[FFmpeg-cvslog] Fix muxing mjpeg in swf.

[Carl Eugen Hoyos]

ffmpeg | branch: release/0.7 | Carl Eugen Hoyos <cehoyos at ag.or.at> | Wed Sep 12 13:08:27 2012 +0200| [3ed505863b067e73eee837a9e9f76efdbc692142] | committer: Carl Eugen Hoyos

Fix muxing mjpeg in swf.
(cherry picked from commit 7680d99b4302e476076cc1b8f2567f47c2aaef4d)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3ed505863b067e73eee837a9e9f76efdbc692142
---

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

diff --git a/libavformat/swfenc.c b/libavformat/swfenc.c
index 09c2d61..7d7daac 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;