Use next_pts if pkt->dts is unknown. In an ideal world this would not be needed

but sadly there are cases where the timestamps cannot be found without decoding.

Originally committed as revision 12130 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -1066,7 +1066,7 @@ static int output_packet(AVInputStream *ist, int ist_index,
     ptr = pkt->data;
     while (len > 0) {
     handle_eof:
-        if(!pkt || ptr != pkt->data){
+        if(!pkt || ptr != pkt->data || pkt->dts == AV_NOPTS_VALUE){
             ist->pts= ist->next_pts; // needed for last packet if vsync=0 and for multi pkt
         } else if (pkt->dts != AV_NOPTS_VALUE) { //FIXME seems redundant, as libavformat does this too
             ist->next_pts = ist->pts = av_rescale_q(pkt->dts, ist->st->time_base, AV_TIME_BASE_Q);