X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=bitstream.h;fp=bitstream.h;h=df2c0b8bbb912ead15c5c6a9b4a2e019155f872d;hp=fe85aba7475684168d13b0f3614c93953f7d957e;hb=a7722850be9f23daf1e095bc9527ba24faa9719b;hpb=18651668774f785d38189eee9d8389fe69428380 diff --git a/bitstream.h b/bitstream.h index fe85aba7..df2c0b8b 100644 --- a/bitstream.h +++ b/bitstream.h @@ -152,38 +152,41 @@ void init_vlc(struct vlc *vlc, int nb_bits, int nb_codes, const void *bits, void free_vlc(struct vlc *vlc); /** + * Parse a vlc code. * - * if the vlc code is invalid and max_depth=1 than no bits will be removed - * if the vlc code is invalid and max_depth>1 than the number of bits removed - * is undefined + * \param bits The number of bits which will be read at once, must be + * identical to nb_bits in init_vlc() + * + * \param max_depth The number of times bits bits must be read to completely + * read the longest vlc code = (max_vlc_length + bits - 1) / bits. */ -#define GET_VLC(code, gb, table, bits, max_depth)\ -{\ - int n, index, nb_bits;\ -\ - index= SHOW_UBITS(re, gb, bits);\ - code = table[index][0];\ - n = table[index][1];\ -\ - if(max_depth > 1 && n < 0){\ - LAST_SKIP_BITS(re, gb, bits)\ - UPDATE_CACHE(re, gb)\ -\ - nb_bits = -n;\ -\ - index= SHOW_UBITS(re, gb, nb_bits) + code;\ - code = table[index][0];\ - n = table[index][1];\ - if(max_depth > 2 && n < 0){\ - LAST_SKIP_BITS(re, gb, nb_bits)\ - UPDATE_CACHE(re, gb)\ -\ - nb_bits = -n;\ -\ - index= SHOW_UBITS(re, gb, nb_bits) + code;\ - code = table[index][0];\ - n = table[index][1];\ - }\ - }\ - SKIP_BITS(re, gb, n)\ +static inline int get_vlc(struct getbit_context *gb, VLC_TYPE(*table)[2], + int bits, int max_depth) +{ + int n, idx, nb_bits, code; + + OPEN_READER(re, gb) + UPDATE_CACHE(re, gb) + idx = SHOW_UBITS(re, gb, bits); + code = table[idx][0]; + n = table[idx][1]; + if (max_depth > 1 && n < 0) { + LAST_SKIP_BITS(re, gb, bits) + UPDATE_CACHE(re, gb) + nb_bits = -n; + idx = SHOW_UBITS(re, gb, nb_bits) + code; + code = table[idx][0]; + n = table[idx][1]; + if (max_depth > 2 && n < 0) { + LAST_SKIP_BITS(re, gb, nb_bits) + UPDATE_CACHE(re, gb) + nb_bits = -n; + idx = SHOW_UBITS(re, gb, nb_bits) + code; + code = table[idx][0]; + n = table[idx][1]; + } + } + SKIP_BITS(re, gb, n) + CLOSE_READER(re, gb) + return code; }