[FFmpeg-cvslog] cook: prevent div-by-zero if channels is zero.

[Ronald S. Bultje]

ffmpeg | branch: release/0.8 | Ronald S. Bultje <rsbultje at gmail.com> | Fri Feb 17 12:10:33 2012 -0800| [d031302e0ec6bfddb905f4827782f9e6e338cf9d] | committer: Reinhard Tartler

cook: prevent div-by-zero if channels is zero.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable at libav.org
(cherry picked from commit 941fc1ea1ed7f7d99a8b9e2607b41f2f2820394a)

Signed-off-by: Anton Khirnov <anton at khirnov.net>
Signed-off-by: Reinhard Tartler <siretart at tauware.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d031302e0ec6bfddb905f4827782f9e6e338cf9d
---

 libavcodec/cook.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/libavcodec/cook.c b/libavcodec/cook.c
index a8fa01e..429b4d0 100644
--- a/libavcodec/cook.c
+++ b/libavcodec/cook.c
@@ -1066,6 +1066,10 @@ static av_cold int cook_decode_init(AVCodecContext *avctx)
     q->sample_rate = avctx->sample_rate;
     q->nb_channels = avctx->channels;
     q->bit_rate = avctx->bit_rate;
+    if (!q->nb_channels) {
+        av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
+        return AVERROR_INVALIDDATA;
+    }
 
     /* Initialize RNG. */
     av_lfg_init(&q->random_state, 0);