diff options
author | Michael Niedermayer <michaelni@gmx.at> | 2003-07-13 15:06:45 +0400 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2003-07-13 15:06:45 +0400 |
commit | d9e6a6c629c073e3432e76a320245ce3616b4f3f (patch) | |
tree | b0857112369a3d5e112f12c5fcfe427108df720d /libavcodec/golomb.h | |
parent | 25bd2349ed9f0ac8fce4d8233acb27c52f520d45 (diff) |
golomb rice code cleanup / simplify (~0.5% compression gain and slightly faster)
jpegls style golomb rice coder
Originally committed as revision 2040 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/golomb.h')
-rw-r--r-- | libavcodec/golomb.h | 90 |
1 files changed, 76 insertions, 14 deletions
diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h index 9861b18d1a..7c73f3bae6 100644 --- a/libavcodec/golomb.h +++ b/libavcodec/golomb.h @@ -179,7 +179,7 @@ static inline int svq3_get_se_golomb(GetBitContext *gb){ } /** - * read unsigned golomb rice code. + * read unsigned golomb rice code (ffv1). */ static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){ unsigned int buf; @@ -190,7 +190,7 @@ static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len buf=GET_CACHE(re, gb); log= av_log2(buf); -//printf("buf:%X log:%d\n", buf, log); + if(log > 31-limit){ buf >>= log - k; buf += (30-log)<<k; @@ -198,15 +198,62 @@ static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len CLOSE_READER(re, gb); return buf; - }else if(log == 31-limit){ - buf >>= log - esc_len; - buf -= 1<<esc_len; - LAST_SKIP_BITS(re, gb, esc_len + limit + 1); + }else{ + buf >>= 32 - limit - esc_len; + LAST_SKIP_BITS(re, gb, esc_len + limit); CLOSE_READER(re, gb); - return buf + 1; - }else - return -1; + return buf + limit - 1; + } +} + +/** + * read unsigned golomb rice code (jpegls). + */ +static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){ + unsigned int buf; + int log; + + OPEN_READER(re, gb); + UPDATE_CACHE(re, gb); + buf=GET_CACHE(re, gb); + + log= av_log2(buf); + + if(log > 31-12){ + buf >>= log - k; + buf += (30-log)<<k; + LAST_SKIP_BITS(re, gb, 32 + k - log); + CLOSE_READER(re, gb); + + return buf; + }else{ + int i; + for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){ + LAST_SKIP_BITS(re, gb, 1); + UPDATE_CACHE(re, gb); + } + SKIP_BITS(re, gb, 1); + + if(i < limit - 1){ + if(k){ + buf = SHOW_UBITS(re, gb, k); + LAST_SKIP_BITS(re, gb, k); + }else{ + buf=0; + } + + CLOSE_READER(re, gb); + return buf + (i<<k); + }else if(i == limit - 1){ + buf = SHOW_UBITS(re, gb, esc_len); + LAST_SKIP_BITS(re, gb, esc_len); + CLOSE_READER(re, gb); + + return buf + 1; + }else + return -1; + } } #ifdef TRACE @@ -312,7 +359,7 @@ static inline void set_se_golomb(PutBitContext *pb, int i){ } /** - * write unsigned golomb rice code. + * write unsigned golomb rice code (ffv1). */ static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){ int e; @@ -323,9 +370,24 @@ static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int if(e<limit){ put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1))); }else{ -// printf("set %08X, %d\n", (1<<esc_len) + i - 1, limit + esc_len + 1); - put_bits(pb, limit + esc_len + 1, (1<<esc_len) + i - 1); -// put_bits(pb, 1, limit + 1); -// put_bits(pb, i - 1, esc_len); + put_bits(pb, limit + esc_len, i - limit + 1); + } +} + +/** + * write unsigned golomb rice code (jpegls). + */ +static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){ + int e; + + assert(i>=0); + + e= (i>>k) + 1; + if(e<limit){ + put_bits(pb, e, 1); + put_bits(pb, k, i&((1<<k)-1)); + }else{ + put_bits(pb, limit , 1); + put_bits(pb, esc_len, i - 1); } } |