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Streaming t.140 subtitles.

Posted: 29 Jul 2010 17:55
by Helio-2000
Hi,
I was trying to test t.140 streaming functionallity that was added in version 0.9.2.

For that purpose, I have two PCs running Windows and VLC 1.1.1. I am using one of them as RTSP server, transcoding to H.264 AAC and enabling t.140 subtitles. The other PC is used as RTSP client. The question is I don't get any subtitles in the client neither Wireshark shows any t.140 RTP datagrams being sent through the network interface.

Nevertheles, with wireshark I can see that RTSP server is advertising its t.140 capability. And if I enable the option "Overlay subtitiles on the video" I succesfully get subtitles on the client, however I really wanted to test t.140 streaming functionallity.

So, I have basically two questions:

Is t.140 streaming input currently supported or only output?
If only output is supported, what did you use as a client for testing VLC t.140 output streaming capability?

Thank you.

Re: Streaming t.140 subtitles.

Posted: 29 Jul 2010 18:05
by Jean-Baptiste Kempf
Only output.
no idea about clients.

Re: Streaming t.140 subtitles.

Posted: 29 Jul 2010 21:39
by Rémi Denis-Courmont
Only output is implemented. Input would require support in live555 first.

Re: Streaming t.140 subtitles.

Posted: 30 Jul 2010 09:39
by Helio-2000
Hi, thank you for your answers.

Provided that I was willing to support t.140 input in live555 how much effort would it take, in your opinion, resolving the integration between RTP text reception with live555 and conversion into suitable subtitles for VLC ? Is there a framework for this or should it be also developed?

Thank you.

Re: Streaming t.140 subtitles.

Posted: 31 Jul 2010 09:56
by Rémi Denis-Courmont
T.140 is really just plain UTF-8 text inside RTP. It should quite easy.