Fill missing pts in during muxing when we know that they are equal to dts.

Originally committed as revision 13970 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/utils.c

@@ -2445,6 +2445,9 @@ static int compute_pkt_fields2(AVStream *st, AVPacket *pkt){
         }
     }
 
+    if(pkt->pts == AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE && delay==0)
+        pkt->pts= pkt->dts;
+
     //XXX/FIXME this is a temporary hack until all encoders output pts
     if((pkt->pts == 0 || pkt->pts == AV_NOPTS_VALUE) && pkt->dts == AV_NOPTS_VALUE && !delay){
         pkt->dts=