[mythtv] Recording multiple channels on a single DVB transport

[Ed W]

>The TVRec is built around one-recording per tuner.
>But this is still possible.
>  
>

It occured to me that you could hook into the call to "get a free tuner" 
and instead of calling it only once at startup of a tvrec, instead call 
it every time you change channel.  Introduce an extra param which is the 
wanted channel and you now have some interesting flexibility

So now when you change channel it's possible that you will be handed a 
whole new device that you can then call "tune" on.  Consider a case with 
two tuners, both recording some channel on different multiplexes.  You 
should be able to call "get free tuner('BBC ONE')" and if one of the 
tuners is recording something on the same mux then you would get back 
that tuner device.  Then if you change channels you do the same again 
and perhaps end up with the tuner which is on the other mux

The interesting thing we could do here is also make this work with 
normal analog cards and all cards where there is an overlap in programs, 
eg recording back to back programs, one with a 5 min overrun and the 
other with a 5 min pre-start.

If the device is just told to tune and then feeds a stream out to the 
recorder then it's possible for two recorders to use the same device at 
the same time (including analog channels), so you can then share a tuner 
for two recordings which are on the same channel (eg live tv watching 
the same channel as something which is recording, or two recordings 
which overlap in time)

I'm never going to have enough time now to code this, but it doesn't 
seem to be desperately hard to fiddle the architecture around to support 
this I think?

Ed W