[FFmpeg-cvslog] avcodec/aacdec_fixed: Fix runtime error: left shift of 1 by 31 places cannot be represented in type 'int'

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Sun May 28 18:09:47 2017 +0200| [228093ec9368dba09a33c1a3f15b5966b1d871e7] | committer: Michael Niedermayer

avcodec/aacdec_fixed: Fix runtime error: left shift of 1 by 31 places cannot be represented in type 'int'

Fixes: 1878/clusterfuzz-testcase-minimized-6441918630199296

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 6b9cb5d26a2d9905093621d12785bc5903dce66d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=228093ec9368dba09a33c1a3f15b5966b1d871e7
---

 libavcodec/aacdec_fixed.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/aacdec_fixed.c b/libavcodec/aacdec_fixed.c
index b78a27a236..7945c46355 100644
--- a/libavcodec/aacdec_fixed.c
+++ b/libavcodec/aacdec_fixed.c
@@ -211,8 +211,8 @@ static void noise_scale(int *coefs, int scale, int band_energy, int len)
         for (i=0; i<len; i++) {
             coefs[i] = 0;
         }
-    } else if (s > 0) {
-        round = 1 << (s-1);
+    } else if (s >= 0) {
+        round = s ? 1 << (s-1) : 0;
         for (i=0; i<len; i++) {
             out = (int)(((int64_t)coefs[i] * c) >> 32);
             coefs[i] = ((int)(out+round) >> s) * ssign;