diff options
author | Jason Garrett-Glaser <darkshikari@gmail.com> | 2010-08-07 16:30:44 +0400 |
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committer | Jason Garrett-Glaser <darkshikari@gmail.com> | 2010-08-07 16:30:44 +0400 |
commit | b70c95e05a9a344e06fc4db896217ee372913d39 (patch) | |
tree | 82f0c456831081bb88f8b280283c89034888f631 /libavcodec/h264_cavlc.c | |
parent | 91af5601c14908c3d23d881c4cd2b725d5ad2bde (diff) |
H.264: 8% faster CAVLC zero-run decoding
Originally committed as revision 24736 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/h264_cavlc.c')
-rw-r--r-- | libavcodec/h264_cavlc.c | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c index 0475e9454a..6f3bcad782 100644 --- a/libavcodec/h264_cavlc.c +++ b/libavcodec/h264_cavlc.c @@ -367,7 +367,7 @@ static int decode_residual(H264Context *h, GetBitContext *gb, DCTELEM *block, in MpegEncContext * const s = &h->s; static const int coeff_token_table_index[17]= {0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3}; int level[16]; - int zeros_left, coeff_num, coeff_token, total_coeff, i, j, trailing_ones, run_before; + int zeros_left, coeff_token, total_coeff, i, trailing_ones, run_before; //FIXME put trailing_onex into the context @@ -488,39 +488,36 @@ static int decode_residual(H264Context *h, GetBitContext *gb, DCTELEM *block, in zeros_left= get_vlc2(gb, (total_zeros_vlc-1)[ total_coeff ].table, TOTAL_ZEROS_VLC_BITS, 1); } - coeff_num = zeros_left + total_coeff - 1; - j = scantable[coeff_num]; + scantable += zeros_left + total_coeff - 1; if(n > 24){ - block[j] = level[0]; - for(i=1;i<total_coeff;i++) { - if(zeros_left <= 0) - run_before = 0; - else if(zeros_left < 7){ + block[*scantable] = level[0]; + for(i=1;i<total_coeff && zeros_left > 0;i++) { + if(zeros_left < 7) run_before= get_vlc2(gb, (run_vlc-1)[zeros_left].table, RUN_VLC_BITS, 1); - }else{ + else run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2); - } zeros_left -= run_before; - coeff_num -= 1 + run_before; - j= scantable[ coeff_num ]; - - block[j]= level[i]; + scantable -= 1 + run_before; + block[*scantable]= level[i]; + } + for(;i<total_coeff;i++) { + scantable--; + block[*scantable]= level[i]; } }else{ - block[j] = (level[0] * qmul[j] + 32)>>6; - for(i=1;i<total_coeff;i++) { - if(zeros_left <= 0) - run_before = 0; - else if(zeros_left < 7){ + block[*scantable] = (level[0] * qmul[*scantable] + 32)>>6; + for(i=1;i<total_coeff && zeros_left > 0;i++) { + if(zeros_left < 7) run_before= get_vlc2(gb, (run_vlc-1)[zeros_left].table, RUN_VLC_BITS, 1); - }else{ + else run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2); - } zeros_left -= run_before; - coeff_num -= 1 + run_before; - j= scantable[ coeff_num ]; - - block[j]= (level[i] * qmul[j] + 32)>>6; + scantable -= 1 + run_before; + block[*scantable]= (level[i] * qmul[*scantable] + 32)>>6; + } + for(;i<total_coeff;i++) { + scantable--; + block[*scantable]= (level[i] * qmul[*scantable] + 32)>>6; } } |