How do you multiplex a teletext stream in with video and audio with mpegtsmux?

Plugin and library development
1

Hello GStreamer’s,
I’ve been using mpegtsmux for a few years now for video and audio muxing however, I have a need to mux a teletext stream similar to subtitling.
Has anyone successfully multiplexed teletext in with a video and audio source?

If so how did you prepare the source? there is caps for teletext and a function to prepare the PES subpicture/x-dvb; application/x-teletext; meta/x-klv, parsed=true

The function “mpegtsmux_ttxt.c” to prepare the PES therefore I’m satisfised muxing teletext and subpicture (subtitles) can be done.
Here’s what the function achieves: -

/* from EN 300 472 spec: ITU-R System B Teletext in DVB
*

  • PES packet = PES header + PES payload data
  • where PES header must be fixed at 45 bytes (likely by using PES stuffing)
  • PES packet must completely fill an integral number of TS packets
  • using (184 bytes) payload data only (so no adaptation field stuffing)
    */

Happy to use what you have and for anyone to advise what to do?

Thanks

2

Use the application/x-teletext caps to create pad to the mux into mpegtsmux is broken? assumes it subtitles and assigns the wrong PES descriptor for it.

Can anyone confirm?

3

What are the caps of the stream you are trying to mux ? We don’t have any element in gstreamer that can actually generate teletext

4

Hi @bilboed
I understand there isn’t and element and are able to use appsrc to pass the data in gstreamer.
The issue is using mpegtsmux and the caps application/x-teletext, mpegtsmux treats it as subtitles and assigned it incorrectly.

How do I raise a bug in mpegtsmux?

5

https://gstreamer.freedesktop.org/documentation/contribute/index.html?gi-language=c#how-to-file-issues-and-request-for-enhancements