From b20c71409b24460983ba5d9afa0716714f9e0f7d Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 6 May 2017 12:10:59 +0200 Subject: [PATCH] avcodec/fic: Fix multiple left shift of negative value -15 Fixes: 1356/clusterfuzz-testcase-minimized-6008489086287872 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/fic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/fic.c b/libavcodec/fic.c index 2bec3d7b03..3805f70722 100644 --- a/libavcodec/fic.c +++ b/libavcodec/fic.c @@ -95,8 +95,8 @@ static av_always_inline void fic_idct(int16_t *blk, int step, int shift, int rnd const int t7 = t3 - t1; const int t8 = 17734 * blk[2 * step] - 42813 * blk[6 * step]; const int t9 = 17734 * blk[6 * step] + 42814 * blk[2 * step]; - const int tA = (blk[0 * step] - blk[4 * step] << 15) + rnd; - const int tB = (blk[0 * step] + blk[4 * step] << 15) + rnd; + const int tA = (blk[0 * step] - blk[4 * step]) * 32768 + rnd; + const int tB = (blk[0 * step] + blk[4 * step]) * 32768 + rnd; blk[0 * step] = ( t4 + t9 + tB) >> shift; blk[1 * step] = ( t6 + t7 + t8 + tA) >> shift; blk[2 * step] = ( t6 - t7 - t8 + tA) >> shift;