avformat/mpegtsenc: set AVFMT_NODIMENSIONS

This allows remuxing streams from one mpegts container to another,
without requiring avformat_find_stream_info() (or using `ffmpeg
-probesize 32` on the cli).
Signed-off-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mpegtsenc.c

@@ -1983,6 +1983,6 @@ AVOutputFormat ff_mpegts_muxer = {
     .write_trailer  = mpegts_write_end,
     .deinit         = mpegts_deinit,
     .check_bitstream = mpegts_check_bitstream,
-    .flags          = AVFMT_ALLOW_FLUSH | AVFMT_VARIABLE_FPS,
+    .flags          = AVFMT_ALLOW_FLUSH | AVFMT_VARIABLE_FPS | AVFMT_NODIMENSIONS,
     .priv_class     = &mpegts_muxer_class,
 };