[FFmpeg-cvslog] flvenc: don't write random data if seek fails

[Björn Axelsson]

ffmpeg | branch: master | Björn Axelsson <bjorn.axelsson at intinor.se> | Thu Dec 13 14:48:25 2012 +0100| [2947e7b7a7378e4899c57a86f029fb20dc0f010c] | committer: Michael Niedermayer

flvenc: don't write random data if seek fails

The FLV muxer tries to update the header in write_trailer, which is
impossible if writing to a pipe or network stream. Don't write header
data if seek to header fails.

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2947e7b7a7378e4899c57a86f029fb20dc0f010c
---

 libavformat/flvenc.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index c528bf5..6ee0dd3 100644
--- a/libavformat/flvenc.c
+++ b/libavformat/flvenc.c
@@ -426,10 +426,14 @@ static int flv_write_trailer(AVFormatContext *s)
     file_size = avio_tell(pb);
 
     /* update information */
-    avio_seek(pb, flv->duration_offset, SEEK_SET);
-    put_amf_double(pb, flv->duration / (double)1000);
-    avio_seek(pb, flv->filesize_offset, SEEK_SET);
-    put_amf_double(pb, file_size);
+    if(avio_seek(pb, flv->duration_offset, SEEK_SET) < 0)
+        av_log(s, AV_LOG_WARNING, "Failed to update header with correct duration.\n");
+    else
+        put_amf_double(pb, flv->duration / (double)1000);
+    if(avio_seek(pb, flv->filesize_offset, SEEK_SET) < 0)
+        av_log(s, AV_LOG_WARNING, "Failed to update header with correct filesize.\n");
+    else
+        put_amf_double(pb, file_size);
 
     avio_seek(pb, file_size, SEEK_SET);
     return 0;