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ffmpeg
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avcodec/wmv2dec: Skip I frame if its smaller than 1/8 of the minimal size 

Frames that small are not valid and of limited use for error concealment, while
being very computationally intensive to process.

Fixes: Timeout
Fixes: 11168/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMV2_fuzzer-5733782032744448

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2018-11-27 23:37:03 +01:00
parent 09ec182864
commit d6f4341522
1 changed files with 8 additions and 0 deletions
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8
libavcodec/wmv2dec.c
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@ -181,6 +181,14 @@ int ff_wmv2_decode_secondary_picture_header(MpegEncContext *s)
}
s->dc_table_index = get_bits1(&s->gb);
// at minimum one bit per macroblock is required at least in a valid frame,
// we discard frames much smaller than this. Frames smaller than 1/8 of the
// smallest "black/skip" frame generally contain not much recoverable content
// while at the same time they have the highest computational requirements
// per byte
if (get_bits_left(&s->gb) * 8LL < (s->width+15)/16 * ((s->height+15)/16))
return AVERROR_INVALIDDATA;
}
s->inter_intra_pred = 0;
s->no_rounding = 1;