Revert "mpegts: do not set pts for missing dts in video streams"

This reverts commit f65afef1df.

If only pts is coded then dts must be equal pts
See Rec. ITU-T H.222.0 (06/2012) / ISO/IEC 13818-1:2013 (E) 2.7.5

Found-by: Baptiste Coudurier

libavformat/mpegts.c

@@ -996,10 +996,7 @@ static int mpegts_push_data(MpegTSFilter *filter,
                 pes->pts = AV_NOPTS_VALUE;
                 pes->dts = AV_NOPTS_VALUE;
                 if ((flags & 0xc0) == 0x80) {
-                    pes->pts = ff_parse_pes_pts(r);
-                    /* video pts is not monotonic, can't be used for dts */
-                    if (pes->st->codec->codec_type != AVMEDIA_TYPE_VIDEO)
-                        pes->dts = pes->pts;
+                    pes->dts = pes->pts = ff_parse_pes_pts(r);
                     r += 5;
                 } else if ((flags & 0xc0) == 0xc0) {
                     pes->pts = ff_parse_pes_pts(r);