[mythtv] [mythtv-commits] Ticket #1772: Allow Multiple Channels rom 1 Transponder...

Petr Stehlik pstehlik at sophics.cz
Sat Sep 23 10:19:14 UTC 2006

Stuart Auchterlonie píše v So 23. 09. 2006 v 10:49 +0100:

> There would need to be several "logical" inputs for each card.
> At least in DVB land the set of available channels that can
> be recorded simultaneously is governed by which multiplex they
> are on.
> Here we have 6 muxes, so we would have 6 logical inputs that
> are mutually exclusive...

Well, on a DVB-S you can receive hundreds of muxes so I am surprised it
should be implemented this way.

I thought it would work this way: the scheduler is about to start
recording B while recording A is in progress. The scheduler checks and
see that A and B are in the same mux so it simply asks the demuxer to
record also the recording B from the same stream. When recording A
finishes the card is not freed - the recording B "owns" it now. We would
just need to know (from the tuner) that the A,B recordings share the
same mux.

I imagine it as a system of hardlinks in Unix filesystem. Say I have a
file A containing some data and I'll create a hardlink named B. B and A
will share the same physical data. When you remove the file A the
physical data continues to exist since the B hardlink exists (and B now
owns the data). Only when you remove also the B file the data is removed
from disk (unless you created hardlink C pointing to A or B in the

It could be similar to what scheduler does when LiveTV is playing - it
tries to find a free input/card and if there is none it asks the viewer
what to do with the LiveTV - whether to stop it or give up on the
recording. Now the multiplex-enhanced scheduler would simply try to
search for an already running recording from the same multiplex and if
it found it it would join that recording on the card. If there wouldn't
be any sibling recording in progress then no problem, it would work as
always, but if there was a recording from the same mux then joining it
would be a nice bonus.

Sorry for wasting so much bytes on explaining something that is either
incorrect or well known but I still feel like this could be implemented
not as a complete rewrite of half of Myth but rather as "try this
multiplex thingy for a nice bonus and if it won't work then nevermind".

I can imagine that system of recording priorities could kill (or
seriously complicate) this idea so I am ignoring them for now :-)


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