[FFmpeg-devel] [PATCHv5 4/4] lavc: add teletext decoder using libzvbi
Carl Eugen Hoyos
cehoyos at ag.or.at
Sat Aug 24 22:57:54 CEST 2013
Marton Balint <cus <at> passwd.hu> writes:
> > Or in other words: Is one FFmpeg subtitle
> > stream provided for all pages plus one
> > stream for each subtitle page?
> > Or is this not a good idea?
> At the moment, a single subtitle stream is provided for
> all the teletext packets, and the decoder decides which
> pages to decode from these teletext packets.
Meaning you cannot decode / reencode two teletext subtitle
pages at the same time, or do I misunderstand?
> Creating separate streams in the demuxer for each entry
> in the teletext descriptor may have it's advantages, but
> I can't think of a way to split the teletext packets to
> multiple streams without decoding the whole teletext in
> the demuxer first.
(Doesn't this sentence indicate that this should be solved
before the patch gets applied?)
> Also I don't know if the mpegts demuxer will like if we
> just start adding streams with the same PID values...
I believe this is done with TrueHD / AC-3 streams.
> The only way I see is if we pass all teletext packets to
> all these streams, and as a packet side data also pass a
> default page filter to the decoder, but I don't know if
> that is something we should do...
> Anyway, since we definitely need a stream with all the
> teletext packets, these extra subtitle streams can be
> added later :P
Thank you for the explanations, Carl Eugen
More information about the ffmpeg-devel