avcodec/mpeg12dec: Fix runtime error: left shift of negative value

Fixes: 608/clusterfuzz-testcase-603978286392934

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-02-19 18:47:13 +01:00
parent a9f3e4b138
commit 706757d26d

View File

@ -865,8 +865,8 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
s->last_mv[i][0][1]);
/* full_pel: only for MPEG-1 */
if (s->full_pel[i]) {
s->mv[i][0][0] <<= 1;
s->mv[i][0][1] <<= 1;
s->mv[i][0][0] *= 2;
s->mv[i][0][1] *= 2;
}
}
}