[FFmpeg-devel] [RFC] DVB teletext and PTS

Michael Niedermayer michaelni at gmx.at
Sun Sep 23 04:16:49 CEST 2012

On Sat, Sep 15, 2012 at 04:29:02PM +0200, Reimar Döffinger wrote:
> Hello,
> when specifying PTS handling for DVB teletext they made quite a mess it
> seems (see Annex A of ETSI EN 300 472), which resulted in some stations
> not using sensible PTS values (for example for ORF the teletext PTS
> values seem to indicate a time multiple hours after the video time,
> I have a ORF1HD.ts sample here but I don't remember where exactly it
> is from).
> For ordinary teletext, processing them straight away works fine, but
> will completely mess up teletext based subtitles.
> This will work for hardware decoders, because at the same time a
> "maximum retention time" of 40 ms was specified.
> Now the question is: how should we handle this? Would a patch/hack that
> limits DVB teletext time stamps to last stream ts + 40 ms be acceptable for
> example? It's not really accurate since it should be next ts + 40 ms
> though, and quite hacky. But I can't really think of anything better.

sounds reasonable, but i dont understand the prev/next ts issue
what ts is this ? pcr ? dts ? something more complex ?


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I do not agree with what you have to say, but I'll defend to the death your
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