From 17aed996bc35a020416e10075f1e6cc61b6cf805 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffmpeg@gmail.com>
Date: Sun, 23 Dec 2018 00:34:57 +0100
Subject: [PATCH] lavf/vividas: Do not increase extradata_size after
 allocation.

Avoids a crash in avcodec_parameters_from_context().
---
 libavformat/vividas.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/vividas.c b/libavformat/vividas.c
index e199b05d69..00a1a0f6ef 100644
--- a/libavformat/vividas.c
+++ b/libavformat/vividas.c
@@ -392,7 +392,8 @@ static void track_header(VividasDemuxContext *viv, AVFormatContext *s,  uint8_t
                 offset += data_len[j];
             }
 
-            st->codecpar->extradata_size = offset;
+            if (offset < st->codecpar->extradata_size)
+                st->codecpar->extradata_size = offset;
         }
     }