Restructuring of code

code/external/libsmacker/smk_bitstream.h

@@ -0,0 +1,63 @@
+/*
+	libsmacker - A C library for decoding .smk Smacker Video files
+	Copyright (C) 2012-2013 Greg Kennedy
+
+	See smacker.h for more information.
+
+	smk_bitstream.h
+		SMK bitstream structure. Presents a block of raw bytes one
+		bit at a time, and protects against over-read.
+*/
+
+#ifndef SMK_BITSTREAM_H
+#define SMK_BITSTREAM_H
+
+/*
+	Bitstream structure
+	Pointer to raw block of data and a size limit.
+	Maintains internal pointers to byte_num and bit_number.
+*/
+struct smk_bit_t
+{
+	unsigned char *bitstream;
+	unsigned long size;
+
+	unsigned long byte_num;
+	char bit_num;
+};
+
+/* BITSTREAM Functions */
+/* Initialize a bitstream */
+struct smk_bit_t *smk_bs_init(unsigned char *, const unsigned long);
+
+/* Align the bitstream to next-byte boundary. */
+/* As it turns out, this isn't needed. */
+/* void smk_bs_align(struct smk_bit_t *); */
+
+/* This macro interrogates return code from bs_read_1 and
+	jumps to error label if problems occur. */
+#define smk_bs_safe_read_1(t,uc) \
+{ \
+	if ((char)(uc = smk_bs_read_1(t)) < 0) \
+	{ \
+		fprintf(stderr,"libsmacker::smk_bs_safe_read_1(" #t "," #uc ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
+		goto error; \
+	} \
+}
+/* Read a single bit from the bitstream, and advance.
+	Returns -1 on error. */
+char smk_bs_read_1(struct smk_bit_t *);
+
+#define smk_bs_safe_read_8(t,s) \
+{ \
+	if ((short)(s = smk_bs_read_8(t)) < 0) \
+	{ \
+		fprintf(stderr,"libsmacker::smk_bs_safe_read_8(" #t "," #s ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
+		goto error; \
+	} \
+}
+/* Read eight bits from the bitstream (one byte), and advance.
+	Returns -1 on error. */
+short smk_bs_read_8(struct smk_bit_t *);
+
+#endif