@@ -403,10 +403,14 @@ 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;