[mythtv-users] LiveTV conflicts with scheduled recording - despite unused tuners on the same box!

[Michael T. Dean]

On 07/02/2009 02:35 AM, Jarod Wilson wrote:
> On Thursday 02 July 2009 02:21:51 David Brodbeck wrote:
>   
>> Jarod Wilson wrote:
>>     
>>> That would probably be more optimal. As they say, "patches welcome!" ;)
>> I suspect the real answer is that Myth's scheduler just isn't very 
>> agile.  I've noticed when I add a new show it takes a minute or two for 
>> the scheduler to add it to the upcoming recordings list, so it probably 
>> just can't reschedule fast enough to cope with that kind of situation.
>>     
> Don't know the scheduler code at all myself, but in head its like this:
>
> You rarely add a recording seconds before it starts, so the scheduler
> can be lazy, only periodically checking if there's new stuff to get
> scheduled. Otherwise, we're polling constantly for almost no reason.
> The actual act of rescheduling can be done plenty fast, once we know
> there's something to reschedule, I believe.
>
> A "reschedule immediate[*] recordings NOW" interface might be a nice
> addition (might already exist and just need more wiring, I dunno).
>
> [*] immediate ~= in the next hour or so
>   

When you add a new rule, Myth modifies the existing schedule to include
that new rule as opposed to doing a complete reschedule from scratch
(which should /only/ be done when the master backend first starts and
just after mythfilldatabase runs).  Any time that something that could
affect the recording schedule occurs (including creation of a new rule,
the choice you specify in that dialog you're shown when a recording
wants your LiveTV input, or shutting down a backend, or ...) the
scheduler runs immediately to account for the changes.

I think the main reason that the scheduler acts the way it does--and
assumes that 2 inputs are /never/ equal is for
consistency/predictability.  If it /always/ acts the same way, there are
many fewer problems/corner-cases to deal with in the code.  And, since
the option, "Avoid conflicts..." is available for those who choose to
use LiveTV and have "equal" inputs, there's no need to add problems for
those of us who don't use LiveTV.  :)  If you want to use LiveTV and
have both equal and not equal inputs, you can choose to put your
preferred LiveTV card as the last--or, better, with at least 2 digital
cards and multirec, you can even do some tricks to get a high-quality
input for LiveTV and still generally avoid getting kicked when a
recording starts (
http://www.gossamer-threads.com/lists/mythtv/dev/369358#369358 ).

>> This also poses problems for joining something "in progress" without 
>> LiveTV.  I don't think the scheduler will start a recording on a show 
>> that's already started; I think it will always try to wait for the next 
>> showing.
>>     
> By default, yes, I believe that is the case. But you can override it
> and tell it to record anyway.

The scheduler will only defer recording of a show that's already in
progress /if/ a rerun of that show is shown in the available listings
(i.e. if it re-airs in the next 2 weeks).  If a rerun is /not/ listed,
Myth's scheduler will allow the partial recording.  I.e. it does what
you probably want when setting an "any time" rule--it records the
/whole/ show instead of part of it.

However, if you want the already-in-progress partial airing, you should
not be using an "any time" rule, but should use "Record only this
showing"--which will always (even if there's a rerun within 2 weeks)
record the specified showing.

Note also that depending on your settings, the UI in LiveTV may make it
/seem/ like you can't tell Myth to record an already-in-progress show
without LiveTV.  There are settings:

Use select to change the channel in the program guide
If enabled, the Select key will change the channel while using the
program guide during live TV.  If disabled, the select key will bring up
the recording options screen.

and

Record Threshold
If the option to use Select to change the channel is on, pressing Select
on a show that is at least this many minutes into the future will
schedule a recording.

So, with the first option enabled, if a show begins far enough into the
future (by default 16 minutes), Myth will just add a rule to record it. 
If it's already airing, it will switch to that channel.

Mike