[FFmpeg-cvslog] avcodec/ffv1dec_template: Fix undefined shift

[Michael Niedermayer]

ffmpeg | branch: release/3.2 | Michael Niedermayer <michael at niedermayer.cc> | Fri Aug 11 18:20:03 2017 +0200| [04db307c77c18b6e1832a086f676db0db9c152a7] | committer: Michael Niedermayer

avcodec/ffv1dec_template: Fix undefined shift

Fixes: runtime error: left shift of negative value -127
Fixes: 2834/clusterfuzz-testcase-minimized-5988039123795968

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 62702eebded6c6341d214405812a981f80e46ea2)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=04db307c77c18b6e1832a086f676db0db9c152a7
---

 libavcodec/ffv1dec_template.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/ffv1dec_template.c b/libavcodec/ffv1dec_template.c
index 892ccf22fa..f2f7432339 100644
--- a/libavcodec/ffv1dec_template.c
+++ b/libavcodec/ffv1dec_template.c
@@ -149,7 +149,7 @@ static void RENAME(decode_rgb_frame)(FFV1Context *s, uint8_t *src[3], int w, int
             }
 
             if (lbd)
-                *((uint32_t*)(src[0] + x*4 + stride[0]*y)) = b + (g<<8) + (r<<16) + (a<<24);
+                *((uint32_t*)(src[0] + x*4 + stride[0]*y)) = b + ((unsigned)g<<8) + ((unsigned)r<<16) + ((unsigned)a<<24);
             else if (sizeof(TYPE) == 4) {
                 *((uint16_t*)(src[0] + x*2 + stride[0]*y)) = g;
                 *((uint16_t*)(src[1] + x*2 + stride[1]*y)) = b;