.2.1: decode the DC coefficient difference */
+        HUFF_DECODE( s, br_state, dctbl, return FALSE, label1 );
+        if ( s ) {
+            CHECK_BIT_BUFFER( br_state, s, return FALSE );
+
+            r = GET_BITS( s );
+            s = HUFF_EXTEND( r, s );
+        }
+
+        /* Shortcut if component's values are not interesting */
+        if ( !compptr->component_needed ) {
+            goto skip_ACs;
+        }
+
+        /* Convert DC difference to actual value, update last_dc_val */
+        s += state.last_dc_val[ci];
+        state.last_dc_val[ci] = s;
+        /* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */
+        ( *block )[0] = (JCOEF) s;
+
+        /* Do we need to decode the AC coefficients for this component? */
+        if ( compptr->DCT_scaled_size > 1 ) {
+
+            /* Section F.2.2.2: decode the AC coefficients */
+            /* Since zeroes are skipped, output area must be cleared beforehand */
+            for ( k = 1; k < DCTSIZE2; k++ ) {
+                HUFF_DECODE( s, br_state, actbl, return FALSE, label2 );
+
+                r = s >> 4;
+                s &= 15;
+
+                if ( s ) {
+                    k += r;
+
+                    CHECK_BIT_BUFFER( br_state, s, return FALSE );
+                    r = GET_BITS( s );
+                    s = HUFF_EXTEND( r, s );
+                    /* Output coefficient in natural (dezigzagged) order.
+                     * Note: the extra entries in jpeg_natural_order[] will save us
+                     * if k >= DCTSIZE2, which could happen if the data is corrupted.
+                     */
+                    ( *block )[jpeg_natural_order[k]] = (JCOEF) s;
+                } else {
+                    if ( r != 15 ) {
+                        break;
+                    }
+                    k += 15;
+                }
+            }
+
+        } else {
+skip_ACs:
+
+            /* Section F.2.2.2: decode the AC coefficients */
+            /* In this path we just discard the values */
+            for ( k = 1; k < DCTSIZE2; k++ ) {
+                HUFF_DECODE( s, br_state, actbl, return FALSE, label3 );
+
+                r = s >> 4;
+                s &= 15;
+
+                if ( s ) {
+                    k += r;
+
+                    CHECK_BIT_BUFFER( br_state, s, return FALSE );
+                    DROP_BITS( s );
+                } else {
+                    if ( r != 15 ) {
+                        break;
+                    }
+                    k += 15;
+                }
+            }
+
+        }
+    }
+
+    /* Completed MCU, so update state */
+    BITREAD_SAVE_STATE( cinfo, entropy->bitstate );
+    ASSIGN_STATE( entropy->saved, state );
+
+    /* Account for restart interval (no-op if not using restarts) */
+    entropy->restarts_to_go--;
+
+    return TRUE;
+}
+
+
+/*
+ * Module initialization routine for Huffman entropy decoding.
+ */
+
+GLOBAL void
+jinit_huff_decoder( j_decompress_ptr cinfo ) {
+    huff_entropy_ptr entropy;
+    int i;
+
+    entropy = (huff_entropy_ptr)
+              ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                           SIZEOF( huff_entropy_decoder ) );
+    cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
+    entropy->pub.start_pass = start_pass_huff_decoder;
+    entropy->pub.decode_mcu = decode_mcu;
+
+    /* Mark tables unallocated */
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
+    }
+}

neo/renderer/jpeg-6/jdhuff.h

@@ -0,0 +1,202 @@
+/*
+ * jdhuff.h
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains declarations for Huffman entropy decoding routines
+ * that are shared between the sequential decoder (jdhuff.c) and the
+ * progressive decoder (jdphuff.c).  No other modules need to see these.
+ */
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_make_d_derived_tbl	jMkDDerived
+#define jpeg_fill_bit_buffer	jFilBitBuf
+#define jpeg_huff_decode	jHufDecode
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/* Derived data constructed for each Huffman table */
+
+#define HUFF_LOOKAHEAD	8	/* # of bits of lookahead */
+
+typedef struct {
+  /* Basic tables: (element [0] of each array is unused) */
+  INT32 mincode[17];		/* smallest code of length k */
+  INT32 maxcode[18];		/* largest code of length k (-1 if none) */
+  /* (maxcode[17] is a sentinel to ensure jpeg_huff_decode terminates) */
+  int valptr[17];		/* huffval[] index of 1st symbol of length k */
+
+  /* Link to public Huffman table (needed only in jpeg_huff_decode) */
+  JHUFF_TBL *pub;
+
+  /* Lookahead tables: indexed by the next HUFF_LOOKAHEAD bits of
+   * the input data stream.  If the next Huffman code is no more
+   * than HUFF_LOOKAHEAD bits long, we can obtain its length and
+   * the corresponding symbol directly from these tables.
+   */
+  int look_nbits[1<<HUFF_LOOKAHEAD]; /* # bits, or 0 if too long */
+  UINT8 look_sym[1<<HUFF_LOOKAHEAD]; /* symbol, or unused */
+} d_derived_tbl;
+
+/* Expand a Huffman table definition into the derived format */
+EXTERN void jpeg_make_d_derived_tbl JPP((j_decompress_ptr cinfo,
+				JHUFF_TBL * htbl, d_derived_tbl ** pdtbl));
+
+
+/*
+ * Fetching the next N bits from the input stream is a time-critical operation
+ * for the Huffman decoders.  We implement it with a combination of inline
+ * macros and out-of-line subroutines.  Note that N (the number of bits
+ * demanded at one time) never exceeds 15 for JPEG use.
+ *
+ * We read source bytes into get_buffer and dole out bits as needed.
+ * If get_buffer already contains enough bits, they are fetched in-line
+ * by the macros CHECK_BIT_BUFFER and GET_BITS.  When there aren't enough
+ * bits, jpeg_fill_bit_buffer is called; it will attempt to fill get_buffer
+ * as full as possible (not just to the number of bits needed; this
+ * prefetching reduces the overhead cost of calling jpeg_fill_bit_buffer).
+ * Note that jpeg_fill_bit_buffer may return FALSE to indicate suspension.
+ * On TRUE return, jpeg_fill_bit_buffer guarantees that get_buffer contains
+ * at least the requested number of bits --- dummy zeroes are inserted if
+ * necessary.
+ */
+
+typedef INT32 bit_buf_type;	/* type of bit-extraction buffer */
+#define BIT_BUF_SIZE  32	/* size of buffer in bits */
+
+/* If long is > 32 bits on your machine, and shifting/masking longs is
+ * reasonably fast, making bit_buf_type be long and setting BIT_BUF_SIZE
+ * appropriately should be a win.  Unfortunately we can't do this with
+ * something like  #define BIT_BUF_SIZE (sizeof(bit_buf_type)*8)
+ * because not all machines measure sizeof in 8-bit bytes.
+ */
+
+typedef struct {		/* Bitreading state saved across MCUs */
+  bit_buf_type get_buffer;	/* current bit-extraction buffer */
+  int bits_left;		/* # of unused bits in it */
+  boolean printed_eod;		/* flag to suppress multiple warning msgs */
+} bitread_perm_state;
+
+typedef struct {		/* Bitreading working state within an MCU */
+  /* current data source state */
+  const JOCTET * next_input_byte; /* => next byte to read from source */
+  size_t bytes_in_buffer;	/* # of bytes remaining in source buffer */
+  int unread_marker;		/* nonzero if we have hit a marker */
+  /* bit input buffer --- note these values are kept in register variables,
+   * not in this struct, inside the inner loops.
+   */
+  bit_buf_type get_buffer;	/* current bit-extraction buffer */
+  int bits_left;		/* # of unused bits in it */
+  /* pointers needed by jpeg_fill_bit_buffer */
+  j_decompress_ptr cinfo;	/* back link to decompress master record */
+  boolean * printed_eod_ptr;	/* => flag in permanent state */
+} bitread_working_state;
+
+/* Macros to declare and load/save bitread local variables. */
+#define BITREAD_STATE_VARS  \
+	register bit_buf_type get_buffer;  \
+	register int bits_left;  \
+	bitread_working_state br_state
+
+#define BITREAD_LOAD_STATE(cinfop,permstate)  \
+	br_state.cinfo = cinfop; \
+	br_state.next_input_byte = cinfop->src->next_input_byte; \
+	br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \
+	br_state.unread_marker = cinfop->unread_marker; \
+	get_buffer = permstate.get_buffer; \
+	bits_left = permstate.bits_left; \
+	br_state.printed_eod_ptr = & permstate.printed_eod
+
+#define BITREAD_SAVE_STATE(cinfop,permstate)  \
+	cinfop->src->next_input_byte = br_state.next_input_byte; \
+	cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \
+	cinfop->unread_marker = br_state.unread_marker; \
+	permstate.get_buffer = get_buffer; \
+	permstate.bits_left = bits_left
+
+/*
+ * These macros provide the in-line portion of bit fetching.
+ * Use CHECK_BIT_BUFFER to ensure there are N bits in get_buffer
+ * before using GET_BITS, PEEK_BITS, or DROP_BITS.
+ * The variables get_buffer and bits_left are assumed to be locals,
+ * but the state struct might not be (jpeg_huff_decode needs this).
+ *	CHECK_BIT_BUFFER(state,n,action);
+ *		Ensure there are N bits in get_buffer; if suspend, take action.
+ *      val = GET_BITS(n);
+ *		Fetch next N bits.
+ *      val = PEEK_BITS(n);
+ *		Fetch next N bits without removing them from the buffer.
+ *	DROP_BITS(n);
+ *		Discard next N bits.
+ * The value N should be a simple variable, not an expression, because it
+ * is evaluated multiple times.
+ */
+
+#define CHECK_BIT_BUFFER(state,nbits,action) \
+	{ if (bits_left < (nbits)) {  \
+	    if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits))  \
+	      { action; }  \
+	    get_buffer = (state).get_buffer; bits_left = (state).bits_left; } }
+
+#define GET_BITS(nbits) \
+	(((int) (get_buffer >> (bits_left -= (nbits)))) & ((1<<(nbits))-1))
+
+#define PEEK_BITS(nbits) \
+	(((int) (get_buffer >> (bits_left -  (nbits)))) & ((1<<(nbits))-1))
+
+#define DROP_BITS(nbits) \
+	(bits_left -= (nbits))
+
+/* Load up the bit buffer to a depth of at least nbits */
+EXTERN boolean jpeg_fill_bit_buffer JPP((bitread_working_state * state,
+		register bit_buf_type get_buffer, register int bits_left,
+		int nbits));
+
+
+/*
+ * Code for extracting next Huffman-coded symbol from input bit stream.
+ * Again, this is time-critical and we make the main paths be macros.
+ *
+ * We use a lookahead table to process codes of up to HUFF_LOOKAHEAD bits
+ * without looping.  Usually, more than 95% of the Huffman codes will be 8
+ * or fewer bits long.  The few overlength codes are handled with a loop,
+ * which need not be inline code.
+ *
+ * Notes about the HUFF_DECODE macro:
+ * 1. Near the end of the data segment, we may fail to get enough bits
+ *    for a lookahead.  In that case, we do it the hard way.
+ * 2. If the lookahead table contains no entry, the next code must be
+ *    more than HUFF_LOOKAHEAD bits long.
+ * 3. jpeg_huff_decode returns -1 if forced to suspend.
+ */
+
+#define HUFF_DECODE(result,state,htbl,failaction,slowlabel) \
+{ register int nb, look; \
+  if (bits_left < HUFF_LOOKAHEAD) { \
+    if (! jpeg_fill_bit_buffer(&state,get_buffer,bits_left, 0)) {failaction;} \
+    get_buffer = state.get_buffer; bits_left = state.bits_left; \
+    if (bits_left < HUFF_LOOKAHEAD) { \
+      nb = 1; goto slowlabel; \
+    } \
+  } \
+  look = PEEK_BITS(HUFF_LOOKAHEAD); \
+  if ((nb = htbl->look_nbits[look]) != 0) { \
+    DROP_BITS(nb); \
+    result = htbl->look_sym[look]; \
+  } else { \
+    nb = HUFF_LOOKAHEAD+1; \
+slowlabel: \
+    if ((result=jpeg_huff_decode(&state,get_buffer,bits_left,htbl,nb)) < 0) \
+	{ failaction; } \
+    get_buffer = state.get_buffer; bits_left = state.bits_left; \
+  } \
+}
+
+/* Out-of-line case for Huffman code fetching */
+EXTERN int jpeg_huff_decode JPP((bitread_working_state * state,
+		register bit_buf_type get_buffer, register int bits_left,
+		d_derived_tbl * htbl, int min_bits));

neo/renderer/jpeg-6/jdinput.cpp

@@ -0,0 +1,392 @@
+/*
+ * jdinput.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains input control logic for the JPEG decompressor.
+ * These routines are concerned with controlling the decompressor's input
+ * processing (marker reading and coefficient decoding).  The actual input
+ * reading is done in jdmarker.c, jdhuff.c, and jdphuff.c.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private state */
+
+typedef struct {
+    struct jpeg_input_controller pub;/* public fields */
+
+    boolean inheaders;      /* TRUE until first SOS is reached */
+} my_input_controller;
+
+typedef my_input_controller * my_inputctl_ptr;
+
+
+/* Forward declarations */
+METHODDEF int consume_markers JPP( (j_decompress_ptr cinfo) );
+
+
+/*
+ * Routines to calculate various quantities related to the size of the image.
+ */
+
+LOCAL void
+initial_setup( j_decompress_ptr cinfo ) {
+/* Called once, when first SOS marker is reached */
+    int ci;
+    jpeg_component_info * compptr;
+
+    /* Make sure image isn't bigger than I can handle */
+    if ( ( (long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ) ||
+        ( (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION ) ) {
+        ERREXIT1( cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION );
+    }
+
+    /* For now, precision must match compiled-in value... */
+    if ( cinfo->data_precision != BITS_IN_JSAMPLE ) {
+        ERREXIT1( cinfo, JERR_BAD_PRECISION, cinfo->data_precision );
+    }
+
+    /* Check that number of components won't exceed internal array sizes */
+    if ( cinfo->num_components > MAX_COMPONENTS ) {
+        ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+                  MAX_COMPONENTS );
+    }
+
+    /* Compute maximum sampling factors; check factor validity */
+    cinfo->max_h_samp_factor = 1;
+    cinfo->max_v_samp_factor = 1;
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        if ( ( compptr->h_samp_factor <= 0 ) || ( compptr->h_samp_factor > MAX_SAMP_FACTOR ) ||
+            ( compptr->v_samp_factor <= 0 ) || ( compptr->v_samp_factor > MAX_SAMP_FACTOR ) ) {
+            ERREXIT( cinfo, JERR_BAD_SAMPLING );
+        }
+        cinfo->max_h_samp_factor = MAX( cinfo->max_h_samp_factor,
+                                        compptr->h_samp_factor );
+        cinfo->max_v_samp_factor = MAX( cinfo->max_v_samp_factor,
+                                        compptr->v_samp_factor );
+    }
+
+    /* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE.
+     * In the full decompressor, this will be overridden by jdmaster.c;
+     * but in the transcoder, jdmaster.c is not used, so we must do it here.
+     */
+    cinfo->min_DCT_scaled_size = DCTSIZE;
+
+    /* Compute dimensions of components */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        compptr->DCT_scaled_size = DCTSIZE;
+        /* Size in DCT blocks */
+        compptr->width_in_blocks = (JDIMENSION)
+                                   jdiv_round_up( (long) cinfo->image_width * (long) compptr->h_samp_factor,
+                                                 (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
+        compptr->height_in_blocks = (JDIMENSION)
+                                    jdiv_round_up( (long) cinfo->image_height * (long) compptr->v_samp_factor,
+                                                  (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+        /* downsampled_width and downsampled_height will also be overridden by
+         * jdmaster.c if we are doing full decompression.  The transcoder library
+         * doesn't use these values, but the calling application might.
+         */
+        /* Size in samples */
+        compptr->downsampled_width = (JDIMENSION)
+                                     jdiv_round_up( (long) cinfo->image_width * (long) compptr->h_samp_factor,
+                                                   (long) cinfo->max_h_samp_factor );
+        compptr->downsampled_height = (JDIMENSION)
+                                      jdiv_round_up( (long) cinfo->image_height * (long) compptr->v_samp_factor,
+                                                    (long) cinfo->max_v_samp_factor );
+        /* Mark component needed, until color conversion says otherwise */
+        compptr->component_needed = TRUE;
+        /* Mark no quantization table yet saved for component */
+        compptr->quant_table = NULL;
+    }
+
+    /* Compute number of fully interleaved MCU rows. */
+    cinfo->total_iMCU_rows = (JDIMENSION)
+                             jdiv_round_up( (long) cinfo->image_height,
+                                           (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+
+    /* Decide whether file contains multiple scans */
+    if ( ( cinfo->comps_in_scan < cinfo->num_components ) || ( cinfo->progressive_mode ) ) {
+        cinfo->inputctl->has_multiple_scans = TRUE;
+    } else {
+        cinfo->inputctl->has_multiple_scans = FALSE;
+    }
+}
+
+
+LOCAL void
+per_scan_setup( j_decompress_ptr cinfo ) {
+/* Do computations that are needed before processing a JPEG scan */
+/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */
+    int ci, mcublks, tmp;
+    jpeg_component_info * compptr;
+
+    if ( cinfo->comps_in_scan == 1 ) {
+
+        /* Noninterleaved (single-component) scan */
+        compptr = cinfo->cur_comp_info[0];
+
+        /* Overall image size in MCUs */
+        cinfo->MCUs_per_row = compptr->width_in_blocks;
+        cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
+
+        /* For noninterleaved scan, always one block per MCU */
+        compptr->MCU_width = 1;
+        compptr->MCU_height = 1;
+        compptr->MCU_blocks = 1;
+        compptr->MCU_sample_width = compptr->DCT_scaled_size;
+        compptr->last_col_width = 1;
+        /* For noninterleaved scans, it is convenient to define last_row_height
+         * as the number of block rows present in the last iMCU row.
+         */
+        tmp = (int) ( compptr->height_in_blocks % compptr->v_samp_factor );
+        if ( tmp == 0 ) {
+            tmp = compptr->v_samp_factor;
+        }
+        compptr->last_row_height = tmp;
+
+        /* Prepare array describing MCU composition */
+        cinfo->blocks_in_MCU = 1;
+        cinfo->MCU_membership[0] = 0;
+
+    } else {
+
+        /* Interleaved (multi-component) scan */
+        if ( ( cinfo->comps_in_scan <= 0 ) || ( cinfo->comps_in_scan > MAX_COMPS_IN_SCAN ) ) {
+            ERREXIT2( cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
+                      MAX_COMPS_IN_SCAN );
+        }
+
+        /* Overall image size in MCUs */
+        cinfo->MCUs_per_row = (JDIMENSION)
+                              jdiv_round_up( (long) cinfo->image_width,
+                                            (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
+        cinfo->MCU_rows_in_scan = (JDIMENSION)
+                                  jdiv_round_up( (long) cinfo->image_height,
+                                                (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+
+        cinfo->blocks_in_MCU = 0;
+
+        for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+            compptr = cinfo->cur_comp_info[ci];
+            /* Sampling factors give # of blocks of component in each MCU */
+            compptr->MCU_width = compptr->h_samp_factor;
+            compptr->MCU_height = compptr->v_samp_factor;
+            compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
+            compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size;
+            /* Figure number of non-dummy blocks in last MCU column & row */
+            tmp = (int) ( compptr->width_in_blocks % compptr->MCU_width );
+            if ( tmp == 0 ) {
+                tmp = compptr->MCU_width;
+            }
+            compptr->last_col_width = tmp;
+            tmp = (int) ( compptr->height_in_blocks % compptr->MCU_height );
+            if ( tmp == 0 ) {
+                tmp = compptr->MCU_height;
+            }
+            compptr->last_row_height = tmp;
+            /* Prepare array describing MCU composition */
+            mcublks = compptr->MCU_blocks;
+            if ( cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU ) {
+                ERREXIT( cinfo, JERR_BAD_MCU_SIZE );
+            }
+            while ( mcublks-- > 0 ) {
+                cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
+            }
+        }
+
+    }
+}
+
+
+/*
+ * Save away a copy of the Q-table referenced by each component present
+ * in the current scan, unless already saved during a prior scan.
+ *
+ * In a multiple-scan JPEG file, the encoder could assign different components
+ * the same Q-table slot number, but change table definitions between scans
+ * so that each component uses a different Q-table.  (The IJG encoder is not
+ * currently capable of doing this, but other encoders might.)  Since we want
+ * to be able to dequantize all the components at the end of the file, this
+ * means that we have to save away the table actually used for each component.
+ * We do this by copying the table at the start of the first scan containing
+ * the component.
+ * The JPEG spec prohibits the encoder from changing the contents of a Q-table
+ * slot between scans of a component using that slot.  If the encoder does so
+ * anyway, this decoder will simply use the Q-table values that were current
+ * at the start of the first scan for the component.
+ *
+ * The decompressor output side looks only at the saved quant tables,
+ * not at the current Q-table slots.
+ */
+
+LOCAL void
+latch_quant_tables( j_decompress_ptr cinfo ) {
+    int ci, qtblno;
+    jpeg_component_info * compptr;
+    JQUANT_TBL * qtbl;
+
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        /* No work if we already saved Q-table for this component */
+        if ( compptr->quant_table != NULL ) {
+            continue;
+        }
+        /* Make sure specified quantization table is present */
+        qtblno = compptr->quant_tbl_no;
+        if ( ( qtblno < 0 ) || ( qtblno >= NUM_QUANT_TBLS ) ||
+            ( cinfo->quant_tbl_ptrs[qtblno] == NULL ) ) {
+            ERREXIT1( cinfo, JERR_NO_QUANT_TABLE, qtblno );
+        }
+        /* OK, save away the quantization table */
+        qtbl = (JQUANT_TBL *)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                            SIZEOF( JQUANT_TBL ) );
+        MEMCOPY( qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF( JQUANT_TBL ) );
+        compptr->quant_table = qtbl;
+    }
+}
+
+
+/*
+ * Initialize the input modules to read a scan of compressed data.
+ * The first call to this is done by jdmaster.c after initializing
+ * the entire decompressor (during jpeg_start_decompress).
+ * Subsequent calls come from consume_markers, below.
+ */
+
+METHODDEF void
+start_input_pass( j_decompress_ptr cinfo ) {
+    per_scan_setup( cinfo );
+    latch_quant_tables( cinfo );
+    ( *cinfo->entropy->start_pass )( cinfo );
+    ( *cinfo->coef->start_input_pass )( cinfo );
+    cinfo->inputctl->consume_input = cinfo->coef->consume_data;
+}
+
+
+/*
+ * Finish up after inputting a compressed-data scan.
+ * This is called by the coefficient controller after it's read all
+ * the expected data of the scan.
+ */
+
+METHODDEF void
+finish_input_pass( j_decompress_ptr cinfo ) {
+    cinfo->inputctl->consume_input = consume_markers;
+}
+
+
+/*
+ * Read JPEG markers before, between, or after compressed-data scans.
+ * Change state as necessary when a new scan is reached.
+ * Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
+ *
+ * The consume_input method pointer points either here or to the
+ * coefficient controller's consume_data routine, depending on whether
+ * we are reading a compressed data segment or inter-segment markers.
+ */
+
+METHODDEF int
+consume_markers( j_decompress_ptr cinfo ) {
+    my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
+    int val;
+
+    if ( inputctl->pub.eoi_reached ) {/* After hitting EOI, read no further */
+        return JPEG_REACHED_EOI;
+    }
+
+    val = ( *cinfo->marker->read_markers )( cinfo );
+
+    switch ( val ) {
+        case JPEG_REACHED_SOS:/* Found SOS */
+            if ( inputctl->inheaders ) {/* 1st SOS */
+                initial_setup( cinfo );
+                inputctl->inheaders = FALSE;
+                /* Note: start_input_pass must be called by jdmaster.c
+                 * before any more input can be consumed.  jdapi.c is
+                 * responsible for enforcing this sequencing.
+                 */
+            } else {    /* 2nd or later SOS marker */
+                if ( !inputctl->pub.has_multiple_scans ) {
+                    ERREXIT( cinfo, JERR_EOI_EXPECTED );
+                }                      /* Oops, I wasn't expecting this! */
+                start_input_pass( cinfo );
+            }
+            break;
+        case JPEG_REACHED_EOI:/* Found EOI */
+            inputctl->pub.eoi_reached = TRUE;
+            if ( inputctl->inheaders ) {/* Tables-only datastream, apparently */
+                if ( cinfo->marker->saw_SOF ) {
+                    ERREXIT( cinfo, JERR_SOF_NO_SOS );
+                }
+            } else {
+                /* Prevent infinite loop in coef ctlr's decompress_data routine
+                 * if user set output_scan_number larger than number of scans.
+                 */
+                if ( cinfo->output_scan_number > cinfo->input_scan_number ) {
+                    cinfo->output_scan_number = cinfo->input_scan_number;
+                }
+            }
+            break;
+        case JPEG_SUSPENDED:
+            break;
+    }
+
+    return val;
+}
+
+
+/*
+ * Reset state to begin a fresh datastream.
+ */
+
+METHODDEF void
+reset_input_controller( j_decompress_ptr cinfo ) {
+    my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
+
+    inputctl->pub.consume_input = consume_markers;
+    inputctl->pub.has_multiple_scans = FALSE;/* "unknown" would be better */
+    inputctl->pub.eoi_reached = FALSE;
+    inputctl->inheaders = TRUE;
+    /* Reset other modules */
+    ( *cinfo->err->reset_error_mgr )( (j_common_ptr) cinfo );
+    ( *cinfo->marker->reset_marker_reader )( cinfo );
+    /* Reset progression state -- would be cleaner if entropy decoder did this */
+    cinfo->coef_bits = NULL;
+}
+
+
+/*
+ * Initialize the input controller module.
+ * This is called only once, when the decompression object is created.
+ */
+
+GLOBAL void
+jinit_input_controller( j_decompress_ptr cinfo ) {
+    my_inputctl_ptr inputctl;
+
+    /* Create subobject in permanent pool */
+    inputctl = (my_inputctl_ptr)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
+                                            SIZEOF( my_input_controller ) );
+    cinfo->inputctl = (struct jpeg_input_controller *) inputctl;
+    /* Initialize method pointers */
+    inputctl->pub.consume_input = consume_markers;
+    inputctl->pub.reset_input_controller = reset_input_controller;
+    inputctl->pub.start_input_pass = start_input_pass;
+    inputctl->pub.finish_input_pass = finish_input_pass;
+    /* Initialize state: can't use reset_input_controller since we don't
+     * want to try to reset other modules yet.
+     */
+    inputctl->pub.has_multiple_scans = FALSE;/* "unknown" would be better */
+    inputctl->pub.eoi_reached = FALSE;
+    inputctl->inheaders = TRUE;
+}

neo/renderer/jpeg-6/jdmainct.cpp

@@ -0,0 +1,514 @@
+/*
+ * jdmainct.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the main buffer controller for decompression.
+ * The main buffer lies between the JPEG decompressor proper and the
+ * post-processor; it holds downsampled data in the JPEG colorspace.
+ *
+ * Note that this code is bypassed in raw-data mode, since the application
+ * supplies the equivalent of the main buffer in that case.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * In the current system design, the main buffer need never be a full-image
+ * buffer; any full-height buffers will be found inside the coefficient or
+ * postprocessing controllers.  Nonetheless, the main controller is not
+ * trivial.  Its responsibility is to provide context rows for upsampling/
+ * rescaling, and doing this in an efficient fashion is a bit tricky.
+ *
+ * Postprocessor input data is counted in "row groups".  A row group
+ * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
+ * sample rows of each component.  (We require DCT_scaled_size values to be
+ * chosen such that these numbers are integers.  In practice DCT_scaled_size
+ * values will likely be powers of two, so we actually have the stronger
+ * condition that DCT_scaled_size / min_DCT_scaled_size is an integer.)
+ * Upsampling will typically produce max_v_samp_factor pixel rows from each
+ * row group (times any additional scale factor that the upsampler is
+ * applying).
+ *
+ * The coefficient controller will deliver data to us one iMCU row at a time;
+ * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or
+ * exactly min_DCT_scaled_size row groups.  (This amount of data corresponds
+ * to one row of MCUs when the image is fully interleaved.)  Note that the
+ * number of sample rows varies across components, but the number of row
+ * groups does not.  Some garbage sample rows may be included in the last iMCU
+ * row at the bottom of the image.
+ *
+ * Depending on the vertical scaling algorithm used, the upsampler may need
+ * access to the sample row(s) above and below its current input row group.
+ * The upsampler is required to set need_context_rows TRUE at global selection
+ * time if so.  When need_context_rows is FALSE, this controller can simply
+ * obtain one iMCU row at a time from the coefficient controller and dole it
+ * out as row groups to the postprocessor.
+ *
+ * When need_context_rows is TRUE, this controller guarantees that the buffer
+ * passed to postprocessing contains at least one row group's worth of samples
+ * above and below the row group(s) being processed.  Note that the context
+ * rows "above" the first passed row group appear at negative row offsets in
+ * the passed buffer.  At the top and bottom of the image, the required
+ * context rows are manufactured by duplicating the first or last real sample
+ * row; this avoids having special cases in the upsampling inner loops.
+ *
+ * The amount of context is fixed at one row group just because that's a
+ * convenient number for this controller to work with.  The existing
+ * upsamplers really only need one sample row of context.  An upsampler
+ * supporting arbitrary output rescaling might wish for more than one row
+ * group of context when shrinking the image; tough, we don't handle that.
+ * (This is justified by the assumption that downsizing will be handled mostly
+ * by adjusting the DCT_scaled_size values, so that the actual scale factor at
+ * the upsample step needn't be much less than one.)
+ *
+ * To provide the desired context, we have to retain the last two row groups
+ * of one iMCU row while reading in the next iMCU row.  (The last row group
+ * can't be processed until we have another row group for its below-context,
+ * and so we have to save the next-to-last group too for its above-context.)
+ * We could do this most simply by copying data around in our buffer, but
+ * that'd be very slow.  We can avoid copying any data by creating a rather
+ * strange pointer structure.  Here's how it works.  We allocate a workspace
+ * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number
+ * of row groups per iMCU row).  We create two sets of redundant pointers to
+ * the workspace.  Labeling the physical row groups 0 to M+1, the synthesized
+ * pointer lists look like this:
+ *                   M+1                          M-1
+ * master pointer --> 0         master pointer --> 0
+ *                    1                            1
+ *                   ...                          ...
+ *                   M-3                          M-3
+ *                   M-2                           M
+ *                   M-1                          M+1
+ *                    M                           M-2
+ *                   M+1                          M-1
+ *                    0                            0
+ * We read alternate iMCU rows using each master pointer; thus the last two
+ * row groups of the previous iMCU row remain un-overwritten in the workspace.
+ * The pointer lists are set up so that the required context rows appear to
+ * be adjacent to the proper places when we pass the pointer lists to the
+ * upsampler.
+ *
+ * The above pictures describe the normal state of the pointer lists.
+ * At top and bottom of the image, we diddle the pointer lists to duplicate
+ * the first or last sample row as necessary (this is cheaper than copying
+ * sample rows around).
+ *
+ * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1.  In that
+ * situation each iMCU row provides only one row group so the buffering logic
+ * must be different (eg, we must read two iMCU rows before we can emit the
+ * first row group).  For now, we simply do not support providing context
+ * rows when min_DCT_scaled_size is 1.  That combination seems unlikely to
+ * be worth providing --- if someone wants a 1/8th-size preview, they probably
+ * want it quick and dirty, so a context-free upsampler is sufficient.
+ */
+
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_d_main_controller pub;/* public fields */
+
+    /* Pointer to allocated workspace (M or M+2 row groups). */
+    JSAMPARRAY buffer[MAX_COMPONENTS];
+
+    boolean    buffer_full; /* Have we gotten an iMCU row from decoder? */
+    JDIMENSION rowgroup_ctr;/* counts row groups output to postprocessor */
+
+    /* Remaining fields are only used in the context case. */
+
+    /* These are the master pointers to the funny-order pointer lists. */
+    JSAMPIMAGE xbuffer[2];  /* pointers to weird pointer lists */
+
+    int        whichptr;/* indicates which pointer set is now in use */
+    int        context_state; /* process_data state machine status */
+    JDIMENSION rowgroups_avail; /* row groups available to postprocessor */
+    JDIMENSION iMCU_row_ctr;/* counts iMCU rows to detect image top/bot */
+} my_main_controller;
+
+typedef my_main_controller * my_main_ptr;
+
+/* context_state values: */
+#define CTX_PREPARE_FOR_IMCU    0   /* need to prepare for MCU row */
+#define CTX_PROCESS_IMCU    1   /* feeding iMCU to postprocessor */
+#define CTX_POSTPONED_ROW   2   /* feeding postponed row group */
+
+
+/* Forward declarations */
+METHODDEF void process_data_simple_main
+JPP( ( j_decompress_ptr cinfo, JSAMPARRAY output_buf,
+       JDIMENSION * out_row_ctr, JDIMENSION out_rows_avail ) );
+METHODDEF void process_data_context_main
+JPP( ( j_decompress_ptr cinfo, JSAMPARRAY output_buf,
+       JDIMENSION * out_row_ctr, JDIMENSION out_rows_avail ) );
+#ifdef QUANT_2PASS_SUPPORTED
+METHODDEF void process_data_crank_post
+JPP( ( j_decompress_ptr cinfo, JSAMPARRAY output_buf,
+       JDIMENSION * out_row_ctr, JDIMENSION out_rows_avail ) );
+#endif
+
+
+LOCAL void
+alloc_funny_pointers( j_decompress_ptr cinfo ) {
+/* Allocate space for the funny pointer lists.
+ * This is done only once, not once per pass.
+ */
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+    int ci, rgroup;
+    int M = cinfo->min_DCT_scaled_size;
+    jpeg_component_info * compptr;
+    JSAMPARRAY xbuf;
+
+    /* Get top-level space for component array pointers.
+     * We alloc both arrays with one call to save a few cycles.
+     */
+    main->xbuffer[0] = (JSAMPIMAGE)
+                       ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                    cinfo->num_components * 2 * SIZEOF( JSAMPARRAY ) );
+    main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        rgroup = ( compptr->v_samp_factor * compptr->DCT_scaled_size ) /
+                 cinfo->min_DCT_scaled_size; /* height of a row group of component */
+        /* Get space for pointer lists --- M+4 row groups in each list.
+         * We alloc both pointer lists with one call to save a few cycles.
+         */
+        xbuf = (JSAMPARRAY)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                            2 * ( rgroup * ( M + 4 ) ) * SIZEOF( JSAMPROW ) );
+        xbuf += rgroup; /* want one row group at negative offsets */
+        main->xbuffer[0][ci] = xbuf;
+        xbuf += rgroup * ( M + 4 );
+        main->xbuffer[1][ci] = xbuf;
+    }
+}
+
+
+LOCAL void
+make_funny_pointers( j_decompress_ptr cinfo ) {
+/* Create the funny pointer lists discussed in the comments above.
+ * The actual workspace is already allocated (in main->buffer),
+ * and the space for the pointer lists is allocated too.
+ * This routine just fills in the curiously ordered lists.
+ * This will be repeated at the beginning of each pass.
+ */
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+    int ci, i, rgroup;
+    int M = cinfo->min_DCT_scaled_size;
+    jpeg_component_info * compptr;
+    JSAMPARRAY buf, xbuf0, xbuf1;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        rgroup = ( compptr->v_samp_factor * compptr->DCT_scaled_size ) /
+                 cinfo->min_DCT_scaled_size; /* height of a row group of component */
+        xbuf0 = main->xbuffer[0][ci];
+        xbuf1 = main->xbuffer[1][ci];
+        /* First copy the workspace pointers as-is */
+        buf = main->buffer[ci];
+        for ( i = 0; i < rgroup * ( M + 2 ); i++ ) {
+            xbuf0[i] = xbuf1[i] = buf[i];
+        }
+        /* In the second list, put the last four row groups in swapped order */
+        for ( i = 0; i < rgroup * 2; i++ ) {
+            xbuf1[rgroup * ( M - 2 ) + i] = buf[rgroup * M + i];
+            xbuf1[rgroup * M + i] = buf[rgroup * ( M - 2 ) + i];
+        }
+        /* The wraparound pointers at top and bottom will be filled later
+         * (see set_wraparound_pointers, below).  Initially we want the "above"
+         * pointers to duplicate the first actual data line.  This only needs
+         * to happen in xbuffer[0].
+         */
+        for ( i = 0; i < rgroup; i++ ) {
+            xbuf0[i - rgroup] = xbuf0[0];
+        }
+    }
+}
+
+
+LOCAL void
+set_wraparound_pointers( j_decompress_ptr cinfo ) {
+/* Set up the "wraparound" pointers at top and bottom of the pointer lists.
+ * This changes the pointer list state from top-of-image to the normal state.
+ */
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+    int ci, i, rgroup;
+    int M = cinfo->min_DCT_scaled_size;
+    jpeg_component_info * compptr;
+    JSAMPARRAY xbuf0, xbuf1;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        rgroup = ( compptr->v_samp_factor * compptr->DCT_scaled_size ) /
+                 cinfo->min_DCT_scaled_size; /* height of a row group of component */
+        xbuf0 = main->xbuffer[0][ci];
+        xbuf1 = main->xbuffer[1][ci];
+        for ( i = 0; i < rgroup; i++ ) {
+            xbuf0[i - rgroup] = xbuf0[rgroup * ( M + 1 ) + i];
+            xbuf1[i - rgroup] = xbuf1[rgroup * ( M + 1 ) + i];
+            xbuf0[rgroup * ( M + 2 ) + i] = xbuf0[i];
+            xbuf1[rgroup * ( M + 2 ) + i] = xbuf1[i];
+        }
+    }
+}
+
+
+LOCAL void
+set_bottom_pointers( j_decompress_ptr cinfo ) {
+/* Change the pointer lists to duplicate the last sample row at the bottom
+ * of the image.  whichptr indicates which xbuffer holds the final iMCU row.
+ * Also sets rowgroups_avail to indicate number of nondummy row groups in row.
+ */
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+    int ci, i, rgroup, iMCUheight, rows_left;
+    jpeg_component_info * compptr;
+    JSAMPARRAY xbuf;
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Count sample rows in one iMCU row and in one row group */
+        iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size;
+        rgroup = iMCUheight / cinfo->min_DCT_scaled_size;
+        /* Count nondummy sample rows remaining for this component */
+        rows_left = (int) ( compptr->downsampled_height % (JDIMENSION) iMCUheight );
+        if ( rows_left == 0 ) {
+            rows_left = iMCUheight;
+        }
+        /* Count nondummy row groups.  Should get same answer for each component,
+         * so we need only do it once.
+         */
+        if ( ci == 0 ) {
+            main->rowgroups_avail = (JDIMENSION) ( ( rows_left - 1 ) / rgroup + 1 );
+        }
+        /* Duplicate the last real sample row rgroup*2 times; this pads out the
+         * last partial rowgroup and ensures at least one full rowgroup of context.
+         */
+        xbuf = main->xbuffer[main->whichptr][ci];
+        for ( i = 0; i < rgroup * 2; i++ ) {
+            xbuf[rows_left + i] = xbuf[rows_left - 1];
+        }
+    }
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF void
+start_pass_main( j_decompress_ptr cinfo, J_BUF_MODE pass_mode ) {
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+
+    switch ( pass_mode ) {
+        case JBUF_PASS_THRU:
+            if ( cinfo->upsample->need_context_rows ) {
+                main->pub.process_data = process_data_context_main;
+                make_funny_pointers( cinfo );/* Create the xbuffer[] lists */
+                main->whichptr = 0;/* Read first iMCU row into xbuffer[0] */
+                main->context_state = CTX_PREPARE_FOR_IMCU;
+                main->iMCU_row_ctr = 0;
+            } else {
+                /* Simple case with no context needed */
+                main->pub.process_data = process_data_simple_main;
+            }
+            main->buffer_full = FALSE;/* Mark buffer empty */
+            main->rowgroup_ctr = 0;
+            break;
+#ifdef QUANT_2PASS_SUPPORTED
+        case JBUF_CRANK_DEST:
+            /* For last pass of 2-pass quantization, just crank the postprocessor */
+            main->pub.process_data = process_data_crank_post;
+            break;
+#endif
+        default:
+            ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            break;
+    }
+}
+
+
+/*
+ * Process some data.
+ * This handles the simple case where no context is required.
+ */
+
+METHODDEF void
+process_data_simple_main( j_decompress_ptr cinfo,
+                          JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                          JDIMENSION out_rows_avail ) {
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+    JDIMENSION rowgroups_avail;
+
+    /* Read input data if we haven't filled the main buffer yet */
+    if ( !main->buffer_full ) {
+        if ( !( *cinfo->coef->decompress_data )( cinfo, main->buffer ) ) {
+            return;
+        }               /* suspension forced, can do nothing more */
+        main->buffer_full = TRUE;/* OK, we have an iMCU row to work with */
+    }
+
+    /* There are always min_DCT_scaled_size row groups in an iMCU row. */
+    rowgroups_avail = (JDIMENSION) cinfo->min_DCT_scaled_size;
+    /* Note: at the bottom of the image, we may pass extra garbage row groups
+     * to the postprocessor.  The postprocessor has to check for bottom
+     * of image anyway (at row resolution), so no point in us doing it too.
+     */
+
+    /* Feed the postprocessor */
+    ( *cinfo->post->post_process_data )( cinfo, main->buffer,
+                                         &main->rowgroup_ctr, rowgroups_avail,
+                                         output_buf, out_row_ctr, out_rows_avail );
+
+    /* Has postprocessor consumed all the data yet? If so, mark buffer empty */
+    if ( main->rowgroup_ctr >= rowgroups_avail ) {
+        main->buffer_full = FALSE;
+        main->rowgroup_ctr = 0;
+    }
+}
+
+
+/*
+ * Process some data.
+ * This handles the case where context rows must be provided.
+ */
+
+METHODDEF void
+process_data_context_main( j_decompress_ptr cinfo,
+                           JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                           JDIMENSION out_rows_avail ) {
+    my_main_ptr main = (my_main_ptr) cinfo->main;
+
+    /* Read input data if we haven't filled the main buffer yet */
+    if ( !main->buffer_full ) {
+        if ( !( *cinfo->coef->decompress_data )( cinfo,
+                                                 main->xbuffer[main->whichptr] ) ) {
+            return;
+        }               /* suspension forced, can do nothing more */
+        main->buffer_full = TRUE;/* OK, we have an iMCU row to work with */
+        main->iMCU_row_ctr++; /* count rows received */
+    }
+
+    /* Postprocessor typically will not swallow all the input data it is handed
+     * in one call (due to filling the output buffer first).  Must be prepared
+     * to exit and restart.  This switch lets us keep track of how far we got.
+     * Note that each case falls through to the next on successful completion.
+     */
+    switch ( main->context_state ) {
+        case CTX_POSTPONED_ROW:
+            /* Call postprocessor using previously set pointers for postponed row */
+            ( *cinfo->post->post_process_data )( cinfo, main->xbuffer[main->whichptr],
+                                                 &main->rowgroup_ctr, main->rowgroups_avail,
+                                                 output_buf, out_row_ctr, out_rows_avail );
+            if ( main->rowgroup_ctr < main->rowgroups_avail ) {
+                return;
+            }           /* Need to suspend */
+            main->context_state = CTX_PREPARE_FOR_IMCU;
+            if ( *out_row_ctr >= out_rows_avail ) {
+                return;
+            }           /* Postprocessor exactly filled output buf */
+            /*FALLTHROUGH*/
+        case CTX_PREPARE_FOR_IMCU:
+            /* Prepare to process first M-1 row groups of this iMCU row */
+            main->rowgroup_ctr = 0;
+            main->rowgroups_avail = (JDIMENSION) ( cinfo->min_DCT_scaled_size - 1 );
+            /* Check for bottom of image: if so, tweak pointers to "duplicate"
+             * the last sample row, and adjust rowgroups_avail to ignore padding rows.
+             */
+            if ( main->iMCU_row_ctr == cinfo->total_iMCU_rows ) {
+                set_bottom_pointers( cinfo );
+            }
+            main->context_state = CTX_PROCESS_IMCU;
+            /*FALLTHROUGH*/
+        case CTX_PROCESS_IMCU:
+            /* Call postprocessor using previously set pointers */
+            ( *cinfo->post->post_process_data )( cinfo, main->xbuffer[main->whichptr],
+                                                 &main->rowgroup_ctr, main->rowgroups_avail,
+                                                 output_buf, out_row_ctr, out_rows_avail );
+            if ( main->rowgroup_ctr < main->rowgroups_avail ) {
+                return;
+            }           /* Need to suspend */
+            /* After the first iMCU, change wraparound pointers to normal state */
+            if ( main->iMCU_row_ctr == 1 ) {
+                set_wraparound_pointers( cinfo );
+            }
+            /* Prepare to load new iMCU row using other xbuffer list */
+            main->whichptr ^= 1;/* 0=>1 or 1=>0 */
+            main->buffer_full = FALSE;
+            /* Still need to process last row group of this iMCU row, */
+            /* which is saved at index M+1 of the other xbuffer */
+            main->rowgroup_ctr = (JDIMENSION) ( cinfo->min_DCT_scaled_size + 1 );
+            main->rowgroups_avail = (JDIMENSION) ( cinfo->min_DCT_scaled_size + 2 );
+            main->context_state = CTX_POSTPONED_ROW;
+    }
+}
+
+
+/*
+ * Process some data.
+ * Final pass of two-pass quantization: just call the postprocessor.
+ * Source data will be the postprocessor controller's internal buffer.
+ */
+
+#ifdef QUANT_2PASS_SUPPORTED
+
+METHODDEF void
+process_data_crank_post( j_decompress_ptr cinfo,
+                         JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                         JDIMENSION out_rows_avail ) {
+    ( *cinfo->post->post_process_data )( cinfo, (JSAMPIMAGE) NULL,
+                                         (JDIMENSION *) NULL, (JDIMENSION) 0,
+                                         output_buf, out_row_ctr, out_rows_avail );
+}
+
+#endif /* QUANT_2PASS_SUPPORTED */
+
+
+/*
+ * Initialize main buffer controller.
+ */
+
+GLOBAL void
+jinit_d_main_controller( j_decompress_ptr cinfo, boolean need_full_buffer ) {
+    my_main_ptr main;
+    int ci, rgroup, ngroups;
+    jpeg_component_info * compptr;
+
+    main = (my_main_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_main_controller ) );
+    cinfo->main = (struct jpeg_d_main_controller *) main;
+    main->pub.start_pass = start_pass_main;
+
+    if ( need_full_buffer ) {/* shouldn't happen */
+        ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+    }
+
+    /* Allocate the workspace.
+     * ngroups is the number of row groups we need.
+     */
+    if ( cinfo->upsample->need_context_rows ) {
+        if ( cinfo->min_DCT_scaled_size < 2 ) {/* unsupported, see comments above */
+            ERREXIT( cinfo, JERR_NOTIMPL );
+        }
+        alloc_funny_pointers( cinfo );/* Alloc space for xbuffer[] lists */
+        ngroups = cinfo->min_DCT_scaled_size + 2;
+    } else {
+        ngroups = cinfo->min_DCT_scaled_size;
+    }
+
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        rgroup = ( compptr->v_samp_factor * compptr->DCT_scaled_size ) /
+                 cinfo->min_DCT_scaled_size; /* height of a row group of component */
+        main->buffer[ci] = ( *cinfo->mem->alloc_sarray )
+                           ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                            compptr->width_in_blocks * compptr->DCT_scaled_size,
+                            (JDIMENSION) ( rgroup * ngroups ) );
+    }
+}

neo/renderer/jpeg-6/jdmaster.cpp

@@ -0,0 +1,568 @@
+/*
+ * jdmaster.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains master control logic for the JPEG decompressor.
+ * These routines are concerned with selecting the modules to be executed
+ * and with determining the number of passes and the work to be done in each
+ * pass.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private state */
+
+typedef struct {
+    struct jpeg_decomp_master pub;/* public fields */
+
+    int pass_number;    /* # of passes completed */
+
+    boolean using_merged_upsample;/* TRUE if using merged upsample/cconvert */
+
+    /* Saved references to initialized quantizer modules,
+     * in case we need to switch modes.
+     */
+    struct jpeg_color_quantizer * quantizer_1pass;
+    struct jpeg_color_quantizer * quantizer_2pass;
+} my_decomp_master;
+
+typedef my_decomp_master * my_master_ptr;
+
+
+/*
+ * Determine whether merged upsample/color conversion should be used.
+ * CRUCIAL: this must match the actual capabilities of jdmerge.c!
+ */
+
+LOCAL boolean
+use_merged_upsample( j_decompress_ptr cinfo ) {
+#ifdef UPSAMPLE_MERGING_SUPPORTED
+    /* Merging is the equivalent of plain box-filter upsampling */
+    if ( ( cinfo->do_fancy_upsampling ) || ( cinfo->CCIR601_sampling ) ) {
+        return FALSE;
+    }
+    /* jdmerge.c only supports YCC=>RGB color conversion */
+    if ( ( cinfo->jpeg_color_space != JCS_YCbCr ) || ( cinfo->num_components != 3 ) ||
+        ( cinfo->out_color_space != JCS_RGB ) ||
+        ( cinfo->out_color_components != RGB_PIXELSIZE ) ) {
+        return FALSE;
+    }
+    /* and it only handles 2h1v or 2h2v sampling ratios */
+    if ( ( cinfo->comp_info[0].h_samp_factor != 2 ) ||
+        ( cinfo->comp_info[1].h_samp_factor != 1 ) ||
+        ( cinfo->comp_info[2].h_samp_factor != 1 ) ||
+        ( cinfo->comp_info[0].v_samp_factor >  2 ) ||
+        ( cinfo->comp_info[1].v_samp_factor != 1 ) ||
+        ( cinfo->comp_info[2].v_samp_factor != 1 ) ) {
+        return FALSE;
+    }
+    /* furthermore, it doesn't work if we've scaled the IDCTs differently */
+    if ( ( cinfo->comp_info[0].DCT_scaled_size != cinfo->min_DCT_scaled_size ) ||
+        ( cinfo->comp_info[1].DCT_scaled_size != cinfo->min_DCT_scaled_size ) ||
+        ( cinfo->comp_info[2].DCT_scaled_size != cinfo->min_DCT_scaled_size ) ) {
+        return FALSE;
+    }
+    /* ??? also need to test for upsample-time rescaling, when & if supported */
+    return TRUE;        /* by golly, it'll work... */
+
+#else
+    return FALSE;
+
+#endif
+}
+
+
+/*
+ * Compute output image dimensions and related values.
+ * NOTE: this is exported for possible use by application.
+ * Hence it mustn't do anything that can't be done twice.
+ * Also note that it may be called before the master module is initialized!
+ */
+
+GLOBAL void
+jpeg_calc_output_dimensions( j_decompress_ptr cinfo ) {
+/* Do computations that are needed before master selection phase */
+#if 0   // JDC: commented out to remove warning
+    int ci;
+    jpeg_component_info * compptr;
+#endif
+
+    /* Prevent application from calling me at wrong times */
+    if ( cinfo->global_state != DSTATE_READY ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+#ifdef IDCT_SCALING_SUPPORTED
+
+    /* Compute actual output image dimensions and DCT scaling choices. */
+    if ( cinfo->scale_num * 8 <= cinfo->scale_denom ) {
+        /* Provide 1/8 scaling */
+        cinfo->output_width = (JDIMENSION)
+                              jdiv_round_up( (long) cinfo->image_width, 8L );
+        cinfo->output_height = (JDIMENSION)
+                               jdiv_round_up( (long) cinfo->image_height, 8L );
+        cinfo->min_DCT_scaled_size = 1;
+    } else if ( cinfo->scale_num * 4 <= cinfo->scale_denom ) {
+        /* Provide 1/4 scaling */
+        cinfo->output_width = (JDIMENSION)
+                              jdiv_round_up( (long) cinfo->image_width, 4L );
+        cinfo->output_height = (JDIMENSION)
+                               jdiv_round_up( (long) cinfo->image_height, 4L );
+        cinfo->min_DCT_scaled_size = 2;
+    } else if ( cinfo->scale_num * 2 <= cinfo->scale_denom ) {
+        /* Provide 1/2 scaling */
+        cinfo->output_width = (JDIMENSION)
+                              jdiv_round_up( (long) cinfo->image_width, 2L );
+        cinfo->output_height = (JDIMENSION)
+                               jdiv_round_up( (long) cinfo->image_height, 2L );
+        cinfo->min_DCT_scaled_size = 4;
+    } else {
+        /* Provide 1/1 scaling */
+        cinfo->output_width = cinfo->image_width;
+        cinfo->output_height = cinfo->image_height;
+        cinfo->min_DCT_scaled_size = DCTSIZE;
+    }
+    /* In selecting the actual DCT scaling for each component, we try to
+     * scale up the chroma components via IDCT scaling rather than upsampling.
+     * This saves time if the upsampler gets to use 1:1 scaling.
+     * Note this code assumes that the supported DCT scalings are powers of 2.
+     */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        int ssize = cinfo->min_DCT_scaled_size;
+        while ( ssize < DCTSIZE &&
+               ( compptr->h_samp_factor * ssize * 2 <=
+                 cinfo->max_h_samp_factor * cinfo->min_DCT_scaled_size ) &&
+               ( compptr->v_samp_factor * ssize * 2 <=
+                 cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size ) ) {
+            ssize = ssize * 2;
+        }
+        compptr->DCT_scaled_size = ssize;
+    }
+
+    /* Recompute downsampled dimensions of components;
+     * application needs to know these if using raw downsampled data.
+     */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Size in samples, after IDCT scaling */
+        compptr->downsampled_width = (JDIMENSION)
+                                     jdiv_round_up( (long) cinfo->image_width *
+                                                   (long) ( compptr->h_samp_factor * compptr->DCT_scaled_size ),
+                                                   (long) ( cinfo->max_h_samp_factor * DCTSIZE ) );
+        compptr->downsampled_height = (JDIMENSION)
+                                      jdiv_round_up( (long) cinfo->image_height *
+                                                    (long) ( compptr->v_samp_factor * compptr->DCT_scaled_size ),
+                                                    (long) ( cinfo->max_v_samp_factor * DCTSIZE ) );
+    }
+
+#else /* !IDCT_SCALING_SUPPORTED */
+
+    /* Hardwire it to "no scaling" */
+    cinfo->output_width = cinfo->image_width;
+    cinfo->output_height = cinfo->image_height;
+    /* jdinput.c has already initialized DCT_scaled_size to DCTSIZE,
+     * and has computed unscaled downsampled_width and downsampled_height.
+     */
+
+#endif /* IDCT_SCALING_SUPPORTED */
+
+    /* Report number of components in selected colorspace. */
+    /* Probably this should be in the color conversion module... */
+    switch ( cinfo->out_color_space ) {
+        case JCS_GRAYSCALE:
+            cinfo->out_color_components = 1;
+            break;
+        case JCS_RGB:
+#if RGB_PIXELSIZE != 3
+            cinfo->out_color_components = RGB_PIXELSIZE;
+            break;
+#endif /* else share code with YCbCr */
+        case JCS_YCbCr:
+            cinfo->out_color_components = 3;
+            break;
+        case JCS_CMYK:
+        case JCS_YCCK:
+            cinfo->out_color_components = 4;
+            break;
+        default:    /* else must be same colorspace as in file */
+            cinfo->out_color_components = cinfo->num_components;
+            break;
+    }
+    cinfo->output_components = ( cinfo->quantize_colors ? 1 :
+                                 cinfo->out_color_components );
+
+    /* See if upsampler will want to emit more than one row at a time */
+    if ( use_merged_upsample( cinfo ) ) {
+        cinfo->rec_outbuf_height = cinfo->max_v_samp_factor;
+    } else {
+        cinfo->rec_outbuf_height = 1;
+    }
+}
+
+
+/*
+ * Several decompression processes need to range-limit values to the range
+ * 0..MAXJSAMPLE; the input value may fall somewhat outside this range
+ * due to noise introduced by quantization, roundoff error, etc.  These
+ * processes are inner loops and need to be as fast as possible.  On most
+ * machines, particularly CPUs with pipelines or instruction prefetch,
+ * a (subscript-check-less) C table lookup
+ *		x = sample_range_limit[x];
+ * is faster than explicit tests
+ *		if (x < 0)  x = 0;
+ *		else if (x > MAXJSAMPLE)  x = MAXJSAMPLE;
+ * These processes all use a common table prepared by the routine below.
+ *
+ * For most steps we can mathematically guarantee that the initial value
+ * of x is within MAXJSAMPLE+1 of the legal range, so a table running from
+ * -(MAXJSAMPLE+1) to 2*MAXJSAMPLE+1 is sufficient.  But for the initial
+ * limiting step (just after the IDCT), a wildly out-of-range value is
+ * possible if the input data is corrupt.  To avoid any chance of indexing
+ * off the end of memory and getting a bad-pointer trap, we perform the
+ * post-IDCT limiting thus:
+ *		x = range_limit[x & MASK];
+ * where MASK is 2 bits wider than legal sample data, ie 10 bits for 8-bit
+ * samples.  Under normal circumstances this is more than enough range and
+ * a correct output will be generated; with bogus input data the mask will
+ * cause wraparound, and we will safely generate a bogus-but-in-range output.
+ * For the post-IDCT step, we want to convert the data from signed to unsigned
+ * representation by adding CENTERJSAMPLE at the same time that we limit it.
+ * So the post-IDCT limiting table ends up looking like this:
+ *   CENTERJSAMPLE,CENTERJSAMPLE+1,...,MAXJSAMPLE,
+ *   MAXJSAMPLE (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
+ *   0          (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
+ *   0,1,...,CENTERJSAMPLE-1
+ * Negative inputs select values from the upper half of the table after
+ * masking.
+ *
+ * We can save some space by overlapping the start of the post-IDCT table
+ * with the simpler range limiting table.  The post-IDCT table begins at
+ * sample_range_limit + CENTERJSAMPLE.
+ *
+ * Note that the table is allocated in near data space on PCs; it's small
+ * enough and used often enough to justify this.
+ */
+
+LOCAL void
+prepare_range_limit_table( j_decompress_ptr cinfo ) {
+/* Allocate and fill in the sample_range_limit table */
+    JSAMPLE * table;
+    int i;
+
+    table = (JSAMPLE *)
+            ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                         ( 5 * ( MAXJSAMPLE + 1 ) + CENTERJSAMPLE ) * SIZEOF( JSAMPLE ) );
+    table += ( MAXJSAMPLE + 1 );/* allow negative subscripts of simple table */
+    cinfo->sample_range_limit = table;
+    /* First segment of "simple" table: limit[x] = 0 for x < 0 */
+    MEMZERO( table - ( MAXJSAMPLE + 1 ), ( MAXJSAMPLE + 1 ) * SIZEOF( JSAMPLE ) );
+    /* Main part of "simple" table: limit[x] = x */
+    for ( i = 0; i <= MAXJSAMPLE; i++ ) {
+        table[i] = (JSAMPLE) i;
+    }
+    table += CENTERJSAMPLE; /* Point to where post-IDCT table starts */
+    /* End of simple table, rest of first half of post-IDCT table */
+    for ( i = CENTERJSAMPLE; i < 2 * ( MAXJSAMPLE + 1 ); i++ ) {
+        table[i] = MAXJSAMPLE;
+    }
+    /* Second half of post-IDCT table */
+    MEMZERO( table + ( 2 * ( MAXJSAMPLE + 1 ) ),
+            ( 2 * ( MAXJSAMPLE + 1 ) - CENTERJSAMPLE ) * SIZEOF( JSAMPLE ) );
+    MEMCOPY( table + ( 4 * ( MAXJSAMPLE + 1 ) - CENTERJSAMPLE ),
+            cinfo->sample_range_limit, CENTERJSAMPLE * SIZEOF( JSAMPLE ) );
+}
+
+
+/*
+ * Master selection of decompression modules.
+ * This is done once at jpeg_start_decompress time.  We determine
+ * which modules will be used and give them appropriate initialization calls.
+ * We also initialize the decompressor input side to begin consuming data.
+ *
+ * Since jpeg_read_header has finished, we know what is in the SOF
+ * and (first) SOS markers.  We also have all the application parameter
+ * settings.
+ */
+
+LOCAL void
+master_selection( j_decompress_ptr cinfo ) {
+    my_master_ptr master = (my_master_ptr) cinfo->master;
+    boolean use_c_buffer;
+    long samplesperrow;
+    JDIMENSION jd_samplesperrow;
+
+    /* Initialize dimensions and other stuff */
+    jpeg_calc_output_dimensions( cinfo );
+    prepare_range_limit_table( cinfo );
+
+    /* Width of an output scanline must be representable as JDIMENSION. */
+    samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components;
+    jd_samplesperrow = (JDIMENSION) samplesperrow;
+    if ( (long) jd_samplesperrow != samplesperrow ) {
+        ERREXIT( cinfo, JERR_WIDTH_OVERFLOW );
+    }
+
+    /* Initialize my private state */
+    master->pass_number = 0;
+    master->using_merged_upsample = use_merged_upsample( cinfo );
+
+    /* Color quantizer selection */
+    master->quantizer_1pass = NULL;
+    master->quantizer_2pass = NULL;
+    /* No mode changes if not using buffered-image mode. */
+    if ( ( !cinfo->quantize_colors ) || ( !cinfo->buffered_image ) ) {
+        cinfo->enable_1pass_quant = FALSE;
+        cinfo->enable_external_quant = FALSE;
+        cinfo->enable_2pass_quant = FALSE;
+    }
+    if ( cinfo->quantize_colors ) {
+        if ( cinfo->raw_data_out ) {
+            ERREXIT( cinfo, JERR_NOTIMPL );
+        }
+        /* 2-pass quantizer only works in 3-component color space. */
+        if ( cinfo->out_color_components != 3 ) {
+            cinfo->enable_1pass_quant = TRUE;
+            cinfo->enable_external_quant = FALSE;
+            cinfo->enable_2pass_quant = FALSE;
+            cinfo->colormap = NULL;
+        } else if ( cinfo->colormap != NULL ) {
+            cinfo->enable_external_quant = TRUE;
+        } else if ( cinfo->two_pass_quantize ) {
+            cinfo->enable_2pass_quant = TRUE;
+        } else {
+            cinfo->enable_1pass_quant = TRUE;
+        }
+
+        if ( cinfo->enable_1pass_quant ) {
+#ifdef QUANT_1PASS_SUPPORTED
+            jinit_1pass_quantizer( cinfo );
+            master->quantizer_1pass = cinfo->cquantize;
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        }
+
+        /* We use the 2-pass code to map to external colormaps. */
+        if ( ( cinfo->enable_2pass_quant ) || ( cinfo->enable_external_quant ) ) {
+#ifdef QUANT_2PASS_SUPPORTED
+            jinit_2pass_quantizer( cinfo );
+            master->quantizer_2pass = cinfo->cquantize;
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        }
+        /* If both quantizers are initialized, the 2-pass one is left active;
+         * this is necessary for starting with quantization to an external map.
+         */
+    }
+
+    /* Post-processing: in particular, color conversion first */
+    if ( !cinfo->raw_data_out ) {
+        if ( master->using_merged_upsample ) {
+#ifdef UPSAMPLE_MERGING_SUPPORTED
+            jinit_merged_upsampler( cinfo );/* does color conversion too */
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        } else {
+            jinit_color_deconverter( cinfo );
+            jinit_upsampler( cinfo );
+        }
+        jinit_d_post_controller( cinfo, cinfo->enable_2pass_quant );
+    }
+    /* Inverse DCT */
+    jinit_inverse_dct( cinfo );
+    /* Entropy decoding: either Huffman or arithmetic coding. */
+    if ( cinfo->arith_code ) {
+        ERREXIT( cinfo, JERR_ARITH_NOTIMPL );
+    } else {
+        if ( cinfo->progressive_mode ) {
+#ifdef D_PROGRESSIVE_SUPPORTED
+            jinit_phuff_decoder( cinfo );
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        } else {
+            jinit_huff_decoder( cinfo );
+        }
+    }
+
+    /* Initialize principal buffer controllers. */
+    use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image;
+    jinit_d_coef_controller( cinfo, use_c_buffer );
+
+    if ( !cinfo->raw_data_out ) {
+        jinit_d_main_controller( cinfo, FALSE /* never need full buffer here */ );
+    }
+
+    /* We can now tell the memory manager to allocate virtual arrays. */
+    ( *cinfo->mem->realize_virt_arrays )( (j_common_ptr) cinfo );
+
+    /* Initialize input side of decompressor to consume first scan. */
+    ( *cinfo->inputctl->start_input_pass )( cinfo );
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+    /* If jpeg_start_decompress will read the whole file, initialize
+     * progress monitoring appropriately.  The input step is counted
+     * as one pass.
+     */
+    if ( ( cinfo->progress != NULL ) && ( !cinfo->buffered_image ) &&
+        ( cinfo->inputctl->has_multiple_scans ) ) {
+        int nscans;
+        /* Estimate number of scans to set pass_limit. */
+        if ( cinfo->progressive_mode ) {
+            /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
+            nscans = 2 + 3 * cinfo->num_components;
+        } else {
+            /* For a nonprogressive multiscan file, estimate 1 scan per component. */
+            nscans = cinfo->num_components;
+        }
+        cinfo->progress->pass_counter = 0L;
+        cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
+        cinfo->progress->completed_passes = 0;
+        cinfo->progress->total_passes = ( cinfo->enable_2pass_quant ? 3 : 2 );
+        /* Count the input pass as done */
+        master->pass_number++;
+    }
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+}
+
+
+/*
+ * Per-pass setup.
+ * This is called at the beginning of each output pass.  We determine which
+ * modules will be active during this pass and give them appropriate
+ * start_pass calls.  We also set is_dummy_pass to indicate whether this
+ * is a "real" output pass or a dummy pass for color quantization.
+ * (In the latter case, jdapi.c will crank the pass to completion.)
+ */
+
+METHODDEF void
+prepare_for_output_pass( j_decompress_ptr cinfo ) {
+    my_master_ptr master = (my_master_ptr) cinfo->master;
+
+    if ( master->pub.is_dummy_pass ) {
+#ifdef QUANT_2PASS_SUPPORTED
+        /* Final pass of 2-pass quantization */
+        master->pub.is_dummy_pass = FALSE;
+        ( *cinfo->cquantize->start_pass )( cinfo, FALSE );
+        ( *cinfo->post->start_pass )( cinfo, JBUF_CRANK_DEST );
+        ( *cinfo->main->start_pass )( cinfo, JBUF_CRANK_DEST );
+#else
+        ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif /* QUANT_2PASS_SUPPORTED */
+    } else {
+        if ( ( cinfo->quantize_colors ) && ( cinfo->colormap == NULL ) ) {
+            /* Select new quantization method */
+            if ( ( cinfo->two_pass_quantize ) && ( cinfo->enable_2pass_quant ) ) {
+                cinfo->cquantize = master->quantizer_2pass;
+                master->pub.is_dummy_pass = TRUE;
+            } else if ( cinfo->enable_1pass_quant ) {
+                cinfo->cquantize = master->quantizer_1pass;
+            } else {
+                ERREXIT( cinfo, JERR_MODE_CHANGE );
+            }
+        }
+        ( *cinfo->idct->start_pass )( cinfo );
+        ( *cinfo->coef->start_output_pass )( cinfo );
+        if ( !cinfo->raw_data_out ) {
+            if ( !master->using_merged_upsample ) {
+                ( *cinfo->cconvert->start_pass )( cinfo );
+            }
+            ( *cinfo->upsample->start_pass )( cinfo );
+            if ( cinfo->quantize_colors ) {
+                ( *cinfo->cquantize->start_pass )( cinfo, master->pub.is_dummy_pass );
+            }
+            ( *cinfo->post->start_pass )( cinfo,
+                                         ( master->pub.is_dummy_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU ) );
+            ( *cinfo->main->start_pass )( cinfo, JBUF_PASS_THRU );
+        }
+    }
+
+    /* Set up progress monitor's pass info if present */
+    if ( cinfo->progress != NULL ) {
+        cinfo->progress->completed_passes = master->pass_number;
+        cinfo->progress->total_passes = master->pass_number +
+                                        ( master->pub.is_dummy_pass ? 2 : 1 );
+        /* In buffered-image mode, we assume one more output pass if EOI not
+         * yet reached, but no more passes if EOI has been reached.
+         */
+        if ( ( cinfo->buffered_image ) && ( !cinfo->inputctl->eoi_reached ) ) {
+            cinfo->progress->total_passes += ( cinfo->enable_2pass_quant ? 2 : 1 );
+        }
+    }
+}
+
+
+/*
+ * Finish up at end of an output pass.
+ */
+
+METHODDEF void
+finish_output_pass( j_decompress_ptr cinfo ) {
+    my_master_ptr master = (my_master_ptr) cinfo->master;
+
+    if ( cinfo->quantize_colors ) {
+        ( *cinfo->cquantize->finish_pass )( cinfo );
+    }
+    master->pass_number++;
+}
+
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+
+/*
+ * Switch to a new external colormap between output passes.
+ */
+
+GLOBAL void
+jpeg_new_colormap( j_decompress_ptr cinfo ) {
+    my_master_ptr master = (my_master_ptr) cinfo->master;
+
+    /* Prevent application from calling me at wrong times */
+    if ( cinfo->global_state != DSTATE_BUFIMAGE ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+
+    if ( ( cinfo->quantize_colors ) && ( cinfo->enable_external_quant ) &&
+        ( cinfo->colormap != NULL ) ) {
+        /* Select 2-pass quantizer for external colormap use */
+        cinfo->cquantize = master->quantizer_2pass;
+        /* Notify quantizer of colormap change */
+        ( *cinfo->cquantize->new_color_map )( cinfo );
+        master->pub.is_dummy_pass = FALSE;/* just in case */
+    } else {
+        ERREXIT( cinfo, JERR_MODE_CHANGE );
+    }
+}
+
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+
+
+/*
+ * Initialize master decompression control and select active modules.
+ * This is performed at the start of jpeg_start_decompress.
+ */
+
+GLOBAL void
+jinit_master_decompress( j_decompress_ptr cinfo ) {
+    my_master_ptr master;
+
+    master = (my_master_ptr)
+             ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                          SIZEOF( my_decomp_master ) );
+    cinfo->master = (struct jpeg_decomp_master *) master;
+    master->pub.prepare_for_output_pass = prepare_for_output_pass;
+    master->pub.finish_output_pass = finish_output_pass;
+
+    master->pub.is_dummy_pass = FALSE;
+
+    master_selection( cinfo );
+}

neo/renderer/jpeg-6/jdmerge.cpp

@@ -0,0 +1,396 @@
+/*
+ * jdmerge.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains code for merged upsampling/color conversion.
+ *
+ * This file combines functions from jdsample.c and jdcolor.c;
+ * read those files first to understand what's going on.
+ *
+ * When the chroma components are to be upsampled by simple replication
+ * (ie, box filtering), we can save some work in color conversion by
+ * calculating all the output pixels corresponding to a pair of chroma
+ * samples at one time.  In the conversion equations
+ *	R = Y           + K1 * Cr
+ *	G = Y + K2 * Cb + K3 * Cr
+ *	B = Y + K4 * Cb
+ * only the Y term varies among the group of pixels corresponding to a pair
+ * of chroma samples, so the rest of the terms can be calculated just once.
+ * At typical sampling ratios, this eliminates half or three-quarters of the
+ * multiplications needed for color conversion.
+ *
+ * This file currently provides implementations for the following cases:
+ *	YCbCr => RGB color conversion only.
+ *	Sampling ratios of 2h1v or 2h2v.
+ *	No scaling needed at upsample time.
+ *	Corner-aligned (non-CCIR601) sampling alignment.
+ * Other special cases could be added, but in most applications these are
+ * the only common cases.  (For uncommon cases we fall back on the more
+ * general code in jdsample.c and jdcolor.c.)
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+#ifdef UPSAMPLE_MERGING_SUPPORTED
+
+
+/* Private subobject */
+
+typedef struct {
+    struct jpeg_upsampler pub;  /* public fields */
+
+    /* Pointer to routine to do actual upsampling/conversion of one row group */
+    JMETHOD( void, upmethod, ( j_decompress_ptr cinfo,
+                               JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+                               JSAMPARRAY output_buf ) );
+
+    /* Private state for YCC->RGB conversion */
+    int *   Cr_r_tab;   /* => table for Cr to R conversion */
+    int *   Cb_b_tab;   /* => table for Cb to B conversion */
+    INT32 * Cr_g_tab;   /* => table for Cr to G conversion */
+    INT32 * Cb_g_tab;   /* => table for Cb to G conversion */
+
+    /* For 2:1 vertical sampling, we produce two output rows at a time.
+     * We need a "spare" row buffer to hold the second output row if the
+     * application provides just a one-row buffer; we also use the spare
+     * to discard the dummy last row if the image height is odd.
+     */
+    JSAMPROW spare_row;
+    boolean  spare_full;    /* T if spare buffer is occupied */
+
+    JDIMENSION out_row_width;/* samples per output row */
+    JDIMENSION rows_to_go;  /* counts rows remaining in image */
+} my_upsampler;
+
+typedef my_upsampler * my_upsample_ptr;
+
+#define SCALEBITS   16  /* speediest right-shift on some machines */
+#define ONE_HALF    ( (INT32) 1 << ( SCALEBITS - 1 ) )
+#define FIX( x )      ( (INT32) ( ( x ) * ( 1L << SCALEBITS ) + 0.5 ) )
+
+
+/*
+ * Initialize tables for YCC->RGB colorspace conversion.
+ * This is taken directly from jdcolor.c; see that file for more info.
+ */
+
+LOCAL void
+build_ycc_rgb_table( j_decompress_ptr cinfo ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+    int i;
+    INT32 x;
+    SHIFT_TEMPS
+
+    upsample->Cr_r_tab = (int *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( int ) );
+    upsample->Cb_b_tab = (int *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( int ) );
+    upsample->Cr_g_tab = (INT32 *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( INT32 ) );
+    upsample->Cb_g_tab = (INT32 *)
+                         ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                      ( MAXJSAMPLE + 1 ) * SIZEOF( INT32 ) );
+
+    for ( i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++ ) {
+        /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
+        /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
+        /* Cr=>R value is nearest int to 1.40200 * x */
+        upsample->Cr_r_tab[i] = (int)
+                                RIGHT_SHIFT( FIX( 1.40200 ) * x + ONE_HALF, SCALEBITS );
+        /* Cb=>B value is nearest int to 1.77200 * x */
+        upsample->Cb_b_tab[i] = (int)
+                                RIGHT_SHIFT( FIX( 1.77200 ) * x + ONE_HALF, SCALEBITS );
+        /* Cr=>G value is scaled-up -0.71414 * x */
+        upsample->Cr_g_tab[i] = ( -FIX( 0.71414 ) ) * x;
+        /* Cb=>G value is scaled-up -0.34414 * x */
+        /* We also add in ONE_HALF so that need not do it in inner loop */
+        upsample->Cb_g_tab[i] = ( -FIX( 0.34414 ) ) * x + ONE_HALF;
+    }
+}
+
+
+/*
+ * Initialize for an upsampling pass.
+ */
+
+METHODDEF void
+start_pass_merged_upsample( j_decompress_ptr cinfo ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+
+    /* Mark the spare buffer empty */
+    upsample->spare_full = FALSE;
+    /* Initialize total-height counter for detecting bottom of image */
+    upsample->rows_to_go = cinfo->output_height;
+}
+
+
+/*
+ * Control routine to do upsampling (and color conversion).
+ *
+ * The control routine just handles the row buffering considerations.
+ */
+
+METHODDEF void
+merged_2v_upsample( j_decompress_ptr cinfo,
+                    JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+                    JDIMENSION in_row_groups_avail,
+                    JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                    JDIMENSION out_rows_avail ) {
+/* 2:1 vertical sampling case: may need a spare row. */
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+    JSAMPROW work_ptrs[2];
+    JDIMENSION num_rows;    /* number of rows returned to caller */
+
+    if ( upsample->spare_full ) {
+        /* If we have a spare row saved from a previous cycle, just return it. */
+        jcopy_sample_rows( &upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
+                           1, upsample->out_row_width );
+        num_rows = 1;
+        upsample->spare_full = FALSE;
+    } else {
+        /* Figure number of rows to return to caller. */
+        num_rows = 2;
+        /* Not more than the distance to the end of the image. */
+        if ( num_rows > upsample->rows_to_go ) {
+            num_rows = upsample->rows_to_go;
+        }
+        /* And not more than what the client can accept: */
+        out_rows_avail -= *out_row_ctr;
+        if ( num_rows > out_rows_avail ) {
+            num_rows = out_rows_avail;
+        }
+        /* Create output pointer array for upsampler. */
+        work_ptrs[0] = output_buf[*out_row_ctr];
+        if ( num_rows > 1 ) {
+            work_ptrs[1] = output_buf[*out_row_ctr + 1];
+        } else {
+            work_ptrs[1] = upsample->spare_row;
+            upsample->spare_full = TRUE;
+        }
+        /* Now do the upsampling. */
+        ( *upsample->upmethod )( cinfo, input_buf, *in_row_group_ctr, work_ptrs );
+    }
+
+    /* Adjust counts */
+    *out_row_ctr += num_rows;
+    upsample->rows_to_go -= num_rows;
+    /* When the buffer is emptied, declare this input row group consumed */
+    if ( !upsample->spare_full ) {
+        ( *in_row_group_ctr )++;
+    }
+}
+
+
+METHODDEF void
+merged_1v_upsample( j_decompress_ptr cinfo,
+                    JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+                    JDIMENSION in_row_groups_avail,
+                    JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                    JDIMENSION out_rows_avail ) {
+/* 1:1 vertical sampling case: much easier, never need a spare row. */
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+
+    /* Just do the upsampling. */
+    ( *upsample->upmethod )( cinfo, input_buf, *in_row_group_ctr,
+                             output_buf + *out_row_ctr );
+    /* Adjust counts */
+    ( *out_row_ctr )++;
+    ( *in_row_group_ctr )++;
+}
+
+
+/*
+ * These are the routines invoked by the control routines to do
+ * the actual upsampling/conversion.  One row group is processed per call.
+ *
+ * Note: since we may be writing directly into application-supplied buffers,
+ * we have to be honest about the output width; we can't assume the buffer
+ * has been rounded up to an even width.
+ */
+
+
+/*
+ * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
+ */
+
+METHODDEF void
+h2v1_merged_upsample( j_decompress_ptr cinfo,
+                      JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+                      JSAMPARRAY output_buf ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+    register int y, cred, cgreen, cblue;
+    int cb, cr;
+    register JSAMPROW outptr;
+    JSAMPROW inptr0, inptr1, inptr2;
+    JDIMENSION col;
+    /* copy these pointers into registers if possible */
+    register JSAMPLE * range_limit = cinfo->sample_range_limit;
+    int * Crrtab = upsample->Cr_r_tab;
+    int * Cbbtab = upsample->Cb_b_tab;
+    INT32 * Crgtab = upsample->Cr_g_tab;
+    INT32 * Cbgtab = upsample->Cb_g_tab;
+    SHIFT_TEMPS
+
+    inptr0 = input_buf[0][in_row_group_ctr];
+    inptr1 = input_buf[1][in_row_group_ctr];
+    inptr2 = input_buf[2][in_row_group_ctr];
+    outptr = output_buf[0];
+    /* Loop for each pair of output pixels */
+    for ( col = cinfo->output_width >> 1; col > 0; col-- ) {
+        /* Do the chroma part of the calculation */
+        cb = GETJSAMPLE( *inptr1++ );
+        cr = GETJSAMPLE( *inptr2++ );
+        cred = Crrtab[cr];
+        cgreen = (int) RIGHT_SHIFT( Cbgtab[cb] + Crgtab[cr], SCALEBITS );
+        cblue = Cbbtab[cb];
+        /* Fetch 2 Y values and emit 2 pixels */
+        y  = GETJSAMPLE( *inptr0++ );
+        outptr[RGB_RED] =   range_limit[y + cred];
+        outptr[RGB_GREEN] = range_limit[y + cgreen];
+        outptr[RGB_BLUE] =  range_limit[y + cblue];
+        outptr += RGB_PIXELSIZE;
+        y  = GETJSAMPLE( *inptr0++ );
+        outptr[RGB_RED] =   range_limit[y + cred];
+        outptr[RGB_GREEN] = range_limit[y + cgreen];
+        outptr[RGB_BLUE] =  range_limit[y + cblue];
+        outptr += RGB_PIXELSIZE;
+    }
+    /* If image width is odd, do the last output column separately */
+    if ( cinfo->output_width & 1 ) {
+        cb = GETJSAMPLE( *inptr1 );
+        cr = GETJSAMPLE( *inptr2 );
+        cred = Crrtab[cr];
+        cgreen = (int) RIGHT_SHIFT( Cbgtab[cb] + Crgtab[cr], SCALEBITS );
+        cblue = Cbbtab[cb];
+        y  = GETJSAMPLE( *inptr0 );
+        outptr[RGB_RED] =   range_limit[y + cred];
+        outptr[RGB_GREEN] = range_limit[y + cgreen];
+        outptr[RGB_BLUE] =  range_limit[y + cblue];
+    }
+}
+
+
+/*
+ * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
+ */
+
+METHODDEF void
+h2v2_merged_upsample( j_decompress_ptr cinfo,
+                      JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+                      JSAMPARRAY output_buf ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+    register int y, cred, cgreen, cblue;
+    int cb, cr;
+    register JSAMPROW outptr0, outptr1;
+    JSAMPROW inptr00, inptr01, inptr1, inptr2;
+    JDIMENSION col;
+    /* copy these pointers into registers if possible */
+    register JSAMPLE * range_limit = cinfo->sample_range_limit;
+    int * Crrtab = upsample->Cr_r_tab;
+    int * Cbbtab = upsample->Cb_b_tab;
+    INT32 * Crgtab = upsample->Cr_g_tab;
+    INT32 * Cbgtab = upsample->Cb_g_tab;
+    SHIFT_TEMPS
+
+    inptr00 = input_buf[0][in_row_group_ctr * 2];
+    inptr01 = input_buf[0][in_row_group_ctr * 2 + 1];
+    inptr1 = input_buf[1][in_row_group_ctr];
+    inptr2 = input_buf[2][in_row_group_ctr];
+    outptr0 = output_buf[0];
+    outptr1 = output_buf[1];
+    /* Loop for each group of output pixels */
+    for ( col = cinfo->output_width >> 1; col > 0; col-- ) {
+        /* Do the chroma part of the calculation */
+        cb = GETJSAMPLE( *inptr1++ );
+        cr = GETJSAMPLE( *inptr2++ );
+        cred = Crrtab[cr];
+        cgreen = (int) RIGHT_SHIFT( Cbgtab[cb] + Crgtab[cr], SCALEBITS );
+        cblue = Cbbtab[cb];
+        /* Fetch 4 Y values and emit 4 pixels */
+        y  = GETJSAMPLE( *inptr00++ );
+        outptr0[RGB_RED] =   range_limit[y + cred];
+        outptr0[RGB_GREEN] = range_limit[y + cgreen];
+        outptr0[RGB_BLUE] =  range_limit[y + cblue];
+        outptr0 += RGB_PIXELSIZE;
+        y  = GETJSAMPLE( *inptr00++ );
+        outptr0[RGB_RED] =   range_limit[y + cred];
+        outptr0[RGB_GREEN] = range_limit[y + cgreen];
+        outptr0[RGB_BLUE] =  range_limit[y + cblue];
+        outptr0 += RGB_PIXELSIZE;
+        y  = GETJSAMPLE( *inptr01++ );
+        outptr1[RGB_RED] =   range_limit[y + cred];
+        outptr1[RGB_GREEN] = range_limit[y + cgreen];
+        outptr1[RGB_BLUE] =  range_limit[y + cblue];
+        outptr1 += RGB_PIXELSIZE;
+        y  = GETJSAMPLE( *inptr01++ );
+        outptr1[RGB_RED] =   range_limit[y + cred];
+        outptr1[RGB_GREEN] = range_limit[y + cgreen];
+        outptr1[RGB_BLUE] =  range_limit[y + cblue];
+        outptr1 += RGB_PIXELSIZE;
+    }
+    /* If image width is odd, do the last output column separately */
+    if ( cinfo->output_width & 1 ) {
+        cb = GETJSAMPLE( *inptr1 );
+        cr = GETJSAMPLE( *inptr2 );
+        cred = Crrtab[cr];
+        cgreen = (int) RIGHT_SHIFT( Cbgtab[cb] + Crgtab[cr], SCALEBITS );
+        cblue = Cbbtab[cb];
+        y  = GETJSAMPLE( *inptr00 );
+        outptr0[RGB_RED] =   range_limit[y + cred];
+        outptr0[RGB_GREEN] = range_limit[y + cgreen];
+        outptr0[RGB_BLUE] =  range_limit[y + cblue];
+        y  = GETJSAMPLE( *inptr01 );
+        outptr1[RGB_RED] =   range_limit[y + cred];
+        outptr1[RGB_GREEN] = range_limit[y + cgreen];
+        outptr1[RGB_BLUE] =  range_limit[y + cblue];
+    }
+}
+
+
+/*
+ * Module initialization routine for merged upsampling/color conversion.
+ *
+ * NB: this is called under the conditions determined by use_merged_upsample()
+ * in jdmaster.c.  That routine MUST correspond to the actual capabilities
+ * of this module; no safety checks are made here.
+ */
+
+GLOBAL void
+jinit_merged_upsampler( j_decompress_ptr cinfo ) {
+    my_upsample_ptr upsample;
+
+    upsample = (my_upsample_ptr)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                            SIZEOF( my_upsampler ) );
+    cinfo->upsample = (struct jpeg_upsampler *) upsample;
+    upsample->pub.start_pass = start_pass_merged_upsample;
+    upsample->pub.need_context_rows = FALSE;
+
+    upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;
+
+    if ( cinfo->max_v_samp_factor == 2 ) {
+        upsample->pub.upsample = merged_2v_upsample;
+        upsample->upmethod = h2v2_merged_upsample;
+        /* Allocate a spare row buffer */
+        upsample->spare_row = (JSAMPROW)
+                              ( *cinfo->mem->alloc_large )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                           (size_t) ( upsample->out_row_width * SIZEOF( JSAMPLE ) ) );
+    } else {
+        upsample->pub.upsample = merged_1v_upsample;
+        upsample->upmethod = h2v1_merged_upsample;
+        /* No spare row needed */
+        upsample->spare_row = NULL;
+    }
+
+    build_ycc_rgb_table( cinfo );
+}
+
+#endif /* UPSAMPLE_MERGING_SUPPORTED */

neo/renderer/jpeg-6/jdphuff.cpp

@@ -0,0 +1,670 @@
+/*
+ * jdphuff.c
+ *
+ * Copyright (C) 1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy decoding routines for progressive JPEG.
+ *
+ * Much of the complexity here has to do with supporting input suspension.
+ * If the data source module demands suspension, we want to be able to back
+ * up to the start of the current MCU.  To do this, we copy state variables
+ * into local working storage, and update them back to the permanent
+ * storage only upon successful completion of an MCU.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdhuff.h"      /* Declarations shared with jdhuff.c */
+
+
+#ifdef D_PROGRESSIVE_SUPPORTED
+
+/*
+ * Expanded entropy decoder object for progressive Huffman decoding.
+ *
+ * The savable_state subrecord contains fields that change within an MCU,
+ * but must not be updated permanently until we complete the MCU.
+ */
+
+typedef struct {
+    unsigned int EOBRUN;        /* remaining EOBs in EOBRUN */
+    int          last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+} savable_state;
+
+/* This macro is to work around compilers with missing or broken
+ * structure assignment.  You'll need to fix this code if you have
+ * such a compiler and you change MAX_COMPS_IN_SCAN.
+ */
+
+#ifndef NO_STRUCT_ASSIGN
+#define ASSIGN_STATE( dest, src )  ( ( dest ) = ( src ) )
+#else
+#if MAX_COMPS_IN_SCAN == 4
+#define ASSIGN_STATE( dest, src )  \
+    ( ( dest ).EOBRUN = ( src ).EOBRUN, \
+     ( dest ).last_dc_val[0] = ( src ).last_dc_val[0], \
+     ( dest ).last_dc_val[1] = ( src ).last_dc_val[1], \
+     ( dest ).last_dc_val[2] = ( src ).last_dc_val[2], \
+     ( dest ).last_dc_val[3] = ( src ).last_dc_val[3] )
+#endif
+#endif
+
+
+typedef struct {
+    struct jpeg_entropy_decoder pub;/* public fields */
+
+    /* These fields are loaded into local variables at start of each MCU.
+     * In case of suspension, we exit WITHOUT updating them.
+     */
+    bitread_perm_state bitstate;/* Bit buffer at start of MCU */
+    savable_state      saved; /* Other state at start of MCU */
+
+    /* These fields are NOT loaded into local working state. */
+    unsigned int restarts_to_go;/* MCUs left in this restart interval */
+
+    /* Pointers to derived tables (these workspaces have image lifespan) */
+    d_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
+
+    d_derived_tbl * ac_derived_tbl;/* active table during an AC scan */
+} phuff_entropy_decoder;
+
+typedef phuff_entropy_decoder * phuff_entropy_ptr;
+
+/* Forward declarations */
+METHODDEF boolean decode_mcu_DC_first JPP( ( j_decompress_ptr cinfo,
+                                             JBLOCKROW * MCU_data ) );
+METHODDEF boolean decode_mcu_AC_first JPP( ( j_decompress_ptr cinfo,
+                                             JBLOCKROW * MCU_data ) );
+METHODDEF boolean decode_mcu_DC_refine JPP( ( j_decompress_ptr cinfo,
+                                              JBLOCKROW * MCU_data ) );
+METHODDEF boolean decode_mcu_AC_refine JPP( ( j_decompress_ptr cinfo,
+                                              JBLOCKROW * MCU_data ) );
+
+
+/*
+ * Initialize for a Huffman-compressed scan.
+ */
+
+METHODDEF void
+start_pass_phuff_decoder( j_decompress_ptr cinfo ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    boolean is_DC_band, bad;
+    int ci, coefi, tbl;
+    int * coef_bit_ptr;
+    jpeg_component_info * compptr;
+
+    is_DC_band = ( cinfo->Ss == 0 );
+
+    /* Validate scan parameters */
+    bad = FALSE;
+    if ( is_DC_band ) {
+        if ( cinfo->Se != 0 ) {
+            bad = TRUE;
+        }
+    } else {
+        /* need not check Ss/Se < 0 since they came from unsigned bytes */
+        if ( ( cinfo->Ss > cinfo->Se ) || ( cinfo->Se >= DCTSIZE2 ) ) {
+            bad = TRUE;
+        }
+        /* AC scans may have only one component */
+        if ( cinfo->comps_in_scan != 1 ) {
+            bad = TRUE;
+        }
+    }
+    if ( cinfo->Ah != 0 ) {
+        /* Successive approximation refinement scan: must have Al = Ah-1. */
+        if ( cinfo->Al != cinfo->Ah - 1 ) {
+            bad = TRUE;
+        }
+    }
+    if ( cinfo->Al > 13 ) { /* need not check for < 0 */
+        bad = TRUE;
+    }
+    if ( bad ) {
+        ERREXIT4( cinfo, JERR_BAD_PROGRESSION,
+                  cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al );
+    }
+    /* Update progression status, and verify that scan order is legal.
+     * Note that inter-scan inconsistencies are treated as warnings
+     * not fatal errors ... not clear if this is right way to behave.
+     */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        int cindex = cinfo->cur_comp_info[ci]->component_index;
+        coef_bit_ptr = &cinfo->coef_bits[cindex][0];
+        if ( ( !is_DC_band ) && ( coef_bit_ptr[0] < 0 ) ) {/* AC without prior DC scan */
+            WARNMS2( cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0 );
+        }
+        for ( coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++ ) {
+            int expected = ( coef_bit_ptr[coefi] < 0 ) ? 0 : coef_bit_ptr[coefi];
+            if ( cinfo->Ah != expected ) {
+                WARNMS2( cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi );
+            }
+            coef_bit_ptr[coefi] = cinfo->Al;
+        }
+    }
+
+    /* Select MCU decoding routine */
+    if ( cinfo->Ah == 0 ) {
+        if ( is_DC_band ) {
+            entropy->pub.decode_mcu = decode_mcu_DC_first;
+        } else {
+            entropy->pub.decode_mcu = decode_mcu_AC_first;
+        }
+    } else {
+        if ( is_DC_band ) {
+            entropy->pub.decode_mcu = decode_mcu_DC_refine;
+        } else {
+            entropy->pub.decode_mcu = decode_mcu_AC_refine;
+        }
+    }
+
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        compptr = cinfo->cur_comp_info[ci];
+        /* Make sure requested tables are present, and compute derived tables.
+         * We may build same derived table more than once, but it's not expensive.
+         */
+        if ( is_DC_band ) {
+            if ( cinfo->Ah == 0 ) {/* DC refinement needs no table */
+                tbl = compptr->dc_tbl_no;
+                if ( ( tbl < 0 ) || ( tbl >= NUM_HUFF_TBLS ) ||
+                    ( cinfo->dc_huff_tbl_ptrs[tbl] == NULL ) ) {
+                    ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, tbl );
+                }
+                jpeg_make_d_derived_tbl( cinfo, cinfo->dc_huff_tbl_ptrs[tbl],
+                                         &entropy->derived_tbls[tbl] );
+            }
+        } else {
+            tbl = compptr->ac_tbl_no;
+            if ( ( tbl < 0 ) || ( tbl >= NUM_HUFF_TBLS ) ||
+                ( cinfo->ac_huff_tbl_ptrs[tbl] == NULL ) ) {
+                ERREXIT1( cinfo, JERR_NO_HUFF_TABLE, tbl );
+            }
+            jpeg_make_d_derived_tbl( cinfo, cinfo->ac_huff_tbl_ptrs[tbl],
+                                     &entropy->derived_tbls[tbl] );
+            /* remember the single active table */
+            entropy->ac_derived_tbl = entropy->derived_tbls[tbl];
+        }
+        /* Initialize DC predictions to 0 */
+        entropy->saved.last_dc_val[ci] = 0;
+    }
+
+    /* Initialize bitread state variables */
+    entropy->bitstate.bits_left = 0;
+    entropy->bitstate.get_buffer = 0;/* unnecessary, but keeps Purify quiet */
+    entropy->bitstate.printed_eod = FALSE;
+
+    /* Initialize private state variables */
+    entropy->saved.EOBRUN = 0;
+
+    /* Initialize restart counter */
+    entropy->restarts_to_go = cinfo->restart_interval;
+}
+
+
+/*
+ * Figure F.12: extend sign bit.
+ * On some machines, a shift and add will be faster than a table lookup.
+ */
+
+#ifdef AVOID_TABLES
+
+#define HUFF_EXTEND( x, s )  ( ( x ) < ( 1 << ( ( s ) - 1 ) ) ? ( x ) + ( ( ( -1 ) << ( s ) ) + 1 ) : ( x ) )
+
+#else
+
+#define HUFF_EXTEND( x, s )  ( ( x ) < extend_test[s] ? ( x ) + extend_offset[s] : ( x ) )
+
+static const int extend_test[16] =   /* entry n is 2**(n-1) */
+{ 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
+  0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
+
+static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
+{ 0, ( ( -1 ) << 1 ) + 1, ( ( -1 ) << 2 ) + 1, ( ( -1 ) << 3 ) + 1, ( ( -1 ) << 4 ) + 1,
+  ( ( -1 ) << 5 ) + 1, ( ( -1 ) << 6 ) + 1, ( ( -1 ) << 7 ) + 1, ( ( -1 ) << 8 ) + 1,
+  ( ( -1 ) << 9 ) + 1, ( ( -1 ) << 10 ) + 1, ( ( -1 ) << 11 ) + 1, ( ( -1 ) << 12 ) + 1,
+  ( ( -1 ) << 13 ) + 1, ( ( -1 ) << 14 ) + 1, ( ( -1 ) << 15 ) + 1 };
+
+#endif /* AVOID_TABLES */
+
+
+/*
+ * Check for a restart marker & resynchronize decoder.
+ * Returns FALSE if must suspend.
+ */
+
+LOCAL boolean
+process_restart( j_decompress_ptr cinfo ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    int ci;
+
+    /* Throw away any unused bits remaining in bit buffer; */
+    /* include any full bytes in next_marker's count of discarded bytes */
+    cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
+    entropy->bitstate.bits_left = 0;
+
+    /* Advance past the RSTn marker */
+    if ( !( *cinfo->marker->read_restart_marker )( cinfo ) ) {
+        return FALSE;
+    }
+
+    /* Re-initialize DC predictions to 0 */
+    for ( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
+        entropy->saved.last_dc_val[ci] = 0;
+    }
+    /* Re-init EOB run count, too */
+    entropy->saved.EOBRUN = 0;
+
+    /* Reset restart counter */
+    entropy->restarts_to_go = cinfo->restart_interval;
+
+    /* Next segment can get another out-of-data warning */
+    entropy->bitstate.printed_eod = FALSE;
+
+    return TRUE;
+}
+
+
+/*
+ * Huffman MCU decoding.
+ * Each of these routines decodes and returns one MCU's worth of
+ * Huffman-compressed coefficients.
+ * The coefficients are reordered from zigzag order into natural array order,
+ * but are not dequantized.
+ *
+ * The i'th block of the MCU is stored into the block pointed to by
+ * MCU_data[i].  WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.
+ *
+ * We return FALSE if data source requested suspension.  In that case no
+ * changes have been made to permanent state.  (Exception: some output
+ * coefficients may already have been assigned.  This is harmless for
+ * spectral selection, since we'll just re-assign them on the next call.
+ * Successive approximation AC refinement has to be more careful, however.)
+ */
+
+/*
+ * MCU decoding for DC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF boolean
+decode_mcu_DC_first( j_decompress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    int Al = cinfo->Al;
+    register int s, r;
+    int blkn, ci;
+    JBLOCKROW block;
+    BITREAD_STATE_VARS;
+    savable_state state;
+    d_derived_tbl * tbl;
+    jpeg_component_info * compptr;
+
+    /* Process restart marker if needed; may have to suspend */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            if ( !process_restart( cinfo ) ) {
+                return FALSE;
+            }
+        }
+    }
+
+    /* Load up working state */
+    BITREAD_LOAD_STATE( cinfo, entropy->bitstate );
+    ASSIGN_STATE( state, entropy->saved );
+
+    /* Outer loop handles each block in the MCU */
+
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        block = MCU_data[blkn];
+        ci = cinfo->MCU_membership[blkn];
+        compptr = cinfo->cur_comp_info[ci];
+        tbl = entropy->derived_tbls[compptr->dc_tbl_no];
+
+        /* Decode a single block's worth of coefficients */
+
+        /* Section F.2.2.1: decode the DC coefficient difference */
+        HUFF_DECODE( s, br_state, tbl, return FALSE, label1 );
+        if ( s ) {
+            CHECK_BIT_BUFFER( br_state, s, return FALSE );
+
+            r = GET_BITS( s );
+            s = HUFF_EXTEND( r, s );
+        }
+
+        /* Convert DC difference to actual value, update last_dc_val */
+        s += state.last_dc_val[ci];
+        state.last_dc_val[ci] = s;
+        /* Scale and output the DC coefficient (assumes jpeg_natural_order[0]=0) */
+        ( *block )[0] = (JCOEF) ( s << Al );
+    }
+
+    /* Completed MCU, so update state */
+    BITREAD_SAVE_STATE( cinfo, entropy->bitstate );
+    ASSIGN_STATE( entropy->saved, state );
+
+    /* Account for restart interval (no-op if not using restarts) */
+    entropy->restarts_to_go--;
+
+    return TRUE;
+}
+
+
+/*
+ * MCU decoding for AC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF boolean
+decode_mcu_AC_first( j_decompress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    int Se = cinfo->Se;
+    int Al = cinfo->Al;
+    register int s, k, r;
+    unsigned int EOBRUN;
+    JBLOCKROW block;
+    BITREAD_STATE_VARS;
+    d_derived_tbl * tbl;
+
+    /* Process restart marker if needed; may have to suspend */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            if ( !process_restart( cinfo ) ) {
+                return FALSE;
+            }
+        }
+    }
+
+    /* Load up working state.
+     * We can avoid loading/saving bitread state if in an EOB run.
+     */
+    EOBRUN = entropy->saved.EOBRUN;/* only part of saved state we care about */
+
+    /* There is always only one block per MCU */
+
+    if ( EOBRUN > 0 ) { /* if it's a band of zeroes... */
+        EOBRUN--;
+    }                   /* ...process it now (we do nothing) */
+    else {
+        BITREAD_LOAD_STATE( cinfo, entropy->bitstate );
+        block = MCU_data[0];
+        tbl = entropy->ac_derived_tbl;
+
+        for ( k = cinfo->Ss; k <= Se; k++ ) {
+            HUFF_DECODE( s, br_state, tbl, return FALSE, label2 );
+            r = s >> 4;
+            s &= 15;
+            if ( s ) {
+                k += r;
+
+                CHECK_BIT_BUFFER( br_state, s, return FALSE );
+                r = GET_BITS( s );
+                s = HUFF_EXTEND( r, s );
+                /* Scale and output coefficient in natural (dezigzagged) order */
+                ( *block )[jpeg_natural_order[k]] = (JCOEF) ( s << Al );
+            } else {
+                if ( r == 15 ) {/* ZRL */
+                    k += 15;/* skip 15 zeroes in band */
+                } else {/* EOBr, run length is 2^r + appended bits */
+                    EOBRUN = 1 << r;
+                    if ( r ) {/* EOBr, r > 0 */
+                        CHECK_BIT_BUFFER( br_state, r, return FALSE );
+                        r = GET_BITS( r );
+                        EOBRUN += r;
+                    }
+                    EOBRUN--; /* this band is processed at this moment */
+                    break; /* force end-of-band */
+                }
+            }
+        }
+
+        BITREAD_SAVE_STATE( cinfo, entropy->bitstate );
+    }
+
+    /* Completed MCU, so update state */
+    entropy->saved.EOBRUN = EOBRUN;/* only part of saved state we care about */
+
+    /* Account for restart interval (no-op if not using restarts) */
+    entropy->restarts_to_go--;
+
+    return TRUE;
+}
+
+
+/*
+ * MCU decoding for DC successive approximation refinement scan.
+ * Note: we assume such scans can be multi-component, although the spec
+ * is not very clear on the point.
+ */
+
+METHODDEF boolean
+decode_mcu_DC_refine( j_decompress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    int p1 = 1 << cinfo->Al;/* 1 in the bit position being coded */
+    int blkn;
+    JBLOCKROW block;
+    BITREAD_STATE_VARS;
+
+    /* Process restart marker if needed; may have to suspend */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            if ( !process_restart( cinfo ) ) {
+                return FALSE;
+            }
+        }
+    }
+
+    /* Load up working state */
+    BITREAD_LOAD_STATE( cinfo, entropy->bitstate );
+
+    /* Outer loop handles each block in the MCU */
+
+    for ( blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++ ) {
+        block = MCU_data[blkn];
+
+        /* Encoded data is simply the next bit of the two's-complement DC value */
+        CHECK_BIT_BUFFER( br_state, 1, return FALSE );
+        if ( GET_BITS( 1 ) ) {
+            ( *block )[0] |= p1;
+        }
+        /* Note: since we use |=, repeating the assignment later is safe */
+    }
+
+    /* Completed MCU, so update state */
+    BITREAD_SAVE_STATE( cinfo, entropy->bitstate );
+
+    /* Account for restart interval (no-op if not using restarts) */
+    entropy->restarts_to_go--;
+
+    return TRUE;
+}
+
+
+/*
+ * MCU decoding for AC successive approximation refinement scan.
+ */
+
+METHODDEF boolean
+decode_mcu_AC_refine( j_decompress_ptr cinfo, JBLOCKROW * MCU_data ) {
+    phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+    int Se = cinfo->Se;
+    int p1 = 1 << cinfo->Al;/* 1 in the bit position being coded */
+    int m1 = ( -1 ) << cinfo->Al;/* -1 in the bit position being coded */
+    register int s, k, r;
+    unsigned int EOBRUN;
+    JBLOCKROW block;
+    JCOEFPTR thiscoef;
+    BITREAD_STATE_VARS;
+    d_derived_tbl * tbl;
+    int num_newnz;
+    int newnz_pos[DCTSIZE2];
+
+    /* Process restart marker if needed; may have to suspend */
+    if ( cinfo->restart_interval ) {
+        if ( entropy->restarts_to_go == 0 ) {
+            if ( !process_restart( cinfo ) ) {
+                return FALSE;
+            }
+        }
+    }
+
+    /* Load up working state */
+    BITREAD_LOAD_STATE( cinfo, entropy->bitstate );
+    EOBRUN = entropy->saved.EOBRUN;/* only part of saved state we care about */
+
+    /* There is always only one block per MCU */
+    block = MCU_data[0];
+    tbl = entropy->ac_derived_tbl;
+
+    /* If we are forced to suspend, we must undo the assignments to any newly
+     * nonzero coefficients in the block, because otherwise we'd get confused
+     * next time about which coefficients were already nonzero.
+     * But we need not undo addition of bits to already-nonzero coefficients;
+     * instead, we can test the current bit position to see if we already did it.
+     */
+    num_newnz = 0;
+
+    /* initialize coefficient loop counter to start of band */
+    k = cinfo->Ss;
+
+    if ( EOBRUN == 0 ) {
+        for (; k <= Se; k++ ) {
+            HUFF_DECODE( s, br_state, tbl, goto undoit, label3 );
+            r = s >> 4;
+            s &= 15;
+            if ( s ) {
+                if ( s != 1 ) {/* size of new coef should always be 1 */
+                    WARNMS( cinfo, JWRN_HUFF_BAD_CODE );
+                }
+                CHECK_BIT_BUFFER( br_state, 1, goto undoit );
+                if ( GET_BITS( 1 ) ) {
+                    s = p1;
+                }   /* newly nonzero coef is positive */
+                else {
+                    s = m1;
+                }   /* newly nonzero coef is negative */
+            } else {
+                if ( r != 15 ) {
+                    EOBRUN = 1 << r;/* EOBr, run length is 2^r + appended bits */
+                    if ( r ) {
+                        CHECK_BIT_BUFFER( br_state, r, goto undoit );
+                        r = GET_BITS( r );
+                        EOBRUN += r;
+                    }
+                    break; /* rest of block is handled by EOB logic */
+                }
+                /* note s = 0 for processing ZRL */
+            }
+            /* Advance over already-nonzero coefs and r still-zero coefs,
+             * appending correction bits to the nonzeroes.  A correction bit is 1
+             * if the absolute value of the coefficient must be increased.
+             */
+            do {
+                thiscoef = *block + jpeg_natural_order[k];
+                if ( *thiscoef != 0 ) {
+                    CHECK_BIT_BUFFER( br_state, 1, goto undoit );
+                    if ( GET_BITS( 1 ) ) {
+                        if ( ( *thiscoef & p1 ) == 0 ) {/* do nothing if already changed it */
+                            if ( *thiscoef >= 0 ) {
+                                *thiscoef += p1;
+                            } else {
+                                *thiscoef += m1;
+                            }
+                        }
+                    }
+                } else {
+                    if ( --r < 0 ) {
+                        break;
+                    } /* reached target zero coefficient */
+                }
+                k++;
+            } while ( k <= Se );
+            if ( s ) {
+                int pos = jpeg_natural_order[k];
+                /* Output newly nonzero coefficient */
+                ( *block )[pos] = (JCOEF) s;
+                /* Remember its position in case we have to suspend */
+                newnz_pos[num_newnz++] = pos;
+            }
+        }
+    }
+
+    if ( EOBRUN > 0 ) {
+        /* Scan any remaining coefficient positions after the end-of-band
+         * (the last newly nonzero coefficient, if any).  Append a correction
+         * bit to each already-nonzero coefficient.  A correction bit is 1
+         * if the absolute value of the coefficient must be increased.
+         */
+        for (; k <= Se; k++ ) {
+            thiscoef = *block + jpeg_natural_order[k];
+            if ( *thiscoef != 0 ) {
+                CHECK_BIT_BUFFER( br_state, 1, goto undoit );
+                if ( GET_BITS( 1 ) ) {
+                    if ( ( *thiscoef & p1 ) == 0 ) {/* do nothing if already changed it */
+                        if ( *thiscoef >= 0 ) {
+                            *thiscoef += p1;
+                        } else {
+                            *thiscoef += m1;
+                        }
+                    }
+                }
+            }
+        }
+        /* Count one block completed in EOB run */
+        EOBRUN--;
+    }
+
+    /* Completed MCU, so update state */
+    BITREAD_SAVE_STATE( cinfo, entropy->bitstate );
+    entropy->saved.EOBRUN = EOBRUN;/* only part of saved state we care about */
+
+    /* Account for restart interval (no-op if not using restarts) */
+    entropy->restarts_to_go--;
+
+    return TRUE;
+
+undoit:
+    /* Re-zero any output coefficients that we made newly nonzero */
+    while ( num_newnz > 0 ) {
+        ( *block )[newnz_pos[--num_newnz]] = 0;
+    }
+
+    return FALSE;
+}
+
+
+/*
+ * Module initialization routine for progressive Huffman entropy decoding.
+ */
+
+GLOBAL void
+jinit_phuff_decoder( j_decompress_ptr cinfo ) {
+    phuff_entropy_ptr entropy;
+    int * coef_bit_ptr;
+    int ci, i;
+
+    entropy = (phuff_entropy_ptr)
+              ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                           SIZEOF( phuff_entropy_decoder ) );
+    cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
+    entropy->pub.start_pass = start_pass_phuff_decoder;
+
+    /* Mark derived tables unallocated */
+    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
+        entropy->derived_tbls[i] = NULL;
+    }
+
+    /* Create progression status table */
+    cinfo->coef_bits = ( int ( * )[DCTSIZE2] )
+                       ( *cinfo->mem->alloc_small ) ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                                     cinfo->num_components * DCTSIZE2 * SIZEOF( int ) );
+    coef_bit_ptr = &cinfo->coef_bits[0][0];
+    for ( ci = 0; ci < cinfo->num_components; ci++ ) {
+        for ( i = 0; i < DCTSIZE2; i++ ) {
+            *coef_bit_ptr++ = -1;
+        }
+    }
+}
+
+#endif /* D_PROGRESSIVE_SUPPORTED */

neo/renderer/jpeg-6/jdpostct.cpp

@@ -0,0 +1,290 @@
+/*
+ * jdpostct.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the decompression postprocessing controller.
+ * This controller manages the upsampling, color conversion, and color
+ * quantization/reduction steps; specifically, it controls the buffering
+ * between upsample/color conversion and color quantization/reduction.
+ *
+ * If no color quantization/reduction is required, then this module has no
+ * work to do, and it just hands off to the upsample/color conversion code.
+ * An integrated upsample/convert/quantize process would replace this module
+ * entirely.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private buffer controller object */
+
+typedef struct {
+    struct jpeg_d_post_controller pub;/* public fields */
+
+    /* Color quantization source buffer: this holds output data from
+     * the upsample/color conversion step to be passed to the quantizer.
+     * For two-pass color quantization, we need a full-image buffer;
+     * for one-pass operation, a strip buffer is sufficient.
+     */
+    jvirt_sarray_ptr whole_image;/* virtual array, or NULL if one-pass */
+    JSAMPARRAY       buffer;/* strip buffer, or current strip of virtual */
+    JDIMENSION       strip_height; /* buffer size in rows */
+    /* for two-pass mode only: */
+    JDIMENSION starting_row;/* row # of first row in current strip */
+    JDIMENSION next_row;    /* index of next row to fill/empty in strip */
+} my_post_controller;
+
+typedef my_post_controller * my_post_ptr;
+
+
+/* Forward declarations */
+METHODDEF void post_process_1pass
+JPP( ( j_decompress_ptr cinfo,
+       JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+       JDIMENSION in_row_groups_avail,
+       JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+       JDIMENSION out_rows_avail ) );
+#ifdef QUANT_2PASS_SUPPORTED
+METHODDEF void post_process_prepass
+JPP( ( j_decompress_ptr cinfo,
+       JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+       JDIMENSION in_row_groups_avail,
+       JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+       JDIMENSION out_rows_avail ) );
+METHODDEF void post_process_2pass
+JPP( ( j_decompress_ptr cinfo,
+       JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+       JDIMENSION in_row_groups_avail,
+       JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+       JDIMENSION out_rows_avail ) );
+#endif
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF void
+start_pass_dpost( j_decompress_ptr cinfo, J_BUF_MODE pass_mode ) {
+    my_post_ptr post = (my_post_ptr) cinfo->post;
+
+    switch ( pass_mode ) {
+        case JBUF_PASS_THRU:
+            if ( cinfo->quantize_colors ) {
+                /* Single-pass processing with color quantization. */
+                post->pub.post_process_data = post_process_1pass;
+                /* We could be doing buffered-image output before starting a 2-pass
+                 * color quantization; in that case, jinit_d_post_controller did not
+                 * allocate a strip buffer.  Use the virtual-array buffer as workspace.
+                 */
+                if ( post->buffer == NULL ) {
+                    post->buffer = ( *cinfo->mem->access_virt_sarray )
+                                   ( (j_common_ptr) cinfo, post->whole_image,
+                                    (JDIMENSION) 0, post->strip_height, TRUE );
+                }
+            } else {
+                /* For single-pass processing without color quantization,
+                 * I have no work to do; just call the upsampler directly.
+                 */
+                post->pub.post_process_data = cinfo->upsample->upsample;
+            }
+            break;
+#ifdef QUANT_2PASS_SUPPORTED
+        case JBUF_SAVE_AND_PASS:
+            /* First pass of 2-pass quantization */
+            if ( post->whole_image == NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+            post->pub.post_process_data = post_process_prepass;
+            break;
+        case JBUF_CRANK_DEST:
+            /* Second pass of 2-pass quantization */
+            if ( post->whole_image == NULL ) {
+                ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            }
+            post->pub.post_process_data = post_process_2pass;
+            break;
+#endif /* QUANT_2PASS_SUPPORTED */
+        default:
+            ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+            break;
+    }
+    post->starting_row = post->next_row = 0;
+}
+
+
+/*
+ * Process some data in the one-pass (strip buffer) case.
+ * This is used for color precision reduction as well as one-pass quantization.
+ */
+
+METHODDEF void
+post_process_1pass( j_decompress_ptr cinfo,
+                    JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+                    JDIMENSION in_row_groups_avail,
+                    JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                    JDIMENSION out_rows_avail ) {
+    my_post_ptr post = (my_post_ptr) cinfo->post;
+    JDIMENSION num_rows, max_rows;
+
+    /* Fill the buffer, but not more than what we can dump out in one go. */
+    /* Note we rely on the upsampler to detect bottom of image. */
+    max_rows = out_rows_avail - *out_row_ctr;
+    if ( max_rows > post->strip_height ) {
+        max_rows = post->strip_height;
+    }
+    num_rows = 0;
+    ( *cinfo->upsample->upsample )( cinfo,
+                                    input_buf, in_row_group_ctr, in_row_groups_avail,
+                                    post->buffer, &num_rows, max_rows );
+    /* Quantize and emit data. */
+    ( *cinfo->cquantize->color_quantize )( cinfo,
+                                           post->buffer, output_buf + *out_row_ctr, (int) num_rows );
+    *out_row_ctr += num_rows;
+}
+
+
+#ifdef QUANT_2PASS_SUPPORTED
+
+/*
+ * Process some data in the first pass of 2-pass quantization.
+ */
+
+METHODDEF void
+post_process_prepass( j_decompress_ptr cinfo,
+                      JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+                      JDIMENSION in_row_groups_avail,
+                      JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                      JDIMENSION out_rows_avail ) {
+    my_post_ptr post = (my_post_ptr) cinfo->post;
+    JDIMENSION old_next_row, num_rows;
+
+    /* Reposition virtual buffer if at start of strip. */
+    if ( post->next_row == 0 ) {
+        post->buffer = ( *cinfo->mem->access_virt_sarray )
+                       ( (j_common_ptr) cinfo, post->whole_image,
+                        post->starting_row, post->strip_height, TRUE );
+    }
+
+    /* Upsample some data (up to a strip height's worth). */
+    old_next_row = post->next_row;
+    ( *cinfo->upsample->upsample )( cinfo,
+                                    input_buf, in_row_group_ctr, in_row_groups_avail,
+                                    post->buffer, &post->next_row, post->strip_height );
+
+    /* Allow quantizer to scan new data.  No data is emitted, */
+    /* but we advance out_row_ctr so outer loop can tell when we're done. */
+    if ( post->next_row > old_next_row ) {
+        num_rows = post->next_row - old_next_row;
+        ( *cinfo->cquantize->color_quantize )( cinfo, post->buffer + old_next_row,
+                                               (JSAMPARRAY) NULL, (int) num_rows );
+        *out_row_ctr += num_rows;
+    }
+
+    /* Advance if we filled the strip. */
+    if ( post->next_row >= post->strip_height ) {
+        post->starting_row += post->strip_height;
+        post->next_row = 0;
+    }
+}
+
+
+/*
+ * Process some data in the second pass of 2-pass quantization.
+ */
+
+METHODDEF void
+post_process_2pass( j_decompress_ptr cinfo,
+                    JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+                    JDIMENSION in_row_groups_avail,
+                    JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+                    JDIMENSION out_rows_avail ) {
+    my_post_ptr post = (my_post_ptr) cinfo->post;
+    JDIMENSION num_rows, max_rows;
+
+    /* Reposition virtual buffer if at start of strip. */
+    if ( post->next_row == 0 ) {
+        post->buffer = ( *cinfo->mem->access_virt_sarray )
+                       ( (j_common_ptr) cinfo, post->whole_image,
+                        post->starting_row, post->strip_height, FALSE );
+    }
+
+    /* Determine number of rows to emit. */
+    num_rows = post->strip_height - post->next_row;/* available in strip */
+    max_rows = out_rows_avail - *out_row_ctr;/* available in output area */
+    if ( num_rows > max_rows ) {
+        num_rows = max_rows;
+    }
+    /* We have to check bottom of image here, can't depend on upsampler. */
+    max_rows = cinfo->output_height - post->starting_row;
+    if ( num_rows > max_rows ) {
+        num_rows = max_rows;
+    }
+
+    /* Quantize and emit data. */
+    ( *cinfo->cquantize->color_quantize )( cinfo,
+                                           post->buffer + post->next_row, output_buf + *out_row_ctr,
+                                           (int) num_rows );
+    *out_row_ctr += num_rows;
+
+    /* Advance if we filled the strip. */
+    post->next_row += num_rows;
+    if ( post->next_row >= post->strip_height ) {
+        post->starting_row += post->strip_height;
+        post->next_row = 0;
+    }
+}
+
+#endif /* QUANT_2PASS_SUPPORTED */
+
+
+/*
+ * Initialize postprocessing controller.
+ */
+
+GLOBAL void
+jinit_d_post_controller( j_decompress_ptr cinfo, boolean need_full_buffer ) {
+    my_post_ptr post;
+
+    post = (my_post_ptr)
+           ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                        SIZEOF( my_post_controller ) );
+    cinfo->post = (struct jpeg_d_post_controller *) post;
+    post->pub.start_pass = start_pass_dpost;
+    post->whole_image = NULL;/* flag for no virtual arrays */
+    post->buffer = NULL;    /* flag for no strip buffer */
+
+    /* Create the quantization buffer, if needed */
+    if ( cinfo->quantize_colors ) {
+        /* The buffer strip height is max_v_samp_factor, which is typically
+         * an efficient number of rows for upsampling to return.
+         * (In the presence of output rescaling, we might want to be smarter?)
+         */
+        post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
+        if ( need_full_buffer ) {
+            /* Two-pass color quantization: need full-image storage. */
+            /* We round up the number of rows to a multiple of the strip height. */
+#ifdef QUANT_2PASS_SUPPORTED
+            post->whole_image = ( *cinfo->mem->request_virt_sarray )
+                                ( (j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+                                 cinfo->output_width * cinfo->out_color_components,
+                                 (JDIMENSION) jround_up( (long) cinfo->output_height,
+                                                        (long) post->strip_height ),
+                                 post->strip_height );
+#else
+            ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
+#endif /* QUANT_2PASS_SUPPORTED */
+        } else {
+            /* One-pass color quantization: just make a strip buffer. */
+            post->buffer = ( *cinfo->mem->alloc_sarray )
+                           ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                            cinfo->output_width * cinfo->out_color_components,
+                            post->strip_height );
+        }
+    }
+}

neo/renderer/jpeg-6/jdsample.cpp

@@ -0,0 +1,478 @@
+/*
+ * jdsample.c
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains upsampling routines.
+ *
+ * Upsampling input data is counted in "row groups".  A row group
+ * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
+ * sample rows of each component.  Upsampling will normally produce
+ * max_v_samp_factor pixel rows from each row group (but this could vary
+ * if the upsampler is applying a scale factor of its own).
+ *
+ * An excellent reference for image resampling is
+ *   Digital Image Warping, George Wolberg, 1990.
+ *   Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Pointer to routine to upsample a single component */
+typedef JMETHOD ( void, upsample1_ptr,
+                 ( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                   JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) );
+
+/* Private subobject */
+
+typedef struct {
+    struct jpeg_upsampler pub;  /* public fields */
+
+    /* Color conversion buffer.  When using separate upsampling and color
+     * conversion steps, this buffer holds one upsampled row group until it
+     * has been color converted and output.
+     * Note: we do not allocate any storage for component(s) which are full-size,
+     * ie do not need rescaling.  The corresponding entry of color_buf[] is
+     * simply set to point to the input data array, thereby avoiding copying.
+     */
+    JSAMPARRAY color_buf[MAX_COMPONENTS];
+
+    /* Per-component upsampling method pointers */
+    upsample1_ptr methods[MAX_COMPONENTS];
+
+    int        next_row_out; /* counts rows emitted from color_buf */
+    JDIMENSION rows_to_go;  /* counts rows remaining in image */
+
+    /* Height of an input row group for each component. */
+    int rowgroup_height[MAX_COMPONENTS];
+
+    /* These arrays save pixel expansion factors so that int_expand need not
+     * recompute them each time.  They are unused for other upsampling methods.
+     */
+    UINT8 h_expand[MAX_COMPONENTS];
+    UINT8 v_expand[MAX_COMPONENTS];
+} my_upsampler;
+
+typedef my_upsampler * my_upsample_ptr;
+
+
+/*
+ * Initialize for an upsampling pass.
+ */
+
+METHODDEF void
+start_pass_upsample( j_decompress_ptr cinfo ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+
+    /* Mark the conversion buffer empty */
+    upsample->next_row_out = cinfo->max_v_samp_factor;
+    /* Initialize total-height counter for detecting bottom of image */
+    upsample->rows_to_go = cinfo->output_height;
+}
+
+
+/*
+ * Control routine to do upsampling (and color conversion).
+ *
+ * In this version we upsample each component independently.
+ * We upsample one row group into the conversion buffer, then apply
+ * color conversion a row at a time.
+ */
+
+METHODDEF void
+sep_upsample( j_decompress_ptr cinfo,
+              JSAMPIMAGE input_buf, JDIMENSION * in_row_group_ctr,
+              JDIMENSION in_row_groups_avail,
+              JSAMPARRAY output_buf, JDIMENSION * out_row_ctr,
+              JDIMENSION out_rows_avail ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+    int ci;
+    jpeg_component_info * compptr;
+    JDIMENSION num_rows;
+
+    /* Fill the conversion buffer, if it's empty */
+    if ( upsample->next_row_out >= cinfo->max_v_samp_factor ) {
+        for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+              ci++, compptr++ ) {
+            /* Invoke per-component upsample method.  Notice we pass a POINTER
+             * to color_buf[ci], so that fullsize_upsample can change it.
+             */
+            ( *upsample->methods[ci] )( cinfo, compptr,
+                                        input_buf[ci] + ( *in_row_group_ctr * upsample->rowgroup_height[ci] ),
+                                        upsample->color_buf + ci );
+        }
+        upsample->next_row_out = 0;
+    }
+
+    /* Color-convert and emit rows */
+
+    /* How many we have in the buffer: */
+    num_rows = (JDIMENSION) ( cinfo->max_v_samp_factor - upsample->next_row_out );
+    /* Not more than the distance to the end of the image.  Need this test
+     * in case the image height is not a multiple of max_v_samp_factor:
+     */
+    if ( num_rows > upsample->rows_to_go ) {
+        num_rows = upsample->rows_to_go;
+    }
+    /* And not more than what the client can accept: */
+    out_rows_avail -= *out_row_ctr;
+    if ( num_rows > out_rows_avail ) {
+        num_rows = out_rows_avail;
+    }
+
+    ( *cinfo->cconvert->color_convert )( cinfo, upsample->color_buf,
+                                         (JDIMENSION) upsample->next_row_out,
+                                         output_buf + *out_row_ctr,
+                                         (int) num_rows );
+
+    /* Adjust counts */
+    *out_row_ctr += num_rows;
+    upsample->rows_to_go -= num_rows;
+    upsample->next_row_out += num_rows;
+    /* When the buffer is emptied, declare this input row group consumed */
+    if ( upsample->next_row_out >= cinfo->max_v_samp_factor ) {
+        ( *in_row_group_ctr )++;
+    }
+}
+
+
+/*
+ * These are the routines invoked by sep_upsample to upsample pixel values
+ * of a single component.  One row group is processed per call.
+ */
+
+
+/*
+ * For full-size components, we just make color_buf[ci] point at the
+ * input buffer, and thus avoid copying any data.  Note that this is
+ * safe only because sep_upsample doesn't declare the input row group
+ * "consumed" until we are done color converting and emitting it.
+ */
+
+METHODDEF void
+fullsize_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                   JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    *output_data_ptr = input_data;
+}
+
+
+/*
+ * This is a no-op version used for "uninteresting" components.
+ * These components will not be referenced by color conversion.
+ */
+
+METHODDEF void
+noop_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+               JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    *output_data_ptr = NULL;/* safety check */
+}
+
+
+/*
+ * This version handles any integral sampling ratios.
+ * This is not used for typical JPEG files, so it need not be fast.
+ * Nor, for that matter, is it particularly accurate: the algorithm is
+ * simple replication of the input pixel onto the corresponding output
+ * pixels.  The hi-falutin sampling literature refers to this as a
+ * "box filter".  A box filter tends to introduce visible artifacts,
+ * so if you are actually going to use 3:1 or 4:1 sampling ratios
+ * you would be well advised to improve this code.
+ */
+
+METHODDEF void
+int_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+              JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+    JSAMPARRAY output_data = *output_data_ptr;
+    register JSAMPROW inptr, outptr;
+    register JSAMPLE invalue;
+    register int h;
+    JSAMPROW outend;
+    int h_expand, v_expand;
+    int inrow, outrow;
+
+    h_expand = upsample->h_expand[compptr->component_index];
+    v_expand = upsample->v_expand[compptr->component_index];
+
+    inrow = outrow = 0;
+    while ( outrow < cinfo->max_v_samp_factor ) {
+        /* Generate one output row with proper horizontal expansion */
+        inptr = input_data[inrow];
+        outptr = output_data[outrow];
+        outend = outptr + cinfo->output_width;
+        while ( outptr < outend ) {
+            invalue = *inptr++;/* don't need GETJSAMPLE() here */
+            for ( h = h_expand; h > 0; h-- ) {
+                *outptr++ = invalue;
+            }
+        }
+        /* Generate any additional output rows by duplicating the first one */
+        if ( v_expand > 1 ) {
+            jcopy_sample_rows( output_data, outrow, output_data, outrow + 1,
+                               v_expand - 1, cinfo->output_width );
+        }
+        inrow++;
+        outrow += v_expand;
+    }
+}
+
+
+/*
+ * Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
+ * It's still a box filter.
+ */
+
+METHODDEF void
+h2v1_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+               JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    JSAMPARRAY output_data = *output_data_ptr;
+    register JSAMPROW inptr, outptr;
+    register JSAMPLE invalue;
+    JSAMPROW outend;
+    int inrow;
+
+    for ( inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++ ) {
+        inptr = input_data[inrow];
+        outptr = output_data[inrow];
+        outend = outptr + cinfo->output_width;
+        while ( outptr < outend ) {
+            invalue = *inptr++;/* don't need GETJSAMPLE() here */
+            *outptr++ = invalue;
+            *outptr++ = invalue;
+        }
+    }
+}
+
+
+/*
+ * Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
+ * It's still a box filter.
+ */
+
+METHODDEF void
+h2v2_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+               JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    JSAMPARRAY output_data = *output_data_ptr;
+    register JSAMPROW inptr, outptr;
+    register JSAMPLE invalue;
+    JSAMPROW outend;
+    int inrow, outrow;
+
+    inrow = outrow = 0;
+    while ( outrow < cinfo->max_v_samp_factor ) {
+        inptr = input_data[inrow];
+        outptr = output_data[outrow];
+        outend = outptr + cinfo->output_width;
+        while ( outptr < outend ) {
+            invalue = *inptr++;/* don't need GETJSAMPLE() here */
+            *outptr++ = invalue;
+            *outptr++ = invalue;
+        }
+        jcopy_sample_rows( output_data, outrow, output_data, outrow + 1,
+                           1, cinfo->output_width );
+        inrow++;
+        outrow += 2;
+    }
+}
+
+
+/*
+ * Fancy processing for the common case of 2:1 horizontal and 1:1 vertical.
+ *
+ * The upsampling algorithm is linear interpolation between pixel centers,
+ * also known as a "triangle filter".  This is a good compromise between
+ * speed and visual quality.  The centers of the output pixels are 1/4 and 3/4
+ * of the way between input pixel centers.
+ *
+ * A note about the "bias" calculations: when rounding fractional values to
+ * integer, we do not want to always round 0.5 up to the next integer.
+ * If we did that, we'd introduce a noticeable bias towards larger values.
+ * Instead, this code is arranged so that 0.5 will be rounded up or down at
+ * alternate pixel locations (a simple ordered dither pattern).
+ */
+
+METHODDEF void
+h2v1_fancy_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                     JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    JSAMPARRAY output_data = *output_data_ptr;
+    register JSAMPROW inptr, outptr;
+    register int invalue;
+    register JDIMENSION colctr;
+    int inrow;
+
+    for ( inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++ ) {
+        inptr = input_data[inrow];
+        outptr = output_data[inrow];
+        /* Special case for first column */
+        invalue = GETJSAMPLE( *inptr++ );
+        *outptr++ = (JSAMPLE) invalue;
+        *outptr++ = (JSAMPLE) ( ( invalue * 3 + GETJSAMPLE( *inptr ) + 2 ) >> 2 );
+
+        for ( colctr = compptr->downsampled_width - 2; colctr > 0; colctr-- ) {
+            /* General case: 3/4 * nearer pixel + 1/4 * further pixel */
+            invalue = GETJSAMPLE( *inptr++ ) * 3;
+            *outptr++ = (JSAMPLE) ( ( invalue + GETJSAMPLE( inptr[-2] ) + 1 ) >> 2 );
+            *outptr++ = (JSAMPLE) ( ( invalue + GETJSAMPLE( *inptr ) + 2 ) >> 2 );
+        }
+
+        /* Special case for last column */
+        invalue = GETJSAMPLE( *inptr );
+        *outptr++ = (JSAMPLE) ( ( invalue * 3 + GETJSAMPLE( inptr[-1] ) + 1 ) >> 2 );
+        *outptr++ = (JSAMPLE) invalue;
+    }
+}
+
+
+/*
+ * Fancy processing for the common case of 2:1 horizontal and 2:1 vertical.
+ * Again a triangle filter; see comments for h2v1 case, above.
+ *
+ * It is OK for us to reference the adjacent input rows because we demanded
+ * context from the main buffer controller (see initialization code).
+ */
+
+METHODDEF void
+h2v2_fancy_upsample( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                     JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr ) {
+    JSAMPARRAY output_data = *output_data_ptr;
+    register JSAMPROW inptr0, inptr1, outptr;
+#if BITS_IN_JSAMPLE == 8
+    register int thiscolsum, lastcolsum, nextcolsum;
+#else
+    register INT32 thiscolsum, lastcolsum, nextcolsum;
+#endif
+    register JDIMENSION colctr;
+    int inrow, outrow, v;
+
+    inrow = outrow = 0;
+    while ( outrow < cinfo->max_v_samp_factor ) {
+        for ( v = 0; v < 2; v++ ) {
+            /* inptr0 points to nearest input row, inptr1 points to next nearest */
+            inptr0 = input_data[inrow];
+            if ( v == 0 ) {/* next nearest is row above */
+                inptr1 = input_data[inrow - 1];
+            } else {/* next nearest is row below */
+                inptr1 = input_data[inrow + 1];
+            }
+            outptr = output_data[outrow++];
+
+            /* Special case for first column */
+            thiscolsum = GETJSAMPLE( *inptr0++ ) * 3 + GETJSAMPLE( *inptr1++ );
+            nextcolsum = GETJSAMPLE( *inptr0++ ) * 3 + GETJSAMPLE( *inptr1++ );
+            *outptr++ = (JSAMPLE) ( ( thiscolsum * 4 + 8 ) >> 4 );
+            *outptr++ = (JSAMPLE) ( ( thiscolsum * 3 + nextcolsum + 7 ) >> 4 );
+            lastcolsum = thiscolsum;
+            thiscolsum = nextcolsum;
+
+            for ( colctr = compptr->downsampled_width - 2; colctr > 0; colctr-- ) {
+                /* General case: 3/4 * nearer pixel + 1/4 * further pixel in each */
+                /* dimension, thus 9/16, 3/16, 3/16, 1/16 overall */
+                nextcolsum = GETJSAMPLE( *inptr0++ ) * 3 + GETJSAMPLE( *inptr1++ );
+                *outptr++ = (JSAMPLE) ( ( thiscolsum * 3 + lastcolsum + 8 ) >> 4 );
+                *outptr++ = (JSAMPLE) ( ( thiscolsum * 3 + nextcolsum + 7 ) >> 4 );
+                lastcolsum = thiscolsum;
+                thiscolsum = nextcolsum;
+            }
+
+            /* Special case for last column */
+            *outptr++ = (JSAMPLE) ( ( thiscolsum * 3 + lastcolsum + 8 ) >> 4 );
+            *outptr++ = (JSAMPLE) ( ( thiscolsum * 4 + 7 ) >> 4 );
+        }
+        inrow++;
+    }
+}
+
+
+/*
+ * Module initialization routine for upsampling.
+ */
+
+GLOBAL void
+jinit_upsampler( j_decompress_ptr cinfo ) {
+    my_upsample_ptr upsample;
+    int ci;
+    jpeg_component_info * compptr;
+    boolean need_buffer, do_fancy;
+    int h_in_group, v_in_group, h_out_group, v_out_group;
+
+    upsample = (my_upsample_ptr)
+               ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                            SIZEOF( my_upsampler ) );
+    cinfo->upsample = (struct jpeg_upsampler *) upsample;
+    upsample->pub.start_pass = start_pass_upsample;
+    upsample->pub.upsample = sep_upsample;
+    upsample->pub.need_context_rows = FALSE;/* until we find out differently */
+
+    if ( cinfo->CCIR601_sampling ) {/* this isn't supported */
+        ERREXIT( cinfo, JERR_CCIR601_NOTIMPL );
+    }
+
+    /* jdmainct.c doesn't support context rows when min_DCT_scaled_size = 1,
+     * so don't ask for it.
+     */
+    do_fancy = cinfo->do_fancy_upsampling && cinfo->min_DCT_scaled_size > 1;
+
+    /* Verify we can handle the sampling factors, select per-component methods,
+     * and create storage as needed.
+     */
+    for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+          ci++, compptr++ ) {
+        /* Compute size of an "input group" after IDCT scaling.  This many samples
+         * are to be converted to max_h_samp_factor * max_v_samp_factor pixels.
+         */
+        h_in_group = ( compptr->h_samp_factor * compptr->DCT_scaled_size ) /
+                     cinfo->min_DCT_scaled_size;
+        v_in_group = ( compptr->v_samp_factor * compptr->DCT_scaled_size ) /
+                     cinfo->min_DCT_scaled_size;
+        h_out_group = cinfo->max_h_samp_factor;
+        v_out_group = cinfo->max_v_samp_factor;
+        upsample->rowgroup_height[ci] = v_in_group;/* save for use later */
+        need_buffer = TRUE;
+        if ( !compptr->component_needed ) {
+            /* Don't bother to upsample an uninteresting component. */
+            upsample->methods[ci] = noop_upsample;
+            need_buffer = FALSE;
+        } else if ( h_in_group == h_out_group && v_in_group == v_out_group ) {
+            /* Fullsize components can be processed without any work. */
+            upsample->methods[ci] = fullsize_upsample;
+            need_buffer = FALSE;
+        } else if ( h_in_group * 2 == h_out_group &&
+                    v_in_group == v_out_group ) {
+            /* Special cases for 2h1v upsampling */
+            if ( ( do_fancy ) && ( compptr->downsampled_width > 2 ) ) {
+                upsample->methods[ci] = h2v1_fancy_upsample;
+            } else {
+                upsample->methods[ci] = h2v1_upsample;
+            }
+        } else if ( h_in_group * 2 == h_out_group &&
+                    v_in_group * 2 == v_out_group ) {
+            /* Special cases for 2h2v upsampling */
+            if ( ( do_fancy ) && ( compptr->downsampled_width > 2 ) ) {
+                upsample->methods[ci] = h2v2_fancy_upsample;
+                upsample->pub.need_context_rows = TRUE;
+            } else {
+                upsample->methods[ci] = h2v2_upsample;
+            }
+        } else if ( ( h_out_group % h_in_group ) == 0 &&
+                   ( v_out_group % v_in_group ) == 0 ) {
+            /* Generic integral-factors upsampling method */
+            upsample->methods[ci] = int_upsample;
+            upsample->h_expand[ci] = (UINT8) ( h_out_group / h_in_group );
+            upsample->v_expand[ci] = (UINT8) ( v_out_group / v_in_group );
+        } else {
+            ERREXIT( cinfo, JERR_FRACT_SAMPLE_NOTIMPL );
+        }
+        if ( need_buffer ) {
+            upsample->color_buf[ci] = ( *cinfo->mem->alloc_sarray )
+                                      ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                       (JDIMENSION) jround_up( (long) cinfo->output_width,
+                                                              (long) cinfo->max_h_samp_factor ),
+                                       (JDIMENSION) cinfo->max_v_samp_factor );
+        }
+    }
+}

neo/renderer/jpeg-6/jdtrans.cpp

@@ -0,0 +1,125 @@
+/*
+ * jdtrans.c
+ *
+ * Copyright (C) 1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains library routines for transcoding decompression,
+ * that is, reading raw DCT coefficient arrays from an input JPEG file.
+ * The routines in jdapimin.c will also be needed by a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Forward declarations */
+LOCAL void transdecode_master_selection JPP( (j_decompress_ptr cinfo) );
+
+
+/*
+ * Read the coefficient arrays from a JPEG file.
+ * jpeg_read_header must be completed before calling this.
+ *
+ * The entire image is read into a set of virtual coefficient-block arrays,
+ * one per component.  The return value is a pointer to the array of
+ * virtual-array descriptors.  These can be manipulated directly via the
+ * JPEG memory manager, or handed off to jpeg_write_coefficients().
+ * To release the memory occupied by the virtual arrays, call
+ * jpeg_finish_decompress() when done with the data.
+ *
+ * Returns NULL if suspended.  This case need be checked only if
+ * a suspending data source is used.
+ */
+
+GLOBAL jvirt_barray_ptr *
+jpeg_read_coefficients( j_decompress_ptr cinfo ) {
+    if ( cinfo->global_state == DSTATE_READY ) {
+        /* First call: initialize active modules */
+        transdecode_master_selection( cinfo );
+        cinfo->global_state = DSTATE_RDCOEFS;
+    } else if ( cinfo->global_state != DSTATE_RDCOEFS ) {
+        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
+    }
+    /* Absorb whole file into the coef buffer */
+    for (;; ) {
+        int retcode;
+        /* Call progress monitor hook if present */
+        if ( cinfo->progress != NULL ) {
+            ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
+        }
+        /* Absorb some more input */
+        retcode = ( *cinfo->inputctl->consume_input )( cinfo );
+        if ( retcode == JPEG_SUSPENDED ) {
+            return NULL;
+        }
+        if ( retcode == JPEG_REACHED_EOI ) {
+            break;
+        }
+        /* Advance progress counter if appropriate */
+        if ( ( cinfo->progress != NULL ) &&
+            ( ( retcode == JPEG_ROW_COMPLETED ) || ( retcode == JPEG_REACHED_SOS ) ) ) {
+            if ( ++cinfo->progress->pass_counter >= cinfo->progress->pass_limit ) {
+                /* startup underestimated number of scans; ratchet up one scan */
+                cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
+            }
+        }
+    }
+    /* Set state so that jpeg_finish_decompress does the right thing */
+    cinfo->global_state = DSTATE_STOPPING;
+    return cinfo->coef->coef_arrays;
+}
+
+
+/*
+ * Master selection of decompression modules for transcoding.
+ * This substitutes for jdmaster.c's initialization of the full decompressor.
+ */
+
+LOCAL void
+transdecode_master_selection( j_decompress_ptr cinfo ) {
+    /* Entropy decoding: either Huffman or arithmetic coding. */
+    if ( cinfo->arith_code ) {
+        ERREXIT( cinfo, JERR_ARITH_NOTIMPL );
+    } else {
+        if ( cinfo->progressive_mode ) {
+#ifdef D_PROGRESSIVE_SUPPORTED
+            jinit_phuff_decoder( cinfo );
+#else
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+#endif
+        } else {
+            jinit_huff_decoder( cinfo );
+        }
+    }
+
+    /* Always get a full-image coefficient buffer. */
+    jinit_d_coef_controller( cinfo, TRUE );
+
+    /* We can now tell the memory manager to allocate virtual arrays. */
+    ( *cinfo->mem->realize_virt_arrays )( (j_common_ptr) cinfo );
+
+    /* Initialize input side of decompressor to consume first scan. */
+    ( *cinfo->inputctl->start_input_pass )( cinfo );
+
+    /* Initialize progress monitoring. */
+    if ( cinfo->progress != NULL ) {
+        int nscans;
+        /* Estimate number of scans to set pass_limit. */
+        if ( cinfo->progressive_mode ) {
+            /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
+            nscans = 2 + 3 * cinfo->num_components;
+        } else if ( cinfo->inputctl->has_multiple_scans ) {
+            /* For a nonprogressive multiscan file, estimate 1 scan per component. */
+            nscans = cinfo->num_components;
+        } else {
+            nscans = 1;
+        }
+        cinfo->progress->pass_counter = 0L;
+        cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
+        cinfo->progress->completed_passes = 0;
+        cinfo->progress->total_passes = 1;
+    }
+}

neo/renderer/jpeg-6/jerror.cpp

@@ -0,0 +1,233 @@
+/*
+ * jerror.c
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains simple error-reporting and trace-message routines.
+ * These are suitable for Unix-like systems and others where writing to
+ * stderr is the right thing to do.  Many applications will want to replace
+ * some or all of these routines.
+ *
+ * These routines are used by both the compression and decompression code.
+ */
+
+/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
+
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jversion.h"
+#include "jerror.h"
+
+extern void jpg_Error( const char * fmt, ... );
+extern void jpg_Printf( const char * fmt, ... );
+
+#ifndef EXIT_FAILURE        /* define exit() codes if not provided */
+#define EXIT_FAILURE  1
+#endif
+
+
+/*
+ * Create the message string table.
+ * We do this from the master message list in jerror.h by re-reading
+ * jerror.h with a suitable definition for macro JMESSAGE.
+ * The message table is made an external symbol just in case any applications
+ * want to refer to it directly.
+ */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_std_message_table  jMsgTable
+#endif
+
+#define JMESSAGE( code, string )   string,
+
+const char * const jpeg_std_message_table[] = {
+#include "jerror.h"
+    NULL
+};
+
+
+/*
+ * Error exit handler: must not return to caller.
+ *
+ * Applications may override this if they want to get control back after
+ * an error.  Typically one would longjmp somewhere instead of exiting.
+ * The setjmp buffer can be made a private field within an expanded error
+ * handler object.  Note that the info needed to generate an error message
+ * is stored in the error object, so you can generate the message now or
+ * later, at your convenience.
+ * You should make sure that the JPEG object is cleaned up (with jpeg_abort
+ * or jpeg_destroy) at some point.
+ */
+
+METHODDEF void
+error_exit( j_common_ptr cinfo ) {
+    char buffer[JMSG_LENGTH_MAX];
+
+    /* Create the message */
+    ( *cinfo->err->format_message )( cinfo, buffer );
+
+    /* Let the memory manager delete any temp files before we die */
+    jpeg_destroy( cinfo );
+
+    jpg_Error( "%s\n", buffer );
+}
+
+
+/*
+ * Actual output of an error or trace message.
+ * Applications may override this method to send JPEG messages somewhere
+ * other than stderr.
+ */
+
+METHODDEF void
+output_message( j_common_ptr cinfo ) {
+    char buffer[JMSG_LENGTH_MAX];
+
+    /* Create the message */
+    ( *cinfo->err->format_message )( cinfo, buffer );
+
+    /* Send it to stderr, adding a newline */
+    jpg_Printf( "%s\n", buffer );
+}
+
+
+/*
+ * Decide whether to emit a trace or warning message.
+ * msg_level is one of:
+ *   -1: recoverable corrupt-data warning, may want to abort.
+ *    0: important advisory messages (always display to user).
+ *    1: first level of tracing detail.
+ *    2,3,...: successively more detailed tracing messages.
+ * An application might override this method if it wanted to abort on warnings
+ * or change the policy about which messages to display.
+ */
+
+METHODDEF void
+emit_message( j_common_ptr cinfo, int msg_level ) {
+    struct jpeg_error_mgr * err = cinfo->err;
+
+    if ( msg_level < 0 ) {
+        /* It's a warning message.  Since corrupt files may generate many warnings,
+         * the policy implemented here is to show only the first warning,
+         * unless trace_level >= 3.
+         */
+        if ( ( err->num_warnings == 0 ) || ( err->trace_level >= 3 ) ) {
+            ( *err->output_message )( cinfo );
+        }
+        /* Always count warnings in num_warnings. */
+        err->num_warnings++;
+    } else {
+        /* It's a trace message.  Show it if trace_level >= msg_level. */
+        if ( err->trace_level >= msg_level ) {
+            ( *err->output_message )( cinfo );
+        }
+    }
+}
+
+
+/*
+ * Format a message string for the most recent JPEG error or message.
+ * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
+ * characters.  Note that no '\n' character is added to the string.
+ * Few applications should need to override this method.
+ */
+
+METHODDEF void
+format_message( j_common_ptr cinfo, char * buffer ) {
+    struct jpeg_error_mgr * err = cinfo->err;
+    int msg_code = err->msg_code;
+    const char * msgtext = NULL;
+    const char * msgptr;
+    char ch;
+    boolean isstring;
+
+    /* Look up message string in proper table */
+    if ( ( msg_code > 0 ) && ( msg_code <= err->last_jpeg_message ) ) {
+        msgtext = err->jpeg_message_table[msg_code];
+    } else if ( err->addon_message_table != NULL &&
+                msg_code >= err->first_addon_message &&
+                msg_code <= err->last_addon_message ) {
+        msgtext = err->addon_message_table[msg_code - err->first_addon_message];
+    }
+
+    /* Defend against bogus message number */
+    if ( msgtext == NULL ) {
+        err->msg_parm.i[0] = msg_code;
+        msgtext = err->jpeg_message_table[0];
+    }
+
+    /* Check for string parameter, as indicated by %s in the message text */
+    isstring = FALSE;
+    msgptr = msgtext;
+    while ( ( ch = *msgptr++ ) != '\0' ) {
+        if ( ch == '%' ) {
+            if ( *msgptr == 's' ) {
+                isstring = TRUE;
+            }
+            break;
+        }
+    }
+
+    /* Format the message into the passed buffer */
+    if ( isstring ) {
+        sprintf( buffer, msgtext, err->msg_parm.s );
+    } else {
+        sprintf( buffer, msgtext,
+                 err->msg_parm.i[0], err->msg_parm.i[1],
+                 err->msg_parm.i[2], err->msg_parm.i[3],
+                 err->msg_parm.i[4], err->msg_parm.i[5],
+                 err->msg_parm.i[6], err->msg_parm.i[7] );
+    }
+}
+
+
+/*
+ * Reset error state variables at start of a new image.
+ * This is called during compression startup to reset trace/error
+ * processing to default state, without losing any application-specific
+ * method pointers.  An application might possibly want to override
+ * this method if it has additional error processing state.
+ */
+
+METHODDEF void
+reset_error_mgr( j_common_ptr cinfo ) {
+    cinfo->err->num_warnings = 0;
+    /* trace_level is not reset since it is an application-supplied parameter */
+    cinfo->err->msg_code = 0;/* may be useful as a flag for "no error" */
+}
+
+
+/*
+ * Fill in the standard error-handling methods in a jpeg_error_mgr object.
+ * Typical call is:
+ *	struct jpeg_compress_struct cinfo;
+ *	struct jpeg_error_mgr err;
+ *
+ *	cinfo.err = jpeg_std_error(&err);
+ * after which the application may override some of the methods.
+ */
+
+GLOBAL struct jpeg_error_mgr *
+jpeg_std_error( struct jpeg_error_mgr * err ) {
+    err->error_exit = error_exit;
+    err->emit_message = emit_message;
+    err->output_message = output_message;
+    err->format_message = format_message;
+    err->reset_error_mgr = reset_error_mgr;
+
+    err->trace_level = 0;   /* default = no tracing */
+    err->num_warnings = 0;  /* no warnings emitted yet */
+    err->msg_code = 0;      /* may be useful as a flag for "no error" */
+
+    /* Initialize message table pointers */
+    err->jpeg_message_table = jpeg_std_message_table;
+    err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
+
+    err->addon_message_table = NULL;
+    err->first_addon_message = 0;/* for safety */
+    err->last_addon_message = 0;
+
+    return err;
+}

neo/renderer/jpeg-6/jerror.h

@@ -0,0 +1,273 @@
+/*
+ * jerror.h
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file defines the error and message codes for the JPEG library.
+ * Edit this file to add new codes, or to translate the message strings to
+ * some other language.
+ * A set of error-reporting macros are defined too.  Some applications using
+ * the JPEG library may wish to include this file to get the error codes
+ * and/or the macros.
+ */
+
+/*
+ * To define the enum list of message codes, include this file without
+ * defining macro JMESSAGE.  To create a message string table, include it
+ * again with a suitable JMESSAGE definition (see jerror.c for an example).
+ */
+#ifndef JMESSAGE
+#ifndef JERROR_H
+/* First time through, define the enum list */
+#define JMAKE_ENUM_LIST
+#else
+/* Repeated inclusions of this file are no-ops unless JMESSAGE is defined */
+#define JMESSAGE(code,string)
+#endif /* JERROR_H */
+#endif /* JMESSAGE */
+
+#ifdef JMAKE_ENUM_LIST
+
+typedef enum {
+
+#define JMESSAGE(code,string)	code ,
+
+#endif /* JMAKE_ENUM_LIST */
+
+JMESSAGE(JMSG_NOMESSAGE, "Bogus message code %d") /* Must be first entry! */
+
+/* For maintenance convenience, list is alphabetical by message code name */
+JMESSAGE(JERR_ARITH_NOTIMPL,
+	 "Sorry, there are legal restrictions on arithmetic coding")
+JMESSAGE(JERR_BAD_ALIGN_TYPE, "ALIGN_TYPE is wrong, please fix")
+JMESSAGE(JERR_BAD_ALLOC_CHUNK, "MAX_ALLOC_CHUNK is wrong, please fix")
+JMESSAGE(JERR_BAD_BUFFER_MODE, "Bogus buffer control mode")
+JMESSAGE(JERR_BAD_COMPONENT_ID, "Invalid component ID %d in SOS")
+JMESSAGE(JERR_BAD_DCTSIZE, "IDCT output block size %d not supported")
+JMESSAGE(JERR_BAD_IN_COLORSPACE, "Bogus input colorspace")
+JMESSAGE(JERR_BAD_J_COLORSPACE, "Bogus JPEG colorspace")
+JMESSAGE(JERR_BAD_LENGTH, "Bogus marker length")
+JMESSAGE(JERR_BAD_MCU_SIZE, "Sampling factors too large for interleaved scan")
+JMESSAGE(JERR_BAD_POOL_ID, "Invalid memory pool code %d")
+JMESSAGE(JERR_BAD_PRECISION, "Unsupported JPEG data precision %d")
+JMESSAGE(JERR_BAD_PROGRESSION,
+	 "Invalid progressive parameters Ss=%d Se=%d Ah=%d Al=%d")
+JMESSAGE(JERR_BAD_PROG_SCRIPT,
+	 "Invalid progressive parameters at scan script entry %d")
+JMESSAGE(JERR_BAD_SAMPLING, "Bogus sampling factors")
+JMESSAGE(JERR_BAD_SCAN_SCRIPT, "Invalid scan script at entry %d")
+JMESSAGE(JERR_BAD_STATE, "Improper call to JPEG library in state %d")
+JMESSAGE(JERR_BAD_VIRTUAL_ACCESS, "Bogus virtual array access")
+JMESSAGE(JERR_BUFFER_SIZE, "Buffer passed to JPEG library is too small")
+JMESSAGE(JERR_CANT_SUSPEND, "Suspension not allowed here")
+JMESSAGE(JERR_CCIR601_NOTIMPL, "CCIR601 sampling not implemented yet")
+JMESSAGE(JERR_COMPONENT_COUNT, "Too many color components: %d, max %d")
+JMESSAGE(JERR_CONVERSION_NOTIMPL, "Unsupported color conversion request")
+JMESSAGE(JERR_DAC_INDEX, "Bogus DAC index %d")
+JMESSAGE(JERR_DAC_VALUE, "Bogus DAC value 0x%x")
+JMESSAGE(JERR_DHT_COUNTS, "Bogus DHT counts")
+JMESSAGE(JERR_DHT_INDEX, "Bogus DHT index %d")
+JMESSAGE(JERR_DQT_INDEX, "Bogus DQT index %d")
+JMESSAGE(JERR_EMPTY_IMAGE, "Empty JPEG image (DNL not supported)")
+JMESSAGE(JERR_EMS_READ, "Read from EMS failed")
+JMESSAGE(JERR_EMS_WRITE, "Write to EMS failed")
+JMESSAGE(JERR_EOI_EXPECTED, "Didn't expect more than one scan")
+JMESSAGE(JERR_FILE_READ, "Input file read error")
+JMESSAGE(JERR_FILE_WRITE, "Output file write error --- out of disk space?")
+JMESSAGE(JERR_FRACT_SAMPLE_NOTIMPL, "Fractional sampling not implemented yet")
+JMESSAGE(JERR_HUFF_CLEN_OVERFLOW, "Huffman code size table overflow")
+JMESSAGE(JERR_HUFF_MISSING_CODE, "Missing Huffman code table entry")
+JMESSAGE(JERR_IMAGE_TOO_BIG, "Maximum supported image dimension is %u pixels")
+JMESSAGE(JERR_INPUT_EMPTY, "Empty input file")
+JMESSAGE(JERR_INPUT_EOF, "Premature end of input file")
+JMESSAGE(JERR_MISMATCHED_QUANT_TABLE,
+	 "Cannot transcode due to multiple use of quantization table %d")
+JMESSAGE(JERR_MISSING_DATA, "Scan script does not transmit all data")
+JMESSAGE(JERR_MODE_CHANGE, "Invalid color quantization mode change")
+JMESSAGE(JERR_NOTIMPL, "Not implemented yet")
+JMESSAGE(JERR_NOT_COMPILED, "Requested feature was omitted at compile time")
+JMESSAGE(JERR_NO_BACKING_STORE, "Backing store not supported")
+JMESSAGE(JERR_NO_HUFF_TABLE, "Huffman table 0x%02x was not defined")
+JMESSAGE(JERR_NO_IMAGE, "JPEG datastream contains no image")
+JMESSAGE(JERR_NO_QUANT_TABLE, "Quantization table 0x%02x was not defined")
+JMESSAGE(JERR_NO_SOI, "Not a JPEG file: starts with 0x%02x 0x%02x")
+JMESSAGE(JERR_OUT_OF_MEMORY, "Insufficient memory (case %d)")
+JMESSAGE(JERR_QUANT_COMPONENTS,
+	 "Cannot quantize more than %d color components")
+JMESSAGE(JERR_QUANT_FEW_COLORS, "Cannot quantize to fewer than %d colors")
+JMESSAGE(JERR_QUANT_MANY_COLORS, "Cannot quantize to more than %d colors")
+JMESSAGE(JERR_SOF_DUPLICATE, "Invalid JPEG file structure: two SOF markers")
+JMESSAGE(JERR_SOF_NO_SOS, "Invalid JPEG file structure: missing SOS marker")
+JMESSAGE(JERR_SOF_UNSUPPORTED, "Unsupported JPEG process: SOF type 0x%02x")
+JMESSAGE(JERR_SOI_DUPLICATE, "Invalid JPEG file structure: two SOI markers")
+JMESSAGE(JERR_SOS_NO_SOF, "Invalid JPEG file structure: SOS before SOF")
+JMESSAGE(JERR_TFILE_CREATE, "Failed to create temporary file %s")
+JMESSAGE(JERR_TFILE_READ, "Read failed on temporary file")
+JMESSAGE(JERR_TFILE_SEEK, "Seek failed on temporary file")
+JMESSAGE(JERR_TFILE_WRITE,
+	 "Write failed on temporary file --- out of disk space?")
+JMESSAGE(JERR_TOO_LITTLE_DATA, "Application transferred too few scanlines")
+JMESSAGE(JERR_UNKNOWN_MARKER, "Unsupported marker type 0x%02x")
+JMESSAGE(JERR_VIRTUAL_BUG, "Virtual array controller messed up")
+JMESSAGE(JERR_WIDTH_OVERFLOW, "Image too wide for this implementation")
+JMESSAGE(JERR_XMS_READ, "Read from XMS failed")
+JMESSAGE(JERR_XMS_WRITE, "Write to XMS failed")
+JMESSAGE(JMSG_COPYRIGHT, JCOPYRIGHT)
+JMESSAGE(JMSG_VERSION, JVERSION)
+JMESSAGE(JTRC_16BIT_TABLES,
+	 "Caution: quantization tables are too coarse for baseline JPEG")
+JMESSAGE(JTRC_ADOBE,
+	 "Adobe APP14 marker: version %d, flags 0x%04x 0x%04x, transform %d")
+JMESSAGE(JTRC_APP0, "Unknown APP0 marker (not JFIF), length %u")
+JMESSAGE(JTRC_APP14, "Unknown APP14 marker (not Adobe), length %u")
+JMESSAGE(JTRC_DAC, "Define Arithmetic Table 0x%02x: 0x%02x")
+JMESSAGE(JTRC_DHT, "Define Huffman Table 0x%02x")
+JMESSAGE(JTRC_DQT, "Define Quantization Table %d  precision %d")
+JMESSAGE(JTRC_DRI, "Define Restart Interval %u")
+JMESSAGE(JTRC_EMS_CLOSE, "Freed EMS handle %u")
+JMESSAGE(JTRC_EMS_OPEN, "Obtained EMS handle %u")
+JMESSAGE(JTRC_EOI, "End Of Image")
+JMESSAGE(JTRC_HUFFBITS, "        %3d %3d %3d %3d %3d %3d %3d %3d")
+JMESSAGE(JTRC_JFIF, "JFIF APP0 marker, density %dx%d  %d")
+JMESSAGE(JTRC_JFIF_BADTHUMBNAILSIZE,
+	 "Warning: thumbnail image size does not match data length %u")
+JMESSAGE(JTRC_JFIF_MINOR, "Unknown JFIF minor revision number %d.%02d")
+JMESSAGE(JTRC_JFIF_THUMBNAIL, "    with %d x %d thumbnail image")
+JMESSAGE(JTRC_MISC_MARKER, "Skipping marker 0x%02x, length %u")
+JMESSAGE(JTRC_PARMLESS_MARKER, "Unexpected marker 0x%02x")
+JMESSAGE(JTRC_QUANTVALS, "        %4u %4u %4u %4u %4u %4u %4u %4u")
+JMESSAGE(JTRC_QUANT_3_NCOLORS, "Quantizing to %d = %d*%d*%d colors")
+JMESSAGE(JTRC_QUANT_NCOLORS, "Quantizing to %d colors")
+JMESSAGE(JTRC_QUANT_SELECTED, "Selected %d colors for quantization")
+JMESSAGE(JTRC_RECOVERY_ACTION, "At marker 0x%02x, recovery action %d")
+JMESSAGE(JTRC_RST, "RST%d")
+JMESSAGE(JTRC_SMOOTH_NOTIMPL,
+	 "Smoothing not supported with nonstandard sampling ratios")
+JMESSAGE(JTRC_SOF, "Start Of Frame 0x%02x: width=%u, height=%u, components=%d")
+JMESSAGE(JTRC_SOF_COMPONENT, "    Component %d: %dhx%dv q=%d")
+JMESSAGE(JTRC_SOI, "Start of Image")
+JMESSAGE(JTRC_SOS, "Start Of Scan: %d components")
+JMESSAGE(JTRC_SOS_COMPONENT, "    Component %d: dc=%d ac=%d")
+JMESSAGE(JTRC_SOS_PARAMS, "  Ss=%d, Se=%d, Ah=%d, Al=%d")
+JMESSAGE(JTRC_TFILE_CLOSE, "Closed temporary file %s")
+JMESSAGE(JTRC_TFILE_OPEN, "Opened temporary file %s")
+JMESSAGE(JTRC_UNKNOWN_IDS,
+	 "Unrecognized component IDs %d %d %d, assuming YCbCr")
+JMESSAGE(JTRC_XMS_CLOSE, "Freed XMS handle %u")
+JMESSAGE(JTRC_XMS_OPEN, "Obtained XMS handle %u")
+JMESSAGE(JWRN_ADOBE_XFORM, "Unknown Adobe color transform code %d")
+JMESSAGE(JWRN_BOGUS_PROGRESSION,
+	 "Inconsistent progression sequence for component %d coefficient %d")
+JMESSAGE(JWRN_EXTRANEOUS_DATA,
+	 "Corrupt JPEG data: %u extraneous bytes before marker 0x%02x")
+JMESSAGE(JWRN_HIT_MARKER, "Corrupt JPEG data: premature end of data segment")
+JMESSAGE(JWRN_HUFF_BAD_CODE, "Corrupt JPEG data: bad Huffman code")
+JMESSAGE(JWRN_JFIF_MAJOR, "Warning: unknown JFIF revision number %d.%02d")
+JMESSAGE(JWRN_JPEG_EOF, "Premature end of JPEG file")
+JMESSAGE(JWRN_MUST_RESYNC,
+	 "Corrupt JPEG data: found marker 0x%02x instead of RST%d")
+JMESSAGE(JWRN_NOT_SEQUENTIAL, "Invalid SOS parameters for sequential JPEG")
+JMESSAGE(JWRN_TOO_MUCH_DATA, "Application transferred too many scanlines")
+
+#ifdef JMAKE_ENUM_LIST
+
+  JMSG_LASTMSGCODE
+} J_MESSAGE_CODE;
+
+#undef JMAKE_ENUM_LIST
+#endif /* JMAKE_ENUM_LIST */
+
+/* Zap JMESSAGE macro so that future re-inclusions do nothing by default */
+#undef JMESSAGE
+
+
+#ifndef JERROR_H
+#define JERROR_H
+
+/* Macros to simplify using the error and trace message stuff */
+/* The first parameter is either type of cinfo pointer */
+
+/* Fatal errors (print message and exit) */
+#define ERREXIT(cinfo,code)  \
+  ((cinfo)->err->msg_code = (code), \
+   (*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
+#define ERREXIT1(cinfo,code,p1)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
+#define ERREXIT2(cinfo,code,p1,p2)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (cinfo)->err->msg_parm.i[1] = (p2), \
+   (*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
+#define ERREXIT3(cinfo,code,p1,p2,p3)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (cinfo)->err->msg_parm.i[1] = (p2), \
+   (cinfo)->err->msg_parm.i[2] = (p3), \
+   (*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
+#define ERREXIT4(cinfo,code,p1,p2,p3,p4)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (cinfo)->err->msg_parm.i[1] = (p2), \
+   (cinfo)->err->msg_parm.i[2] = (p3), \
+   (cinfo)->err->msg_parm.i[3] = (p4), \
+   (*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
+#define ERREXITS(cinfo,code,str)  \
+  ((cinfo)->err->msg_code = (code), \
+   strncpy((cinfo)->err->msg_parm.s, (str), JMSG_STR_PARM_MAX), \
+   (*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
+
+#define MAKESTMT(stuff)		do { stuff } while (0)
+
+/* Nonfatal errors (we can keep going, but the data is probably corrupt) */
+#define WARNMS(cinfo,code)  \
+  ((cinfo)->err->msg_code = (code), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), -1))
+#define WARNMS1(cinfo,code,p1)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), -1))
+#define WARNMS2(cinfo,code,p1,p2)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (cinfo)->err->msg_parm.i[1] = (p2), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), -1))
+
+/* Informational/debugging messages */
+#define TRACEMS(cinfo,lvl,code)  \
+  ((cinfo)->err->msg_code = (code), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
+#define TRACEMS1(cinfo,lvl,code,p1)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
+#define TRACEMS2(cinfo,lvl,code,p1,p2)  \
+  ((cinfo)->err->msg_code = (code), \
+   (cinfo)->err->msg_parm.i[0] = (p1), \
+   (cinfo)->err->msg_parm.i[1] = (p2), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
+#define TRACEMS3(cinfo,lvl,code,p1,p2,p3)  \
+  MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
+	   _mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); \
+	   (cinfo)->err->msg_code = (code); \
+	   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
+#define TRACEMS4(cinfo,lvl,code,p1,p2,p3,p4)  \
+  MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
+	   _mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); _mp[3] = (p4); \
+	   (cinfo)->err->msg_code = (code); \
+	   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
+#define TRACEMS8(cinfo,lvl,code,p1,p2,p3,p4,p5,p6,p7,p8)  \
+  MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
+	   _mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); _mp[3] = (p4); \
+	   _mp[4] = (p5); _mp[5] = (p6); _mp[6] = (p7); _mp[7] = (p8); \
+	   (cinfo)->err->msg_code = (code); \
+	   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
+#define TRACEMSS(cinfo,lvl,code,str)  \
+  ((cinfo)->err->msg_code = (code), \
+   strncpy((cinfo)->err->msg_parm.s, (str), JMSG_STR_PARM_MAX), \
+   (*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
+
+#endif /* JERROR_H */

neo/renderer/jpeg-6/jfdctflt.cpp

@@ -0,0 +1,167 @@
+/*
+ * jfdctflt.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a floating-point implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * This implementation should be more accurate than either of the integer
+ * DCT implementations.  However, it may not give the same results on all
+ * machines because of differences in roundoff behavior.  Speed will depend
+ * on the hardware's floating point capacity.
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column.  Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT.  Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README).  The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs.  These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries.  The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with a fixed-point
+ * implementation, accuracy is lost due to imprecise representation of the
+ * scaled quantization values.  However, that problem does not arise if
+ * we use floating point arithmetic.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL void
+jpeg_fdct_float( FAST_FLOAT * data ) {
+    FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+    FAST_FLOAT tmp10, tmp11, tmp12, tmp13;
+    FAST_FLOAT z1, z2, z3, z4, z5, z11, z13;
+    FAST_FLOAT * dataptr;
+    int ctr;
+
+    /* Pass 1: process rows. */
+
+    dataptr = data;
+    for ( ctr = DCTSIZE - 1; ctr >= 0; ctr-- ) {
+        tmp0 = dataptr[0] + dataptr[7];
+        tmp7 = dataptr[0] - dataptr[7];
+        tmp1 = dataptr[1] + dataptr[6];
+        tmp6 = dataptr[1] - dataptr[6];
+        tmp2 = dataptr[2] + dataptr[5];
+        tmp5 = dataptr[2] - dataptr[5];
+        tmp3 = dataptr[3] + dataptr[4];
+        tmp4 = dataptr[3] - dataptr[4];
+
+        /* Even part */
+
+        tmp10 = tmp0 + tmp3;/* phase 2 */
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        dataptr[0] = tmp10 + tmp11;/* phase 3 */
+        dataptr[4] = tmp10 - tmp11;
+
+        z1 = ( tmp12 + tmp13 ) * ( (FAST_FLOAT) 0.707106781 );/* c4 */
+        dataptr[2] = tmp13 + z1;/* phase 5 */
+        dataptr[6] = tmp13 - z1;
+
+        /* Odd part */
+
+        tmp10 = tmp4 + tmp5;/* phase 2 */
+        tmp11 = tmp5 + tmp6;
+        tmp12 = tmp6 + tmp7;
+
+        /* The rotator is modified from fig 4-8 to avoid extra negations. */
+        z5 = ( tmp10 - tmp12 ) * ( (FAST_FLOAT) 0.382683433 );/* c6 */
+        z2 = ( (FAST_FLOAT) 0.541196100 ) * tmp10 + z5;/* c2-c6 */
+        z4 = ( (FAST_FLOAT) 1.306562965 ) * tmp12 + z5;/* c2+c6 */
+        z3 = tmp11 * ( (FAST_FLOAT) 0.707106781 );/* c4 */
+
+        z11 = tmp7 + z3;    /* phase 5 */
+        z13 = tmp7 - z3;
+
+        dataptr[5] = z13 + z2;/* phase 6 */
+        dataptr[3] = z13 - z2;
+        dataptr[1] = z11 + z4;
+        dataptr[7] = z11 - z4;
+
+        dataptr += DCTSIZE; /* advance pointer to next row */
+    }
+
+    /* Pass 2: process columns. */
+
+    dataptr = data;
+    for ( ctr = DCTSIZE - 1; ctr >= 0; ctr-- ) {
+        tmp0 = dataptr[DCTSIZE * 0] + dataptr[DCTSIZE * 7];
+        tmp7 = dataptr[DCTSIZE * 0] - dataptr[DCTSIZE * 7];
+        tmp1 = dataptr[DCTSIZE * 1] + dataptr[DCTSIZE * 6];
+        tmp6 = dataptr[DCTSIZE * 1] - dataptr[DCTSIZE * 6];
+        tmp2 = dataptr[DCTSIZE * 2] + dataptr[DCTSIZE * 5];
+        tmp5 = dataptr[DCTSIZE * 2] - dataptr[DCTSIZE * 5];
+        tmp3 = dataptr[DCTSIZE * 3] + dataptr[DCTSIZE * 4];
+        tmp4 = dataptr[DCTSIZE * 3] - dataptr[DCTSIZE * 4];
+
+        /* Even part */
+
+        tmp10 = tmp0 + tmp3;/* phase 2 */
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        dataptr[DCTSIZE * 0] = tmp10 + tmp11;/* phase 3 */
+        dataptr[DCTSIZE * 4] = tmp10 - tmp11;
+
+        z1 = ( tmp12 + tmp13 ) * ( (FAST_FLOAT) 0.707106781 );/* c4 */
+        dataptr[DCTSIZE * 2] = tmp13 + z1;/* phase 5 */
+        dataptr[DCTSIZE * 6] = tmp13 - z1;
+
+        /* Odd part */
+
+        tmp10 = tmp4 + tmp5;/* phase 2 */
+        tmp11 = tmp5 + tmp6;
+        tmp12 = tmp6 + tmp7;
+
+        /* The rotator is modified from fig 4-8 to avoid extra negations. */
+        z5 = ( tmp10 - tmp12 ) * ( (FAST_FLOAT) 0.382683433 );/* c6 */
+        z2 = ( (FAST_FLOAT) 0.541196100 ) * tmp10 + z5;/* c2-c6 */
+        z4 = ( (FAST_FLOAT) 1.306562965 ) * tmp12 + z5;/* c2+c6 */
+        z3 = tmp11 * ( (FAST_FLOAT) 0.707106781 );/* c4 */
+
+        z11 = tmp7 + z3;    /* phase 5 */
+        z13 = tmp7 - z3;
+
+        dataptr[DCTSIZE * 5] = z13 + z2;/* phase 6 */
+        dataptr[DCTSIZE * 3] = z13 - z2;
+        dataptr[DCTSIZE * 1] = z11 + z4;
+        dataptr[DCTSIZE * 7] = z11 - z4;
+
+        dataptr++;      /* advance pointer to next column */
+    }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */

neo/renderer/jpeg-6/jfdctfst.cpp

@@ -0,0 +1,223 @@
+/*
+ * jfdctfst.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a fast, not so accurate integer implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column.  Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT.  Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README).  The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs.  These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries.  The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with fixed-point math,
+ * accuracy is lost due to imprecise representation of the scaled
+ * quantization values.  The smaller the quantization table entry, the less
+ * precise the scaled value, so this implementation does worse with high-
+ * quality-setting files than with low-quality ones.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef DCT_IFAST_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/* Scaling decisions are generally the same as in the LL&M algorithm;
+ * see jfdctint.c for more details.  However, we choose to descale
+ * (right shift) multiplication products as soon as they are formed,
+ * rather than carrying additional fractional bits into subsequent additions.
+ * This compromises accuracy slightly, but it lets us save a few shifts.
+ * More importantly, 16-bit arithmetic is then adequate (for 8-bit samples)
+ * everywhere except in the multiplications proper; this saves a good deal
+ * of work on 16-bit-int machines.
+ *
+ * Again to save a few shifts, the intermediate results between pass 1 and
+ * pass 2 are not upscaled, but are represented only to integral precision.
+ *
+ * A final compromise is to represent the multiplicative constants to only
+ * 8 fractional bits, rather than 13.  This saves some shifting work on some
+ * machines, and may also reduce the cost of multiplication (since there
+ * are fewer one-bits in the constants).
+ */
+
+#define CONST_BITS  8
+
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 8
+#define FIX_0_382683433  ( (INT32)   98 )     /* FIX(0.382683433) */
+#define FIX_0_541196100  ( (INT32)  139 )     /* FIX(0.541196100) */
+#define FIX_0_707106781  ( (INT32)  181 )     /* FIX(0.707106781) */
+#define FIX_1_306562965  ( (INT32)  334 )     /* FIX(1.306562965) */
+#else
+#define FIX_0_382683433  FIX( 0.382683433 )
+#define FIX_0_541196100  FIX( 0.541196100 )
+#define FIX_0_707106781  FIX( 0.707106781 )
+#define FIX_1_306562965  FIX( 1.306562965 )
+#endif
+
+
+/* We can gain a little more speed, with a further compromise in accuracy,
+ * by omitting the addition in a descaling shift.  This yields an incorrectly
+ * rounded result half the time...
+ */
+
+#ifndef USE_ACCURATE_ROUNDING
+#undef DESCALE
+#define DESCALE( x, n )  RIGHT_SHIFT( x, n )
+#endif
+
+
+/* Multiply a DCTELEM variable by an INT32 constant, and immediately
+ * descale to yield a DCTELEM result.
+ */
+
+#define MULTIPLY( var, const )  ( (DCTELEM) DESCALE( ( var ) * ( const ), CONST_BITS ) )
+
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL void
+jpeg_fdct_ifast( DCTELEM * data ) {
+    DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+    DCTELEM tmp10, tmp11, tmp12, tmp13;
+    DCTELEM z1, z2, z3, z4, z5, z11, z13;
+    DCTELEM * dataptr;
+    int ctr;
+    SHIFT_TEMPS
+
+    /* Pass 1: process rows. */
+
+    dataptr = data;
+    for ( ctr = DCTSIZE - 1; ctr >= 0; ctr-- ) {
+        tmp0 = dataptr[0] + dataptr[7];
+        tmp7 = dataptr[0] - dataptr[7];
+        tmp1 = dataptr[1] + dataptr[6];
+        tmp6 = dataptr[1] - dataptr[6];
+        tmp2 = dataptr[2] + dataptr[5];
+        tmp5 = dataptr[2] - dataptr[5];
+        tmp3 = dataptr[3] + dataptr[4];
+        tmp4 = dataptr[3] - dataptr[4];
+
+        /* Even part */
+
+        tmp10 = tmp0 + tmp3;/* phase 2 */
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        dataptr[0] = tmp10 + tmp11;/* phase 3 */
+        dataptr[4] = tmp10 - tmp11;
+
+        z1 = MULTIPLY( tmp12 + tmp13, FIX_0_707106781 );/* c4 */
+        dataptr[2] = tmp13 + z1;/* phase 5 */
+        dataptr[6] = tmp13 - z1;
+
+        /* Odd part */
+
+        tmp10 = tmp4 + tmp5;/* phase 2 */
+        tmp11 = tmp5 + tmp6;
+        tmp12 = tmp6 + tmp7;
+
+        /* The rotator is modified from fig 4-8 to avoid extra negations. */
+        z5 = MULTIPLY( tmp10 - tmp12, FIX_0_382683433 );/* c6 */
+        z2 = MULTIPLY( tmp10, FIX_0_541196100 ) + z5;/* c2-c6 */
+        z4 = MULTIPLY( tmp12, FIX_1_306562965 ) + z5;/* c2+c6 */
+        z3 = MULTIPLY( tmp11, FIX_0_707106781 );/* c4 */
+
+        z11 = tmp7 + z3;    /* phase 5 */
+        z13 = tmp7 - z3;
+
+        dataptr[5] = z13 + z2;/* phase 6 */
+        dataptr[3] = z13 - z2;
+        dataptr[1] = z11 + z4;
+        dataptr[7] = z11 - z4;
+
+        dataptr += DCTSIZE; /* advance pointer to next row */
+    }
+
+    /* Pass 2: process columns. */
+
+    dataptr = data;
+    for ( ctr = DCTSIZE - 1; ctr >= 0; ctr-- ) {
+        tmp0 = dataptr[DCTSIZE * 0] + dataptr[DCTSIZE * 7];
+        tmp7 = dataptr[DCTSIZE * 0] - dataptr[DCTSIZE * 7];
+        tmp1 = dataptr[DCTSIZE * 1] + dataptr[DCTSIZE * 6];
+        tmp6 = dataptr[DCTSIZE * 1] - dataptr[DCTSIZE * 6];
+        tmp2 = dataptr[DCTSIZE * 2] + dataptr[DCTSIZE * 5];
+        tmp5 = dataptr[DCTSIZE * 2] - dataptr[DCTSIZE * 5];
+        tmp3 = dataptr[DCTSIZE * 3] + dataptr[DCTSIZE * 4];
+        tmp4 = dataptr[DCTSIZE * 3] - dataptr[DCTSIZE * 4];
+
+        /* Even part */
+
+        tmp10 = tmp0 + tmp3;/* phase 2 */
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        dataptr[DCTSIZE * 0] = tmp10 + tmp11;/* phase 3 */
+        dataptr[DCTSIZE * 4] = tmp10 - tmp11;
+
+        z1 = MULTIPLY( tmp12 + tmp13, FIX_0_707106781 );/* c4 */
+        dataptr[DCTSIZE * 2] = tmp13 + z1;/* phase 5 */
+        dataptr[DCTSIZE * 6] = tmp13 - z1;
+
+        /* Odd part */
+
+        tmp10 = tmp4 + tmp5;/* phase 2 */
+        tmp11 = tmp5 + tmp6;
+        tmp12 = tmp6 + tmp7;
+
+        /* The rotator is modified from fig 4-8 to avoid extra negations. */
+        z5 = MULTIPLY( tmp10 - tmp12, FIX_0_382683433 );/* c6 */
+        z2 = MULTIPLY( tmp10, FIX_0_541196100 ) + z5;/* c2-c6 */
+        z4 = MULTIPLY( tmp12, FIX_1_306562965 ) + z5;/* c2+c6 */
+        z3 = MULTIPLY( tmp11, FIX_0_707106781 );/* c4 */
+
+        z11 = tmp7 + z3;    /* phase 5 */
+        z13 = tmp7 - z3;
+
+        dataptr[DCTSIZE * 5] = z13 + z2;/* phase 6 */
+        dataptr[DCTSIZE * 3] = z13 - z2;
+        dataptr[DCTSIZE * 1] = z11 + z4;
+        dataptr[DCTSIZE * 7] = z11 - z4;
+
+        dataptr++;      /* advance pointer to next column */
+    }
+}
+
+#endif /* DCT_IFAST_SUPPORTED */

neo/renderer/jpeg-6/jfdctint.cpp

@@ -0,0 +1,282 @@
+/*
+ * jfdctint.c
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a slow-but-accurate integer implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column.  Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on an algorithm described in
+ *   C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
+ *   Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
+ *   Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
+ * The primary algorithm described there uses 11 multiplies and 29 adds.
+ * We use their alternate method with 12 multiplies and 32 adds.
+ * The advantage of this method is that no data path contains more than one
+ * multiplication; this allows a very simple and accurate implementation in
+ * scaled fixed-point arithmetic, with a minimal number of shifts.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef DCT_ISLOW_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/*
+ * The poop on this scaling stuff is as follows:
+ *
+ * Each 1-D DCT step produces outputs which are a factor of sqrt(N)
+ * larger than the true DCT outputs.  The final outputs are therefore
+ * a factor of N larger than desired; since N=8 this can be cured by
+ * a simple right shift at the end of the algorithm.  The advantage of
+ * this arrangement is that we save two multiplications per 1-D DCT,
+ * because the y0 and y4 outputs need not be divided by sqrt(N).
+ * In the IJG code, this factor of 8 is removed by the quantization step
+ * (in jcdctmgr.c), NOT in this module.
+ *
+ * We have to do addition and subtraction of the integer inputs, which
+ * is no problem, and multiplication by fractional constants, which is
+ * a problem to do in integer arithmetic.  We multiply all the constants
+ * by CONST_SCALE and convert them to integer constants (thus retaining
+ * CONST_BITS bits of precision in the constants).  After doing a
+ * multiplication we have to divide the product by CONST_SCALE, with proper
+ * rounding, to produce the correct output.  This division can be done
+ * cheaply as a right shift of CONST_BITS bits.  We postpone shifting
+ * as long as possible so that partial sums can be added together with
+ * full fractional precision.
+ *
+ * The outputs of the first pass are scaled up by PASS1_BITS bits so that
+ * they are represented to better-than-integral precision.  These outputs
+ * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
+ * with the recommended scaling.  (For 12-bit sample data, the intermediate
+ * array is INT32 anyway.)
+ *
+ * To avoid overflow of the 32-bit intermediate results in pass 2, we must
+ * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26.  Error analysis
+ * shows that the values given below are the most effective.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS  13
+#define PASS1_BITS  2
+#else
+#define CONST_BITS  13
+#define PASS1_BITS  1       /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 13
+#define FIX_0_298631336  ( (INT32)  2446 )    /* FIX(0.298631336) */
+#define FIX_0_390180644  ( (INT32)  3196 )    /* FIX(0.390180644) */
+#define FIX_0_541196100  ( (INT32)  4433 )    /* FIX(0.541196100) */
+#define FIX_0_765366865  ( (INT32)  6270 )    /* FIX(0.765366865) */
+#define FIX_0_899976223  ( (INT32)  7373 )    /* FIX(0.899976223) */
+#define FIX_1_175875602  ( (INT32)  9633 )    /* FIX(1.175875602) */
+#define FIX_1_501321110  ( (INT32)  12299 )   /* FIX(1.501321110) */
+#define FIX_1_847759065  ( (INT32)  15137 )   /* FIX(1.847759065) */
+#define FIX_1_961570560  ( (INT32)  16069 )   /* FIX(1.961570560) */
+#define FIX_2_053119869  ( (INT32)  16819 )   /* FIX(2.053119869) */
+#define FIX_2_562915447  ( (INT32)  20995 )   /* FIX(2.562915447) */
+#define FIX_3_072711026  ( (INT32)  25172 )   /* FIX(3.072711026) */
+#else
+#define FIX_0_298631336  FIX( 0.298631336 )
+#define FIX_0_390180644  FIX( 0.390180644 )
+#define FIX_0_541196100  FIX( 0.541196100 )
+#define FIX_0_765366865  FIX( 0.765366865 )
+#define FIX_0_899976223  FIX( 0.899976223 )
+#define FIX_1_175875602  FIX( 1.175875602 )
+#define FIX_1_501321110  FIX( 1.501321110 )
+#define FIX_1_847759065  FIX( 1.847759065 )
+#define FIX_1_961570560  FIX( 1.961570560 )
+#define FIX_2_053119869  FIX( 2.053119869 )
+#define FIX_2_562915447  FIX( 2.562915447 )
+#define FIX_3_072711026  FIX( 3.072711026 )
+#endif
+
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * For 8-bit samples with the recommended scaling, all the variable
+ * and constant values involved are no more than 16 bits wide, so a
+ * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
+ * For 12-bit samples, a full 32-bit multiplication will be needed.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MULTIPLY( var, const )  MULTIPLY16C16( var, const )
+#else
+#define MULTIPLY( var, const )  ( ( var ) * ( const ) )
+#endif
+
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL void
+jpeg_fdct_islow( DCTELEM * data ) {
+    INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+    INT32 tmp10, tmp11, tmp12, tmp13;
+    INT32 z1, z2, z3, z4, z5;
+    DCTELEM * dataptr;
+    int ctr;
+    SHIFT_TEMPS
+
+    /* Pass 1: process rows. */
+    /* Note results are scaled up by sqrt(8) compared to a true DCT; */
+    /* furthermore, we scale the results by 2**PASS1_BITS. */
+
+    dataptr = data;
+    for ( ctr = DCTSIZE - 1; ctr >= 0; ctr-- ) {
+        tmp0 = dataptr[0] + dataptr[7];
+        tmp7 = dataptr[0] - dataptr[7];
+        tmp1 = dataptr[1] + dataptr[6];
+        tmp6 = dataptr[1] - dataptr[6];
+        tmp2 = dataptr[2] + dataptr[5];
+        tmp5 = dataptr[2] - dataptr[5];
+        tmp3 = dataptr[3] + dataptr[4];
+        tmp4 = dataptr[3] - dataptr[4];
+
+        /* Even part per LL&M figure 1 --- note that published figure is faulty;
+         * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+         */
+
+        tmp10 = tmp0 + tmp3;
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        dataptr[0] = (DCTELEM) ( ( tmp10 + tmp11 ) << PASS1_BITS );
+        dataptr[4] = (DCTELEM) ( ( tmp10 - tmp11 ) << PASS1_BITS );
+
+        z1 = MULTIPLY( tmp12 + tmp13, FIX_0_541196100 );
+        dataptr[2] = (DCTELEM) DESCALE( z1 + MULTIPLY( tmp13, FIX_0_765366865 ),
+                                        CONST_BITS - PASS1_BITS );
+        dataptr[6] = (DCTELEM) DESCALE( z1 + MULTIPLY( tmp12, -FIX_1_847759065 ),
+                                        CONST_BITS - PASS1_BITS );
+
+        /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
+         * cK represents cos(K*pi/16).
+         * i0..i3 in the paper are tmp4..tmp7 here.
+         */
+
+        z1 = tmp4 + tmp7;
+        z2 = tmp5 + tmp6;
+        z3 = tmp4 + tmp6;
+        z4 = tmp5 + tmp7;
+        z5 = MULTIPLY( z3 + z4, FIX_1_175875602 );/* sqrt(2) * c3 */
+
+        tmp4 = MULTIPLY( tmp4, FIX_0_298631336 );/* sqrt(2) * (-c1+c3+c5-c7) */
+        tmp5 = MULTIPLY( tmp5, FIX_2_053119869 );/* sqrt(2) * ( c1+c3-c5+c7) */
+        tmp6 = MULTIPLY( tmp6, FIX_3_072711026 );/* sqrt(2) * ( c1+c3+c5-c7) */
+        tmp7 = MULTIPLY( tmp7, FIX_1_501321110 );/* sqrt(2) * ( c1+c3-c5-c7) */
+        z1 = MULTIPLY( z1, -FIX_0_899976223 );/* sqrt(2) * (c7-c3) */
+        z2 = MULTIPLY( z2, -FIX_2_562915447 );/* sqrt(2) * (-c1-c3) */
+        z3 = MULTIPLY( z3, -FIX_1_961570560 );/* sqrt(2) * (-c3-c5) */
+        z4 = MULTIPLY( z4, -FIX_0_390180644 );/* sqrt(2) * (c5-c3) */
+
+        z3 += z5;
+        z4 += z5;
+
+        dataptr[7] = (DCTELEM) DESCALE( tmp4 + z1 + z3, CONST_BITS - PASS1_BITS );
+        dataptr[5] = (DCTELEM) DESCALE( tmp5 + z2 + z4, CONST_BITS - PASS1_BITS );
+        dataptr[3] = (DCTELEM) DESCALE( tmp6 + z2 + z3, CONST_BITS - PASS1_BITS );
+        dataptr[1] = (DCTELEM) DESCALE( tmp7 + z1 + z4, CONST_BITS - PASS1_BITS );
+
+        dataptr += DCTSIZE; /* advance pointer to next row */
+    }
+
+    /* Pass 2: process columns.
+     * We remove the PASS1_BITS scaling, but leave the results scaled up
+     * by an overall factor of 8.
+     */
+
+    dataptr = data;
+    for ( ctr = DCTSIZE - 1; ctr >= 0; ctr-- ) {
+        tmp0 = dataptr[DCTSIZE * 0] + dataptr[DCTSIZE * 7];
+        tmp7 = dataptr[DCTSIZE * 0] - dataptr[DCTSIZE * 7];
+        tmp1 = dataptr[DCTSIZE * 1] + dataptr[DCTSIZE * 6];
+        tmp6 = dataptr[DCTSIZE * 1] - dataptr[DCTSIZE * 6];
+        tmp2 = dataptr[DCTSIZE * 2] + dataptr[DCTSIZE * 5];
+        tmp5 = dataptr[DCTSIZE * 2] - dataptr[DCTSIZE * 5];
+        tmp3 = dataptr[DCTSIZE * 3] + dataptr[DCTSIZE * 4];
+        tmp4 = dataptr[DCTSIZE * 3] - dataptr[DCTSIZE * 4];
+
+        /* Even part per LL&M figure 1 --- note that published figure is faulty;
+         * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+         */
+
+        tmp10 = tmp0 + tmp3;
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        dataptr[DCTSIZE * 0] = (DCTELEM) DESCALE( tmp10 + tmp11, PASS1_BITS );
+        dataptr[DCTSIZE * 4] = (DCTELEM) DESCALE( tmp10 - tmp11, PASS1_BITS );
+
+        z1 = MULTIPLY( tmp12 + tmp13, FIX_0_541196100 );
+        dataptr[DCTSIZE * 2] = (DCTELEM) DESCALE( z1 + MULTIPLY( tmp13, FIX_0_765366865 ),
+                                                  CONST_BITS + PASS1_BITS );
+        dataptr[DCTSIZE * 6] = (DCTELEM) DESCALE( z1 + MULTIPLY( tmp12, -FIX_1_847759065 ),
+                                                  CONST_BITS + PASS1_BITS );
+
+        /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
+         * cK represents cos(K*pi/16).
+         * i0..i3 in the paper are tmp4..tmp7 here.
+         */
+
+        z1 = tmp4 + tmp7;
+        z2 = tmp5 + tmp6;
+        z3 = tmp4 + tmp6;
+        z4 = tmp5 + tmp7;
+        z5 = MULTIPLY( z3 + z4, FIX_1_175875602 );/* sqrt(2) * c3 */
+
+        tmp4 = MULTIPLY( tmp4, FIX_0_298631336 );/* sqrt(2) * (-c1+c3+c5-c7) */
+        tmp5 = MULTIPLY( tmp5, FIX_2_053119869 );/* sqrt(2) * ( c1+c3-c5+c7) */
+        tmp6 = MULTIPLY( tmp6, FIX_3_072711026 );/* sqrt(2) * ( c1+c3+c5-c7) */
+        tmp7 = MULTIPLY( tmp7, FIX_1_501321110 );/* sqrt(2) * ( c1+c3-c5-c7) */
+        z1 = MULTIPLY( z1, -FIX_0_899976223 );/* sqrt(2) * (c7-c3) */
+        z2 = MULTIPLY( z2, -FIX_2_562915447 );/* sqrt(2) * (-c1-c3) */
+        z3 = MULTIPLY( z3, -FIX_1_961570560 );/* sqrt(2) * (-c3-c5) */
+        z4 = MULTIPLY( z4, -FIX_0_390180644 );/* sqrt(2) * (c5-c3) */
+
+        z3 += z5;
+        z4 += z5;
+
+        dataptr[DCTSIZE * 7] = (DCTELEM) DESCALE( tmp4 + z1 + z3,
+                                                  CONST_BITS + PASS1_BITS );
+        dataptr[DCTSIZE * 5] = (DCTELEM) DESCALE( tmp5 + z2 + z4,
+                                                  CONST_BITS + PASS1_BITS );
+        dataptr[DCTSIZE * 3] = (DCTELEM) DESCALE( tmp6 + z2 + z3,
+                                                  CONST_BITS + PASS1_BITS );
+        dataptr[DCTSIZE * 1] = (DCTELEM) DESCALE( tmp7 + z1 + z4,
+                                                  CONST_BITS + PASS1_BITS );
+
+        dataptr++;      /* advance pointer to next column */
+    }
+}
+
+#endif /* DCT_ISLOW_SUPPORTED */

neo/renderer/jpeg-6/jidctflt.cpp

@@ -0,0 +1,240 @@
+/*
+ * jidctflt.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a floating-point implementation of the
+ * inverse DCT (Discrete Cosine Transform).  In the IJG code, this routine
+ * must also perform dequantization of the input coefficients.
+ *
+ * This implementation should be more accurate than either of the integer
+ * IDCT implementations.  However, it may not give the same results on all
+ * machines because of differences in roundoff behavior.  Speed will depend
+ * on the hardware's floating point capacity.
+ *
+ * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
+ * on each row (or vice versa, but it's more convenient to emit a row at
+ * a time).  Direct algorithms are also available, but they are much more
+ * complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT.  Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README).  The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs.  These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries.  The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with a fixed-point
+ * implementation, accuracy is lost due to imprecise representation of the
+ * scaled quantization values.  However, that problem does not arise if
+ * we use floating point arithmetic.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce a float result.
+ */
+
+#define DEQUANTIZE( coef, quantval )  ( ( (FAST_FLOAT) ( coef ) ) * ( quantval ) )
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients.
+ */
+
+GLOBAL void
+jpeg_idct_float( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                 JCOEFPTR coef_block,
+                 JSAMPARRAY output_buf, JDIMENSION output_col ) {
+    FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+    FAST_FLOAT tmp10, tmp11, tmp12, tmp13;
+    FAST_FLOAT z5, z10, z11, z12, z13;
+    JCOEFPTR inptr;
+    FLOAT_MULT_TYPE * quantptr;
+    FAST_FLOAT * wsptr;
+    JSAMPROW outptr;
+    JSAMPLE * range_limit = IDCT_range_limit( cinfo );
+    int ctr;
+    FAST_FLOAT workspace[DCTSIZE2];/* buffers data between passes */
+    SHIFT_TEMPS
+
+    /* Pass 1: process columns from input, store into work array. */
+
+    inptr = coef_block;
+    quantptr = (FLOAT_MULT_TYPE *) compptr->dct_table;
+    wsptr = workspace;
+    for ( ctr = DCTSIZE; ctr > 0; ctr-- ) {
+        /* Due to quantization, we will usually find that many of the input
+         * coefficients are zero, especially the AC terms.  We can exploit this
+         * by short-circuiting the IDCT calculation for any column in which all
+         * the AC terms are zero.  In that case each output is equal to the
+         * DC coefficient (with scale factor as needed).
+         * With typical images and quantization tables, half or more of the
+         * column DCT calculations can be simplified this way.
+         */
+
+        if ( ( inptr[DCTSIZE * 1] | inptr[DCTSIZE * 2] | inptr[DCTSIZE * 3] |
+               inptr[DCTSIZE * 4] | inptr[DCTSIZE * 5] | inptr[DCTSIZE * 6] |
+               inptr[DCTSIZE * 7] ) == 0 ) {
+            /* AC terms all zero */
+            FAST_FLOAT dcval = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+
+            wsptr[DCTSIZE * 0] = dcval;
+            wsptr[DCTSIZE * 1] = dcval;
+            wsptr[DCTSIZE * 2] = dcval;
+            wsptr[DCTSIZE * 3] = dcval;
+            wsptr[DCTSIZE * 4] = dcval;
+            wsptr[DCTSIZE * 5] = dcval;
+            wsptr[DCTSIZE * 6] = dcval;
+            wsptr[DCTSIZE * 7] = dcval;
+
+            inptr++;    /* advance pointers to next column */
+            quantptr++;
+            wsptr++;
+            continue;
+        }
+
+        /* Even part */
+
+        tmp0 = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+        tmp1 = DEQUANTIZE( inptr[DCTSIZE * 2], quantptr[DCTSIZE * 2] );
+        tmp2 = DEQUANTIZE( inptr[DCTSIZE * 4], quantptr[DCTSIZE * 4] );
+        tmp3 = DEQUANTIZE( inptr[DCTSIZE * 6], quantptr[DCTSIZE * 6] );
+
+        tmp10 = tmp0 + tmp2;/* phase 3 */
+        tmp11 = tmp0 - tmp2;
+
+        tmp13 = tmp1 + tmp3;/* phases 5-3 */
+        tmp12 = ( tmp1 - tmp3 ) * ( (FAST_FLOAT) 1.414213562 ) - tmp13;/* 2*c4 */
+
+        tmp0 = tmp10 + tmp13;/* phase 2 */
+        tmp3 = tmp10 - tmp13;
+        tmp1 = tmp11 + tmp12;
+        tmp2 = tmp11 - tmp12;
+
+        /* Odd part */
+
+        tmp4 = DEQUANTIZE( inptr[DCTSIZE * 1], quantptr[DCTSIZE * 1] );
+        tmp5 = DEQUANTIZE( inptr[DCTSIZE * 3], quantptr[DCTSIZE * 3] );
+        tmp6 = DEQUANTIZE( inptr[DCTSIZE * 5], quantptr[DCTSIZE * 5] );
+        tmp7 = DEQUANTIZE( inptr[DCTSIZE * 7], quantptr[DCTSIZE * 7] );
+
+        z13 = tmp6 + tmp5;  /* phase 6 */
+        z10 = tmp6 - tmp5;
+        z11 = tmp4 + tmp7;
+        z12 = tmp4 - tmp7;
+
+        tmp7 = z11 + z13;   /* phase 5 */
+        tmp11 = ( z11 - z13 ) * ( (FAST_FLOAT) 1.414213562 );/* 2*c4 */
+
+        z5 = ( z10 + z12 ) * ( (FAST_FLOAT) 1.847759065 );/* 2*c2 */
+        tmp10 = ( (FAST_FLOAT) 1.082392200 ) * z12 - z5;/* 2*(c2-c6) */
+        tmp12 = ( (FAST_FLOAT) -2.613125930 ) * z10 + z5;/* -2*(c2+c6) */
+
+        tmp6 = tmp12 - tmp7;/* phase 2 */
+        tmp5 = tmp11 - tmp6;
+        tmp4 = tmp10 + tmp5;
+
+        wsptr[DCTSIZE * 0] = tmp0 + tmp7;
+        wsptr[DCTSIZE * 7] = tmp0 - tmp7;
+        wsptr[DCTSIZE * 1] = tmp1 + tmp6;
+        wsptr[DCTSIZE * 6] = tmp1 - tmp6;
+        wsptr[DCTSIZE * 2] = tmp2 + tmp5;
+        wsptr[DCTSIZE * 5] = tmp2 - tmp5;
+        wsptr[DCTSIZE * 4] = tmp3 + tmp4;
+        wsptr[DCTSIZE * 3] = tmp3 - tmp4;
+
+        inptr++;        /* advance pointers to next column */
+        quantptr++;
+        wsptr++;
+    }
+
+    /* Pass 2: process rows from work array, store into output array. */
+    /* Note that we must descale the results by a factor of 8 == 2**3. */
+
+    wsptr = workspace;
+    for ( ctr = 0; ctr < DCTSIZE; ctr++ ) {
+        outptr = output_buf[ctr] + output_col;
+        /* Rows of zeroes can be exploited in the same way as we did with columns.
+         * However, the column calculation has created many nonzero AC terms, so
+         * the simplification applies less often (typically 5% to 10% of the time).
+         * And testing floats for zero is relatively expensive, so we don't bother.
+         */
+
+        /* Even part */
+
+        tmp10 = wsptr[0] + wsptr[4];
+        tmp11 = wsptr[0] - wsptr[4];
+
+        tmp13 = wsptr[2] + wsptr[6];
+        tmp12 = ( wsptr[2] - wsptr[6] ) * ( (FAST_FLOAT) 1.414213562 ) - tmp13;
+
+        tmp0 = tmp10 + tmp13;
+        tmp3 = tmp10 - tmp13;
+        tmp1 = tmp11 + tmp12;
+        tmp2 = tmp11 - tmp12;
+
+        /* Odd part */
+
+        z13 = wsptr[5] + wsptr[3];
+        z10 = wsptr[5] - wsptr[3];
+        z11 = wsptr[1] + wsptr[7];
+        z12 = wsptr[1] - wsptr[7];
+
+        tmp7 = z11 + z13;
+        tmp11 = ( z11 - z13 ) * ( (FAST_FLOAT) 1.414213562 );
+
+        z5 = ( z10 + z12 ) * ( (FAST_FLOAT) 1.847759065 );/* 2*c2 */
+        tmp10 = ( (FAST_FLOAT) 1.082392200 ) * z12 - z5;/* 2*(c2-c6) */
+        tmp12 = ( (FAST_FLOAT) -2.613125930 ) * z10 + z5;/* -2*(c2+c6) */
+
+        tmp6 = tmp12 - tmp7;
+        tmp5 = tmp11 - tmp6;
+        tmp4 = tmp10 + tmp5;
+
+        /* Final output stage: scale down by a factor of 8 and range-limit */
+
+        outptr[0] = range_limit[(int) DESCALE( (INT32) ( tmp0 + tmp7 ), 3 )
+                                & RANGE_MASK];
+        outptr[7] = range_limit[(int) DESCALE( (INT32) ( tmp0 - tmp7 ), 3 )
+                                & RANGE_MASK];
+        outptr[1] = range_limit[(int) DESCALE( (INT32) ( tmp1 + tmp6 ), 3 )
+                                & RANGE_MASK];
+        outptr[6] = range_limit[(int) DESCALE( (INT32) ( tmp1 - tmp6 ), 3 )
+                                & RANGE_MASK];
+        outptr[2] = range_limit[(int) DESCALE( (INT32) ( tmp2 + tmp5 ), 3 )
+                                & RANGE_MASK];
+        outptr[5] = range_limit[(int) DESCALE( (INT32) ( tmp2 - tmp5 ), 3 )
+                                & RANGE_MASK];
+        outptr[4] = range_limit[(int) DESCALE( (INT32) ( tmp3 + tmp4 ), 3 )
+                                & RANGE_MASK];
+        outptr[3] = range_limit[(int) DESCALE( (INT32) ( tmp3 - tmp4 ), 3 )
+                                & RANGE_MASK];
+
+        wsptr += DCTSIZE;   /* advance pointer to next row */
+    }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */

neo/renderer/jpeg-6/jidctfst.cpp

@@ -0,0 +1,366 @@
+/*
+ * jidctfst.c
+ *
+ * Copyright (C) 1994-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a fast, not so accurate integer implementation of the
+ * inverse DCT (Discrete Cosine Transform).  In the IJG code, this routine
+ * must also perform dequantization of the input coefficients.
+ *
+ * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
+ * on each row (or vice versa, but it's more convenient to emit a row at
+ * a time).  Direct algorithms are also available, but they are much more
+ * complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT.  Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README).  The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs.  These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries.  The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with fixed-point math,
+ * accuracy is lost due to imprecise representation of the scaled
+ * quantization values.  The smaller the quantization table entry, the less
+ * precise the scaled value, so this implementation does worse with high-
+ * quality-setting files than with low-quality ones.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef DCT_IFAST_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/* Scaling decisions are generally the same as in the LL&M algorithm;
+ * see jidctint.c for more details.  However, we choose to descale
+ * (right shift) multiplication products as soon as they are formed,
+ * rather than carrying additional fractional bits into subsequent additions.
+ * This compromises accuracy slightly, but it lets us save a few shifts.
+ * More importantly, 16-bit arithmetic is then adequate (for 8-bit samples)
+ * everywhere except in the multiplications proper; this saves a good deal
+ * of work on 16-bit-int machines.
+ *
+ * The dequantized coefficients are not integers because the AA&N scaling
+ * factors have been incorporated.  We represent them scaled up by PASS1_BITS,
+ * so that the first and second IDCT rounds have the same input scaling.
+ * For 8-bit JSAMPLEs, we choose IFAST_SCALE_BITS = PASS1_BITS so as to
+ * avoid a descaling shift; this compromises accuracy rather drastically
+ * for small quantization table entries, but it saves a lot of shifts.
+ * For 12-bit JSAMPLEs, there's no hope of using 16x16 multiplies anyway,
+ * so we use a much larger scaling factor to preserve accuracy.
+ *
+ * A final compromise is to represent the multiplicative constants to only
+ * 8 fractional bits, rather than 13.  This saves some shifting work on some
+ * machines, and may also reduce the cost of multiplication (since there
+ * are fewer one-bits in the constants).
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS  8
+#define PASS1_BITS  2
+#else
+#define CONST_BITS  8
+#define PASS1_BITS  1       /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 8
+#define FIX_1_082392200  ( (INT32)  277 )     /* FIX(1.082392200) */
+#define FIX_1_414213562  ( (INT32)  362 )     /* FIX(1.414213562) */
+#define FIX_1_847759065  ( (INT32)  473 )     /* FIX(1.847759065) */
+#define FIX_2_613125930  ( (INT32)  669 )     /* FIX(2.613125930) */
+#else
+#define FIX_1_082392200  FIX( 1.082392200 )
+#define FIX_1_414213562  FIX( 1.414213562 )
+#define FIX_1_847759065  FIX( 1.847759065 )
+#define FIX_2_613125930  FIX( 2.613125930 )
+#endif
+
+
+/* We can gain a little more speed, with a further compromise in accuracy,
+ * by omitting the addition in a descaling shift.  This yields an incorrectly
+ * rounded result half the time...
+ */
+
+#ifndef USE_ACCURATE_ROUNDING
+#undef DESCALE
+#define DESCALE( x, n )  RIGHT_SHIFT( x, n )
+#endif
+
+
+/* Multiply a DCTELEM variable by an INT32 constant, and immediately
+ * descale to yield a DCTELEM result.
+ */
+
+#define MULTIPLY( var, const )  ( (DCTELEM) DESCALE( ( var ) * ( const ), CONST_BITS ) )
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce a DCTELEM result.  For 8-bit data a 16x16->16
+ * multiplication will do.  For 12-bit data, the multiplier table is
+ * declared INT32, so a 32-bit multiply will be used.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define DEQUANTIZE( coef, quantval )  ( ( (IFAST_MULT_TYPE) ( coef ) ) * ( quantval ) )
+#else
+#define DEQUANTIZE( coef, quantval )  \
+    DESCALE( ( coef ) * ( quantval ), IFAST_SCALE_BITS - PASS1_BITS )
+#endif
+
+
+/* Like DESCALE, but applies to a DCTELEM and produces an int.
+ * We assume that int right shift is unsigned if INT32 right shift is.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define ISHIFT_TEMPS    DCTELEM ishift_temp;
+#if BITS_IN_JSAMPLE == 8
+#define DCTELEMBITS  16     /* DCTELEM may be 16 or 32 bits */
+#else
+#define DCTELEMBITS  32     /* DCTELEM must be 32 bits */
+#endif
+#define IRIGHT_SHIFT( x, shft )  \
+    ( ( ishift_temp = ( x ) ) < 0 ? \
+                      ( ishift_temp >> ( shft ) ) | ( ( ~( (DCTELEM) 0 ) ) << ( DCTELEMBITS - ( shft ) ) ) : \
+                      ( ishift_temp >> ( shft ) ) )
+#else
+#define ISHIFT_TEMPS
+#define IRIGHT_SHIFT( x, shft )    ( ( x ) >> ( shft ) )
+#endif
+
+#ifdef USE_ACCURATE_ROUNDING
+#define IDESCALE( x, n )  ( (int) IRIGHT_SHIFT( ( x ) + ( 1 << ( ( n ) - 1 ) ), n ) )
+#else
+#define IDESCALE( x, n )  ( (int) IRIGHT_SHIFT( x, n ) )
+#endif
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients.
+ */
+
+GLOBAL void
+jpeg_idct_ifast( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                 JCOEFPTR coef_block,
+                 JSAMPARRAY output_buf, JDIMENSION output_col ) {
+    DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+    DCTELEM tmp10, tmp11, tmp12, tmp13;
+    DCTELEM z5, z10, z11, z12, z13;
+    JCOEFPTR inptr;
+    IFAST_MULT_TYPE * quantptr;
+    int * wsptr;
+    JSAMPROW outptr;
+    JSAMPLE * range_limit = IDCT_range_limit( cinfo );
+    int ctr;
+    int workspace[DCTSIZE2];/* buffers data between passes */
+    SHIFT_TEMPS         /* for DESCALE */
+    ISHIFT_TEMPS        /* for IDESCALE */
+
+    /* Pass 1: process columns from input, store into work array. */
+
+    inptr = coef_block;
+    quantptr = (IFAST_MULT_TYPE *) compptr->dct_table;
+    wsptr = workspace;
+    for ( ctr = DCTSIZE; ctr > 0; ctr-- ) {
+        /* Due to quantization, we will usually find that many of the input
+         * coefficients are zero, especially the AC terms.  We can exploit this
+         * by short-circuiting the IDCT calculation for any column in which all
+         * the AC terms are zero.  In that case each output is equal to the
+         * DC coefficient (with scale factor as needed).
+         * With typical images and quantization tables, half or more of the
+         * column DCT calculations can be simplified this way.
+         */
+
+        if ( ( inptr[DCTSIZE * 1] | inptr[DCTSIZE * 2] | inptr[DCTSIZE * 3] |
+               inptr[DCTSIZE * 4] | inptr[DCTSIZE * 5] | inptr[DCTSIZE * 6] |
+               inptr[DCTSIZE * 7] ) == 0 ) {
+            /* AC terms all zero */
+            int dcval = (int) DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+
+            wsptr[DCTSIZE * 0] = dcval;
+            wsptr[DCTSIZE * 1] = dcval;
+            wsptr[DCTSIZE * 2] = dcval;
+            wsptr[DCTSIZE * 3] = dcval;
+            wsptr[DCTSIZE * 4] = dcval;
+            wsptr[DCTSIZE * 5] = dcval;
+            wsptr[DCTSIZE * 6] = dcval;
+            wsptr[DCTSIZE * 7] = dcval;
+
+            inptr++;    /* advance pointers to next column */
+            quantptr++;
+            wsptr++;
+            continue;
+        }
+
+        /* Even part */
+
+        tmp0 = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+        tmp1 = DEQUANTIZE( inptr[DCTSIZE * 2], quantptr[DCTSIZE * 2] );
+        tmp2 = DEQUANTIZE( inptr[DCTSIZE * 4], quantptr[DCTSIZE * 4] );
+        tmp3 = DEQUANTIZE( inptr[DCTSIZE * 6], quantptr[DCTSIZE * 6] );
+
+        tmp10 = tmp0 + tmp2;/* phase 3 */
+        tmp11 = tmp0 - tmp2;
+
+        tmp13 = tmp1 + tmp3;/* phases 5-3 */
+        tmp12 = MULTIPLY( tmp1 - tmp3, FIX_1_414213562 ) - tmp13;/* 2*c4 */
+
+        tmp0 = tmp10 + tmp13;/* phase 2 */
+        tmp3 = tmp10 - tmp13;
+        tmp1 = tmp11 + tmp12;
+        tmp2 = tmp11 - tmp12;
+
+        /* Odd part */
+
+        tmp4 = DEQUANTIZE( inptr[DCTSIZE * 1], quantptr[DCTSIZE * 1] );
+        tmp5 = DEQUANTIZE( inptr[DCTSIZE * 3], quantptr[DCTSIZE * 3] );
+        tmp6 = DEQUANTIZE( inptr[DCTSIZE * 5], quantptr[DCTSIZE * 5] );
+        tmp7 = DEQUANTIZE( inptr[DCTSIZE * 7], quantptr[DCTSIZE * 7] );
+
+        z13 = tmp6 + tmp5;  /* phase 6 */
+        z10 = tmp6 - tmp5;
+        z11 = tmp4 + tmp7;
+        z12 = tmp4 - tmp7;
+
+        tmp7 = z11 + z13;   /* phase 5 */
+        tmp11 = MULTIPLY( z11 - z13, FIX_1_414213562 );/* 2*c4 */
+
+        z5 = MULTIPLY( z10 + z12, FIX_1_847759065 );/* 2*c2 */
+        tmp10 = MULTIPLY( z12, FIX_1_082392200 ) - z5;/* 2*(c2-c6) */
+        tmp12 = MULTIPLY( z10, -FIX_2_613125930 ) + z5;/* -2*(c2+c6) */
+
+        tmp6 = tmp12 - tmp7;/* phase 2 */
+        tmp5 = tmp11 - tmp6;
+        tmp4 = tmp10 + tmp5;
+
+        wsptr[DCTSIZE * 0] = (int) ( tmp0 + tmp7 );
+        wsptr[DCTSIZE * 7] = (int) ( tmp0 - tmp7 );
+        wsptr[DCTSIZE * 1] = (int) ( tmp1 + tmp6 );
+        wsptr[DCTSIZE * 6] = (int) ( tmp1 - tmp6 );
+        wsptr[DCTSIZE * 2] = (int) ( tmp2 + tmp5 );
+        wsptr[DCTSIZE * 5] = (int) ( tmp2 - tmp5 );
+        wsptr[DCTSIZE * 4] = (int) ( tmp3 + tmp4 );
+        wsptr[DCTSIZE * 3] = (int) ( tmp3 - tmp4 );
+
+        inptr++;        /* advance pointers to next column */
+        quantptr++;
+        wsptr++;
+    }
+
+    /* Pass 2: process rows from work array, store into output array. */
+    /* Note that we must descale the results by a factor of 8 == 2**3, */
+    /* and also undo the PASS1_BITS scaling. */
+
+    wsptr = workspace;
+    for ( ctr = 0; ctr < DCTSIZE; ctr++ ) {
+        outptr = output_buf[ctr] + output_col;
+        /* Rows of zeroes can be exploited in the same way as we did with columns.
+         * However, the column calculation has created many nonzero AC terms, so
+         * the simplification applies less often (typically 5% to 10% of the time).
+         * On machines with very fast multiplication, it's possible that the
+         * test takes more time than it's worth.  In that case this section
+         * may be commented out.
+         */
+
+#ifndef NO_ZERO_ROW_TEST
+        if ( ( wsptr[1] | wsptr[2] | wsptr[3] | wsptr[4] | wsptr[5] | wsptr[6] |
+               wsptr[7] ) == 0 ) {
+            /* AC terms all zero */
+            JSAMPLE dcval = range_limit[IDESCALE( wsptr[0], PASS1_BITS + 3 )
+                                        & RANGE_MASK];
+
+            outptr[0] = dcval;
+            outptr[1] = dcval;
+            outptr[2] = dcval;
+            outptr[3] = dcval;
+            outptr[4] = dcval;
+            outptr[5] = dcval;
+            outptr[6] = dcval;
+            outptr[7] = dcval;
+
+            wsptr += DCTSIZE;/* advance pointer to next row */
+            continue;
+        }
+#endif
+
+        /* Even part */
+
+        tmp10 = ( (DCTELEM) wsptr[0] + (DCTELEM) wsptr[4] );
+        tmp11 = ( (DCTELEM) wsptr[0] - (DCTELEM) wsptr[4] );
+
+        tmp13 = ( (DCTELEM) wsptr[2] + (DCTELEM) wsptr[6] );
+        tmp12 = MULTIPLY( (DCTELEM) wsptr[2] - (DCTELEM) wsptr[6], FIX_1_414213562 )
+                - tmp13;
+
+        tmp0 = tmp10 + tmp13;
+        tmp3 = tmp10 - tmp13;
+        tmp1 = tmp11 + tmp12;
+        tmp2 = tmp11 - tmp12;
+
+        /* Odd part */
+
+        z13 = (DCTELEM) wsptr[5] + (DCTELEM) wsptr[3];
+        z10 = (DCTELEM) wsptr[5] - (DCTELEM) wsptr[3];
+        z11 = (DCTELEM) wsptr[1] + (DCTELEM) wsptr[7];
+        z12 = (DCTELEM) wsptr[1] - (DCTELEM) wsptr[7];
+
+        tmp7 = z11 + z13;   /* phase 5 */
+        tmp11 = MULTIPLY( z11 - z13, FIX_1_414213562 );/* 2*c4 */
+
+        z5 = MULTIPLY( z10 + z12, FIX_1_847759065 );/* 2*c2 */
+        tmp10 = MULTIPLY( z12, FIX_1_082392200 ) - z5;/* 2*(c2-c6) */
+        tmp12 = MULTIPLY( z10, -FIX_2_613125930 ) + z5;/* -2*(c2+c6) */
+
+        tmp6 = tmp12 - tmp7;/* phase 2 */
+        tmp5 = tmp11 - tmp6;
+        tmp4 = tmp10 + tmp5;
+
+        /* Final output stage: scale down by a factor of 8 and range-limit */
+
+        outptr[0] = range_limit[IDESCALE( tmp0 + tmp7, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[7] = range_limit[IDESCALE( tmp0 - tmp7, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[1] = range_limit[IDESCALE( tmp1 + tmp6, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[6] = range_limit[IDESCALE( tmp1 - tmp6, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[2] = range_limit[IDESCALE( tmp2 + tmp5, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[5] = range_limit[IDESCALE( tmp2 - tmp5, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[4] = range_limit[IDESCALE( tmp3 + tmp4, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[3] = range_limit[IDESCALE( tmp3 - tmp4, PASS1_BITS + 3 )
+                                & RANGE_MASK];
+
+        wsptr += DCTSIZE;   /* advance pointer to next row */
+    }
+}
+
+#endif /* DCT_IFAST_SUPPORTED */

neo/renderer/jpeg-6/jidctint.cpp

@@ -0,0 +1,387 @@
+/*
+ * jidctint.c
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a slow-but-accurate integer implementation of the
+ * inverse DCT (Discrete Cosine Transform).  In the IJG code, this routine
+ * must also perform dequantization of the input coefficients.
+ *
+ * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
+ * on each row (or vice versa, but it's more convenient to emit a row at
+ * a time).  Direct algorithms are also available, but they are much more
+ * complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on an algorithm described in
+ *   C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
+ *   Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
+ *   Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
+ * The primary algorithm described there uses 11 multiplies and 29 adds.
+ * We use their alternate method with 12 multiplies and 32 adds.
+ * The advantage of this method is that no data path contains more than one
+ * multiplication; this allows a very simple and accurate implementation in
+ * scaled fixed-point arithmetic, with a minimal number of shifts.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef DCT_ISLOW_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/*
+ * The poop on this scaling stuff is as follows:
+ *
+ * Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
+ * larger than the true IDCT outputs.  The final outputs are therefore
+ * a factor of N larger than desired; since N=8 this can be cured by
+ * a simple right shift at the end of the algorithm.  The advantage of
+ * this arrangement is that we save two multiplications per 1-D IDCT,
+ * because the y0 and y4 inputs need not be divided by sqrt(N).
+ *
+ * We have to do addition and subtraction of the integer inputs, which
+ * is no problem, and multiplication by fractional constants, which is
+ * a problem to do in integer arithmetic.  We multiply all the constants
+ * by CONST_SCALE and convert them to integer constants (thus retaining
+ * CONST_BITS bits of precision in the constants).  After doing a
+ * multiplication we have to divide the product by CONST_SCALE, with proper
+ * rounding, to produce the correct output.  This division can be done
+ * cheaply as a right shift of CONST_BITS bits.  We postpone shifting
+ * as long as possible so that partial sums can be added together with
+ * full fractional precision.
+ *
+ * The outputs of the first pass are scaled up by PASS1_BITS bits so that
+ * they are represented to better-than-integral precision.  These outputs
+ * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
+ * with the recommended scaling.  (To scale up 12-bit sample data further, an
+ * intermediate INT32 array would be needed.)
+ *
+ * To avoid overflow of the 32-bit intermediate results in pass 2, we must
+ * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26.  Error analysis
+ * shows that the values given below are the most effective.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS  13
+#define PASS1_BITS  2
+#else
+#define CONST_BITS  13
+#define PASS1_BITS  1       /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 13
+#define FIX_0_298631336  ( (INT32)  2446 )    /* FIX(0.298631336) */
+#define FIX_0_390180644  ( (INT32)  3196 )    /* FIX(0.390180644) */
+#define FIX_0_541196100  ( (INT32)  4433 )    /* FIX(0.541196100) */
+#define FIX_0_765366865  ( (INT32)  6270 )    /* FIX(0.765366865) */
+#define FIX_0_899976223  ( (INT32)  7373 )    /* FIX(0.899976223) */
+#define FIX_1_175875602  ( (INT32)  9633 )    /* FIX(1.175875602) */
+#define FIX_1_501321110  ( (INT32)  12299 )   /* FIX(1.501321110) */
+#define FIX_1_847759065  ( (INT32)  15137 )   /* FIX(1.847759065) */
+#define FIX_1_961570560  ( (INT32)  16069 )   /* FIX(1.961570560) */
+#define FIX_2_053119869  ( (INT32)  16819 )   /* FIX(2.053119869) */
+#define FIX_2_562915447  ( (INT32)  20995 )   /* FIX(2.562915447) */
+#define FIX_3_072711026  ( (INT32)  25172 )   /* FIX(3.072711026) */
+#else
+#define FIX_0_298631336  FIX( 0.298631336 )
+#define FIX_0_390180644  FIX( 0.390180644 )
+#define FIX_0_541196100  FIX( 0.541196100 )
+#define FIX_0_765366865  FIX( 0.765366865 )
+#define FIX_0_899976223  FIX( 0.899976223 )
+#define FIX_1_175875602  FIX( 1.175875602 )
+#define FIX_1_501321110  FIX( 1.501321110 )
+#define FIX_1_847759065  FIX( 1.847759065 )
+#define FIX_1_961570560  FIX( 1.961570560 )
+#define FIX_2_053119869  FIX( 2.053119869 )
+#define FIX_2_562915447  FIX( 2.562915447 )
+#define FIX_3_072711026  FIX( 3.072711026 )
+#endif
+
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * For 8-bit samples with the recommended scaling, all the variable
+ * and constant values involved are no more than 16 bits wide, so a
+ * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
+ * For 12-bit samples, a full 32-bit multiplication will be needed.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MULTIPLY( var, const )  MULTIPLY16C16( var, const )
+#else
+#define MULTIPLY( var, const )  ( ( var ) * ( const ) )
+#endif
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce an int result.  In this module, both inputs and result
+ * are 16 bits or less, so either int or short multiply will work.
+ */
+
+#define DEQUANTIZE( coef, quantval )  ( ( (ISLOW_MULT_TYPE) ( coef ) ) * ( quantval ) )
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients.
+ */
+
+GLOBAL void
+jpeg_idct_islow( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+                 JCOEFPTR coef_block,
+                 JSAMPARRAY output_buf, JDIMENSION output_col ) {
+    INT32 tmp0, tmp1, tmp2, tmp3;
+    INT32 tmp10, tmp11, tmp12, tmp13;
+    INT32 z1, z2, z3, z4, z5;
+    JCOEFPTR inptr;
+    ISLOW_MULT_TYPE * quantptr;
+    int * wsptr;
+    JSAMPROW outptr;
+    JSAMPLE * range_limit = IDCT_range_limit( cinfo );
+    int ctr;
+    int workspace[DCTSIZE2];/* buffers data between passes */
+    SHIFT_TEMPS
+
+    /* Pass 1: process columns from input, store into work array. */
+    /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
+    /* furthermore, we scale the results by 2**PASS1_BITS. */
+
+    inptr = coef_block;
+    quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+    wsptr = workspace;
+    for ( ctr = DCTSIZE; ctr > 0; ctr-- ) {
+        /* Due to quantization, we will usually find that many of the input
+         * coefficients are zero, especially the AC terms.  We can exploit this
+         * by short-circuiting the IDCT calculation for any column in which all
+         * the AC terms are zero.  In that case each output is equal to the
+         * DC coefficient (with scale factor as needed).
+         * With typical images and quantization tables, half or more of the
+         * column DCT calculations can be simplified this way.
+         */
+
+        if ( ( inptr[DCTSIZE * 1] | inptr[DCTSIZE * 2] | inptr[DCTSIZE * 3] |
+               inptr[DCTSIZE * 4] | inptr[DCTSIZE * 5] | inptr[DCTSIZE * 6] |
+               inptr[DCTSIZE * 7] ) == 0 ) {
+            /* AC terms all zero */
+            int dcval = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] ) << PASS1_BITS;
+
+            wsptr[DCTSIZE * 0] = dcval;
+            wsptr[DCTSIZE * 1] = dcval;
+            wsptr[DCTSIZE * 2] = dcval;
+            wsptr[DCTSIZE * 3] = dcval;
+            wsptr[DCTSIZE * 4] = dcval;
+            wsptr[DCTSIZE * 5] = dcval;
+            wsptr[DCTSIZE * 6] = dcval;
+            wsptr[DCTSIZE * 7] = dcval;
+
+            inptr++;    /* advance pointers to next column */
+            quantptr++;
+            wsptr++;
+            continue;
+        }
+
+        /* Even part: reverse the even part of the forward DCT. */
+        /* The rotator is sqrt(2)*c(-6). */
+
+        z2 = DEQUANTIZE( inptr[DCTSIZE * 2], quantptr[DCTSIZE * 2] );
+        z3 = DEQUANTIZE( inptr[DCTSIZE * 6], quantptr[DCTSIZE * 6] );
+
+        z1 = MULTIPLY( z2 + z3, FIX_0_541196100 );
+        tmp2 = z1 + MULTIPLY( z3, -FIX_1_847759065 );
+        tmp3 = z1 + MULTIPLY( z2, FIX_0_765366865 );
+
+        z2 = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+        z3 = DEQUANTIZE( inptr[DCTSIZE * 4], quantptr[DCTSIZE * 4] );
+
+        tmp0 = ( z2 + z3 ) << CONST_BITS;
+        tmp1 = ( z2 - z3 ) << CONST_BITS;
+
+        tmp10 = tmp0 + tmp3;
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        /* Odd part per figure 8; the matrix is unitary and hence its
+         * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
+         */
+
+        tmp0 = DEQUANTIZE( inptr[DCTSIZE * 7], quantptr[DCTSIZE * 7] );
+        tmp1 = DEQUANTIZE( inptr[DCTSIZE * 5], quantptr[DCTSIZE * 5] );
+        tmp2 = DEQUANTIZE( inptr[DCTSIZE * 3], quantptr[DCTSIZE * 3] );
+        tmp3 = DEQUANTIZE( inptr[DCTSIZE * 1], quantptr[DCTSIZE * 1] );
+
+        z1 = tmp0 + tmp3;
+        z2 = tmp1 + tmp2;
+        z3 = tmp0 + tmp2;
+        z4 = tmp1 + tmp3;
+        z5 = MULTIPLY( z3 + z4, FIX_1_175875602 );/* sqrt(2) * c3 */
+
+        tmp0 = MULTIPLY( tmp0, FIX_0_298631336 );/* sqrt(2) * (-c1+c3+c5-c7) */
+        tmp1 = MULTIPLY( tmp1, FIX_2_053119869 );/* sqrt(2) * ( c1+c3-c5+c7) */
+        tmp2 = MULTIPLY( tmp2, FIX_3_072711026 );/* sqrt(2) * ( c1+c3+c5-c7) */
+        tmp3 = MULTIPLY( tmp3, FIX_1_501321110 );/* sqrt(2) * ( c1+c3-c5-c7) */
+        z1 = MULTIPLY( z1, -FIX_0_899976223 );/* sqrt(2) * (c7-c3) */
+        z2 = MULTIPLY( z2, -FIX_2_562915447 );/* sqrt(2) * (-c1-c3) */
+        z3 = MULTIPLY( z3, -FIX_1_961570560 );/* sqrt(2) * (-c3-c5) */
+        z4 = MULTIPLY( z4, -FIX_0_390180644 );/* sqrt(2) * (c5-c3) */
+
+        z3 += z5;
+        z4 += z5;
+
+        tmp0 += z1 + z3;
+        tmp1 += z2 + z4;
+        tmp2 += z2 + z3;
+        tmp3 += z1 + z4;
+
+        /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
+
+        wsptr[DCTSIZE * 0] = (int) DESCALE( tmp10 + tmp3, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 7] = (int) DESCALE( tmp10 - tmp3, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 1] = (int) DESCALE( tmp11 + tmp2, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 6] = (int) DESCALE( tmp11 - tmp2, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 2] = (int) DESCALE( tmp12 + tmp1, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 5] = (int) DESCALE( tmp12 - tmp1, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 3] = (int) DESCALE( tmp13 + tmp0, CONST_BITS - PASS1_BITS );
+        wsptr[DCTSIZE * 4] = (int) DESCALE( tmp13 - tmp0, CONST_BITS - PASS1_BITS );
+
+        inptr++;        /* advance pointers to next column */
+        quantptr++;
+        wsptr++;
+    }
+
+    /* Pass 2: process rows from work array, store into output array. */
+    /* Note that we must descale the results by a factor of 8 == 2**3, */
+    /* and also undo the PASS1_BITS scaling. */
+
+    wsptr = workspace;
+    for ( ctr = 0; ctr < DCTSIZE; ctr++ ) {
+        outptr = output_buf[ctr] + output_col;
+        /* Rows of zeroes can be exploited in the same way as we did with columns.
+         * However, the column calculation has created many nonzero AC terms, so
+         * the simplification applies less often (typically 5% to 10% of the time).
+         * On machines with very fast multiplication, it's possible that the
+         * test takes more time than it's worth.  In that case this section
+         * may be commented out.
+         */
+
+#ifndef NO_ZERO_ROW_TEST
+        if ( ( wsptr[1] | wsptr[2] | wsptr[3] | wsptr[4] | wsptr[5] | wsptr[6] |
+               wsptr[7] ) == 0 ) {
+            /* AC terms all zero */
+            JSAMPLE dcval = range_limit[(int) DESCALE( (INT32) wsptr[0], PASS1_BITS + 3 )
+                                        & RANGE_MASK];
+
+            outptr[0] = dcval;
+            outptr[1] = dcval;
+            outptr[2] = dcval;
+            outptr[3] = dcval;
+            outptr[4] = dcval;
+            outptr[5] = dcval;
+            outptr[6] = dcval;
+            outptr[7] = dcval;
+
+            wsptr += DCTSIZE;/* advance pointer to next row */
+            continue;
+        }
+#endif
+
+        /* Even part: reverse the even part of the forward DCT. */
+        /* The rotator is sqrt(2)*c(-6). */
+
+        z2 = (INT32) wsptr[2];
+        z3 = (INT32) wsptr[6];
+
+        z1 = MULTIPLY( z2 + z3, FIX_0_541196100 );
+        tmp2 = z1 + MULTIPLY( z3, -FIX_1_847759065 );
+        tmp3 = z1 + MULTIPLY( z2, FIX_0_765366865 );
+
+        tmp0 = ( (INT32) wsptr[0] + (INT32) wsptr[4] ) << CONST_BITS;
+        tmp1 = ( (INT32) wsptr[0] - (INT32) wsptr[4] ) << CONST_BITS;
+
+        tmp10 = tmp0 + tmp3;
+        tmp13 = tmp0 - tmp3;
+        tmp11 = tmp1 + tmp2;
+        tmp12 = tmp1 - tmp2;
+
+        /* Odd part per figure 8; the matrix is unitary and hence its
+         * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
+         */
+
+        tmp0 = (INT32) wsptr[7];
+        tmp1 = (INT32) wsptr[5];
+        tmp2 = (INT32) wsptr[3];
+        tmp3 = (INT32) wsptr[1];
+
+        z1 = tmp0 + tmp3;
+        z2 = tmp1 + tmp2;
+        z3 = tmp0 + tmp2;
+        z4 = tmp1 + tmp3;
+        z5 = MULTIPLY( z3 + z4, FIX_1_175875602 );/* sqrt(2) * c3 */
+
+        tmp0 = MULTIPLY( tmp0, FIX_0_298631336 );/* sqrt(2) * (-c1+c3+c5-c7) */
+        tmp1 = MULTIPLY( tmp1, FIX_2_053119869 );/* sqrt(2) * ( c1+c3-c5+c7) */
+        tmp2 = MULTIPLY( tmp2, FIX_3_072711026 );/* sqrt(2) * ( c1+c3+c5-c7) */
+        tmp3 = MULTIPLY( tmp3, FIX_1_501321110 );/* sqrt(2) * ( c1+c3-c5-c7) */
+        z1 = MULTIPLY( z1, -FIX_0_899976223 );/* sqrt(2) * (c7-c3) */
+        z2 = MULTIPLY( z2, -FIX_2_562915447 );/* sqrt(2) * (-c1-c3) */
+        z3 = MULTIPLY( z3, -FIX_1_961570560 );/* sqrt(2) * (-c3-c5) */
+        z4 = MULTIPLY( z4, -FIX_0_390180644 );/* sqrt(2) * (c5-c3) */
+
+        z3 += z5;
+        z4 += z5;
+
+        tmp0 += z1 + z3;
+        tmp1 += z2 + z4;
+        tmp2 += z2 + z3;
+        tmp3 += z1 + z4;
+
+        /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
+
+        outptr[0] = range_limit[(int) DESCALE( tmp10 + tmp3,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[7] = range_limit[(int) DESCALE( tmp10 - tmp3,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[1] = range_limit[(int) DESCALE( tmp11 + tmp2,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[6] = range_limit[(int) DESCALE( tmp11 - tmp2,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[2] = range_limit[(int) DESCALE( tmp12 + tmp1,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[5] = range_limit[(int) DESCALE( tmp12 - tmp1,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[3] = range_limit[(int) DESCALE( tmp13 + tmp0,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+        outptr[4] = range_limit[(int) DESCALE( tmp13 - tmp0,
+                                               CONST_BITS + PASS1_BITS + 3 )
+                                & RANGE_MASK];
+
+        wsptr += DCTSIZE;   /* advance pointer to next row */
+    }
+}
+
+#endif /* DCT_ISLOW_SUPPORTED */

neo/renderer/jpeg-6/jidctred.cpp

@@ -0,0 +1,396 @@
+/*
+ * jidctred.c
+ *
+ * Copyright (C) 1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains inverse-DCT routines that produce reduced-size output:
+ * either 4x4, 2x2, or 1x1 pixels from an 8x8 DCT block.
+ *
+ * The implementation is based on the Loeffler, Ligtenberg and Moschytz (LL&M)
+ * algorithm used in jidctint.c.  We simply replace each 8-to-8 1-D IDCT step
+ * with an 8-to-4 step that produces the four averages of two adjacent outputs
+ * (or an 8-to-2 step producing two averages of four outputs, for 2x2 output).
+ * These steps were derived by computing the corresponding values at the end
+ * of the normal LL&M code, then simplifying as much as possible.
+ *
+ * 1x1 is trivial: just take the DC coefficient divided by 8.
+ *
+ * See jidctint.c for additional comments.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jdct.h"        /* Private declarations for DCT subsystem */
+
+#ifdef IDCT_SCALING_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+Sorry, this code only copes with 8 x8 DCTs.  /* deliberate syntax err */
+    #endif
+
+
+/* Scaling is the same as in jidctint.c. */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS  13
+#define PASS1_BITS  2
+#else
+#define CONST_BITS  13
+#define PASS1_BITS  1       /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 13
+#define FIX_0_211164243  ( (INT32)  1730 )    /* FIX(0.211164243) */
+#define FIX_0_509795579  ( (INT32)  4176 )    /* FIX(0.509795579) */
+#define FIX_0_601344887  ( (INT32)  4926 )    /* FIX(0.601344887) */
+#define FIX_0_720959822  ( (INT32)  5906 )    /* FIX(0.720959822) */
+#define FIX_0_765366865  ( (INT32)  6270 )    /* FIX(0.765366865) */
+#define FIX_0_850430095  ( (INT32)  6967 )    /* FIX(0.850430095) */
+#define FIX_0_899976223  ( (INT32)  7373 )    /* FIX(0.899976223) */
+#define FIX_1_061594337  ( (INT32)  8697 )    /* FIX(1.061594337) */
+#define FIX_1_272758580  ( (INT32)  10426 )   /* FIX(1.272758580) */
+#define FIX_1_451774981  ( (INT32)  11893 )   /* FIX(1.451774981) */
+#define FIX_1_847759065  ( (INT32)  15137 )   /* FIX(1.847759065) */
+#define FIX_2_172734803  ( (INT32)  17799 )   /* FIX(2.172734803) */
+#define FIX_2_562915447  ( (INT32)  20995 )   /* FIX(2.562915447) */
+#define FIX_3_624509785  ( (INT32)  29692 )   /* FIX(3.624509785) */
+#else
+#define FIX_0_211164243  FIX( 0.211164243 )
+#define FIX_0_509795579  FIX( 0.509795579 )
+#define FIX_0_601344887  FIX( 0.601344887 )
+#define FIX_0_720959822  FIX( 0.720959822 )
+#define FIX_0_765366865  FIX( 0.765366865 )
+#define FIX_0_850430095  FIX( 0.850430095 )
+#define FIX_0_899976223  FIX( 0.899976223 )
+#define FIX_1_061594337  FIX( 1.061594337 )
+#define FIX_1_272758580  FIX( 1.272758580 )
+#define FIX_1_451774981  FIX( 1.451774981 )
+#define FIX_1_847759065  FIX( 1.847759065 )
+#define FIX_2_172734803  FIX( 2.172734803 )
+#define FIX_2_562915447  FIX( 2.562915447 )
+#define FIX_3_624509785  FIX( 3.624509785 )
+#endif
+
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * For 8-bit samples with the recommended scaling, all the variable
+ * and constant values involved are no more than 16 bits wide, so a
+ * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
+ * For 12-bit samples, a full 32-bit multiplication will be needed.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MULTIPLY( var, const )  MULTIPLY16C16( var, const )
+#else
+#define MULTIPLY( var, const )  ( ( var ) * ( const ) )
+#endif
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce an int result.  In this module, both inputs and result
+ * are 16 bits or less, so either int or short multiply will work.
+ */
+
+#define DEQUANTIZE( coef, quantval )  ( ( (ISLOW_MULT_TYPE) ( coef ) ) * ( quantval ) )
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients,
+ * producing a reduced-size 4x4 output block.
+ */
+
+GLOBAL void
+jpeg_idct_4x4( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+               JCOEFPTR coef_block,
+               JSAMPARRAY output_buf, JDIMENSION output_col ) {
+    INT32 tmp0, tmp2, tmp10, tmp12;
+    INT32 z1, z2, z3, z4;
+    JCOEFPTR inptr;
+    ISLOW_MULT_TYPE * quantptr;
+    int * wsptr;
+    JSAMPROW outptr;
+    JSAMPLE * range_limit = IDCT_range_limit( cinfo );
+    int ctr;
+    int workspace[DCTSIZE * 4];/* buffers data between passes */
+    SHIFT_TEMPS
+
+    /* Pass 1: process columns from input, store into work array. */
+
+    inptr = coef_block;
+    quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+    wsptr = workspace;
+    for ( ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr-- ) {
+        /* Don't bother to process column 4, because second pass won't use it */
+        if ( ctr == DCTSIZE - 4 ) {
+            continue;
+        }
+        if ( ( inptr[DCTSIZE * 1] | inptr[DCTSIZE * 2] | inptr[DCTSIZE * 3] |
+               inptr[DCTSIZE * 5] | inptr[DCTSIZE * 6] | inptr[DCTSIZE * 7] ) == 0 ) {
+            /* AC terms all zero; we need not examine term 4 for 4x4 output */
+            int dcval = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] ) << PASS1_BITS;
+
+            wsptr[DCTSIZE * 0] = dcval;
+            wsptr[DCTSIZE * 1] = dcval;
+            wsptr[DCTSIZE * 2] = dcval;
+            wsptr[DCTSIZE * 3] = dcval;
+
+            continue;
+        }
+
+        /* Even part */
+
+        tmp0 = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+        tmp0 <<= ( CONST_BITS + 1 );
+
+        z2 = DEQUANTIZE( inptr[DCTSIZE * 2], quantptr[DCTSIZE * 2] );
+        z3 = DEQUANTIZE( inptr[DCTSIZE * 6], quantptr[DCTSIZE * 6] );
+
+        tmp2 = MULTIPLY( z2, FIX_1_847759065 ) + MULTIPLY( z3, -FIX_0_765366865 );
+
+        tmp10 = tmp0 + tmp2;
+        tmp12 = tmp0 - tmp2;
+
+        /* Odd part */
+
+        z1 = DEQUANTIZE( inptr[DCTSIZE * 7], quantptr[DCTSIZE * 7] );
+        z2 = DEQUANTIZE( inptr[DCTSIZE * 5], quantptr[DCTSIZE * 5] );
+        z3 = DEQUANTIZE( inptr[DCTSIZE * 3], quantptr[DCTSIZE * 3] );
+        z4 = DEQUANTIZE( inptr[DCTSIZE * 1], quantptr[DCTSIZE * 1] );
+
+        tmp0 = MULTIPLY( z1, -FIX_0_211164243 )/* sqrt(2) * (c3-c1) */
+               + MULTIPLY( z2, FIX_1_451774981 )/* sqrt(2) * (c3+c7) */
+               + MULTIPLY( z3, -FIX_2_172734803 )/* sqrt(2) * (-c1-c5) */
+               + MULTIPLY( z4, FIX_1_061594337 );/* sqrt(2) * (c5+c7) */
+
+        tmp2 = MULTIPLY( z1, -FIX_0_509795579 )/* sqrt(2) * (c7-c5) */
+               + MULTIPLY( z2, -FIX_0_601344887 )/* sqrt(2) * (c5-c1) */
+               + MULTIPLY( z3, FIX_0_899976223 )/* sqrt(2) * (c3-c7) */
+               + MULTIPLY( z4, FIX_2_562915447 );/* sqrt(2) * (c1+c3) */
+
+        /* Final output stage */
+
+        wsptr[DCTSIZE * 0] = (int) DESCALE( tmp10 + tmp2, CONST_BITS - PASS1_BITS + 1 );
+        wsptr[DCTSIZE * 3] = (int) DESCALE( tmp10 - tmp2, CONST_BITS - PASS1_BITS + 1 );
+        wsptr[DCTSIZE * 1] = (int) DESCALE( tmp12 + tmp0, CONST_BITS - PASS1_BITS + 1 );
+        wsptr[DCTSIZE * 2] = (int) DESCALE( tmp12 - tmp0, CONST_BITS - PASS1_BITS + 1 );
+    }
+
+    /* Pass 2: process 4 rows from work array, store into output array. */
+
+    wsptr = workspace;
+    for ( ctr = 0; ctr < 4; ctr++ ) {
+        outptr = output_buf[ctr] + output_col;
+        /* It's not clear whether a zero row test is worthwhile here ... */
+
+#ifndef NO_ZERO_ROW_TEST
+        if ( ( wsptr[1] | wsptr[2] | wsptr[3] | wsptr[5] | wsptr[6] |
+               wsptr[7] ) == 0 ) {
+            /* AC terms all zero */
+            JSAMPLE dcval = range_limit[(int) DESCALE( (INT32) wsptr[0], PASS1_BITS + 3 )
+                                        & RANGE_MASK];
+
+            outptr[0] = dcval;
+            outptr[1] = dcval;
+            outptr[2] = dcval;
+            outptr[3] = dcval;
+
+            wsptr += DCTSIZE;/* advance pointer to next row */
+            continue;
+        }
+#endif
+
+        /* Even part */
+
+        tmp0 = ( (INT32) wsptr[0] ) << ( CONST_BITS + 1 );
+
+        tmp2 = MULTIPLY( (INT32) wsptr[2], FIX_1_847759065 )
+               + MULTIPLY( (INT32) wsptr[6], -FIX_0_765366865 );
+
+        tmp10 = tmp0 + tmp2;
+        tmp12 = tmp0 - tmp2;
+
+        /* Odd part */
+
+        z1 = (INT32) wsptr[7];
+        z2 = (INT32) wsptr[5];
+        z3 = (INT32) wsptr[3];
+        z4 = (INT32) wsptr[1];
+
+        tmp0 = MULTIPLY( z1, -FIX_0_211164243 )/* sqrt(2) * (c3-c1) */
+               + MULTIPLY( z2, FIX_1_451774981 )/* sqrt(2) * (c3+c7) */
+               + MULTIPLY( z3, -FIX_2_172734803 )/* sqrt(2) * (-c1-c5) */
+               + MULTIPLY( z4, FIX_1_061594337 );/* sqrt(2) * (c5+c7) */
+
+        tmp2 = MULTIPLY( z1, -FIX_0_509795579 )/* sqrt(2) * (c7-c5) */
+               + MULTIPLY( z2, -FIX_0_601344887 )/* sqrt(2) * (c5-c1) */
+               + MULTIPLY( z3, FIX_0_899976223 )/* sqrt(2) * (c3-c7) */
+               + MULTIPLY( z4, FIX_2_562915447 );/* sqrt(2) * (c1+c3) */
+
+        /* Final output stage */
+
+        outptr[0] = range_limit[(int) DESCALE( tmp10 + tmp2,
+                                               CONST_BITS + PASS1_BITS + 3 + 1 )
+                                & RANGE_MASK];
+        outptr[3] = range_limit[(int) DESCALE( tmp10 - tmp2,
+                                               CONST_BITS + PASS1_BITS + 3 + 1 )
+                                & RANGE_MASK];
+        outptr[1] = range_limit[(int) DESCALE( tmp12 + tmp0,
+                                               CONST_BITS + PASS1_BITS + 3 + 1 )
+                                & RANGE_MASK];
+        outptr[2] = range_limit[(int) DESCALE( tmp12 - tmp0,
+                                               CONST_BITS + PASS1_BITS + 3 + 1 )
+                                & RANGE_MASK];
+
+        wsptr += DCTSIZE;   /* advance pointer to next row */
+    }
+}
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients,
+ * producing a reduced-size 2x2 output block.
+ */
+
+GLOBAL void
+jpeg_idct_2x2( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+               JCOEFPTR coef_block,
+               JSAMPARRAY output_buf, JDIMENSION output_col ) {
+    INT32 tmp0, tmp10, z1;
+    JCOEFPTR inptr;
+    ISLOW_MULT_TYPE * quantptr;
+    int * wsptr;
+    JSAMPROW outptr;
+    JSAMPLE * range_limit = IDCT_range_limit( cinfo );
+    int ctr;
+    int workspace[DCTSIZE * 2];/* buffers data between passes */
+    SHIFT_TEMPS
+
+    /* Pass 1: process columns from input, store into work array. */
+
+    inptr = coef_block;
+    quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+    wsptr = workspace;
+    for ( ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr-- ) {
+        /* Don't bother to process columns 2,4,6 */
+        if ( ( ctr == DCTSIZE - 2 ) || ( ctr == DCTSIZE - 4 ) || ( ctr == DCTSIZE - 6 ) ) {
+            continue;
+        }
+        if ( ( inptr[DCTSIZE * 1] | inptr[DCTSIZE * 3] |
+               inptr[DCTSIZE * 5] | inptr[DCTSIZE * 7] ) == 0 ) {
+            /* AC terms all zero; we need not examine terms 2,4,6 for 2x2 output */
+            int dcval = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] ) << PASS1_BITS;
+
+            wsptr[DCTSIZE * 0] = dcval;
+            wsptr[DCTSIZE * 1] = dcval;
+
+            continue;
+        }
+
+        /* Even part */
+
+        z1 = DEQUANTIZE( inptr[DCTSIZE * 0], quantptr[DCTSIZE * 0] );
+        tmp10 = z1 << ( CONST_BITS + 2 );
+
+        /* Odd part */
+
+        z1 = DEQUANTIZE( inptr[DCTSIZE * 7], quantptr[DCTSIZE * 7] );
+        tmp0 = MULTIPLY( z1, -FIX_0_720959822 );/* sqrt(2) * (c7-c5+c3-c1) */
+        z1 = DEQUANTIZE( inptr[DCTSIZE * 5], quantptr[DCTSIZE * 5] );
+        tmp0 += MULTIPLY( z1, FIX_0_850430095 );/* sqrt(2) * (-c1+c3+c5+c7) */
+        z1 = DEQUANTIZE( inptr[DCTSIZE * 3], quantptr[DCTSIZE * 3] );
+        tmp0 += MULTIPLY( z1, -FIX_1_272758580 );/* sqrt(2) * (-c1+c3-c5-c7) */
+        z1 = DEQUANTIZE( inptr[DCTSIZE * 1], quantptr[DCTSIZE * 1] );
+        tmp0 += MULTIPLY( z1, FIX_3_624509785 );/* sqrt(2) * (c1+c3+c5+c7) */
+
+        /* Final output stage */
+
+        wsptr[DCTSIZE * 0] = (int) DESCALE( tmp10 + tmp0, CONST_BITS - PASS1_BITS + 2 );
+        wsptr[DCTSIZE * 1] = (int) DESCALE( tmp10 - tmp0, CONST_BITS - PASS1_BITS + 2 );
+    }
+
+    /* Pass 2: process 2 rows from work array, store into output array. */
+
+    wsptr = workspace;
+    for ( ctr = 0; ctr < 2; ctr++ ) {
+        outptr = output_buf[ctr] + output_col;
+        /* It's not clear whether a zero row test is worthwhile here ... */
+
+#ifndef NO_ZERO_ROW_TEST
+        if ( ( wsptr[1] | wsptr[3] | wsptr[5] | wsptr[7] ) == 0 ) {
+            /* AC terms all zero */
+            JSAMPLE dcval = range_limit[(int) DESCALE( (INT32) wsptr[0], PASS1_BITS + 3 )
+                                        & RANGE_MASK];
+
+            outptr[0] = dcval;
+            outptr[1] = dcval;
+
+            wsptr += DCTSIZE;/* advance pointer to next row */
+            continue;
+        }
+#endif
+
+        /* Even part */
+
+        tmp10 = ( (INT32) wsptr[0] ) << ( CONST_BITS + 2 );
+
+        /* Odd part */
+
+        tmp0 = MULTIPLY( (INT32) wsptr[7], -FIX_0_720959822 )/* sqrt(2) * (c7-c5+c3-c1) */
+               + MULTIPLY( (INT32) wsptr[5], FIX_0_850430095 )/* sqrt(2) * (-c1+c3+c5+c7) */
+               + MULTIPLY( (INT32) wsptr[3], -FIX_1_272758580 )/* sqrt(2) * (-c1+c3-c5-c7) */
+               + MULTIPLY( (INT32) wsptr[1], FIX_3_624509785 );/* sqrt(2) * (c1+c3+c5+c7) */
+
+        /* Final output stage */
+
+        outptr[0] = range_limit[(int) DESCALE( tmp10 + tmp0,
+                                               CONST_BITS + PASS1_BITS + 3 + 2 )
+                                & RANGE_MASK];
+        outptr[1] = range_limit[(int) DESCALE( tmp10 - tmp0,
+                                               CONST_BITS + PASS1_BITS + 3 + 2 )
+                                & RANGE_MASK];
+
+        wsptr += DCTSIZE;   /* advance pointer to next row */
+    }
+}
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients,
+ * producing a reduced-size 1x1 output block.
+ */
+
+GLOBAL void
+jpeg_idct_1x1( j_decompress_ptr cinfo, jpeg_component_info * compptr,
+               JCOEFPTR coef_block,
+               JSAMPARRAY output_buf, JDIMENSION output_col ) {
+    int dcval;
+    ISLOW_MULT_TYPE * quantptr;
+    JSAMPLE * range_limit = IDCT_range_limit( cinfo );
+    SHIFT_TEMPS
+
+    /* We hardly need an inverse DCT routine for this: just take the
+     * average pixel value, which is one-eighth of the DC coefficient.
+     */
+    quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+    dcval = DEQUANTIZE( coef_block[0], quantptr[0] );
+    dcval = (int) DESCALE( (INT32) dcval, 3 );
+
+    output_buf[0][output_col] = range_limit[dcval & RANGE_MASK];
+}
+
+#endif /* IDCT_SCALING_SUPPORTED */

neo/renderer/jpeg-6/jinclude.h

@@ -0,0 +1,91 @@
+/*
+ * jinclude.h
+ *
+ * Copyright (C) 1991-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file exists to provide a single place to fix any problems with
+ * including the wrong system include files.  (Common problems are taken
+ * care of by the standard jconfig symbols, but on really weird systems
+ * you may have to edit this file.)
+ *
+ * NOTE: this file is NOT intended to be included by applications using the
+ * JPEG library.  Most applications need only include jpeglib.h.
+ */
+
+
+/* Include auto-config file to find out which system include files we need. */
+
+#include "../jpeg-6/jconfig.h"		/* auto configuration options */
+#define JCONFIG_INCLUDED	/* so that jpeglib.h doesn't do it again */
+
+/*
+ * We need the NULL macro and size_t typedef.
+ * On an ANSI-conforming system it is sufficient to include <stddef.h>.
+ * Otherwise, we get them from <stdlib.h> or <stdio.h>; we may have to
+ * pull in <sys/types.h> as well.
+ * Note that the core JPEG library does not require <stdio.h>;
+ * only the default error handler and data source/destination modules do.
+ * But we must pull it in because of the references to FILE in jpeglib.h.
+ * You can remove those references if you want to compile without <stdio.h>.
+ */
+
+#ifdef HAVE_STDDEF_H
+#include <stddef.h>
+#endif
+
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#ifdef NEED_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include <stdio.h>
+
+/*
+ * We need memory copying and zeroing functions, plus strncpy().
+ * ANSI and System V implementations declare these in <string.h>.
+ * BSD doesn't have the mem() functions, but it does have bcopy()/bzero().
+ * Some systems may declare memset and memcpy in <memory.h>.
+ *
+ * NOTE: we assume the size parameters to these functions are of type size_t.
+ * Change the casts in these macros if not!
+ */
+
+#ifdef NEED_BSD_STRINGS
+
+#include <strings.h>
+#define MEMZERO(target,size)	bzero((void *)(target), (size_t)(size))
+#define MEMCOPY(dest,src,size)	bcopy((const void *)(src), (void *)(dest), (size_t)(size))
+
+#else /* not BSD, assume ANSI/SysV string lib */
+
+#include <string.h>
+#define MEMZERO(target,size)	memset((void *)(target), 0, (size_t)(size))
+#define MEMCOPY(dest,src,size)	memcpy((void *)(dest), (const void *)(src), (size_t)(size))
+
+#endif
+
+/*
+ * In ANSI C, and indeed any rational implementation, size_t is also the
+ * type returned by sizeof().  However, it seems there are some irrational
+ * implementations out there, in which sizeof() returns an int even though
+ * size_t is defined as long or unsigned long.  To ensure consistent results
+ * we always use this SIZEOF() macro in place of using sizeof() directly.
+ */
+
+#define SIZEOF(object)	((size_t) sizeof(object))
+
+/*
+ * The modules that use fread() and fwrite() always invoke them through
+ * these macros.  On some systems you may need to twiddle the argument casts.
+ * CAUTION: argument order is different from underlying functions!
+ */
+
+#define JFREAD(file,buf,sizeofbuf)  \
+  ((size_t) fread((void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
+#define JFWRITE(file,buf,sizeofbuf)  \
+  ((size_t) fwrite((const void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))

neo/renderer/jpeg-6/jload.cpp

@@ -0,0 +1,145 @@
+
+#include "../Shared/Shared.h"
+#include "..\Common\Common.h"
+
+/*
+ * Include file for users of JPEG library.
+ * You will need to have included system headers that define at least
+ * the typedefs FILE and size_t before you can include jpeglib.h.
+ * (stdio.h is sufficient on ANSI-conforming systems.)
+ * You may also wish to include "jerror.h".
+ */
+
+#include "jpeglib.h"
+
+
+int LoadJPG( const char * filename, unsigned char ** pic, int * width, int * height ) {
+    /* This struct contains the JPEG decompression parameters and pointers to
+     * working space (which is allocated as needed by the JPEG library).
+     */
+    struct jpeg_decompress_struct cinfo;
+    /* We use our private extension JPEG error handler.
+     * Note that this struct must live as long as the main JPEG parameter
+     * struct, to avoid dangling-pointer problems.
+     */
+    /* This struct represents a JPEG error handler.  It is declared separately
+     * because applications often want to supply a specialized error handler
+     * (see the second half of this file for an example).  But here we just
+     * take the easy way out and use the standard error handler, which will
+     * print a message on stderr and call exit() if compression fails.
+     * Note that this struct must live as long as the main JPEG parameter
+     * struct, to avoid dangling-pointer problems.
+     */
+    struct jpeg_error_mgr jerr;
+    /* More stuff */
+    fileHandle_t infile;    /* source file */
+    JSAMPARRAY buffer;      /* Output row buffer */
+    int row_stride;     /* physical row width in output buffer */
+    unsigned char * out;
+
+    /* In this example we want to open the input file before doing anything else,
+     * so that the setjmp() error recovery below can assume the file is open.
+     * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
+     * requires it in order to read binary files.
+     */
+
+    FS_FOpenFileRead( filename, &infile, qfalse );
+    if ( infile == 0 ) {
+        return 0;
+    }
+
+    /* Step 1: allocate and initialize JPEG decompression object */
+
+    /* We have to set up the error handler first, in case the initialization
+     * step fails.  (Unlikely, but it could happen if you are out of memory.)
+     * This routine fills in the contents of struct jerr, and returns jerr's
+     * address which we place into the link field in cinfo.
+     */
+    cinfo.err = jpeg_std_error( &jerr );
+
+    /* Now we can initialize the JPEG decompression object. */
+    jpeg_create_decompress( &cinfo );
+
+    /* Step 2: specify data source (eg, a file) */
+
+    jpeg_stdio_src( &cinfo, infile );
+
+    /* Step 3: read file parameters with jpeg_read_header() */
+
+    (void) jpeg_read_header( &cinfo, TRUE );
+    /* We can ignore the return value from jpeg_read_header since
+     *   (a) suspension is not possible with the stdio data source, and
+     *   (b) we passed TRUE to reject a tables-only JPEG file as an error.
+     * See libjpeg.doc for more info.
+     */
+
+    /* Step 4: set parameters for decompression */
+
+    /* In this example, we don't need to change any of the defaults set by
+     * jpeg_read_header(), so we do nothing here.
+     */
+
+    /* Step 5: Start decompressor */
+
+    (void) jpeg_start_decompress( &cinfo );
+    /* We can ignore the return value since suspension is not possible
+     * with the stdio data source.
+     */
+
+    /* We may need to do some setup of our own at this point before reading
+     * the data.  After jpeg_start_decompress() we have the correct scaled
+     * output image dimensions available, as well as the output colormap
+     * if we asked for color quantization.
+     * In this example, we need to make an output work buffer of the right size.
+     */
+    /* JSAMPLEs per row in output buffer */
+    row_stride = cinfo.output_width * cinfo.output_components;
+
+    out = Z_Malloc( cinfo.output_width * cinfo.output_height * cinfo.output_components );
+
+    *pic = out;
+    *width = cinfo.output_width;
+    *height = cinfo.output_height;
+
+    /* Step 6: while (scan lines remain to be read) */
+    /*           jpeg_read_scanlines(...); */
+
+    /* Here we use the library's state variable cinfo.output_scanline as the
+     * loop counter, so that we don't have to keep track ourselves.
+     */
+    while ( cinfo.output_scanline < cinfo.output_height ) {
+        /* jpeg_read_scanlines expects an array of pointers to scanlines.
+         * Here the array is only one element long, but you could ask for
+         * more than one scanline at a time if that's more convenient.
+         */
+        buffer = (JSAMPARRAY)out + ( row_stride * cinfo.output_scanline );
+        (void) jpeg_read_scanlines( &cinfo, buffer, 1 );
+    }
+
+    /* Step 7: Finish decompression */
+
+    (void) jpeg_finish_decompress( &cinfo );
+    /* We can ignore the return value since suspension is not possible
+     * with the stdio data source.
+     */
+
+    /* Step 8: Release JPEG decompression object */
+
+    /* This is an important step since it will release a good deal of memory. */
+    jpeg_destroy_decompress( &cinfo );
+
+    /* After finish_decompress, we can close the input file.
+     * Here we postpone it until after no more JPEG errors are possible,
+     * so as to simplify the setjmp error logic above.  (Actually, I don't
+     * think that jpeg_destroy can do an error exit, but why assume anything...)
+     */
+    FS_FCloseFile( infile );
+
+    /* At this point you may want to check to see whether any corrupt-data
+     * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
+     */
+
+    /* And we're done! */
+    return 1;
+}
+

neo/renderer/jpeg-6/jmemansi.cpp

@@ -0,0 +1,161 @@
+/*
+ * jmemansi.c
+ *
+ * Copyright (C) 1992-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides a simple generic implementation of the system-
+ * dependent portion of the JPEG memory manager.  This implementation
+ * assumes that you have the ANSI-standard library routine tmpfile().
+ * Also, the problem of determining the amount of memory available
+ * is shoved onto the user.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jmemsys.h"     /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H       /* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP( (size_t size) );
+extern void free JPP( (void * ptr) );
+#endif
+
+#ifndef SEEK_SET        /* pre-ANSI systems may not define this; */
+#define SEEK_SET  0     /* if not, assume 0 is correct */
+#endif
+
+
+/*
+ * Memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL void *
+jpeg_get_small( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_small( j_common_ptr cinfo, void * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL void FAR *
+jpeg_get_large( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void FAR *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_large( j_common_ptr cinfo, void FAR * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM     /* so can override from makefile */
+#define DEFAULT_MAX_MEM     1000000L /* default: one megabyte */
+#endif
+
+GLOBAL long
+jpeg_mem_available( j_common_ptr cinfo, long min_bytes_needed,
+                    long max_bytes_needed, long already_allocated ) {
+    return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed.  You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+
+METHODDEF void
+read_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                    void FAR * buffer_address,
+                    long file_offset, long byte_count ) {
+    if ( fseek( info->temp_file, file_offset, SEEK_SET ) ) {
+        ERREXIT( cinfo, JERR_TFILE_SEEK );
+    }
+    if ( JFREAD( info->temp_file, buffer_address, byte_count )
+         != (size_t) byte_count ) {
+        ERREXIT( cinfo, JERR_TFILE_READ );
+    }
+}
+
+
+METHODDEF void
+write_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                     void FAR * buffer_address,
+                     long file_offset, long byte_count ) {
+    if ( fseek( info->temp_file, file_offset, SEEK_SET ) ) {
+        ERREXIT( cinfo, JERR_TFILE_SEEK );
+    }
+    if ( JFWRITE( info->temp_file, buffer_address, byte_count )
+         != (size_t) byte_count ) {
+        ERREXIT( cinfo, JERR_TFILE_WRITE );
+    }
+}
+
+
+METHODDEF void
+close_backing_store( j_common_ptr cinfo, backing_store_ptr info ) {
+    fclose( info->temp_file );
+    /* Since this implementation uses tmpfile() to create the file,
+     * no explicit file deletion is needed.
+     */
+}
+
+
+/*
+ * Initial opening of a backing-store object.
+ *
+ * This version uses tmpfile(), which constructs a suitable file name
+ * behind the scenes.  We don't have to use info->temp_name[] at all;
+ * indeed, we can't even find out the actual name of the temp file.
+ */
+
+GLOBAL void
+jpeg_open_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                         long total_bytes_needed ) {
+    if ( ( info->temp_file = tmpfile() ) == NULL ) {
+        ERREXITS( cinfo, JERR_TFILE_CREATE, "" );
+    }
+    info->read_backing_store = read_backing_store;
+    info->write_backing_store = write_backing_store;
+    info->close_backing_store = close_backing_store;
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL long
+jpeg_mem_init( j_common_ptr cinfo ) {
+    return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
+}
+
+GLOBAL void
+jpeg_mem_term( j_common_ptr cinfo ) {
+    /* no work */
+}

neo/renderer/jpeg-6/jmemdos.cpp

@@ -0,0 +1,639 @@
+/*
+ * jmemdos.c
+ *
+ * Copyright (C) 1992-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides an MS-DOS-compatible implementation of the system-
+ * dependent portion of the JPEG memory manager.  Temporary data can be
+ * stored in extended or expanded memory as well as in regular DOS files.
+ *
+ * If you use this file, you must be sure that NEED_FAR_POINTERS is defined
+ * if you compile in a small-data memory model; it should NOT be defined if
+ * you use a large-data memory model.  This file is not recommended if you
+ * are using a flat-memory-space 386 environment such as DJGCC or Watcom C.
+ * Also, this code will NOT work if struct fields are aligned on greater than
+ * 2-byte boundaries.
+ *
+ * Based on code contributed by Ge' Weijers.
+ */
+
+/*
+ * If you have both extended and expanded memory, you may want to change the
+ * order in which they are tried in jopen_backing_store.  On a 286 machine
+ * expanded memory is usually faster, since extended memory access involves
+ * an expensive protected-mode-and-back switch.  On 386 and better, extended
+ * memory is usually faster.  As distributed, the code tries extended memory
+ * first (what? not everyone has a 386? :-).
+ *
+ * You can disable use of extended/expanded memory entirely by altering these
+ * definitions or overriding them from the Makefile (eg, -DEMS_SUPPORTED=0).
+ */
+
+#ifndef XMS_SUPPORTED
+#define XMS_SUPPORTED  1
+#endif
+#ifndef EMS_SUPPORTED
+#define EMS_SUPPORTED  1
+#endif
+
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jmemsys.h"     /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H       /* <stdlib.h> should declare these */
+extern void * malloc JPP( (size_t size) );
+extern void free JPP( (void * ptr) );
+extern char * getenv JPP( (const char * name) );
+#endif
+
+#ifdef NEED_FAR_POINTERS
+
+#ifdef __TURBOC__
+/* These definitions work for Borland C (Turbo C) */
+#include <alloc.h>       /* need farmalloc(), farfree() */
+#define far_malloc( x )   farmalloc( x )
+#define far_free( x ) farfree( x )
+#else
+/* These definitions work for Microsoft C and compatible compilers */
+#include <malloc.h>      /* need _fmalloc(), _ffree() */
+#define far_malloc( x )   _fmalloc( x )
+#define far_free( x ) _ffree( x )
+#endif
+
+#else /* not NEED_FAR_POINTERS */
+
+#define far_malloc( x )   malloc( x )
+#define far_free( x ) free( x )
+
+#endif /* NEED_FAR_POINTERS */
+
+#ifdef DONT_USE_B_MODE      /* define mode parameters for fopen() */
+#define READ_BINARY "r"
+#else
+#define READ_BINARY "rb"
+#endif
+
+#if MAX_ALLOC_CHUNK >= 65535L   /* make sure jconfig.h got this right */
+MAX_ALLOC_CHUNK should be less than 64 K.  /* deliberate syntax error */
+    #endif
+
+
+/*
+ * Declarations for assembly-language support routines (see jmemdosa.asm).
+ *
+ * The functions are declared "far" as are all pointer arguments;
+ * this ensures the assembly source code will work regardless of the
+ * compiler memory model.  We assume "short" is 16 bits, "long" is 32.
+ */
+
+typedef void far * XMSDRIVER;   /* actually a pointer to code */
+typedef struct {        /* registers for calling XMS driver */
+    unsigned short ax, dx, bx;
+    void far *     ds_si;
+} XMScontext;
+typedef struct {        /* registers for calling EMS driver */
+    unsigned short ax, dx, bx;
+    void far *     ds_si;
+} EMScontext;
+
+EXTERN short far jdos_open JPP( ( short far * handle, char far * filename ) );
+EXTERN short far jdos_close JPP( (short handle) );
+EXTERN short far jdos_seek JPP( ( short handle, long offset ) );
+EXTERN short far jdos_read JPP( ( short handle, void far * buffer,
+                                  unsigned short count ) );
+EXTERN short far jdos_write JPP( ( short handle, void far * buffer,
+                                   unsigned short count ) );
+EXTERN void far jxms_getdriver JPP( (XMSDRIVER far *) );
+EXTERN void far jxms_calldriver JPP( ( XMSDRIVER, XMScontext far * ) );
+EXTERN short far jems_available JPP( (void) );
+EXTERN void far jems_calldriver JPP( (EMScontext far *) );
+
+
+/*
+ * Selection of a file name for a temporary file.
+ * This is highly system-dependent, and you may want to customize it.
+ */
+
+static int next_file_num;   /* to distinguish among several temp files */
+
+LOCAL void
+select_file_name( char * fname ) {
+    const char * env;
+    char * ptr;
+    FILE * tfile;
+
+    /* Keep generating file names till we find one that's not in use */
+    for (;; ) {
+        /* Get temp directory name from environment TMP or TEMP variable;
+         * if none, use "."
+         */
+        if ( ( env = (const char *) getenv( "TMP" ) ) == NULL ) {
+            if ( ( env = (const char *) getenv( "TEMP" ) ) == NULL ) {
+                env = ".";
+            }
+        }
+        if ( *env == '\0' ) {/* null string means "." */
+            env = ".";
+        }
+        ptr = fname;    /* copy name to fname */
+        while ( *env != '\0' ) {
+            *ptr++ = *env++;
+        }
+        if ( ( ptr[-1] != '\\' ) && ( ptr[-1] != '/' ) ) {
+            *ptr++ = '\\';
+        }               /* append backslash if not in env variable */
+        /* Append a suitable file name */
+        next_file_num++;    /* advance counter */
+        sprintf( ptr, "JPG%03d.TMP", next_file_num );
+        /* Probe to see if file name is already in use */
+        if ( ( tfile = fopen( fname, READ_BINARY ) ) == NULL ) {
+            break;
+        }
+        fclose( tfile );/* oops, it's there; close tfile & try again */
+    }
+}
+
+
+/*
+ * Near-memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL void *
+jpeg_get_small( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_small( j_common_ptr cinfo, void * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * "Large" objects are allocated in far memory, if possible
+ */
+
+GLOBAL void FAR *
+jpeg_get_large( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void FAR *) far_malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_large( j_common_ptr cinfo, void FAR * object, size_t sizeofobject ) {
+    far_free( object );
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM     /* so can override from makefile */
+#define DEFAULT_MAX_MEM     300000L /* for total usage about 450K */
+#endif
+
+GLOBAL long
+jpeg_mem_available( j_common_ptr cinfo, long min_bytes_needed,
+                    long max_bytes_needed, long already_allocated ) {
+    return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed.  You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+/*
+ * For MS-DOS we support three types of backing storage:
+ *   1. Conventional DOS files.  We access these by direct DOS calls rather
+ *      than via the stdio package.  This provides a bit better performance,
+ *      but the real reason is that the buffers to be read or written are FAR.
+ *      The stdio library for small-data memory models can't cope with that.
+ *   2. Extended memory, accessed per the XMS V2.0 specification.
+ *   3. Expanded memory, accessed per the LIM/EMS 4.0 specification.
+ * You'll need copies of those specs to make sense of the related code.
+ * The specs are available by Internet FTP from the SIMTEL archives
+ * (oak.oakland.edu and its various mirror sites).  See files
+ * pub/msdos/microsoft/xms20.arc and pub/msdos/info/limems41.zip.
+ */
+
+
+/*
+ * Access methods for a DOS file.
+ */
+
+
+METHODDEF void
+read_file_store( j_common_ptr cinfo, backing_store_ptr info,
+                 void FAR * buffer_address,
+                 long file_offset, long byte_count ) {
+    if ( jdos_seek( info->handle.file_handle, file_offset ) ) {
+        ERREXIT( cinfo, JERR_TFILE_SEEK );
+    }
+    /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */
+    if ( byte_count > 65535L ) {/* safety check */
+        ERREXIT( cinfo, JERR_BAD_ALLOC_CHUNK );
+    }
+    if ( jdos_read( info->handle.file_handle, buffer_address,
+                    (unsigned short) byte_count ) ) {
+        ERREXIT( cinfo, JERR_TFILE_READ );
+    }
+}
+
+
+METHODDEF void
+write_file_store( j_common_ptr cinfo, backing_store_ptr info,
+                  void FAR * buffer_address,
+                  long file_offset, long byte_count ) {
+    if ( jdos_seek( info->handle.file_handle, file_offset ) ) {
+        ERREXIT( cinfo, JERR_TFILE_SEEK );
+    }
+    /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */
+    if ( byte_count > 65535L ) {/* safety check */
+        ERREXIT( cinfo, JERR_BAD_ALLOC_CHUNK );
+    }
+    if ( jdos_write( info->handle.file_handle, buffer_address,
+                     (unsigned short) byte_count ) ) {
+        ERREXIT( cinfo, JERR_TFILE_WRITE );
+    }
+}
+
+
+METHODDEF void
+close_file_store( j_common_ptr cinfo, backing_store_ptr info ) {
+    jdos_close( info->handle.file_handle );/* close the file */
+    remove( info->temp_name );/* delete the file */
+/* If your system doesn't have remove(), try unlink() instead.
+ * remove() is the ANSI-standard name for this function, but
+ * unlink() was more common in pre-ANSI systems.
+ */
+    TRACEMSS( cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name );
+}
+
+
+LOCAL boolean
+open_file_store( j_common_ptr cinfo, backing_store_ptr info,
+                 long total_bytes_needed ) {
+    short handle;
+
+    select_file_name( info->temp_name );
+    if ( jdos_open( (short far *) &handle, (char far *) info->temp_name ) ) {
+        /* might as well exit since jpeg_open_backing_store will fail anyway */
+        ERREXITS( cinfo, JERR_TFILE_CREATE, info->temp_name );
+        return FALSE;
+    }
+    info->handle.file_handle = handle;
+    info->read_backing_store = read_file_store;
+    info->write_backing_store = write_file_store;
+    info->close_backing_store = close_file_store;
+    TRACEMSS( cinfo, 1, JTRC_TFILE_OPEN, info->temp_name );
+    return TRUE;        /* succeeded */
+}
+
+
+/*
+ * Access methods for extended memory.
+ */
+
+#if XMS_SUPPORTED
+
+static XMSDRIVER xms_driver;    /* saved address of XMS driver */
+
+typedef union {         /* either long offset or real-mode pointer */
+    long       offset;
+    void far * ptr;
+} XMSPTR;
+
+typedef struct {        /* XMS move specification structure */
+    long   length;
+    XMSH   src_handle;
+    XMSPTR src;
+    XMSH   dst_handle;
+    XMSPTR dst;
+} XMSspec;
+
+#define ODD( X )  ( ( ( X ) & 1L ) != 0 )
+
+
+METHODDEF void
+read_xms_store( j_common_ptr cinfo, backing_store_ptr info,
+                void FAR * buffer_address,
+                long file_offset, long byte_count ) {
+    XMScontext ctx;
+    XMSspec spec;
+    char endbuffer[2];
+
+    /* The XMS driver can't cope with an odd length, so handle the last byte
+     * specially if byte_count is odd.  We don't expect this to be common.
+     */
+
+    spec.length = byte_count & ( ~1L );
+    spec.src_handle = info->handle.xms_handle;
+    spec.src.offset = file_offset;
+    spec.dst_handle = 0;
+    spec.dst.ptr = buffer_address;
+
+    ctx.ds_si = (void far *) &spec;
+    ctx.ax = 0x0b00;    /* EMB move */
+    jxms_calldriver( xms_driver, (XMScontext far *) &ctx );
+    if ( ctx.ax != 1 ) {
+        ERREXIT( cinfo, JERR_XMS_READ );
+    }
+
+    if ( ODD( byte_count ) ) {
+        read_xms_store( cinfo, info, (void FAR *) endbuffer,
+                        file_offset + byte_count - 1L, 2L );
+        ( (char FAR *) buffer_address )[byte_count - 1L] = endbuffer[0];
+    }
+}
+
+
+METHODDEF void
+write_xms_store( j_common_ptr cinfo, backing_store_ptr info,
+                 void FAR * buffer_address,
+                 long file_offset, long byte_count ) {
+    XMScontext ctx;
+    XMSspec spec;
+    char endbuffer[2];
+
+    /* The XMS driver can't cope with an odd length, so handle the last byte
+     * specially if byte_count is odd.  We don't expect this to be common.
+     */
+
+    spec.length = byte_count & ( ~1L );
+    spec.src_handle = 0;
+    spec.src.ptr = buffer_address;
+    spec.dst_handle = info->handle.xms_handle;
+    spec.dst.offset = file_offset;
+
+    ctx.ds_si = (void far *) &spec;
+    ctx.ax = 0x0b00;    /* EMB move */
+    jxms_calldriver( xms_driver, (XMScontext far *) &ctx );
+    if ( ctx.ax != 1 ) {
+        ERREXIT( cinfo, JERR_XMS_WRITE );
+    }
+
+    if ( ODD( byte_count ) ) {
+        read_xms_store( cinfo, info, (void FAR *) endbuffer,
+                        file_offset + byte_count - 1L, 2L );
+        endbuffer[0] = ( (char FAR *) buffer_address )[byte_count - 1L];
+        write_xms_store( cinfo, info, (void FAR *) endbuffer,
+                         file_offset + byte_count - 1L, 2L );
+    }
+}
+
+
+METHODDEF void
+close_xms_store( j_common_ptr cinfo, backing_store_ptr info ) {
+    XMScontext ctx;
+
+    ctx.dx = info->handle.xms_handle;
+    ctx.ax = 0x0a00;
+    jxms_calldriver( xms_driver, (XMScontext far *) &ctx );
+    TRACEMS1( cinfo, 1, JTRC_XMS_CLOSE, info->handle.xms_handle );
+    /* we ignore any error return from the driver */
+}
+
+
+LOCAL boolean
+open_xms_store( j_common_ptr cinfo, backing_store_ptr info,
+                long total_bytes_needed ) {
+    XMScontext ctx;
+
+    /* Get address of XMS driver */
+    jxms_getdriver( (XMSDRIVER far *) &xms_driver );
+    if ( xms_driver == NULL ) {
+        return FALSE;
+    }                   /* no driver to be had */
+
+    /* Get version number, must be >= 2.00 */
+    ctx.ax = 0x0000;
+    jxms_calldriver( xms_driver, (XMScontext far *) &ctx );
+    if ( ctx.ax < (unsigned short) 0x0200 ) {
+        return FALSE;
+    }
+
+    /* Try to get space (expressed in kilobytes) */
+    ctx.dx = (unsigned short) ( ( total_bytes_needed + 1023L ) >> 10 );
+    ctx.ax = 0x0900;
+    jxms_calldriver( xms_driver, (XMScontext far *) &ctx );
+    if ( ctx.ax != 1 ) {
+        return FALSE;
+    }
+
+    /* Succeeded, save the handle and away we go */
+    info->handle.xms_handle = ctx.dx;
+    info->read_backing_store = read_xms_store;
+    info->write_backing_store = write_xms_store;
+    info->close_backing_store = close_xms_store;
+    TRACEMS1( cinfo, 1, JTRC_XMS_OPEN, ctx.dx );
+    return TRUE;        /* succeeded */
+}
+
+#endif /* XMS_SUPPORTED */
+
+
+/*
+ * Access methods for expanded memory.
+ */
+
+#if EMS_SUPPORTED
+
+/* The EMS move specification structure requires word and long fields aligned
+ * at odd byte boundaries.  Some compilers will align struct fields at even
+ * byte boundaries.  While it's usually possible to force byte alignment,
+ * that causes an overall performance penalty and may pose problems in merging
+ * JPEG into a larger application.  Instead we accept some rather dirty code
+ * here.  Note this code would fail if the hardware did not allow odd-byte
+ * word & long accesses, but all 80x86 CPUs do.
+ */
+
+typedef void far * EMSPTR;
+
+typedef union {         /* EMS move specification structure */
+    long length;        /* It's easy to access first 4 bytes */
+    char bytes[18];     /* Misaligned fields in here! */
+} EMSspec;
+
+/* Macros for accessing misaligned fields */
+#define FIELD_AT( spec, offset, type )  ( *( (type *) &( spec.bytes[offset] ) ) )
+#define SRC_TYPE( spec )      FIELD_AT( spec, 4, char )
+#define SRC_HANDLE( spec )    FIELD_AT( spec, 5, EMSH )
+#define SRC_OFFSET( spec )    FIELD_AT( spec, 7, unsigned short )
+#define SRC_PAGE( spec )      FIELD_AT( spec, 9, unsigned short )
+#define SRC_PTR( spec )       FIELD_AT( spec, 7, EMSPTR )
+#define DST_TYPE( spec )      FIELD_AT( spec, 11, char )
+#define DST_HANDLE( spec )    FIELD_AT( spec, 12, EMSH )
+#define DST_OFFSET( spec )    FIELD_AT( spec, 14, unsigned short )
+#define DST_PAGE( spec )      FIELD_AT( spec, 16, unsigned short )
+#define DST_PTR( spec )       FIELD_AT( spec, 14, EMSPTR )
+
+#define EMSPAGESIZE 16384L  /* gospel, see the EMS specs */
+
+#define HIBYTE( W )  ( ( ( W ) >> 8 ) & 0xFF )
+#define LOBYTE( W )  ( ( W ) & 0xFF )
+
+
+METHODDEF void
+read_ems_store( j_common_ptr cinfo, backing_store_ptr info,
+                void FAR * buffer_address,
+                long file_offset, long byte_count ) {
+    EMScontext ctx;
+    EMSspec spec;
+
+    spec.length = byte_count;
+    SRC_TYPE( spec ) = 1;
+    SRC_HANDLE( spec ) = info->handle.ems_handle;
+    SRC_PAGE( spec )   = (unsigned short) ( file_offset / EMSPAGESIZE );
+    SRC_OFFSET( spec ) = (unsigned short) ( file_offset % EMSPAGESIZE );
+    DST_TYPE( spec ) = 0;
+    DST_HANDLE( spec ) = 0;
+    DST_PTR( spec )    = buffer_address;
+
+    ctx.ds_si = (void far *) &spec;
+    ctx.ax = 0x5700;    /* move memory region */
+    jems_calldriver( (EMScontext far *) &ctx );
+    if ( HIBYTE( ctx.ax ) != 0 ) {
+        ERREXIT( cinfo, JERR_EMS_READ );
+    }
+}
+
+
+METHODDEF void
+write_ems_store( j_common_ptr cinfo, backing_store_ptr info,
+                 void FAR * buffer_address,
+                 long file_offset, long byte_count ) {
+    EMScontext ctx;
+    EMSspec spec;
+
+    spec.length = byte_count;
+    SRC_TYPE( spec ) = 0;
+    SRC_HANDLE( spec ) = 0;
+    SRC_PTR( spec )    = buffer_address;
+    DST_TYPE( spec ) = 1;
+    DST_HANDLE( spec ) = info->handle.ems_handle;
+    DST_PAGE( spec )   = (unsigned short) ( file_offset / EMSPAGESIZE );
+    DST_OFFSET( spec ) = (unsigned short) ( file_offset % EMSPAGESIZE );
+
+    ctx.ds_si = (void far *) &spec;
+    ctx.ax = 0x5700;    /* move memory region */
+    jems_calldriver( (EMScontext far *) &ctx );
+    if ( HIBYTE( ctx.ax ) != 0 ) {
+        ERREXIT( cinfo, JERR_EMS_WRITE );
+    }
+}
+
+
+METHODDEF void
+close_ems_store( j_common_ptr cinfo, backing_store_ptr info ) {
+    EMScontext ctx;
+
+    ctx.ax = 0x4500;
+    ctx.dx = info->handle.ems_handle;
+    jems_calldriver( (EMScontext far *) &ctx );
+    TRACEMS1( cinfo, 1, JTRC_EMS_CLOSE, info->handle.ems_handle );
+    /* we ignore any error return from the driver */
+}
+
+
+LOCAL boolean
+open_ems_store( j_common_ptr cinfo, backing_store_ptr info,
+                long total_bytes_needed ) {
+    EMScontext ctx;
+
+    /* Is EMS driver there? */
+    if ( !jems_available() ) {
+        return FALSE;
+    }
+
+    /* Get status, make sure EMS is OK */
+    ctx.ax = 0x4000;
+    jems_calldriver( (EMScontext far *) &ctx );
+    if ( HIBYTE( ctx.ax ) != 0 ) {
+        return FALSE;
+    }
+
+    /* Get version, must be >= 4.0 */
+    ctx.ax = 0x4600;
+    jems_calldriver( (EMScontext far *) &ctx );
+    if ( ( HIBYTE( ctx.ax ) != 0 ) || ( LOBYTE( ctx.ax ) < 0x40 ) ) {
+        return FALSE;
+    }
+
+    /* Try to allocate requested space */
+    ctx.ax = 0x4300;
+    ctx.bx = (unsigned short) ( ( total_bytes_needed + EMSPAGESIZE - 1L ) / EMSPAGESIZE );
+    jems_calldriver( (EMScontext far *) &ctx );
+    if ( HIBYTE( ctx.ax ) != 0 ) {
+        return FALSE;
+    }
+
+    /* Succeeded, save the handle and away we go */
+    info->handle.ems_handle = ctx.dx;
+    info->read_backing_store = read_ems_store;
+    info->write_backing_store = write_ems_store;
+    info->close_backing_store = close_ems_store;
+    TRACEMS1( cinfo, 1, JTRC_EMS_OPEN, ctx.dx );
+    return TRUE;        /* succeeded */
+}
+
+#endif /* EMS_SUPPORTED */
+
+
+/*
+ * Initial opening of a backing-store object.
+ */
+
+GLOBAL void
+jpeg_open_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                         long total_bytes_needed ) {
+    /* Try extended memory, then expanded memory, then regular file. */
+#if XMS_SUPPORTED
+    if ( open_xms_store( cinfo, info, total_bytes_needed ) ) {
+        return;
+    }
+#endif
+#if EMS_SUPPORTED
+    if ( open_ems_store( cinfo, info, total_bytes_needed ) ) {
+        return;
+    }
+#endif
+    if ( open_file_store( cinfo, info, total_bytes_needed ) ) {
+        return;
+    }
+    ERREXITS( cinfo, JERR_TFILE_CREATE, "" );
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL long
+jpeg_mem_init( j_common_ptr cinfo ) {
+    next_file_num = 0;      /* initialize temp file name generator */
+    return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
+}
+
+GLOBAL void
+jpeg_mem_term( j_common_ptr cinfo ) {
+    /* Microsoft C, at least in v6.00A, will not successfully reclaim freed
+     * blocks of size > 32Kbytes unless we give it a kick in the rear, like so:
+     */
+#ifdef NEED_FHEAPMIN
+    _fheapmin();
+#endif
+}

neo/renderer/jpeg-6/jmemname.cpp

@@ -0,0 +1,264 @@
+/*
+ * jmemname.c
+ *
+ * Copyright (C) 1992-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides a generic implementation of the system-dependent
+ * portion of the JPEG memory manager.  This implementation assumes that
+ * you must explicitly construct a name for each temp file.
+ * Also, the problem of determining the amount of memory available
+ * is shoved onto the user.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jmemsys.h"     /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H       /* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP( (size_t size) );
+extern void free JPP( (void * ptr) );
+#endif
+
+#ifndef SEEK_SET        /* pre-ANSI systems may not define this; */
+#define SEEK_SET  0     /* if not, assume 0 is correct */
+#endif
+
+#ifdef DONT_USE_B_MODE      /* define mode parameters for fopen() */
+#define READ_BINARY "r"
+#define RW_BINARY   "w+"
+#else
+#define READ_BINARY "rb"
+#define RW_BINARY   "w+b"
+#endif
+
+
+/*
+ * Selection of a file name for a temporary file.
+ * This is system-dependent!
+ *
+ * The code as given is suitable for most Unix systems, and it is easily
+ * modified for most non-Unix systems.  Some notes:
+ *  1.  The temp file is created in the directory named by TEMP_DIRECTORY.
+ *      The default value is /usr/tmp, which is the conventional place for
+ *      creating large temp files on Unix.  On other systems you'll probably
+ *      want to change the file location.  You can do this by editing the
+ *      #define, or (preferred) by defining TEMP_DIRECTORY in jconfig.h.
+ *
+ *  2.  If you need to change the file name as well as its location,
+ *      you can override the TEMP_FILE_NAME macro.  (Note that this is
+ *      actually a printf format string; it must contain %s and %d.)
+ *      Few people should need to do this.
+ *
+ *  3.  mktemp() is used to ensure that multiple processes running
+ *      simultaneously won't select the same file names.  If your system
+ *      doesn't have mktemp(), define NO_MKTEMP to do it the hard way.
+ *      (If you don't have <errno.h>, also define NO_ERRNO_H.)
+ *
+ *  4.  You probably want to define NEED_SIGNAL_CATCHER so that cjpeg.c/djpeg.c
+ *      will cause the temp files to be removed if you stop the program early.
+ */
+
+#ifndef TEMP_DIRECTORY      /* can override from jconfig.h or Makefile */
+#define TEMP_DIRECTORY  "/usr/tmp/" /* recommended setting for Unix */
+#endif
+
+static int next_file_num;   /* to distinguish among several temp files */
+
+#ifdef NO_MKTEMP
+
+#ifndef TEMP_FILE_NAME      /* can override from jconfig.h or Makefile */
+#define TEMP_FILE_NAME  "%sJPG%03d.TMP"
+#endif
+
+#ifndef NO_ERRNO_H
+#include <errno.h>       /* to define ENOENT */
+#endif
+
+/* ANSI C specifies that errno is a macro, but on older systems it's more
+ * likely to be a plain int variable.  And not all versions of errno.h
+ * bother to declare it, so we have to in order to be most portable.  Thus:
+ */
+#ifndef errno
+extern int errno;
+#endif
+
+
+LOCAL void
+select_file_name( char * fname ) {
+    FILE * tfile;
+
+    /* Keep generating file names till we find one that's not in use */
+    for (;; ) {
+        next_file_num++;    /* advance counter */
+        sprintf( fname, TEMP_FILE_NAME, TEMP_DIRECTORY, next_file_num );
+        if ( ( tfile = fopen( fname, READ_BINARY ) ) == NULL ) {
+            /* fopen could have failed for a reason other than the file not
+             * being there; for example, file there but unreadable.
+             * If <errno.h> isn't available, then we cannot test the cause.
+             */
+#ifdef ENOENT
+            if ( errno != ENOENT ) {
+                continue;
+            }
+#endif
+            break;
+        }
+        fclose( tfile );/* oops, it's there; close tfile & try again */
+    }
+}
+
+#else /* ! NO_MKTEMP */
+
+/* Note that mktemp() requires the initial filename to end in six X's */
+#ifndef TEMP_FILE_NAME      /* can override from jconfig.h or Makefile */
+#define TEMP_FILE_NAME  "%sJPG%dXXXXXX"
+#endif
+
+LOCAL void
+select_file_name( char * fname ) {
+    next_file_num++;    /* advance counter */
+    sprintf( fname, TEMP_FILE_NAME, TEMP_DIRECTORY, next_file_num );
+    mktemp( fname );    /* make sure file name is unique */
+    /* mktemp replaces the trailing XXXXXX with a unique string of characters */
+}
+
+#endif /* NO_MKTEMP */
+
+
+/*
+ * Memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL void *
+jpeg_get_small( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_small( j_common_ptr cinfo, void * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL void FAR *
+jpeg_get_large( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void FAR *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_large( j_common_ptr cinfo, void FAR * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM     /* so can override from makefile */
+#define DEFAULT_MAX_MEM     1000000L /* default: one megabyte */
+#endif
+
+GLOBAL long
+jpeg_mem_available( j_common_ptr cinfo, long min_bytes_needed,
+                    long max_bytes_needed, long already_allocated ) {
+    return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed.  You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+
+METHODDEF void
+read_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                    void FAR * buffer_address,
+                    long file_offset, long byte_count ) {
+    if ( fseek( info->temp_file, file_offset, SEEK_SET ) ) {
+        ERREXIT( cinfo, JERR_TFILE_SEEK );
+    }
+    if ( JFREAD( info->temp_file, buffer_address, byte_count )
+         != (size_t) byte_count ) {
+        ERREXIT( cinfo, JERR_TFILE_READ );
+    }
+}
+
+
+METHODDEF void
+write_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                     void FAR * buffer_address,
+                     long file_offset, long byte_count ) {
+    if ( fseek( info->temp_file, file_offset, SEEK_SET ) ) {
+        ERREXIT( cinfo, JERR_TFILE_SEEK );
+    }
+    if ( JFWRITE( info->temp_file, buffer_address, byte_count )
+         != (size_t) byte_count ) {
+        ERREXIT( cinfo, JERR_TFILE_WRITE );
+    }
+}
+
+
+METHODDEF void
+close_backing_store( j_common_ptr cinfo, backing_store_ptr info ) {
+    fclose( info->temp_file );/* close the file */
+    unlink( info->temp_name );/* delete the file */
+/* If your system doesn't have unlink(), use remove() instead.
+ * remove() is the ANSI-standard name for this function, but if
+ * your system was ANSI you'd be using jmemansi.c, right?
+ */
+    TRACEMSS( cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name );
+}
+
+
+/*
+ * Initial opening of a backing-store object.
+ */
+
+GLOBAL void
+jpeg_open_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                         long total_bytes_needed ) {
+    select_file_name( info->temp_name );
+    if ( ( info->temp_file = fopen( info->temp_name, RW_BINARY ) ) == NULL ) {
+        ERREXITS( cinfo, JERR_TFILE_CREATE, info->temp_name );
+    }
+    info->read_backing_store = read_backing_store;
+    info->write_backing_store = write_backing_store;
+    info->close_backing_store = close_backing_store;
+    TRACEMSS( cinfo, 1, JTRC_TFILE_OPEN, info->temp_name );
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL long
+jpeg_mem_init( j_common_ptr cinfo ) {
+    next_file_num = 0;      /* initialize temp file name generator */
+    return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
+}
+
+GLOBAL void
+jpeg_mem_term( j_common_ptr cinfo ) {
+    /* no work */
+}

neo/renderer/jpeg-6/jmemnobs.cpp

@@ -0,0 +1,95 @@
+/*
+ * jmemnobs.c
+ *
+ * Copyright (C) 1992-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides a really simple implementation of the system-
+ * dependent portion of the JPEG memory manager.  This implementation
+ * assumes that no backing-store files are needed: all required space
+ * can be obtained from ri.Malloc().
+ * This is very portable in the sense that it'll compile on almost anything,
+ * but you'd better have lots of main memory (or virtual memory) if you want
+ * to process big images.
+ * Note that the max_memory_to_use option is ignored by this implementation.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jmemsys.h"     /* import the system-dependent declarations */
+
+/*
+ * Memory allocation and ri.Freeing are controlled by the regular library
+ * routines ri.Malloc() and ri.Free().
+ */
+
+GLOBAL void *
+jpeg_get_small( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_small( j_common_ptr cinfo, void * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL void FAR *
+jpeg_get_large( j_common_ptr cinfo, size_t sizeofobject ) {
+    return (void FAR *) malloc( sizeofobject );
+}
+
+GLOBAL void
+jpeg_free_large( j_common_ptr cinfo, void FAR * object, size_t sizeofobject ) {
+    free( object );
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * Here we always say, "we got all you want bud!"
+ */
+
+GLOBAL long
+jpeg_mem_available( j_common_ptr cinfo, long min_bytes_needed,
+                    long max_bytes_needed, long already_allocated ) {
+    return max_bytes_needed;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Since jpeg_mem_available always promised the moon,
+ * this should never be called and we can just error out.
+ */
+
+GLOBAL void
+jpeg_open_backing_store( j_common_ptr cinfo, backing_store_ptr info,
+                         long total_bytes_needed ) {
+    ERREXIT( cinfo, JERR_NO_BACKING_STORE );
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.  Here, there isn't any.
+ */
+
+GLOBAL long
+jpeg_mem_init( j_common_ptr cinfo ) {
+    return 0;       /* just set max_memory_to_use to 0 */
+}
+
+GLOBAL void
+jpeg_mem_term( j_common_ptr cinfo ) {
+    /* no work */
+}

neo/renderer/jpeg-6/jmemsys.h

@@ -0,0 +1,182 @@
+/*
+ * jmemsys.h
+ *
+ * Copyright (C) 1992-1994, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This include file defines the interface between the system-independent
+ * and system-dependent portions of the JPEG memory manager.  No other
+ * modules need include it.  (The system-independent portion is jmemmgr.c;
+ * there are several different versions of the system-dependent portion.)
+ *
+ * This file works as-is for the system-dependent memory managers supplied
+ * in the IJG distribution.  You may need to modify it if you write a
+ * custom memory manager.  If system-dependent changes are needed in
+ * this file, the best method is to #ifdef them based on a configuration
+ * symbol supplied in jconfig.h, as we have done with USE_MSDOS_MEMMGR.
+ */
+
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_get_small		jGetSmall
+#define jpeg_free_small		jFreeSmall
+#define jpeg_get_large		jGetLarge
+#define jpeg_free_large		jFreeLarge
+#define jpeg_mem_available	jMemAvail
+#define jpeg_open_backing_store	jOpenBackStore
+#define jpeg_mem_init		jMemInit
+#define jpeg_mem_term		jMemTerm
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/*
+ * These two functions are used to allocate and release small chunks of
+ * memory.  (Typically the total amount requested through jpeg_get_small is
+ * no more than 20K or so; this will be requested in chunks of a few K each.)
+ * Behavior should be the same as for the standard library functions malloc
+ * and free; in particular, jpeg_get_small must return NULL on failure.
+ * On most systems, these ARE malloc and free.  jpeg_free_small is passed the
+ * size of the object being freed, just in case it's needed.
+ * On an 80x86 machine using small-data memory model, these manage near heap.
+ */
+
+EXTERN void * jpeg_get_small JPP((j_common_ptr cinfo, size_t sizeofobject));
+EXTERN void jpeg_free_small JPP((j_common_ptr cinfo, void * object,
+				 size_t sizeofobject));
+
+/*
+ * These two functions are used to allocate and release large chunks of
+ * memory (up to the total free space designated by jpeg_mem_available).
+ * The interface is the same as above, except that on an 80x86 machine,
+ * far pointers are used.  On most other machines these are identical to
+ * the jpeg_get/free_small routines; but we keep them separate anyway,
+ * in case a different allocation strategy is desirable for large chunks.
+ */
+
+EXTERN void FAR * jpeg_get_large JPP((j_common_ptr cinfo,size_t sizeofobject));
+EXTERN void jpeg_free_large JPP((j_common_ptr cinfo, void FAR * object,
+				 size_t sizeofobject));
+
+/*
+ * The macro MAX_ALLOC_CHUNK designates the maximum number of bytes that may
+ * be requested in a single call to jpeg_get_large (and jpeg_get_small for that
+ * matter, but that case should never come into play).  This macro is needed
+ * to model the 64Kb-segment-size limit of far addressing on 80x86 machines.
+ * On those machines, we expect that jconfig.h will provide a proper value.
+ * On machines with 32-bit flat address spaces, any large constant may be used.
+ *
+ * NB: jmemmgr.c expects that MAX_ALLOC_CHUNK will be representable as type
+ * size_t and will be a multiple of sizeof(align_type).
+ */
+
+#ifndef MAX_ALLOC_CHUNK		/* may be overridden in jconfig.h */
+#define MAX_ALLOC_CHUNK  1000000000L
+#endif
+
+/*
+ * This routine computes the total space still available for allocation by
+ * jpeg_get_large.  If more space than this is needed, backing store will be
+ * used.  NOTE: any memory already allocated must not be counted.
+ *
+ * There is a minimum space requirement, corresponding to the minimum
+ * feasible buffer sizes; jmemmgr.c will request that much space even if
+ * jpeg_mem_available returns zero.  The maximum space needed, enough to hold
+ * all working storage in memory, is also passed in case it is useful.
+ * Finally, the total space already allocated is passed.  If no better
+ * method is available, cinfo->mem->max_memory_to_use - already_allocated
+ * is often a suitable calculation.
+ *
+ * It is OK for jpeg_mem_available to underestimate the space available
+ * (that'll just lead to more backing-store access than is really necessary).
+ * However, an overestimate will lead to failure.  Hence it's wise to subtract
+ * a slop factor from the true available space.  5% should be enough.
+ *
+ * On machines with lots of virtual memory, any large constant may be returned.
+ * Conversely, zero may be returned to always use the minimum amount of memory.
+ */
+
+EXTERN long jpeg_mem_available JPP((j_common_ptr cinfo,
+				    long min_bytes_needed,
+				    long max_bytes_needed,
+				    long already_allocated));
+
+
+/*
+ * This structure holds whatever state is needed to access a single
+ * backing-store object.  The read/write/close method pointers are called
+ * by jmemmgr.c to manipulate the backing-store object; all other fields
+ * are private to the system-dependent backing store routines.
+ */
+
+#define TEMP_NAME_LENGTH   64	/* max length of a temporary file's name */
+
+#ifdef USE_MSDOS_MEMMGR		/* DOS-specific junk */
+
+typedef unsigned short XMSH;	/* type of extended-memory handles */
+typedef unsigned short EMSH;	/* type of expanded-memory handles */
+
+typedef union {
+  short file_handle;		/* DOS file handle if it's a temp file */
+  XMSH xms_handle;		/* handle if it's a chunk of XMS */
+  EMSH ems_handle;		/* handle if it's a chunk of EMS */
+} handle_union;
+
+#endif /* USE_MSDOS_MEMMGR */
+
+typedef struct backing_store_struct * backing_store_ptr;
+
+typedef struct backing_store_struct {
+  /* Methods for reading/writing/closing this backing-store object */
+  JMETHOD(void, read_backing_store, (j_common_ptr cinfo,
+				     backing_store_ptr info,
+				     void FAR * buffer_address,
+				     long file_offset, long byte_count));
+  JMETHOD(void, write_backing_store, (j_common_ptr cinfo,
+				      backing_store_ptr info,
+				      void FAR * buffer_address,
+				      long file_offset, long byte_count));
+  JMETHOD(void, close_backing_store, (j_common_ptr cinfo,
+				      backing_store_ptr info));
+
+  /* Private fields for system-dependent backing-store management */
+#ifdef USE_MSDOS_MEMMGR
+  /* For the MS-DOS manager (jmemdos.c), we need: */
+  handle_union handle;		/* reference to backing-store storage object */
+  char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
+#else
+  /* For a typical implementation with temp files, we need: */
+  FILE * temp_file;		/* stdio reference to temp file */
+  char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */
+#endif
+} backing_store_info;
+
+/*
+ * Initial opening of a backing-store object.  This must fill in the
+ * read/write/close pointers in the object.  The read/write routines
+ * may take an error exit if the specified maximum file size is exceeded.
+ * (If jpeg_mem_available always returns a large value, this routine can
+ * just take an error exit.)
+ */
+
+EXTERN void jpeg_open_backing_store JPP((j_common_ptr cinfo,
+					 backing_store_ptr info,
+					 long total_bytes_needed));
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.  jpeg_mem_init will be called before anything is
+ * allocated (and, therefore, nothing in cinfo is of use except the error
+ * manager pointer).  It should return a suitable default value for
+ * max_memory_to_use; this may subsequently be overridden by the surrounding
+ * application.  (Note that max_memory_to_use is only important if
+ * jpeg_mem_available chooses to consult it ... no one else will.)
+ * jpeg_mem_term may assume that all requested memory has been freed and that
+ * all opened backing-store objects have been closed.
+ */
+
+EXTERN long jpeg_mem_init JPP((j_common_ptr cinfo));
+EXTERN void jpeg_mem_term JPP((j_common_ptr cinfo));

neo/renderer/jpeg-6/jmorecfg.h

@@ -0,0 +1,352 @@
+/*
+ * jmorecfg.h
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains additional configuration options that customize the
+ * JPEG software for special applications or support machine-dependent
+ * optimizations.  Most users will not need to touch this file.
+ */
+
+
+/*
+ * Define BITS_IN_JSAMPLE as either
+ *   8   for 8-bit sample values (the usual setting)
+ *   12  for 12-bit sample values
+ * Only 8 and 12 are legal data precisions for lossy JPEG according to the
+ * JPEG standard, and the IJG code does not support anything else!
+ * We do not support run-time selection of data precision, sorry.
+ */
+
+#define BITS_IN_JSAMPLE  8	/* use 8 or 12 */
+
+
+/*
+ * Maximum number of components (color channels) allowed in JPEG image.
+ * To meet the letter of the JPEG spec, set this to 255.  However, darn
+ * few applications need more than 4 channels (maybe 5 for CMYK + alpha
+ * mask).  We recommend 10 as a reasonable compromise; use 4 if you are
+ * really short on memory.  (Each allowed component costs a hundred or so
+ * bytes of storage, whether actually used in an image or not.)
+ */
+
+#define MAX_COMPONENTS  10	/* maximum number of image components */
+
+
+/*
+ * Basic data types.
+ * You may need to change these if you have a machine with unusual data
+ * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
+ * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
+ * but it had better be at least 16.
+ */
+
+/* Representation of a single sample (pixel element value).
+ * We frequently allocate large arrays of these, so it's important to keep
+ * them small.  But if you have memory to burn and access to char or short
+ * arrays is very slow on your hardware, you might want to change these.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+/* JSAMPLE should be the smallest type that will hold the values 0..255.
+ * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
+ */
+
+#ifdef HAVE_UNSIGNED_CHAR
+
+typedef unsigned char JSAMPLE;
+#define GETJSAMPLE(value)  ((int) (value))
+
+#else /* not HAVE_UNSIGNED_CHAR */
+
+typedef char JSAMPLE;
+#ifdef CHAR_IS_UNSIGNED
+#define GETJSAMPLE(value)  ((int) (value))
+#else
+#define GETJSAMPLE(value)  ((int) (value) & 0xFF)
+#endif /* CHAR_IS_UNSIGNED */
+
+#endif /* HAVE_UNSIGNED_CHAR */
+
+#define MAXJSAMPLE	255
+#define CENTERJSAMPLE	128
+
+#endif /* BITS_IN_JSAMPLE == 8 */
+
+
+#if BITS_IN_JSAMPLE == 12
+/* JSAMPLE should be the smallest type that will hold the values 0..4095.
+ * On nearly all machines "short" will do nicely.
+ */
+
+typedef short JSAMPLE;
+#define GETJSAMPLE(value)  ((int) (value))
+
+#define MAXJSAMPLE	4095
+#define CENTERJSAMPLE	2048
+
+#endif /* BITS_IN_JSAMPLE == 12 */
+
+
+/* Representation of a DCT frequency coefficient.
+ * This should be a signed value of at least 16 bits; "short" is usually OK.
+ * Again, we allocate large arrays of these, but you can change to int
+ * if you have memory to burn and "short" is really slow.
+ */
+
+typedef short JCOEF;
+
+
+/* Compressed datastreams are represented as arrays of JOCTET.
+ * These must be EXACTLY 8 bits wide, at least once they are written to
+ * external storage.  Note that when using the stdio data source/destination
+ * managers, this is also the data type passed to fread/fwrite.
+ */
+
+#ifdef HAVE_UNSIGNED_CHAR
+
+typedef unsigned char JOCTET;
+#define GETJOCTET(value)  (value)
+
+#else /* not HAVE_UNSIGNED_CHAR */
+
+typedef char JOCTET;
+#ifdef CHAR_IS_UNSIGNED
+#define GETJOCTET(value)  (value)
+#else
+#define GETJOCTET(value)  ((value) & 0xFF)
+#endif /* CHAR_IS_UNSIGNED */
+
+#endif /* HAVE_UNSIGNED_CHAR */
+
+
+/* These typedefs are used for various table entries and so forth.
+ * They must be at least as wide as specified; but making them too big
+ * won't cost a huge amount of memory, so we don't provide special
+ * extraction code like we did for JSAMPLE.  (In other words, these
+ * typedefs live at a different point on the speed/space tradeoff curve.)
+ */
+
+/* UINT8 must hold at least the values 0..255. */
+
+#ifdef HAVE_UNSIGNED_CHAR
+typedef unsigned char UINT8;
+#else /* not HAVE_UNSIGNED_CHAR */
+#ifdef CHAR_IS_UNSIGNED
+typedef char UINT8;
+#else /* not CHAR_IS_UNSIGNED */
+typedef short UINT8;
+#endif /* CHAR_IS_UNSIGNED */
+#endif /* HAVE_UNSIGNED_CHAR */
+
+/* UINT16 must hold at least the values 0..65535. */
+
+#ifdef HAVE_UNSIGNED_SHORT
+typedef unsigned short UINT16;
+#else /* not HAVE_UNSIGNED_SHORT */
+typedef unsigned int UINT16;
+#endif /* HAVE_UNSIGNED_SHORT */
+
+#ifndef __MWERKS__
+#ifndef _BASETSD_H_
+typedef long INT32;
+#endif
+#endif
+
+/* INT16 must hold at least the values -32768..32767. */
+
+#ifndef XMD_H			/* X11/xmd.h correctly defines INT16 */
+typedef short INT16;
+#endif
+
+/* INT32 must hold at least signed 32-bit values. */
+
+//#ifndef XMD_H			/* X11/xmd.h correctly defines INT32 */
+//typedef long INT32;
+//#endif
+
+/* Datatype used for image dimensions.  The JPEG standard only supports
+ * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
+ * "unsigned int" is sufficient on all machines.  However, if you need to
+ * handle larger images and you don't mind deviating from the spec, you
+ * can change this datatype.
+ */
+
+typedef unsigned int JDIMENSION;
+
+#define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
+
+
+/* These defines are used in all function definitions and extern declarations.
+ * You could modify them if you need to change function linkage conventions.
+ * Another application is to make all functions global for use with debuggers
+ * or code profilers that require it.
+ */
+
+#define METHODDEF static	/* a function called through method pointers */
+#define LOCAL	  static	/* a function used only in its module */
+#define GLOBAL			/* a function referenced thru EXTERNs */
+#define EXTERN	  extern	/* a reference to a GLOBAL function */
+
+
+/* Here is the pseudo-keyword for declaring pointers that must be "far"
+ * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
+ * by just saying "FAR *" where such a pointer is needed.  In a few places
+ * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
+ */
+
+#ifdef NEED_FAR_POINTERS
+#undef FAR
+#define FAR  far
+#else
+#undef FAR
+#define FAR
+#endif
+
+
+/*
+ * On a few systems, type boolean and/or its values FALSE, TRUE may appear
+ * in standard header files.  Or you may have conflicts with application-
+ * specific header files that you want to include together with these files.
+ * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
+ */
+
+//#ifndef HAVE_BOOLEAN
+//typedef int boolean;
+//#endif
+#ifndef FALSE			/* in case these macros already exist */
+#define FALSE	0		/* values of boolean */
+#endif
+#ifndef TRUE
+#define TRUE	1
+#endif
+
+
+/*
+ * The remaining options affect code selection within the JPEG library,
+ * but they don't need to be visible to most applications using the library.
+ * To minimize application namespace pollution, the symbols won't be
+ * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
+ */
+
+#ifdef JPEG_INTERNALS
+#define JPEG_INTERNAL_OPTIONS
+#endif
+
+#ifdef JPEG_INTERNAL_OPTIONS
+
+
+/*
+ * These defines indicate whether to include various optional functions.
+ * Undefining some of these symbols will produce a smaller but less capable
+ * library.  Note that you can leave certain source files out of the
+ * compilation/linking process if you've #undef'd the corresponding symbols.
+ * (You may HAVE to do that if your compiler doesn't like null source files.)
+ */
+
+/* Arithmetic coding is unsupported for legal reasons.  Complaints to IBM. */
+
+/* Capability options common to encoder and decoder: */
+
+#undef DCT_ISLOW_SUPPORTED	/* slow but accurate integer algorithm */
+#undef DCT_IFAST_SUPPORTED	/* faster, less accurate integer method */
+#define DCT_FLOAT_SUPPORTED	/* floating-point: accurate, fast on fast HW */
+
+/* Encoder capability options: */
+
+#undef  C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
+#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
+#define C_PROGRESSIVE_SUPPORTED	    /* Progressive JPEG? (Requires MULTISCAN)*/
+#define ENTROPY_OPT_SUPPORTED	    /* Optimization of entropy coding parms? */
+/* Note: if you selected 12-bit data precision, it is dangerous to turn off
+ * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
+ * precision, so jchuff.c normally uses entropy optimization to compute
+ * usable tables for higher precision.  If you don't want to do optimization,
+ * you'll have to supply different default Huffman tables.
+ * The exact same statements apply for progressive JPEG: the default tables
+ * don't work for progressive mode.  (This may get fixed, however.)
+ */
+#define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
+
+/* Decoder capability options: */
+
+#undef  D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
+#undef D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
+#undef D_PROGRESSIVE_SUPPORTED	    /* Progressive JPEG? (Requires MULTISCAN)*/
+#undef BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
+#undef IDCT_SCALING_SUPPORTED	    /* Output rescaling via IDCT? */
+#undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
+#undef UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
+#undef QUANT_1PASS_SUPPORTED	    /* 1-pass color quantization? */
+#undef QUANT_2PASS_SUPPORTED	    /* 2-pass color quantization? */
+
+/* more capability options later, no doubt */
+
+
+/*
+ * Ordering of RGB data in scanlines passed to or from the application.
+ * If your application wants to deal with data in the order B,G,R, just
+ * change these macros.  You can also deal with formats such as R,G,B,X
+ * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
+ * the offsets will also change the order in which colormap data is organized.
+ * RESTRICTIONS:
+ * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
+ * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
+ *    useful if you are using JPEG color spaces other than YCbCr or grayscale.
+ * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
+ *    is not 3 (they don't understand about dummy color components!).  So you
+ *    can't use color quantization if you change that value.
+ */
+
+#define RGB_RED		0	/* Offset of Red in an RGB scanline element */
+#define RGB_GREEN	1	/* Offset of Green */
+#define RGB_BLUE	2	/* Offset of Blue */
+#define RGB_PIXELSIZE	4	/* JSAMPLEs per RGB scanline element */
+
+
+/* Definitions for speed-related optimizations. */
+
+
+/* If your compiler supports inline functions, define INLINE
+ * as the inline keyword; otherwise define it as empty.
+ */
+
+#ifndef INLINE
+#ifdef __GNUC__			/* for instance, GNU C knows about inline */
+#define INLINE __inline__
+#endif
+#ifndef INLINE
+#define INLINE			/* default is to define it as empty */
+#endif
+#endif
+
+
+/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
+ * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
+ * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
+ */
+
+#ifndef MULTIPLIER
+#define MULTIPLIER  int		/* type for fastest integer multiply */
+#endif
+
+
+/* FAST_FLOAT should be either float or double, whichever is done faster
+ * by your compiler.  (Note that this type is only used in the floating point
+ * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
+ * Typically, float is faster in ANSI C compilers, while double is faster in
+ * pre-ANSI compilers (because they insist on converting to double anyway).
+ * The code below therefore chooses float if we have ANSI-style prototypes.
+ */
+
+#ifndef FAST_FLOAT
+#ifdef HAVE_PROTOTYPES
+#define FAST_FLOAT  float
+#else
+#define FAST_FLOAT  double
+#endif
+#endif
+
+#endif /* JPEG_INTERNAL_OPTIONS */

neo/renderer/jpeg-6/jpegint.h

@@ -0,0 +1,388 @@
+/*
+ * jpegint.h
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides common declarations for the various JPEG modules.
+ * These declarations are considered internal to the JPEG library; most
+ * applications using the library shouldn't need to include this file.
+ */
+
+
+/* Declarations for both compression & decompression */
+
+typedef enum {			/* Operating modes for buffer controllers */
+	JBUF_PASS_THRU,		/* Plain stripwise operation */
+	/* Remaining modes require a full-image buffer to have been created */
+	JBUF_SAVE_SOURCE,	/* Run source subobject only, save output */
+	JBUF_CRANK_DEST,	/* Run dest subobject only, using saved data */
+	JBUF_SAVE_AND_PASS	/* Run both subobjects, save output */
+} J_BUF_MODE;
+
+/* Values of global_state field (jdapi.c has some dependencies on ordering!) */
+#define CSTATE_START	100	/* after create_compress */
+#define CSTATE_SCANNING	101	/* start_compress done, write_scanlines OK */
+#define CSTATE_RAW_OK	102	/* start_compress done, write_raw_data OK */
+#define CSTATE_WRCOEFS	103	/* jpeg_write_coefficients done */
+#define DSTATE_START	200	/* after create_decompress */
+#define DSTATE_INHEADER	201	/* reading header markers, no SOS yet */
+#define DSTATE_READY	202	/* found SOS, ready for start_decompress */
+#define DSTATE_PRELOAD	203	/* reading multiscan file in start_decompress*/
+#define DSTATE_PRESCAN	204	/* performing dummy pass for 2-pass quant */
+#define DSTATE_SCANNING	205	/* start_decompress done, read_scanlines OK */
+#define DSTATE_RAW_OK	206	/* start_decompress done, read_raw_data OK */
+#define DSTATE_BUFIMAGE	207	/* expecting jpeg_start_output */
+#define DSTATE_BUFPOST	208	/* looking for SOS/EOI in jpeg_finish_output */
+#define DSTATE_RDCOEFS	209	/* reading file in jpeg_read_coefficients */
+#define DSTATE_STOPPING	210	/* looking for EOI in jpeg_finish_decompress */
+
+
+/* Declarations for compression modules */
+
+/* Master control module */
+struct jpeg_comp_master {
+  JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
+  JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
+  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
+
+  /* State variables made visible to other modules */
+  boolean call_pass_startup;	/* True if pass_startup must be called */
+  boolean is_last_pass;		/* True during last pass */
+};
+
+/* Main buffer control (downsampled-data buffer) */
+struct jpeg_c_main_controller {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, process_data, (j_compress_ptr cinfo,
+			       JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
+			       JDIMENSION in_rows_avail));
+};
+
+/* Compression preprocessing (downsampling input buffer control) */
+struct jpeg_c_prep_controller {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
+				   JSAMPARRAY input_buf,
+				   JDIMENSION *in_row_ctr,
+				   JDIMENSION in_rows_avail,
+				   JSAMPIMAGE output_buf,
+				   JDIMENSION *out_row_group_ctr,
+				   JDIMENSION out_row_groups_avail));
+};
+
+/* Coefficient buffer control */
+struct jpeg_c_coef_controller {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
+				   JSAMPIMAGE input_buf));
+};
+
+/* Colorspace conversion */
+struct jpeg_color_converter {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
+  JMETHOD(void, color_convert, (j_compress_ptr cinfo,
+				JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+				JDIMENSION output_row, int num_rows));
+};
+
+/* Downsampling */
+struct jpeg_downsampler {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
+  JMETHOD(void, downsample, (j_compress_ptr cinfo,
+			     JSAMPIMAGE input_buf, JDIMENSION in_row_index,
+			     JSAMPIMAGE output_buf,
+			     JDIMENSION out_row_group_index));
+
+  boolean need_context_rows;	/* TRUE if need rows above & below */
+};
+
+/* Forward DCT (also controls coefficient quantization) */
+struct jpeg_forward_dct {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
+  /* perhaps this should be an array??? */
+  JMETHOD(void, forward_DCT, (j_compress_ptr cinfo,
+			      jpeg_component_info * compptr,
+			      JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
+			      JDIMENSION start_row, JDIMENSION start_col,
+			      JDIMENSION num_blocks));
+};
+
+/* Entropy encoding */
+struct jpeg_entropy_encoder {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
+  JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
+  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
+};
+
+/* Marker writing */
+struct jpeg_marker_writer {
+  /* write_any_marker is exported for use by applications */
+  /* Probably only COM and APPn markers should be written */
+  JMETHOD(void, write_any_marker, (j_compress_ptr cinfo, int marker,
+				   const JOCTET *dataptr, unsigned int datalen));
+  JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
+  JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
+  JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
+  JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
+  JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
+};
+
+
+/* Declarations for decompression modules */
+
+/* Master control module */
+struct jpeg_decomp_master {
+  JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
+
+  /* State variables made visible to other modules */
+  boolean is_dummy_pass;	/* True during 1st pass for 2-pass quant */
+};
+
+/* Input control module */
+struct jpeg_input_controller {
+  JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
+  JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
+  JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
+
+  /* State variables made visible to other modules */
+  boolean has_multiple_scans;	/* True if file has multiple scans */
+  boolean eoi_reached;		/* True when EOI has been consumed */
+};
+
+/* Main buffer control (downsampled-data buffer) */
+struct jpeg_d_main_controller {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, process_data, (j_decompress_ptr cinfo,
+			       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+			       JDIMENSION out_rows_avail));
+};
+
+/* Coefficient buffer control */
+struct jpeg_d_coef_controller {
+  JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
+  JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
+  JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
+  JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
+				 JSAMPIMAGE output_buf));
+  /* Pointer to array of coefficient virtual arrays, or NULL if none */
+  jvirt_barray_ptr *coef_arrays;
+};
+
+/* Decompression postprocessing (color quantization buffer control) */
+struct jpeg_d_post_controller {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
+				    JSAMPIMAGE input_buf,
+				    JDIMENSION *in_row_group_ctr,
+				    JDIMENSION in_row_groups_avail,
+				    JSAMPARRAY output_buf,
+				    JDIMENSION *out_row_ctr,
+				    JDIMENSION out_rows_avail));
+};
+
+/* Marker reading & parsing */
+struct jpeg_marker_reader {
+  JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
+  /* Read markers until SOS or EOI.
+   * Returns same codes as are defined for jpeg_consume_input:
+   * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
+   */
+  JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
+  /* Read a restart marker --- exported for use by entropy decoder only */
+  jpeg_marker_parser_method read_restart_marker;
+  /* Application-overridable marker processing methods */
+  jpeg_marker_parser_method process_COM;
+  jpeg_marker_parser_method process_APPn[16];
+
+  /* State of marker reader --- nominally internal, but applications
+   * supplying COM or APPn handlers might like to know the state.
+   */
+  boolean saw_SOI;		/* found SOI? */
+  boolean saw_SOF;		/* found SOF? */
+  int next_restart_num;		/* next restart number expected (0-7) */
+  unsigned int discarded_bytes;	/* # of bytes skipped looking for a marker */
+};
+
+/* Entropy decoding */
+struct jpeg_entropy_decoder {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
+				JBLOCKROW *MCU_data));
+};
+
+/* Inverse DCT (also performs dequantization) */
+typedef JMETHOD(void, inverse_DCT_method_ptr,
+		(j_decompress_ptr cinfo, jpeg_component_info * compptr,
+		 JCOEFPTR coef_block,
+		 JSAMPARRAY output_buf, JDIMENSION output_col));
+
+struct jpeg_inverse_dct {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  /* It is useful to allow each component to have a separate IDCT method. */
+  inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
+};
+
+/* Upsampling (note that upsampler must also call color converter) */
+struct jpeg_upsampler {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, upsample, (j_decompress_ptr cinfo,
+			   JSAMPIMAGE input_buf,
+			   JDIMENSION *in_row_group_ctr,
+			   JDIMENSION in_row_groups_avail,
+			   JSAMPARRAY output_buf,
+			   JDIMENSION *out_row_ctr,
+			   JDIMENSION out_rows_avail));
+
+  boolean need_context_rows;	/* TRUE if need rows above & below */
+};
+
+/* Colorspace conversion */
+struct jpeg_color_deconverter {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
+				JSAMPIMAGE input_buf, JDIMENSION input_row,
+				JSAMPARRAY output_buf, int num_rows));
+};
+
+/* Color quantization or color precision reduction */
+struct jpeg_color_quantizer {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
+  JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
+				 JSAMPARRAY input_buf, JSAMPARRAY output_buf,
+				 int num_rows));
+  JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
+};
+
+
+/* Miscellaneous useful macros */
+
+#undef MAX
+#define MAX(a,b)	((a) > (b) ? (a) : (b))
+#undef MIN
+#define MIN(a,b)	((a) < (b) ? (a) : (b))
+
+
+/* We assume that right shift corresponds to signed division by 2 with
+ * rounding towards minus infinity.  This is correct for typical "arithmetic
+ * shift" instructions that shift in copies of the sign bit.  But some
+ * C compilers implement >> with an unsigned shift.  For these machines you
+ * must define RIGHT_SHIFT_IS_UNSIGNED.
+ * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
+ * It is only applied with constant shift counts.  SHIFT_TEMPS must be
+ * included in the variables of any routine using RIGHT_SHIFT.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define SHIFT_TEMPS	INT32 shift_temp;
+#define RIGHT_SHIFT(x,shft)  \
+	((shift_temp = (x)) < 0 ? \
+	 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
+	 (shift_temp >> (shft)))
+#else
+#define SHIFT_TEMPS
+#define RIGHT_SHIFT(x,shft)	((x) >> (shft))
+#endif
+
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jinit_compress_master	jICompress
+#define jinit_c_master_control	jICMaster
+#define jinit_c_main_controller	jICMainC
+#define jinit_c_prep_controller	jICPrepC
+#define jinit_c_coef_controller	jICCoefC
+#define jinit_color_converter	jICColor
+#define jinit_downsampler	jIDownsampler
+#define jinit_forward_dct	jIFDCT
+#define jinit_huff_encoder	jIHEncoder
+#define jinit_phuff_encoder	jIPHEncoder
+#define jinit_marker_writer	jIMWriter
+#define jinit_master_decompress	jIDMaster
+#define jinit_d_main_controller	jIDMainC
+#define jinit_d_coef_controller	jIDCoefC
+#define jinit_d_post_controller	jIDPostC
+#define jinit_input_controller	jIInCtlr
+#define jinit_marker_reader	jIMReader
+#define jinit_huff_decoder	jIHDecoder
+#define jinit_phuff_decoder	jIPHDecoder
+#define jinit_inverse_dct	jIIDCT
+#define jinit_upsampler		jIUpsampler
+#define jinit_color_deconverter	jIDColor
+#define jinit_1pass_quantizer	jI1Quant
+#define jinit_2pass_quantizer	jI2Quant
+#define jinit_merged_upsampler	jIMUpsampler
+#define jinit_memory_mgr	jIMemMgr
+#define jdiv_round_up		jDivRound
+#define jround_up		jRound
+#define jcopy_sample_rows	jCopySamples
+#define jcopy_block_row		jCopyBlocks
+#define jzero_far		jZeroFar
+#define jpeg_zigzag_order	jZIGTable
+#define jpeg_natural_order	jZAGTable
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/* Compression module initialization routines */
+EXTERN void jinit_compress_master JPP((j_compress_ptr cinfo));
+EXTERN void jinit_c_master_control JPP((j_compress_ptr cinfo,
+					boolean transcode_only));
+EXTERN void jinit_c_main_controller JPP((j_compress_ptr cinfo,
+					 boolean need_full_buffer));
+EXTERN void jinit_c_prep_controller JPP((j_compress_ptr cinfo,
+					 boolean need_full_buffer));
+EXTERN void jinit_c_coef_controller JPP((j_compress_ptr cinfo,
+					 boolean need_full_buffer));
+EXTERN void jinit_color_converter JPP((j_compress_ptr cinfo));
+EXTERN void jinit_downsampler JPP((j_compress_ptr cinfo));
+EXTERN void jinit_forward_dct JPP((j_compress_ptr cinfo));
+EXTERN void jinit_huff_encoder JPP((j_compress_ptr cinfo));
+EXTERN void jinit_phuff_encoder JPP((j_compress_ptr cinfo));
+EXTERN void jinit_marker_writer JPP((j_compress_ptr cinfo));
+/* Decompression module initialization routines */
+EXTERN void jinit_master_decompress JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_d_main_controller JPP((j_decompress_ptr cinfo,
+					 boolean need_full_buffer));
+EXTERN void jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
+					 boolean need_full_buffer));
+EXTERN void jinit_d_post_controller JPP((j_decompress_ptr cinfo,
+					 boolean need_full_buffer));
+EXTERN void jinit_input_controller JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_marker_reader JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_huff_decoder JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_inverse_dct JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_upsampler JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_color_deconverter JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
+EXTERN void jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
+/* Memory manager initialization */
+EXTERN void jinit_memory_mgr JPP((j_common_ptr cinfo));
+
+/* Utility routines in jutils.c */
+EXTERN long jdiv_round_up JPP((long a, long b));
+EXTERN long jround_up JPP((long a, long b));
+EXTERN void jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
+				   JSAMPARRAY output_array, int dest_row,
+				   int num_rows, JDIMENSION num_cols));
+EXTERN void jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
+				 JDIMENSION num_blocks));
+EXTERN void jzero_far JPP((void FAR * target, size_t bytestozero));
+/* Constant tables in jutils.c */
+extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
+extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
+
+/* Suppress undefined-structure complaints if necessary. */
+
+#ifdef INCOMPLETE_TYPES_BROKEN
+#ifndef AM_MEMORY_MANAGER	/* only jmemmgr.c defines these */
+struct jvirt_sarray_control { long dummy; };
+struct jvirt_barray_control { long dummy; };
+#endif
+#endif /* INCOMPLETE_TYPES_BROKEN */

neo/renderer/jpeg-6/jpegtran.cpp

@@ -0,0 +1,381 @@
+/*
+ * jpegtran.c
+ *
+ * Copyright (C) 1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a command-line user interface for JPEG transcoding.
+ * It is very similar to cjpeg.c, but provides lossless transcoding between
+ * different JPEG file formats.
+ */
+
+#include "cdjpeg.h"      /* Common decls for cjpeg/djpeg applications */
+#include "jversion.h"        /* for version message */
+
+#ifdef USE_CCOMMAND     /* command-line reader for Macintosh */
+#ifdef __MWERKS__
+#include <SIOUX.h>              /* Metrowerks declares it here */
+#endif
+#ifdef THINK_C
+#include <console.h>     /* Think declares it here */
+#endif
+#endif
+
+
+/*
+ * Argument-parsing code.
+ * The switch parser is designed to be useful with DOS-style command line
+ * syntax, ie, intermixed switches and file names, where only the switches
+ * to the left of a given file name affect processing of that file.
+ * The main program in this file doesn't actually use this capability...
+ */
+
+
+static const char * progname;   /* program name for error messages */
+static char * outfilename;  /* for -outfile switch */
+
+
+LOCAL void
+usage( void ) {
+/* complain about bad command line */
+    fprintf( stderr, "usage: %s [switches] ", progname );
+#ifdef TWO_FILE_COMMANDLINE
+    fprintf( stderr, "inputfile outputfile\n" );
+#else
+    fprintf( stderr, "[inputfile]\n" );
+#endif
+
+    fprintf( stderr, "Switches (names may be abbreviated):\n" );
+#ifdef ENTROPY_OPT_SUPPORTED
+    fprintf( stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n" );
+#endif
+#ifdef C_PROGRESSIVE_SUPPORTED
+    fprintf( stderr, "  -progressive   Create progressive JPEG file\n" );
+#endif
+    fprintf( stderr, "Switches for advanced users:\n" );
+    fprintf( stderr, "  -restart N     Set restart interval in rows, or in blocks with B\n" );
+    fprintf( stderr, "  -maxmemory N   Maximum memory to use (in kbytes)\n" );
+    fprintf( stderr, "  -outfile name  Specify name for output file\n" );
+    fprintf( stderr, "  -verbose  or  -debug   Emit debug output\n" );
+    fprintf( stderr, "Switches for wizards:\n" );
+#ifdef C_ARITH_CODING_SUPPORTED
+    fprintf( stderr, "  -arithmetic    Use arithmetic coding\n" );
+#endif
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+    fprintf( stderr, "  -scans file    Create multi-scan JPEG per script file\n" );
+#endif
+    exit( EXIT_FAILURE );
+}
+
+
+LOCAL int
+parse_switches( j_compress_ptr cinfo, int argc, char ** argv,
+                int last_file_arg_seen, boolean for_real ) {
+/* Parse optional switches.
+ * Returns argv[] index of first file-name argument (== argc if none).
+ * Any file names with indexes <= last_file_arg_seen are ignored;
+ * they have presumably been processed in a previous iteration.
+ * (Pass 0 for last_file_arg_seen on the first or only iteration.)
+ * for_real is FALSE on the first (dummy) pass; we may skip any expensive
+ * processing.
+ */
+    int argn;
+    char * arg;
+    boolean simple_progressive;
+    char * scansarg = NULL; /* saves -scans parm if any */
+
+    /* Set up default JPEG parameters. */
+    simple_progressive = FALSE;
+    outfilename = NULL;
+    cinfo->err->trace_level = 0;
+
+    /* Scan command line options, adjust parameters */
+
+    for ( argn = 1; argn < argc; argn++ ) {
+        arg = argv[argn];
+        if ( *arg != '-' ) {
+            /* Not a switch, must be a file name argument */
+            if ( argn <= last_file_arg_seen ) {
+                outfilename = NULL;/* -outfile applies to just one input file */
+                continue; /* ignore this name if previously processed */
+            }
+            break;      /* else done parsing switches */
+        }
+        arg++;      /* advance past switch marker character */
+
+        if ( keymatch( arg, "arithmetic", 1 ) ) {
+            /* Use arithmetic coding. */
+#ifdef C_ARITH_CODING_SUPPORTED
+            cinfo->arith_code = TRUE;
+#else
+            fprintf( stderr, "%s: sorry, arithmetic coding not supported\n",
+                     progname );
+            exit( EXIT_FAILURE );
+#endif
+
+        } else if ( keymatch( arg, "debug", 1 ) || keymatch( arg, "verbose", 1 ) ) {
+            /* Enable debug printouts. */
+            /* On first -d, print version identification */
+            static boolean printed_version = FALSE;
+
+            if ( !printed_version ) {
+                fprintf( stderr, "Independent JPEG Group's JPEGTRAN, version %s\n%s\n",
+                         JVERSION, JCOPYRIGHT );
+                printed_version = TRUE;
+            }
+            cinfo->err->trace_level++;
+
+        } else if ( keymatch( arg, "maxmemory", 3 ) ) {
+            /* Maximum memory in Kb (or Mb with 'm'). */
+            long lval;
+            char ch = 'x';
+
+            if ( ++argn >= argc ) {/* advance to next argument */
+                usage();
+            }
+            if ( sscanf( argv[argn], "%ld%c", &lval, &ch ) < 1 ) {
+                usage();
+            }
+            if ( ( ch == 'm' ) || ( ch == 'M' ) ) {
+                lval *= 1000L;
+            }
+            cinfo->mem->max_memory_to_use = lval * 1000L;
+
+        } else if ( keymatch( arg, "optimize", 1 ) || keymatch( arg, "optimise", 1 ) ) {
+            /* Enable entropy parm optimization. */
+#ifdef ENTROPY_OPT_SUPPORTED
+            cinfo->optimize_coding = TRUE;
+#else
+            fprintf( stderr, "%s: sorry, entropy optimization was not compiled\n",
+                     progname );
+            exit( EXIT_FAILURE );
+#endif
+
+        } else if ( keymatch( arg, "outfile", 4 ) ) {
+            /* Set output file name. */
+            if ( ++argn >= argc ) {/* advance to next argument */
+                usage();
+            }
+            outfilename = argv[argn];/* save it away for later use */
+
+        } else if ( keymatch( arg, "progressive", 1 ) ) {
+            /* Select simple progressive mode. */
+#ifdef C_PROGRESSIVE_SUPPORTED
+            simple_progressive = TRUE;
+            /* We must postpone execution until num_components is known. */
+#else
+            fprintf( stderr, "%s: sorry, progressive output was not compiled\n",
+                     progname );
+            exit( EXIT_FAILURE );
+#endif
+
+        } else if ( keymatch( arg, "restart", 1 ) ) {
+            /* Restart interval in MCU rows (or in MCUs with 'b'). */
+            long lval;
+            char ch = 'x';
+
+            if ( ++argn >= argc ) {/* advance to next argument */
+                usage();
+            }
+            if ( sscanf( argv[argn], "%ld%c", &lval, &ch ) < 1 ) {
+                usage();
+            }
+            if ( ( lval < 0 ) || ( lval > 65535L ) ) {
+                usage();
+            }
+            if ( ( ch == 'b' ) || ( ch == 'B' ) ) {
+                cinfo->restart_interval = (unsigned int) lval;
+                cinfo->restart_in_rows = 0;/* else prior '-restart n' overrides me */
+            } else {
+                cinfo->restart_in_rows = (int) lval;
+                /* restart_interval will be computed during startup */
+            }
+
+        } else if ( keymatch( arg, "scans", 2 ) ) {
+            /* Set scan script. */
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+            if ( ++argn >= argc ) {/* advance to next argument */
+                usage();
+            }
+            scansarg = argv[argn];
+            /* We must postpone reading the file in case -progressive appears. */
+#else
+            fprintf( stderr, "%s: sorry, multi-scan output was not compiled\n",
+                     progname );
+            exit( EXIT_FAILURE );
+#endif
+
+        } else {
+            usage();    /* bogus switch */
+        }
+    }
+
+    /* Post-switch-scanning cleanup */
+
+    if ( for_real ) {
+
+#ifdef C_PROGRESSIVE_SUPPORTED
+        if ( simple_progressive ) {/* process -progressive; -scans can override */
+            jpeg_simple_progression( cinfo );
+        }
+#endif
+
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+        if ( scansarg != NULL ) {/* process -scans if it was present */
+            if ( !read_scan_script( cinfo, scansarg ) ) {
+                usage();
+            }
+        }
+#endif
+    }
+
+    return argn;        /* return index of next arg (file name) */
+}
+
+
+/*
+ * The main program.
+ */
+
+GLOBAL int
+main( int argc, char ** argv ) {
+    struct jpeg_decompress_struct srcinfo;
+    struct jpeg_compress_struct dstinfo;
+    struct jpeg_error_mgr jsrcerr, jdsterr;
+#ifdef PROGRESS_REPORT
+    struct cdjpeg_progress_mgr progress;
+#endif
+    jvirt_barray_ptr * coef_arrays;
+    int file_index;
+    FILE * input_file;
+    FILE * output_file;
+
+    /* On Mac, fetch a command line. */
+#ifdef USE_CCOMMAND
+    argc = ccommand( &argv );
+#endif
+
+    progname = argv[0];
+    if ( ( progname == NULL ) || ( progname[0] == 0 ) ) {
+        progname = "jpegtran";
+    }                       /* in case C library doesn't provide it */
+
+    /* Initialize the JPEG decompression object with default error handling. */
+    srcinfo.err = jpeg_std_error( &jsrcerr );
+    jpeg_create_decompress( &srcinfo );
+    /* Initialize the JPEG compression object with default error handling. */
+    dstinfo.err = jpeg_std_error( &jdsterr );
+    jpeg_create_compress( &dstinfo );
+
+    /* Now safe to enable signal catcher.
+     * Note: we assume only the decompression object will have virtual arrays.
+     */
+#ifdef NEED_SIGNAL_CATCHER
+    enable_signal_catcher( ( j_common_ptr ) & srcinfo );
+#endif
+
+    /* Scan command line to find file names.
+     * It is convenient to use just one switch-parsing routine, but the switch
+     * values read here are ignored; we will rescan the switches after opening
+     * the input file.
+     */
+
+    file_index = parse_switches( &dstinfo, argc, argv, 0, FALSE );
+    jsrcerr.trace_level = jdsterr.trace_level;
+
+#ifdef TWO_FILE_COMMANDLINE
+    /* Must have either -outfile switch or explicit output file name */
+    if ( outfilename == NULL ) {
+        if ( file_index != argc - 2 ) {
+            fprintf( stderr, "%s: must name one input and one output file\n",
+                     progname );
+            usage();
+        }
+        outfilename = argv[file_index + 1];
+    } else {
+        if ( file_index != argc - 1 ) {
+            fprintf( stderr, "%s: must name one input and one output file\n",
+                     progname );
+            usage();
+        }
+    }
+#else
+    /* Unix style: expect zero or one file name */
+    if ( file_index < argc - 1 ) {
+        fprintf( stderr, "%s: only one input file\n", progname );
+        usage();
+    }
+#endif /* TWO_FILE_COMMANDLINE */
+
+    /* Open the input file. */
+    if ( file_index < argc ) {
+        if ( ( input_file = fopen( argv[file_index], READ_BINARY ) ) == NULL ) {
+            fprintf( stderr, "%s: can't open %s\n", progname, argv[file_index] );
+            exit( EXIT_FAILURE );
+        }
+    } else {
+        /* default input file is stdin */
+        input_file = read_stdin();
+    }
+
+    /* Open the output file. */
+    if ( outfilename != NULL ) {
+        if ( ( output_file = fopen( outfilename, WRITE_BINARY ) ) == NULL ) {
+            fprintf( stderr, "%s: can't open %s\n", progname, outfilename );
+            exit( EXIT_FAILURE );
+        }
+    } else {
+        /* default output file is stdout */
+        output_file = write_stdout();
+    }
+
+#ifdef PROGRESS_REPORT
+    start_progress_monitor( ( j_common_ptr ) & dstinfo, &progress );
+#endif
+
+    /* Specify data source for decompression */
+    jpeg_stdio_src( &srcinfo, input_file );
+
+    /* Read file header */
+    (void) jpeg_read_header( &srcinfo, TRUE );
+
+    /* Read source file as DCT coefficients */
+    coef_arrays = jpeg_read_coefficients( &srcinfo );
+
+    /* Initialize destination compression parameters from source values */
+    jpeg_copy_critical_parameters( &srcinfo, &dstinfo );
+
+    /* Adjust default compression parameters by re-parsing the options */
+    file_index = parse_switches( &dstinfo, argc, argv, 0, TRUE );
+
+    /* Specify data destination for compression */
+    jpeg_stdio_dest( &dstinfo, output_file );
+
+    /* Start compressor */
+    jpeg_write_coefficients( &dstinfo, coef_arrays );
+
+    /* ought to copy source comments here... */
+
+    /* Finish compression and release memory */
+    jpeg_finish_compress( &dstinfo );
+    jpeg_destroy_compress( &dstinfo );
+    (void) jpeg_finish_decompress( &srcinfo );
+    jpeg_destroy_decompress( &srcinfo );
+
+    /* Close files, if we opened them */
+    if ( input_file != stdin ) {
+        fclose( input_file );
+    }
+    if ( output_file != stdout ) {
+        fclose( output_file );
+    }
+
+#ifdef PROGRESS_REPORT
+    end_progress_monitor( ( j_common_ptr ) & dstinfo );
+#endif
+
+    /* All done. */
+    exit( jsrcerr.num_warnings + jdsterr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS );
+    return 0;       /* suppress no-return-value warnings */
+}

neo/renderer/jpeg-6/jquant1.cpp

@@ -0,0 +1,857 @@
+/*
+ * jquant1.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains 1-pass color quantization (color mapping) routines.
+ * These routines provide mapping to a fixed color map using equally spaced
+ * color values.  Optional Floyd-Steinberg or ordered dithering is available.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+#ifdef QUANT_1PASS_SUPPORTED
+
+
+/*
+ * The main purpose of 1-pass quantization is to provide a fast, if not very
+ * high quality, colormapped output capability.  A 2-pass quantizer usually
+ * gives better visual quality; however, for quantized grayscale output this
+ * quantizer is perfectly adequate.  Dithering is highly recommended with this
+ * quantizer, though you can turn it off if you really want to.
+ *
+ * In 1-pass quantization the colormap must be chosen in advance of seeing the
+ * image.  We use a map consisting of all combinations of Ncolors[i] color
+ * values for the i'th component.  The Ncolors[] values are chosen so that
+ * their product, the total number of colors, is no more than that requested.
+ * (In most cases, the product will be somewhat less.)
+ *
+ * Since the colormap is orthogonal, the representative value for each color
+ * component can be determined without considering the other components;
+ * then these indexes can be combined into a colormap index by a standard
+ * N-dimensional-array-subscript calculation.  Most of the arithmetic involved
+ * can be precalculated and stored in the lookup table colorindex[].
+ * colorindex[i][j] maps pixel value j in component i to the nearest
+ * representative value (grid plane) for that component; this index is
+ * multiplied by the array stride for component i, so that the
+ * index of the colormap entry closest to a given pixel value is just
+ *    sum( colorindex[component-number][pixel-component-value] )
+ * Aside from being fast, this scheme allows for variable spacing between
+ * representative values with no additional lookup cost.
+ *
+ * If gamma correction has been applied in color conversion, it might be wise
+ * to adjust the color grid spacing so that the representative colors are
+ * equidistant in linear space.  At this writing, gamma correction is not
+ * implemented by jdcolor, so nothing is done here.
+ */
+
+
+/* Declarations for ordered dithering.
+ *
+ * We use a standard 16x16 ordered dither array.  The basic concept of ordered
+ * dithering is described in many references, for instance Dale Schumacher's
+ * chapter II.2 of Graphics Gems II (James Arvo, ed. Academic Press, 1991).
+ * In place of Schumacher's comparisons against a "threshold" value, we add a
+ * "dither" value to the input pixel and then round the result to the nearest
+ * output value.  The dither value is equivalent to (0.5 - threshold) times
+ * the distance between output values.  For ordered dithering, we assume that
+ * the output colors are equally spaced; if not, results will probably be
+ * worse, since the dither may be too much or too little at a given point.
+ *
+ * The normal calculation would be to form pixel value + dither, range-limit
+ * this to 0..MAXJSAMPLE, and then index into the colorindex table as usual.
+ * We can skip the separate range-limiting step by extending the colorindex
+ * table in both directions.
+ */
+
+#define ODITHER_SIZE  16    /* dimension of dither matrix */
+/* NB: if ODITHER_SIZE is not a power of 2, ODITHER_MASK uses will break */
+#define ODITHER_CELLS ( ODITHER_SIZE * ODITHER_SIZE )   /* # cells in matrix */
+#define ODITHER_MASK  ( ODITHER_SIZE - 1 ) /* mask for wrapping around counters */
+
+typedef int ODITHER_MATRIX[ODITHER_SIZE][ODITHER_SIZE];
+typedef int ( *ODITHER_MATRIX_PTR )[ODITHER_SIZE];
+
+static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = {
+    /* Bayer's order-4 dither array.  Generated by the code given in
+     * Stephen Hawley's article "Ordered Dithering" in Graphics Gems I.
+     * The values in this array must range from 0 to ODITHER_CELLS-1.
+     */
+    {   0, 192, 48, 240, 12, 204, 60, 252,  3, 195, 51, 243, 15, 207, 63, 255 },
+    { 128, 64, 176, 112, 140, 76, 188, 124, 131, 67, 179, 115, 143, 79, 191, 127 },
+    {  32, 224, 16, 208, 44, 236, 28, 220, 35, 227, 19, 211, 47, 239, 31, 223 },
+    { 160, 96, 144, 80, 172, 108, 156, 92, 163, 99, 147, 83, 175, 111, 159, 95 },
+    {   8, 200, 56, 248,  4, 196, 52, 244, 11, 203, 59, 251,  7, 199, 55, 247 },
+    { 136, 72, 184, 120, 132, 68, 180, 116, 139, 75, 187, 123, 135, 71, 183, 119 },
+    {  40, 232, 24, 216, 36, 228, 20, 212, 43, 235, 27, 219, 39, 231, 23, 215 },
+    { 168, 104, 152, 88, 164, 100, 148, 84, 171, 107, 155, 91, 167, 103, 151, 87 },
+    {   2, 194, 50, 242, 14, 206, 62, 254,  1, 193, 49, 241, 13, 205, 61, 253 },
+    { 130, 66, 178, 114, 142, 78, 190, 126, 129, 65, 177, 113, 141, 77, 189, 125 },
+    {  34, 226, 18, 210, 46, 238, 30, 222, 33, 225, 17, 209, 45, 237, 29, 221 },
+    { 162, 98, 146, 82, 174, 110, 158, 94, 161, 97, 145, 81, 173, 109, 157, 93 },
+    {  10, 202, 58, 250,  6, 198, 54, 246,  9, 201, 57, 249,  5, 197, 53, 245 },
+    { 138, 74, 186, 122, 134, 70, 182, 118, 137, 73, 185, 121, 133, 69, 181, 117 },
+    {  42, 234, 26, 218, 38, 230, 22, 214, 41, 233, 25, 217, 37, 229, 21, 213 },
+    { 170, 106, 154, 90, 166, 102, 150, 86, 169, 105, 153, 89, 165, 101, 149, 85 }
+};
+
+
+/* Declarations for Floyd-Steinberg dithering.
+ *
+ * Errors are accumulated into the array fserrors[], at a resolution of
+ * 1/16th of a pixel count.  The error at a given pixel is propagated
+ * to its not-yet-processed neighbors using the standard F-S fractions,
+ *		...	(here)	7/16
+ *		3/16	5/16	1/16
+ * We work left-to-right on even rows, right-to-left on odd rows.
+ *
+ * We can get away with a single array (holding one row's worth of errors)
+ * by using it to store the current row's errors at pixel columns not yet
+ * processed, but the next row's errors at columns already processed.  We
+ * need only a few extra variables to hold the errors immediately around the
+ * current column.  (If we are lucky, those variables are in registers, but
+ * even if not, they're probably cheaper to access than array elements are.)
+ *
+ * The fserrors[] array is indexed [component#][position].
+ * We provide (#columns + 2) entries per component; the extra entry at each
+ * end saves us from special-casing the first and last pixels.
+ *
+ * Note: on a wide image, we might not have enough room in a PC's near data
+ * segment to hold the error array; so it is allocated with alloc_large.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+typedef INT16 FSERROR;      /* 16 bits should be enough */
+typedef int LOCFSERROR;     /* use 'int' for calculation temps */
+#else
+typedef INT32 FSERROR;      /* may need more than 16 bits */
+typedef INT32 LOCFSERROR;   /* be sure calculation temps are big enough */
+#endif
+
+typedef FSERROR FAR * FSERRPTR;  /* pointer to error array (in FAR storage!) */
+
+
+/* Private subobject */
+
+#define MAX_Q_COMPS 4       /* max components I can handle */
+
+typedef struct {
+    struct jpeg_color_quantizer pub;/* public fields */
+
+    /* Initially allocated colormap is saved here */
+    JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */
+    int        sv_actual; /* number of entries in use */
+
+    JSAMPARRAY colorindex;  /* Precomputed mapping for speed */
+    /* colorindex[i][j] = index of color closest to pixel value j in component i,
+     * premultiplied as described above.  Since colormap indexes must fit into
+     * JSAMPLEs, the entries of this array will too.
+     */
+    boolean is_padded;      /* is the colorindex padded for odither? */
+
+    int Ncolors[MAX_Q_COMPS];/* # of values alloced to each component */
+
+    /* Variables for ordered dithering */
+    int                row_index; /* cur row's vertical index in dither matrix */
+    ODITHER_MATRIX_PTR odither[MAX_Q_COMPS];/* one dither array per component */
+
+    /* Variables for Floyd-Steinberg dithering */
+    FSERRPTR fserrors[MAX_Q_COMPS];/* accumulated errors */
+    boolean  on_odd_row;    /* flag to remember which row we are on */
+} my_cquantizer;
+
+typedef my_cquantizer * my_cquantize_ptr;
+
+
+/*
+ * Policy-making subroutines for create_colormap and create_colorindex.
+ * These routines determine the colormap to be used.  The rest of the module
+ * only assumes that the colormap is orthogonal.
+ *
+ *  * select_ncolors decides how to divvy up the available colors
+ *    among the components.
+ *  * output_value defines the set of representative values for a component.
+ *  * largest_input_value defines the mapping from input values to
+ *    representative values for a component.
+ * Note that the latter two routines may impose different policies for
+ * different components, though this is not currently done.
+ */
+
+
+LOCAL int
+select_ncolors( j_decompress_ptr cinfo, int Ncolors[] ) {
+/* Determine allocation of desired colors to components, */
+/* and fill in Ncolors[] array to indicate choice. */
+/* Return value is total number of colors (product of Ncolors[] values). */
+    int nc = cinfo->out_color_components;/* number of color components */
+    int max_colors = cinfo->desired_number_of_colors;
+    int total_colors, iroot, i, j;
+    boolean changed;
+    long temp;
+    static const int RGB_order[3] = { RGB_GREEN, RGB_RED, RGB_BLUE };
+
+    /* We can allocate at least the nc'th root of max_colors per component. */
+    /* Compute floor(nc'th root of max_colors). */
+    iroot = 1;
+    do {
+        iroot++;
+        temp = iroot;   /* set temp = iroot ** nc */
+        for ( i = 1; i < nc; i++ ) {
+            temp *= iroot;
+        }
+    } while ( temp <= (long) max_colors );/* repeat till iroot exceeds root */
+    iroot--;        /* now iroot = floor(root) */
+
+    /* Must have at least 2 color values per component */
+    if ( iroot < 2 ) {
+        ERREXIT1( cinfo, JERR_QUANT_FEW_COLORS, (int) temp );
+    }
+
+    /* Initialize to iroot color values for each component */
+    total_colors = 1;
+    for ( i = 0; i < nc; i++ ) {
+        Ncolors[i] = iroot;
+        total_colors *= iroot;
+    }
+    /* We may be able to increment the count for one or more components without
+     * exceeding max_colors, though we know not all can be incremented.
+     * Sometimes, the first component can be incremented more than once!
+     * (Example: for 16 colors, we start at 2*2*2, go to 3*2*2, then 4*2*2.)
+     * In RGB colorspace, try to increment G first, then R, then B.
+     */
+    do {
+        changed = FALSE;
+        for ( i = 0; i < nc; i++ ) {
+            j = ( cinfo->out_color_space == JCS_RGB ? RGB_order[i] : i );
+            /* calculate new total_colors if Ncolors[j] is incremented */
+            temp = total_colors / Ncolors[j];
+            temp *= Ncolors[j] + 1;/* done in long arith to avoid oflo */
+            if ( temp > (long) max_colors ) {
+                break;
+            }       /* won't fit, done with this pass */
+            Ncolors[j]++; /* OK, apply the increment */
+            total_colors = (int) temp;
+            changed = TRUE;
+        }
+    } while ( changed );
+
+    return total_colors;
+}
+
+
+LOCAL int
+output_value( j_decompress_ptr cinfo, int ci, int j, int maxj ) {
+/* Return j'th output value, where j will range from 0 to maxj */
+/* The output values must fall in 0..MAXJSAMPLE in increasing order */
+/* We always provide values 0 and MAXJSAMPLE for each component;
+ * any additional values are equally spaced between these limits.
+ * (Forcing the upper and lower values to the limits ensures that
+ * dithering can't produce a color outside the selected gamut.)
+ */
+    return (int) ( ( (INT32) j * MAXJSAMPLE + maxj / 2 ) / maxj );
+}
+
+
+LOCAL int
+largest_input_value( j_decompress_ptr cinfo, int ci, int j, int maxj ) {
+/* Return largest input value that should map to j'th output value */
+/* Must have largest(j=0) >= 0, and largest(j=maxj) >= MAXJSAMPLE */
+/* Breakpoints are halfway between values returned by output_value */
+    return (int) ( ( (INT32) ( 2 * j + 1 ) * MAXJSAMPLE + maxj ) / ( 2 * maxj ) );
+}
+
+
+/*
+ * Create the colormap.
+ */
+
+LOCAL void
+create_colormap( j_decompress_ptr cinfo ) {
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    JSAMPARRAY colormap;    /* Created colormap */
+    int total_colors;   /* Number of distinct output colors */
+    int i, j, k, nci, blksize, blkdist, ptr, val;
+
+    /* Select number of colors for each component */
+    total_colors = select_ncolors( cinfo, cquantize->Ncolors );
+
+    /* Report selected color counts */
+    if ( cinfo->out_color_components == 3 ) {
+        TRACEMS4( cinfo, 1, JTRC_QUANT_3_NCOLORS,
+                  total_colors, cquantize->Ncolors[0],
+                  cquantize->Ncolors[1], cquantize->Ncolors[2] );
+    } else {
+        TRACEMS1( cinfo, 1, JTRC_QUANT_NCOLORS, total_colors );
+    }
+
+    /* Allocate and fill in the colormap. */
+    /* The colors are ordered in the map in standard row-major order, */
+    /* i.e. rightmost (highest-indexed) color changes most rapidly. */
+
+    colormap = ( *cinfo->mem->alloc_sarray )
+               ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                (JDIMENSION) total_colors, (JDIMENSION) cinfo->out_color_components );
+
+    /* blksize is number of adjacent repeated entries for a component */
+    /* blkdist is distance between groups of identical entries for a component */
+    blkdist = total_colors;
+
+    for ( i = 0; i < cinfo->out_color_components; i++ ) {
+        /* fill in colormap entries for i'th color component */
+        nci = cquantize->Ncolors[i];/* # of distinct values for this color */
+        blksize = blkdist / nci;
+        for ( j = 0; j < nci; j++ ) {
+            /* Compute j'th output value (out of nci) for component */
+            val = output_value( cinfo, i, j, nci - 1 );
+            /* Fill in all colormap entries that have this value of this component */
+            for ( ptr = j * blksize; ptr < total_colors; ptr += blkdist ) {
+                /* fill in blksize entries beginning at ptr */
+                for ( k = 0; k < blksize; k++ ) {
+                    colormap[i][ptr + k] = (JSAMPLE) val;
+                }
+            }
+        }
+        blkdist = blksize;  /* blksize of this color is blkdist of next */
+    }
+
+    /* Save the colormap in private storage,
+     * where it will survive color quantization mode changes.
+     */
+    cquantize->sv_colormap = colormap;
+    cquantize->sv_actual = total_colors;
+}
+
+
+/*
+ * Create the color index table.
+ */
+
+LOCAL void
+create_colorindex( j_decompress_ptr cinfo ) {
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    JSAMPROW indexptr;
+    int i, j, k, nci, blksize, val, pad;
+
+    /* For ordered dither, we pad the color index tables by MAXJSAMPLE in
+     * each direction (input index values can be -MAXJSAMPLE .. 2*MAXJSAMPLE).
+     * This is not necessary in the other dithering modes.  However, we
+     * flag whether it was done in case user changes dithering mode.
+     */
+    if ( cinfo->dither_mode == JDITHER_ORDERED ) {
+        pad = MAXJSAMPLE * 2;
+        cquantize->is_padded = TRUE;
+    } else {
+        pad = 0;
+        cquantize->is_padded = FALSE;
+    }
+
+    cquantize->colorindex = ( *cinfo->mem->alloc_sarray )
+                            ( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                             (JDIMENSION) ( MAXJSAMPLE + 1 + pad ),
+                             (JDIMENSION) cinfo->out_color_components );
+
+    /* blksize is number of adjacent repeated entries for a component */
+    blksize = cquantize->sv_actual;
+
+    for ( i = 0; i < cinfo->out_color_components; i++ ) {
+        /* fill in colorindex entries for i'th color component */
+        nci = cquantize->Ncolors[i];/* # of distinct values for this color */
+        blksize = blksize / nci;
+
+        /* adjust colorindex pointers to provide padding at negative indexes. */
+        if ( pad ) {
+            cquantize->colorindex[i] += MAXJSAMPLE;
+        }
+
+        /* in loop, val = index of current output value, */
+        /* and k = largest j that maps to current val */
+        indexptr = cquantize->colorindex[i];
+        val = 0;
+        k = largest_input_value( cinfo, i, 0, nci - 1 );
+        for ( j = 0; j <= MAXJSAMPLE; j++ ) {
+            while ( j > k ) {/* advance val if past boundary */
+                k = largest_input_value( cinfo, i, ++val, nci - 1 );
+            }
+            /* premultiply so that no multiplication needed in main processing */
+            indexptr[j] = (JSAMPLE) ( val * blksize );
+        }
+        /* Pad at both ends if necessary */
+        if ( pad ) {
+            for ( j = 1; j <= MAXJSAMPLE; j++ ) {
+                indexptr[-j] = indexptr[0];
+                indexptr[MAXJSAMPLE + j] = indexptr[MAXJSAMPLE];
+            }
+        }
+    }
+}
+
+
+/*
+ * Create an ordered-dither array for a component having ncolors
+ * distinct output values.
+ */
+
+LOCAL ODITHER_MATRIX_PTR
+make_odither_array( j_decompress_ptr cinfo, int ncolors ) {
+    ODITHER_MATRIX_PTR odither;
+    int j, k;
+    INT32 num, den;
+
+    odither = (ODITHER_MATRIX_PTR)
+              ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                           SIZEOF( ODITHER_MATRIX ) );
+    /* The inter-value distance for this color is MAXJSAMPLE/(ncolors-1).
+     * Hence the dither value for the matrix cell with fill order f
+     * (f=0..N-1) should be (N-1-2*f)/(2*N) * MAXJSAMPLE/(ncolors-1).
+     * On 16-bit-int machine, be careful to avoid overflow.
+     */
+    den = 2 * ODITHER_CELLS * ( (INT32) ( ncolors - 1 ) );
+    for ( j = 0; j < ODITHER_SIZE; j++ ) {
+        for ( k = 0; k < ODITHER_SIZE; k++ ) {
+            num = ( (INT32) ( ODITHER_CELLS - 1 - 2 * ( (int)base_dither_matrix[j][k] ) ) )
+                  * MAXJSAMPLE;
+            /* Ensure round towards zero despite C's lack of consistency
+             * about rounding negative values in integer division...
+             */
+            odither[j][k] = (int) ( num < 0 ? -( ( -num ) / den ) : num / den );
+        }
+    }
+    return odither;
+}
+
+
+/*
+ * Create the ordered-dither tables.
+ * Components having the same number of representative colors may
+ * share a dither table.
+ */
+
+LOCAL void
+create_odither_tables( j_decompress_ptr cinfo ) {
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    ODITHER_MATRIX_PTR odither;
+    int i, j, nci;
+
+    for ( i = 0; i < cinfo->out_color_components; i++ ) {
+        nci = cquantize->Ncolors[i];/* # of distinct values for this color */
+        odither = NULL; /* search for matching prior component */
+        for ( j = 0; j < i; j++ ) {
+            if ( nci == cquantize->Ncolors[j] ) {
+                odither = cquantize->odither[j];
+                break;
+            }
+        }
+        if ( odither == NULL ) {/* need a new table? */
+            odither = make_odither_array( cinfo, nci );
+        }
+        cquantize->odither[i] = odither;
+    }
+}
+
+
+/*
+ * Map some rows of pixels to the output colormapped representation.
+ */
+
+METHODDEF void
+color_quantize( j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+                JSAMPARRAY output_buf, int num_rows ) {
+/* General case, no dithering */
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    JSAMPARRAY colorindex = cquantize->colorindex;
+    register int pixcode, ci;
+    register JSAMPROW ptrin, ptrout;
+    int row;
+    JDIMENSION col;
+    JDIMENSION width = cinfo->output_width;
+    register int nc = cinfo->out_color_components;
+
+    for ( row = 0; row < num_rows; row++ ) {
+        ptrin = input_buf[row];
+        ptrout = output_buf[row];
+        for ( col = width; col > 0; col-- ) {
+            pixcode = 0;
+            for ( ci = 0; ci < nc; ci++ ) {
+                pixcode += GETJSAMPLE( colorindex[ci][GETJSAMPLE( *ptrin++ )] );
+            }
+            *ptrout++ = (JSAMPLE) pixcode;
+        }
+    }
+}
+
+
+METHODDEF void
+color_quantize3( j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+                 JSAMPARRAY output_buf, int num_rows ) {
+/* Fast path for out_color_components==3, no dithering */
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    register int pixcode;
+    register JSAMPROW ptrin, ptrout;
+    JSAMPROW colorindex0 = cquantize->colorindex[0];
+    JSAMPROW colorindex1 = cquantize->colorindex[1];
+    JSAMPROW colorindex2 = cquantize->colorindex[2];
+    int row;
+    JDIMENSION col;
+    JDIMENSION width = cinfo->output_width;
+
+    for ( row = 0; row < num_rows; row++ ) {
+        ptrin = input_buf[row];
+        ptrout = output_buf[row];
+        for ( col = width; col > 0; col-- ) {
+            pixcode  = GETJSAMPLE( colorindex0[GETJSAMPLE( *ptrin++ )] );
+            pixcode += GETJSAMPLE( colorindex1[GETJSAMPLE( *ptrin++ )] );
+            pixcode += GETJSAMPLE( colorindex2[GETJSAMPLE( *ptrin++ )] );
+            *ptrout++ = (JSAMPLE) pixcode;
+        }
+    }
+}
+
+
+METHODDEF void
+quantize_ord_dither( j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+                     JSAMPARRAY output_buf, int num_rows ) {
+/* General case, with ordered dithering */
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    register JSAMPROW input_ptr;
+    register JSAMPROW output_ptr;
+    JSAMPROW colorindex_ci;
+    int * dither;       /* points to active row of dither matrix */
+    int row_index, col_index;/* current indexes into dither matrix */
+    int nc = cinfo->out_color_components;
+    int ci;
+    int row;
+    JDIMENSION col;
+    JDIMENSION width = cinfo->output_width;
+
+    for ( row = 0; row < num_rows; row++ ) {
+        /* Initialize output values to 0 so can process components separately */
+        jzero_far( (void FAR *) output_buf[row],
+                  (size_t) ( width * SIZEOF( JSAMPLE ) ) );
+        row_index = cquantize->row_index;
+        for ( ci = 0; ci < nc; ci++ ) {
+            input_ptr = input_buf[row] + ci;
+            output_ptr = output_buf[row];
+            colorindex_ci = cquantize->colorindex[ci];
+            dither = cquantize->odither[ci][row_index];
+            col_index = 0;
+
+            for ( col = width; col > 0; col-- ) {
+                /* Form pixel value + dither, range-limit to 0..MAXJSAMPLE,
+                 * select output value, accumulate into output code for this pixel.
+                 * Range-limiting need not be done explicitly, as we have extended
+                 * the colorindex table to produce the right answers for out-of-range
+                 * inputs.  The maximum dither is +- MAXJSAMPLE; this sets the
+                 * required amount of padding.
+                 */
+                *output_ptr += colorindex_ci[GETJSAMPLE( *input_ptr ) + dither[col_index]];
+                input_ptr += nc;
+                output_ptr++;
+                col_index = ( col_index + 1 ) & ODITHER_MASK;
+            }
+        }
+        /* Advance row index for next row */
+        row_index = ( row_index + 1 ) & ODITHER_MASK;
+        cquantize->row_index = row_index;
+    }
+}
+
+
+METHODDEF void
+quantize3_ord_dither( j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+                      JSAMPARRAY output_buf, int num_rows ) {
+/* Fast path for out_color_components==3, with ordered dithering */
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    register int pixcode;
+    register JSAMPROW input_ptr;
+    register JSAMPROW output_ptr;
+    JSAMPROW colorindex0 = cquantize->colorindex[0];
+    JSAMPROW colorindex1 = cquantize->colorindex[1];
+    JSAMPROW colorindex2 = cquantize->colorindex[2];
+    int * dither0;      /* points to active row of dither matrix */
+    int * dither1;
+    int * dither2;
+    int row_index, col_index;/* current indexes into dither matrix */
+    int row;
+    JDIMENSION col;
+    JDIMENSION width = cinfo->output_width;
+
+    for ( row = 0; row < num_rows; row++ ) {
+        row_index = cquantize->row_index;
+        input_ptr = input_buf[row];
+        output_ptr = output_buf[row];
+        dither0 = cquantize->odither[0][row_index];
+        dither1 = cquantize->odither[1][row_index];
+        dither2 = cquantize->odither[2][row_index];
+        col_index = 0;
+
+        for ( col = width; col > 0; col-- ) {
+            pixcode  = GETJSAMPLE( colorindex0[GETJSAMPLE( *input_ptr++ ) +
+                                               dither0[col_index]] );
+            pixcode += GETJSAMPLE( colorindex1[GETJSAMPLE( *input_ptr++ ) +
+                                               dither1[col_index]] );
+            pixcode += GETJSAMPLE( colorindex2[GETJSAMPLE( *input_ptr++ ) +
+                                               dither2[col_index]] );
+            *output_ptr++ = (JSAMPLE) pixcode;
+            col_index = ( col_index + 1 ) & ODITHER_MASK;
+        }
+        row_index = ( row_index + 1 ) & ODITHER_MASK;
+        cquantize->row_index = row_index;
+    }
+}
+
+
+METHODDEF void
+quantize_fs_dither( j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+                    JSAMPARRAY output_buf, int num_rows ) {
+/* General case, with Floyd-Steinberg dithering */
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    register LOCFSERROR cur;/* current error or pixel value */
+    LOCFSERROR belowerr;    /* error for pixel below cur */
+    LOCFSERROR bpreverr;    /* error for below/prev col */
+    LOCFSERROR bnexterr;    /* error for below/next col */
+    LOCFSERROR delta;
+    register FSERRPTR errorptr; /* => fserrors[] at column before current */
+    register JSAMPROW input_ptr;
+    register JSAMPROW output_ptr;
+    JSAMPROW colorindex_ci;
+    JSAMPROW colormap_ci;
+    int pixcode;
+    int nc = cinfo->out_color_components;
+    int dir;        /* 1 for left-to-right, -1 for right-to-left */
+    int dirnc;          /* dir * nc */
+    int ci;
+    int row;
+    JDIMENSION col;
+    JDIMENSION width = cinfo->output_width;
+    JSAMPLE * range_limit = cinfo->sample_range_limit;
+    SHIFT_TEMPS
+
+    for ( row = 0; row < num_rows; row++ ) {
+        /* Initialize output values to 0 so can process components separately */
+        jzero_far( (void FAR *) output_buf[row],
+                  (size_t) ( width * SIZEOF( JSAMPLE ) ) );
+        for ( ci = 0; ci < nc; ci++ ) {
+            input_ptr = input_buf[row] + ci;
+            output_ptr = output_buf[row];
+            if ( cquantize->on_odd_row ) {
+                /* work right to left in this row */
+                input_ptr += ( width - 1 ) * nc;/* so point to rightmost pixel */
+                output_ptr += width - 1;
+                dir = -1;
+                dirnc = -nc;
+                errorptr = cquantize->fserrors[ci] + ( width + 1 );/* => entry after last column */
+            } else {
+                /* work left to right in this row */
+                dir = 1;
+                dirnc = nc;
+                errorptr = cquantize->fserrors[ci];/* => entry before first column */
+            }
+            colorindex_ci = cquantize->colorindex[ci];
+            colormap_ci = cquantize->sv_colormap[ci];
+            /* Preset error values: no error propagated to first pixel from left */
+            cur = 0;
+            /* and no error propagated to row below yet */
+            belowerr = bpreverr = 0;
+
+            for ( col = width; col > 0; col-- ) {
+                /* cur holds the error propagated from the previous pixel on the
+                 * current line.  Add the error propagated from the previous line
+                 * to form the complete error correction term for this pixel, and
+                 * round the error term (which is expressed * 16) to an integer.
+                 * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct
+                 * for either sign of the error value.
+                 * Note: errorptr points to *previous* column's array entry.
+                 */
+                cur = RIGHT_SHIFT( cur + errorptr[dir] + 8, 4 );
+                /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE.
+                 * The maximum error is +- MAXJSAMPLE; this sets the required size
+                 * of the range_limit array.
+                 */
+                cur += GETJSAMPLE( *input_ptr );
+                cur = GETJSAMPLE( range_limit[cur] );
+                /* Select output value, accumulate into output code for this pixel */
+                pixcode = GETJSAMPLE( colorindex_ci[cur] );
+                *output_ptr += (JSAMPLE) pixcode;
+                /* Compute actual representation error at this pixel */
+                /* Note: we can do this even though we don't have the final */
+                /* pixel code, because the colormap is orthogonal. */
+                cur -= GETJSAMPLE( colormap_ci[pixcode] );
+                /* Compute error fractions to be propagated to adjacent pixels.
+                 * Add these into the running sums, and simultaneously shift the
+                 * next-line error sums left by 1 column.
+                 */
+                bnexterr = cur;
+                delta = cur * 2;
+                cur += delta;/* form error * 3 */
+                errorptr[0] = (FSERROR) ( bpreverr + cur );
+                cur += delta;/* form error * 5 */
+                bpreverr = belowerr + cur;
+                belowerr = bnexterr;
+                cur += delta;/* form error * 7 */
+                /* At this point cur contains the 7/16 error value to be propagated
+                 * to the next pixel on the current line, and all the errors for the
+                 * next line have been shifted over. We are therefore ready to move on.
+                 */
+                input_ptr += dirnc;/* advance input ptr to next column */
+                output_ptr += dir;/* advance output ptr to next column */
+                errorptr += dir;/* advance errorptr to current column */
+            }
+            /* Post-loop cleanup: we must unload the final error value into the
+             * final fserrors[] entry.  Note we need not unload belowerr because
+             * it is for the dummy column before or after the actual array.
+             */
+            errorptr[0] = (FSERROR) bpreverr;/* unload prev err into array */
+        }
+        cquantize->on_odd_row = ( cquantize->on_odd_row ? FALSE : TRUE );
+    }
+}
+
+
+/*
+ * Allocate workspace for Floyd-Steinberg errors.
+ */
+
+LOCAL void
+alloc_fs_workspace( j_decompress_ptr cinfo ) {
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    size_t arraysize;
+    int i;
+
+    arraysize = (size_t) ( ( cinfo->output_width + 2 ) * SIZEOF( FSERROR ) );
+    for ( i = 0; i < cinfo->out_color_components; i++ ) {
+        cquantize->fserrors[i] = (FSERRPTR)
+                                 ( *cinfo->mem->alloc_large )( (j_common_ptr) cinfo, JPOOL_IMAGE, arraysize );
+    }
+}
+
+
+/*
+ * Initialize for one-pass color quantization.
+ */
+
+METHODDEF void
+start_pass_1_quant( j_decompress_ptr cinfo, boolean is_pre_scan ) {
+    my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+    size_t arraysize;
+    int i;
+
+    /* Install my colormap. */
+    cinfo->colormap = cquantize->sv_colormap;
+    cinfo->actual_number_of_colors = cquantize->sv_actual;
+
+    /* Initialize for desired dithering mode. */
+    switch ( cinfo->dither_mode ) {
+        case JDITHER_NONE:
+            if ( cinfo->out_color_components == 3 ) {
+                cquantize->pub.color_quantize = color_quantize3;
+            } else {
+                cquantize->pub.color_quantize = color_quantize;
+            }
+            break;
+        case JDITHER_ORDERED:
+            if ( cinfo->out_color_components == 3 ) {
+                cquantize->pub.color_quantize = quantize3_ord_dither;
+            } else {
+                cquantize->pub.color_quantize = quantize_ord_dither;
+            }
+            cquantize->row_index = 0;/* initialize state for ordered dither */
+            /* If user changed to ordered dither from another mode,
+             * we must recreate the color index table with padding.
+             * This will cost extra space, but probably isn't very likely.
+             */
+            if ( !cquantize->is_padded ) {
+                create_colorindex( cinfo );
+            }
+            /* Create ordered-dither tables if we didn't already. */
+            if ( cquantize->odither[0] == NULL ) {
+                create_odither_tables( cinfo );
+            }
+            break;
+        case JDITHER_FS:
+            cquantize->pub.color_quantize = quantize_fs_dither;
+            cquantize->on_odd_row = FALSE;/* initialize state for F-S dither */
+            /* Allocate Floyd-Steinberg workspace if didn't already. */
+            if ( cquantize->fserrors[0] == NULL ) {
+                alloc_fs_workspace( cinfo );
+            }
+            /* Initialize the propagated errors to zero. */
+            arraysize = (size_t) ( ( cinfo->output_width + 2 ) * SIZEOF( FSERROR ) );
+            for ( i = 0; i < cinfo->out_color_components; i++ ) {
+                jzero_far( (void FAR *) cquantize->fserrors[i], arraysize );
+            }
+            break;
+        default:
+            ERREXIT( cinfo, JERR_NOT_COMPILED );
+            break;
+    }
+}
+
+
+/*
+ * Finish up at the end of the pass.
+ */
+
+METHODDEF void
+finish_pass_1_quant( j_decompress_ptr cinfo ) {
+    /* no work in 1-pass case */
+}
+
+
+/*
+ * Switch to a new external colormap between output passes.
+ * Shouldn't get to this module!
+ */
+
+METHODDEF void
+new_color_map_1_quant( j_decompress_ptr cinfo ) {
+    ERREXIT( cinfo, JERR_MODE_CHANGE );
+}
+
+
+/*
+ * Module initialization routine for 1-pass color quantization.
+ */
+
+GLOBAL void
+jinit_1pass_quantizer( j_decompress_ptr cinfo ) {
+    my_cquantize_ptr cquantize;
+
+    cquantize = (my_cquantize_ptr)
+                ( *cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_IMAGE,
+                                             SIZEOF( my_cquantizer ) );
+    cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize;
+    cquantize->pub.start_pass = start_pass_1_quant;
+    cquantize->pub.finish_pass = finish_pass_1_quant;
+    cquantize->pub.new_color_map = new_color_map_1_quant;
+    cquantize->fserrors[0] = NULL;/* Flag FS workspace not allocated */
+    cquantize->odither[0] = NULL;/* Also flag odither arrays not allocated */
+
+    /* Make sure my internal arrays won't overflow */
+    if ( cinfo->out_color_components > MAX_Q_COMPS ) {
+        ERREXIT1( cinfo, JERR_QUANT_COMPONENTS, MAX_Q_COMPS );
+    }
+    /* Make sure colormap indexes can be represented by JSAMPLEs */
+    if ( cinfo->desired_number_of_colors > ( MAXJSAMPLE + 1 ) ) {
+        ERREXIT1( cinfo, JERR_QUANT_MANY_COLORS, MAXJSAMPLE + 1 );
+    }
+
+    /* Create the colormap and color index table. */
+    create_colormap( cinfo );
+    create_colorindex( cinfo );
+
+    /* Allocate Floyd-Steinberg workspace now if requested.
+     * We do this now since it is FAR storage and may affect the memory
+     * manager's space calculations.  If the user changes to FS dither
+     * mode in a later pass, we will allocate the space then, and will
+     * possibly overrun the max_memory_to_use setting.
+     */
+    if ( cinfo->dither_mode == JDITHER_FS ) {
+        alloc_fs_workspace( cinfo );
+    }
+}
+
+#endif /* QUANT_1PASS_SUPPORTED */

neo/renderer/jpeg-6/jutils.cpp

@@ -0,0 +1,171 @@
+/*
+ * jutils.c
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains tables and miscellaneous utility routines needed
+ * for both compression and decompression.
+ * Note we prefix all global names with "j" to minimize conflicts with
+ * a surrounding application.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * jpeg_zigzag_order[i] is the zigzag-order position of the i'th element
+ * of a DCT block read in natural order (left to right, top to bottom).
+ */
+
+const int jpeg_zigzag_order[DCTSIZE2] = {
+    0,  1,  5,  6, 14, 15, 27, 28,
+    2,  4,  7, 13, 16, 26, 29, 42,
+    3,  8, 12, 17, 25, 30, 41, 43,
+    9, 11, 18, 24, 31, 40, 44, 53,
+    10, 19, 23, 32, 39, 45, 52, 54,
+    20, 22, 33, 38, 46, 51, 55, 60,
+    21, 34, 37, 47, 50, 56, 59, 61,
+    35, 36, 48, 49, 57, 58, 62, 63
+};
+
+/*
+ * jpeg_natural_order[i] is the natural-order position of the i'th element
+ * of zigzag order.
+ *
+ * When reading corrupted data, the Huffman decoders could attempt
+ * to reference an entry beyond the end of this array (if the decoded
+ * zero run length reaches past the end of the block).  To prevent
+ * wild stores without adding an inner-loop test, we put some extra
+ * "63"s after the real entries.  This will cause the extra coefficient
+ * to be stored in location 63 of the block, not somewhere random.
+ * The worst case would be a run-length of 15, which means we need 16
+ * fake entries.
+ */
+
+const int jpeg_natural_order[DCTSIZE2 + 16] = {
+    0,  1,  8, 16,  9,  2,  3, 10,
+    17, 24, 32, 25, 18, 11,  4,  5,
+    12, 19, 26, 33, 40, 48, 41, 34,
+    27, 20, 13,  6,  7, 14, 21, 28,
+    35, 42, 49, 56, 57, 50, 43, 36,
+    29, 22, 15, 23, 30, 37, 44, 51,
+    58, 59, 52, 45, 38, 31, 39, 46,
+    53, 60, 61, 54, 47, 55, 62, 63,
+    63, 63, 63, 63, 63, 63, 63, 63,/* extra entries for safety in decoder */
+    63, 63, 63, 63, 63, 63, 63, 63
+};
+
+
+/*
+ * Arithmetic utilities
+ */
+
+GLOBAL long
+jdiv_round_up( long a, long b ) {
+/* Compute a/b rounded up to next integer, ie, ceil(a/b) */
+/* Assumes a >= 0, b > 0 */
+    return ( a + b - 1L ) / b;
+}
+
+
+GLOBAL long
+jround_up( long a, long b ) {
+/* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
+/* Assumes a >= 0, b > 0 */
+    a += b - 1L;
+    return a - ( a % b );
+}
+
+
+/* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
+ * and coefficient-block arrays.  This won't work on 80x86 because the arrays
+ * are FAR and we're assuming a small-pointer memory model.  However, some
+ * DOS compilers provide far-pointer versions of memcpy() and memset() even
+ * in the small-model libraries.  These will be used if USE_FMEM is defined.
+ * Otherwise, the routines below do it the hard way.  (The performance cost
+ * is not all that great, because these routines aren't very heavily used.)
+ */
+
+#ifndef NEED_FAR_POINTERS   /* normal case, same as regular macros */
+#define FMEMCOPY( dest, src, size ) MEMCOPY( dest, src, size )
+#define FMEMZERO( target, size )   MEMZERO( target, size )
+#else               /* 80x86 case, define if we can */
+#ifdef USE_FMEM
+#define FMEMCOPY( dest, src, size ) _fmemcpy( (void FAR *)( dest ), (const void FAR *)( src ), (size_t)( size ) )
+#define FMEMZERO( target, size )   _fmemset( (void FAR *)( target ), 0, (size_t)( size ) )
+#endif
+#endif
+
+
+GLOBAL void
+jcopy_sample_rows( JSAMPARRAY input_array, int source_row,
+                   JSAMPARRAY output_array, int dest_row,
+                   int num_rows, JDIMENSION num_cols ) {
+/* Copy some rows of samples from one place to another.
+ * num_rows rows are copied from input_array[source_row++]
+ * to output_array[dest_row++]; these areas may overlap for duplication.
+ * The source and destination arrays must be at least as wide as num_cols.
+ */
+    register JSAMPROW inptr, outptr;
+#ifdef FMEMCOPY
+    register size_t count = (size_t) ( num_cols * SIZEOF( JSAMPLE ) );
+#else
+    register JDIMENSION count;
+#endif
+    register int row;
+
+    input_array += source_row;
+    output_array += dest_row;
+
+    for ( row = num_rows; row > 0; row-- ) {
+        inptr = *input_array++;
+        outptr = *output_array++;
+#ifdef FMEMCOPY
+        FMEMCOPY( outptr, inptr, count );
+#else
+        for ( count = num_cols; count > 0; count-- ) {
+            *outptr++ = *inptr++;
+        }                   /* needn't bother with GETJSAMPLE() here */
+#endif
+    }
+}
+
+
+GLOBAL void
+jcopy_block_row( JBLOCKROW input_row, JBLOCKROW output_row,
+                 JDIMENSION num_blocks ) {
+/* Copy a row of coefficient blocks from one place to another. */
+#ifdef FMEMCOPY
+    FMEMCOPY( output_row, input_row, num_blocks * ( DCTSIZE2 * SIZEOF( JCOEF ) ) );
+#else
+    register JCOEFPTR inptr, outptr;
+    register long count;
+
+    inptr = (JCOEFPTR) input_row;
+    outptr = (JCOEFPTR) output_row;
+    for ( count = (long) num_blocks * DCTSIZE2; count > 0; count-- ) {
+        *outptr++ = *inptr++;
+    }
+#endif
+}
+
+
+GLOBAL void
+jzero_far( void FAR * target, size_t bytestozero ) {
+/* Zero out a chunk of FAR memory. */
+/* This might be sample-array data, block-array data, or alloc_large data. */
+#ifdef FMEMZERO
+    FMEMZERO( target, bytestozero );
+#else
+    register char FAR * ptr = (char FAR *) target;
+    register size_t count;
+
+    for ( count = bytestozero; count > 0; count-- ) {
+        *ptr++ = 0;
+    }
+#endif
+}

neo/renderer/jpeg-6/jversion.h

@@ -0,0 +1,14 @@
+/*
+ * jversion.h
+ *
+ * Copyright (C) 1991-1995, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains software version identification.
+ */
+
+
+#define JVERSION	"6  2-Aug-95"
+
+#define JCOPYRIGHT	"Copyright (C) 1995, Thomas G. Lane"