From 0cb19c30c6a14418eaa6858db303602815fe3ab1 Mon Sep 17 00:00:00 2001
From: Nicolas George <george@nsup.org>
Date: Mon, 25 Apr 2016 13:46:10 +0200
Subject: [PATCH] lavf/concatdec: clear extradata when inserting
 h264_mp4toannexb bsf.

Fix remuxing H.264-in-MP4 to Matroska, possibly others.
---
 libavformat/concatdec.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavformat/concatdec.c b/libavformat/concatdec.c
index b2bab55f70..b3a430e5a0 100644
--- a/libavformat/concatdec.c
+++ b/libavformat/concatdec.c
@@ -214,6 +214,12 @@ static int detect_stream_specific(AVFormatContext *avf, int idx)
         if (!cs->avctx)
             return AVERROR(ENOMEM);
 
+        /* This really should be part of the bsf work.
+           Note: input bitstream filtering will not work with bsf that
+           create extradata from the first packet. */
+        av_freep(&st->codecpar->extradata);
+        st->codecpar->extradata_size = 0;
+
         ret = avcodec_parameters_to_context(cs->avctx, st->codecpar);
         if (ret < 0) {
             avcodec_free_context(&cs->avctx);