From 2cf6afffe54f32ea76aabe758049b574b5a30dfd Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Wed, 12 Sep 2012 13:08:27 +0200
Subject: [PATCH] Fix muxing mjpeg in swf. (cherry picked from commit
 7680d99b4302e476076cc1b8f2567f47c2aaef4d)

---
 libavformat/swfenc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavformat/swfenc.c b/libavformat/swfenc.c
index af812d09eb..0ad7b3342c 100644
--- a/libavformat/swfenc.c
+++ b/libavformat/swfenc.c
@@ -498,8 +498,10 @@ static int swf_write_trailer(AVFormatContext *s)
         avio_wl32(pb, file_size);
         avio_seek(pb, swf->duration_pos, SEEK_SET);
         avio_wl16(pb, swf->video_frame_number);
+        if (swf->vframes_pos) {
         avio_seek(pb, swf->vframes_pos, SEEK_SET);
         avio_wl16(pb, swf->video_frame_number);
+        }
         avio_seek(pb, file_size, SEEK_SET);
     }
     return 0;