[FFmpeg-cvslog] avcodec/amrwbdec: Fix division by 0 in voice_factor()

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Thu Dec  7 15:32:54 2017 +0100| [3d297038a9ab1f518890491765a4771221a7b0cb] | committer: Michael Niedermayer

avcodec/amrwbdec: Fix division by 0 in voice_factor()

The added value matches "Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Extended Adaptive Multi-Rate - Wideband (AMR-WB+) codec; Floating-point ANSI-C code (3GPP TS 26.304 version 14.0.0 Release 14)
Extended Adaptive Multi-Rate - Wideband (AMR-WB+) codec; Floating-point ANSI-C code"

Fixes: runtime error: division by zero
Fixes: 4415/clusterfuzz-testcase-minimized-4677752314658816

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 1d0817d56b66797118880358ea7d7a2acfdca429)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3d297038a9ab1f518890491765a4771221a7b0cb
---

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

diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c
index 57aed874cc..7f2874d35f 100644
--- a/libavcodec/amrwbdec.c
+++ b/libavcodec/amrwbdec.c
@@ -611,7 +611,7 @@ static float voice_factor(float *p_vector, float p_gain,
                                                           AMRWB_SFR_SIZE) *
                     f_gain * f_gain;
 
-    return (p_ener - f_ener) / (p_ener + f_ener);
+    return (p_ener - f_ener) / (p_ener + f_ener + 0.01);
 }
 
 /**