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CnC_Remastered_Collection/code/external/libsmacker/smk_hufftree.h
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2020-06-12 08:15:26 -07:00

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2.8 KiB
C

/*
libsmacker - A C library for decoding .smk Smacker Video files
Copyright (C) 2012-2013 Greg Kennedy
See smacker.h for more information.
smk_hufftree.h
SMK huffmann trees. There are two types:
- a basic 8-bit tree, and
- a "big" 16-bit tree which includes a cache for recently
searched values.
*/
#ifndef SMK_HUFFTREE_H
#define SMK_HUFFTREE_H
#include "smk_bitstream.h"
/*
Tree node structure.
If b0 is non-null, this is a branch, and b1 from the union should be used.
If b0 is null, this is a leaf, and val / escape code from union should be used.
*/
struct smk_huff_t
{
struct smk_huff_t *b0;
union
{
struct smk_huff_t *b1;
struct
{
unsigned short value;
unsigned char escapecode;
} leaf;
} u;
};
/*
"Big"tree struct: holds a huff_t structure,
as well as a cache of three 16-bit values.
*/
struct smk_huff_big_t
{
struct smk_huff_t *t;
unsigned short cache[3];
};
/* function to recursively delete a huffman tree */
void smk_huff_free(struct smk_huff_t *);
/* This macro interrogates return code from smk_huff_lookup and
jumps to error label if problems occur. */
#define smk_huff_safe_build(bs,t) \
{ \
if (!(t = smk_huff_build(bs))) \
{ \
fprintf(stderr,"libsmacker::smk_huff_safe_build(" #bs "," #t ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
goto error; \
} \
}
/* Build a tree from a bitstream */
struct smk_huff_t *smk_huff_build(struct smk_bit_t *);
/* This macro interrogates return code from smk_huff_lookup and
jumps to error label if problems occur. */
#define smk_huff_safe_lookup(bs,t,s) \
{ \
if ((short)(s = smk_huff_lookup(bs,t)) < 0) \
{ \
fprintf(stderr,"libsmacker::smk_huff_safe_lookup(" #bs "," #t "," #s ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
goto error; \
} \
}
/* Look up an 8-bit value in the referenced tree by following a bitstream
returns -1 on error */
short smk_huff_lookup (struct smk_bit_t *, const struct smk_huff_t *);
#define smk_huff_big_safe_build(bs,t) \
{ \
if (!(t = smk_huff_big_build(bs))) \
{ \
fprintf(stderr,"libsmacker::smk_huff_big_safe_build(" #bs "," #t ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
goto error; \
} \
}
/* Build a bigtree from a bitstream */
struct smk_huff_big_t *smk_huff_big_build(struct smk_bit_t *);
#define smk_huff_big_safe_lookup(bs,t,s) \
{ \
if ((s = smk_huff_big_lookup(bs,t)) < 0) \
{ \
fprintf(stderr,"libsmacker::smk_huff_big_safe_lookup(" #bs "," #t "," #s ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
goto error; \
} \
}
/* Look up a 16-bit value in the bigtree by following a bitstream
returns -1 on error */
long smk_huff_big_lookup (struct smk_bit_t *, struct smk_huff_big_t *);
/* Reset the cache in a bigtree */
void smk_huff_big_reset (struct smk_huff_big_t *);
#endif