avcodec/vc1_pred: Fix invalid shift in scaleforsame()

Fixes: left shift of negative value -1
Fixes: 15531/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1IMAGE_fuzzer-5759556258365440

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 2019-07-10 23:27:19 +02:00
parent f31ed8f3b0
commit 6dfda35dd2
1 changed files with 1 additions and 1 deletions

View File

@ -178,7 +178,7 @@ static av_always_inline int scaleforsame(VC1Context *v, int i, int n /* MV */,
brfd = FFMIN(v->brfd, 3);
scalesame = ff_vc1_b_field_mvpred_scales[0][brfd];
n = (n * scalesame >> 8) << hpel;
n = (n * scalesame >> 8) * (1 << hpel);
return n;
}