From 27c729a21f4255c86f6d28c5c7e67938ba35f656 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sun, 11 Jun 2017 14:34:54 +0200
Subject: [PATCH] avcodec/snowdec: Fix runtime error: left shift of negative
 value -1

Fixes: 2197/clusterfuzz-testcase-minimized-6010716676947968

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 2e44126363bc9e23093ceced5d7bde1ee4bbb338)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/snowdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c
index c5ea897aa6..129c4a2f13 100644
--- a/libavcodec/snowdec.c
+++ b/libavcodec/snowdec.c
@@ -553,7 +553,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                 for(; yq<slice_h && yq<h; yq++){
                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
                     for(x=0; x<w; x++){
-                        line[x] <<= FRAC_BITS;
+                        line[x] *= 1<<FRAC_BITS;
                     }
                 }
             }