[sclug] Digital TV card and channel recognition

Dickon Hood dickon-ml at fluff.org
Fri Dec 11 21:03:10 UTC 2009

On Fri, Dec 11, 2009 at 20:39:39 +0000, Andrew Sharp wrote:
: Thanks Dickon!

: Suprisingly, copying the channels.conf for xine from /etc to ~/.xine as 
: suggested by an Ubuntu forum on your search parameter worked straight 
: away.

Yeah.  I'd suggest symlinking from all the odd locations applications seem
to want to read from to a single object somewhere (so updates are
trivial), but it's up to you.

: Wierdly, BBC3 and BBC4 (aka CBBC and CBeebies)

They're not the same thing at all.[0]

They occupy the same A/V PIDs, but have very different service IDs, and if
your media player is behaving correctly (hint: most don't[0]), during
channel changeover, they'll re-parse the PMT[1], note that the A/V PIDs
have disappeared from that channel, and stop displaying video and playing
audio.  Normally, though, they parse them once at startup and cache those
results until you quit them.

I'm told some[2] STBs will show a brief clip of the new channel if they
were tuned to the old one pre-switchover, tuned to something else, then
retuned back again post-switchover, as they cache the PMT to make channel
switching faster.  It's all good fun.

: don't work. Trying 
: the same trick with Kaffeine4 didn't work and I have uninstalled it. I 
: tried installing vlc and it seems to work, except there is no sound with it!

vlc has some quite good logging available.  It *should* work, especially
on anything reasonably modern, so I'm surprised.  It's also worth looking
in its options -- tick the 'Advanced options' box, as it's useless
otherwise -- for something.  It may be defaulting to OSS, or something
daft.  And if you're on Debian, use the version in the debian-multimedia
respository (add 'deb http://www.debian-multimedia.org experimental main'
to /etc/apt/sources.list; it's also worth getting VLC from their own site
with 'deb http://download.videolan.org/pub/videolan/debian sid main'.
Similar exist for Ubuntu, I believe.  They may even be the same thing.).

: Cheers for your help.

No problem.

[0] Yeah, I made that mistake.  Took me forever to work out what I was
getting wrong.

[1] This is amusing if you're splitting a multiplex and retransmitting it.
You have no idea how many pointers to pointers to pointers to pointers you
end up dealing with.  And I may make it worse, so I can trivially switch
configs without restarting.

[2] At least one.

Dickon Hood

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