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authorMichael Niedermayer <michael@niedermayer.cc>2019-07-10 23:27:19 +0200
committerMichael Niedermayer <michael@niedermayer.cc>2020-07-01 12:11:55 +0200
commita2a8b9470a912d6bb852d0eb6e3fc370eac82f07 (patch)
tree5c55d86e363d56c03175a5bc8ec47d76b5b8c9e3
parent4ef3aafa835442a7499c4c455fcc9255aaa98a53 (diff)
downloadffmpeg-a2a8b9470a912d6bb852d0eb6e3fc370eac82f07.tar.gz
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> (cherry picked from commit 6dfda35dd29d2e2a86554d2c05d957a09ab79b0c) Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
-rw-r--r--libavcodec/vc1_pred.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/libavcodec/vc1_pred.c b/libavcodec/vc1_pred.c
index 54712f6b7a..aa8e402af9 100644
--- a/libavcodec/vc1_pred.c
+++ b/libavcodec/vc1_pred.c
@@ -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;
}