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Dynamic DVB Subtitles and problem?

Added by Markus Aarnio about 8 years ago

I have previously used DVBLink as backend. Lately I moved to TVHeadend and it works great except I am experiencing some trouble with DVB subtitle on recordings.
In Finland we use DVB-T for SD and then DVB-T2 for HD content. DVB subtitles work great on SD, but then I have missing subtitles on HD channels.

I contacted Yle regarding subtitiling problems in their channels. They claim that there shouldn't be any problems on stream and subtiles itself.
Then contact explained that there is one technical difference between DVB-T and DVB-T2.
On DVB-T they have been using static pids for subtitles because at the begining quality on receivers were quite poor and those has subtitling issues.
On T2 transmission they have decided to follow specification (dynamic subtitle) and pids/subtitles are only existing on stream when those are been used.

It seems this is causing problems with TVH. It looks like tvh cannot detect changes in transport stream if new DVB subtitile stream is applied during recording.
For my recordings settings I have selected pass profile for the stream and everything should go through.

Is this known issue at all?

Can I override tvh to record DVB subtitile if I dig out pid for it with stream filter?
I added stream filter to use fin subtitles without pid, but it didn't help.


Replies (3)

RE: Dynamic DVB Subtitles and problem? - Added by Mark Clarkstone about 8 years ago

Have you disabled all the rewrite options for the profile, rewrite pmt etc?

If you haven't, try disabling them first, and then open a ticket with a mux sample that contains the dynamic subs. :)

Use wget and a mux link (from the muxes tab) and save an example (20 seconds or so should do it).

RE: Dynamic DVB Subtitles and problem? - Added by Markus Aarnio about 8 years ago

Thank you.
I will try to disable rewrite of pmt etc.
Default stream profile under 'stream' tab is only affecting playback?
And e.g. pass profile in 'Recording' will override above profile selection for recordings, right?

I am not sure if 20sec is enough for sample, may be you need sample of stream where sub pids are not existing and then activated at some point.
I would quess those are not 'fully' dynamic during one specific program.
May be I should try to record sample where subtitling is not available on previous program and then gets activated when new program is scheduled.
However this TS might be few minutes...

RE: Dynamic DVB Subtitles and problem? - Added by Markus Aarnio about 8 years ago

Mark Clarkstone wrote:

Have you disabled all the rewrite options for the profile, rewrite pmt etc?

It seems this did the trick and now subtitiles are in place.
Thank you.

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