From 09a278fdd13cfc16c151190051f362625595c06e Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Thu, 13 Sep 2012 09:26:55 +0200
Subject: [PATCH] Fix muxing mjpeg in swf. (cherry picked from commit
 79234907128390d775ceb1206dd0fed111a17896)

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

diff --git a/libavformat/swfenc.c b/libavformat/swfenc.c
index b433f6b713..c1bb2b7023 100644
--- a/libavformat/swfenc.c
+++ b/libavformat/swfenc.c
@@ -496,8 +496,10 @@ static int swf_write_trailer(AVFormatContext *s)
         put_le32(pb, file_size);
         url_fseek(pb, swf->duration_pos, SEEK_SET);
         put_le16(pb, swf->video_frame_number);
+        if (swf->vframes_pos) {
         url_fseek(pb, swf->vframes_pos, SEEK_SET);
         put_le16(pb, swf->video_frame_number);
+        }
         url_fseek(pb, file_size, SEEK_SET);
     }
     return 0;