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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-05-23 01:06:58 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-05-27 19:01:38 +0200 |
| commit | e6f4d5dc384af334a5c7b61969db9d7d9c1b7e0a (patch) | |
| tree | cd0388b186a20cb715e32f3cf3cf49553c87e298 | |
| parent | 5ddaedcaec39162972b26487e68b75cd37804075 (diff) | |
| download | ffmpeg-e6f4d5dc384af334a5c7b61969db9d7d9c1b7e0a.tar.gz | |
avcodec/ffv1dec_template: Optimize common case in run mode
Fixes: Timeout (14sec -> 9sec)
Fixes: 13398/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFV1_fuzzer-5664106709778432
decode_line() becomes 1% faster for fate/vsynth2-ffv1.avi
for another fate sample there is a 0.5% speedup
the effect should be bigger for files with "flat" colored areas
the new faster branch is used in 97-100% of the cases in fate samples
compared to the older more complex (which i tested)
vsynth3-ffv1-v3-bgr0.avi had the lowest percentual useage of about 97%
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/ffv1dec_template.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/libavcodec/ffv1dec_template.c b/libavcodec/ffv1dec_template.c index 1b7f6c4bf5..0b1d176ba1 100644 --- a/libavcodec/ffv1dec_template.c +++ b/libavcodec/ffv1dec_template.c @@ -86,11 +86,19 @@ static av_always_inline int RENAME(decode_line)(FFV1Context *s, int w, run_mode = 2; } } + if (sample[1][x - 1] == sample[0][x - 1]) { + while (run_count > 1 && w-x > 1) { + sample[1][x] = sample[0][x]; + x++; + run_count--; + } + } else { while (run_count > 1 && w-x > 1) { sample[1][x] = RENAME(predict)(sample[1] + x, sample[0] + x); x++; run_count--; } + } run_count--; if (run_count < 0) { run_mode = 0; |