From 4976a3411f71518d17a57e373b62517f066648fd Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 24 Jun 2017 13:45:35 +0200 Subject: [PATCH] avcodec/mpeg4videodec: Fix GMC with videos of dimension 1 Fixes: runtime error: shift exponent -1 is negative Fixes: 2338/clusterfuzz-testcase-minimized-5153426541379584 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/mpeg4videodec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index d2f22dd372..89c4b367f7 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -171,7 +171,7 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g int a = 2 << s->sprite_warping_accuracy; int rho = 3 - s->sprite_warping_accuracy; int r = 16 / a; - int alpha = 0; + int alpha = 1; int beta = 0; int w = s->width; int h = s->height;