[mythtv] livepriority for cardinput

[Martin Long]

When watching TV, the tuner automatically selects input 1 first, unless it
is being used, then tuner 2 etc. The problem with this is, that the
scheduler also selects tuner 1 first, and doesn't make adjustments on the
fly if you happen to be watching that channel. This means you can often
get 'kicked off' a tuner because the scheduler wants to start recording on
that channel.

This can be annoying, particularly if you are say 30mins behind, because
you lose the buffer, unless you think to 'exit' the recording popup, press
record, to save the buffer, and finally, if the program isn't due to
finish before the recording in question starts, move to another tuner and
set the rest to record (resulting in a split recording).

To work around this, I've set up the recpriory for each input to the same
value as input ID. That way the scheduler selects input 3 first, then 2
then finally will kick me off 1 only if it has to. (ie the scheduler and
liveTV working from opposite ends). This would still create rare
situations where it can trip up, which I'll outline if you like, but I'n
not too bothered about that.

There is still a problem though. Because tuner 3 is now top priority, it
will schedule repeats of shows to record if tuner 3 is in use, instead of
just scheduling them on tuner 2. Fine, you might say, but I would much
rather schedule the first showing if at all possible. That way, if
something goes wrong, or something else gets added later, which conflicts
with the repeat, then I'd be screwed.

What I'd like to suggest, would be a method by which you can make the
scheduler prefer to use tuners 3,2,1 instead of 1,2,3, or alternatively,
make likeTV default to tuner 3, then 2, then 1 (incase of multiple
frontends). It would be ideal for the scheduler and frontends to be using
up the tuners in opposing directions.

It's possible that this may already be implemented, but the database
schema isn't fully documented yet, and a look through the other
documentation doesn't make it clear. Any ideas? If not, I'll look into
working on a patch for this.

Martin