Merge commit 'e2ce1639'

* commit 'e2ce1639':
  mpegts: Support running the write_trailer function without an AVIOContext
Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mpegtsenc.c

@@ -1400,7 +1400,8 @@ static int mpegts_write_end(AVFormatContext *s)
     MpegTSService *service;
     int i;
 
-    mpegts_write_flush(s);
+    if (s->pb)
+        mpegts_write_flush(s);
 
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st = s->streams[i];