From 9959a52b14bcfa3e5baeb3fc8a86c04bbc0d3d5d Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Sun, 16 Oct 2016 22:39:47 +0200
Subject: [PATCH] astdec: fix division by zero

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
---
 libavformat/astdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/astdec.c b/libavformat/astdec.c
index f3ca721ccf..7a53d0bb70 100644
--- a/libavformat/astdec.c
+++ b/libavformat/astdec.c
@@ -90,7 +90,7 @@ static int ast_read_packet(AVFormatContext *s, AVPacket *pkt)
     pos  = avio_tell(s->pb);
     type = avio_rl32(s->pb);
     size = avio_rb32(s->pb);
-    if (size > INT_MAX / s->streams[0]->codecpar->channels)
+    if (!s->streams[0]->codecpar->channels || size > INT_MAX / s->streams[0]->codecpar->channels)
         return AVERROR_INVALIDDATA;
 
     size *= s->streams[0]->codecpar->channels;