avcodec/mdec: Fix runtime error: left shift of negative value -127

Fixes undefined behavior
Fixes: 1275/clusterfuzz-testcase-minimized-6718162017976320

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 2017-04-27 02:27:16 +02:00
parent 966cbfbc83
commit 6ca82975b7

View File

@ -73,7 +73,7 @@ static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
if (diff >= 0xffff)
return AVERROR_INVALIDDATA;
a->last_dc[component] += diff;
block[0] = a->last_dc[component] << 3;
block[0] = a->last_dc[component] * (1 << 3);
}
i = 0;