diff options
author | Michael Niedermayer | 2003-04-04 14:42:28 +0000 |
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committer | Michael Niedermayer | 2003-04-04 14:42:28 +0000 |
commit | 0da71265d84b587c7159cd82708ca60ad050dd4c (patch) | |
tree | fc97766fbbea1ab3af9df1aa9e4f37f8b0aca02d /libavcodec/golomb.h | |
parent | 6aafe463e5d1483b95ad259334c45d2741c92fb2 (diff) |
H264 decoder & demuxer
Originally committed as revision 1732 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/golomb.h')
-rw-r--r-- | libavcodec/golomb.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h new file mode 100644 index 0000000000..552c01730e --- /dev/null +++ b/libavcodec/golomb.h @@ -0,0 +1,215 @@ +/* + * exp golomb vlc stuff + * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/** + * @file golomb.h + * @brief + * exp golomb vlc stuff + * @author Michael Niedermayer <michaelni@gmx.at> + */ + +extern const uint8_t ff_golomb_vlc_len[512]; +extern const uint8_t ff_ue_golomb_vlc_code[512]; +extern const int8_t ff_se_golomb_vlc_code[512]; +extern const uint8_t ff_ue_golomb_len[256]; + + + /** + * read unsigned exp golomb code. + */ +static inline int get_ue_golomb(GetBitContext *gb){ + unsigned int buf; + int log; + + OPEN_READER(re, gb); + UPDATE_CACHE(re, gb); + buf=GET_CACHE(re, gb); + + if(buf >= (1<<27)){ + buf >>= 32 - 9; + LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]); + CLOSE_READER(re, gb); + + return ff_ue_golomb_vlc_code[buf]; + }else{ + log= 2*av_log2(buf) - 31; + buf>>= log; + buf--; + LAST_SKIP_BITS(re, gb, 32 - log); + CLOSE_READER(re, gb); + + return buf; + } +} + +/** + * read unsigned truncated exp golomb code. + */ +static inline int get_te0_golomb(GetBitContext *gb, int range){ + assert(range >= 1); + + if(range==1) return 0; + else if(range==2) return get_bits1(gb); + else return get_ue_golomb(gb); +} + +/** + * read unsigned truncated exp golomb code. + */ +static inline int get_te_golomb(GetBitContext *gb, int range){ + assert(range >= 1); + + if(range==2) return get_bits1(gb); + else return get_ue_golomb(gb); +} + + +/** + * read signed exp golomb code. + */ +static inline int get_se_golomb(GetBitContext *gb){ + unsigned int buf; + int log; + + OPEN_READER(re, gb); + UPDATE_CACHE(re, gb); + buf=GET_CACHE(re, gb); + + if(buf >= (1<<27)){ + buf >>= 32 - 9; + LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]); + CLOSE_READER(re, gb); + + return ff_se_golomb_vlc_code[buf]; + }else{ + log= 2*av_log2(buf) - 31; + buf>>= log; + + LAST_SKIP_BITS(re, gb, 32 - log); + CLOSE_READER(re, gb); + + if(buf&1) buf= -(buf>>1); + else buf= (buf>>1); + + return buf; + } +} + +#ifdef TRACE + +static inline int get_ue(GetBitContext *s, char *file, char *func, int line){ + int show= show_bits(s, 24); + int pos= get_bits_count(s); + int i= get_ue_golomb(s); + int len= get_bits_count(s) - pos; + int bits= show>>(24-len); + + print_bin(bits, len); + + printf("%5d %2d %3d ue @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); + + return i; +} + +static inline int get_se(GetBitContext *s, char *file, char *func, int line){ + int show= show_bits(s, 24); + int pos= get_bits_count(s); + int i= get_se_golomb(s); + int len= get_bits_count(s) - pos; + int bits= show>>(24-len); + + print_bin(bits, len); + + printf("%5d %2d %3d se @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); + + return i; +} + +static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){ + int show= show_bits(s, 24); + int pos= get_bits_count(s); + int i= get_te0_golomb(s, r); + int len= get_bits_count(s) - pos; + int bits= show>>(24-len); + + print_bin(bits, len); + + printf("%5d %2d %3d te @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); + + return i; +} + +#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__) +#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__) +#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__) +#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__) + +#endif + +/** + * write unsigned exp golomb code. + */ +static inline void set_ue_golomb(PutBitContext *pb, int i){ + int e; + + assert(i>=0); + +#if 0 + if(i=0){ + put_bits(pb, 1, 1); + return; + } +#endif + if(i<256) + put_bits(pb, ff_ue_golomb_len[i], i+1); + else{ + e= av_log2(i+1); + + put_bits(pb, 2*e+1, i+1); + } +} + +/** + * write truncated unsigned exp golomb code. + */ +static inline void set_te_golomb(PutBitContext *pb, int i, int range){ + assert(range >= 1); + assert(i<=range); + + if(range==2) put_bits(pb, 1, i); + else set_ue_golomb(pb, i); +} + +/** + * write signed exp golomb code. + */ +static inline void set_se_golomb(PutBitContext *pb, int i){ +#if 0 + if(i<=0) i= -2*i; + else i= 2*i-1; +#elif 1 + i= 2*i-1; + if(i<0) i^= -1; //FIXME check if gcc does the right thing +#else + i= 2*i-1; + i^= (i>>31); +#endif + set_ue_golomb(pb, i); +} |