[mythtv] Pulling apart MPEG2

[Steve Davies]

 >>>> not much on the MPEG2-TS streams tho (that is DVB)
 >
 >>
 >> As far as I understand it, TS streams are a bunch of PS streams wrapped
 >> together and then broadcast in 188 byte packets.  Decoding is trivial if
 >> you can count to 188, but you then need to work out which packets are in
 >> which PS.  There are some progs called ts2ps and ts2pes (from metzlerbros
 >> I think?) which were built as part of the dvb drivers tools in order to
 >> extract the streams you want.
 >>


Looks like we have the same interpretation of TS streams. That at least is
a good start :-) I also already have a copy of the metzlerbros source
code, and will take a look at it in more detail - I had focussed on the
demux driver, and not the tools.


 >> The detail of extracting the correct streams from TS is either that you
 >> know which PIDs you want, or else you can parse an embeded PAT table which
 >> describes the contents of the TS stream.


Yup, I have a reasonable idea of how this works, although I'm still not
100% with the Myth implementation - I'm getting there.


 >> That's a paraphrase, but basically it means that TS can be reduced to PS,
 >> and PS techniques applied from there


Indeed, and with files generated by Myth I have about a 50% chance that
the resultant file will play OK in Myth (depends on the selected digital
channel), mplayer plays/not-plays the same files as Myth, and Xine seems
to play all of them fine.

This is where I want to start pulling the files apart to see what the
differences are under-the-hood.

Regards,
Steve

-- 
Steve Davies                   steve at one47.co.uk

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