[mythtv-users] Reserving an encoder for an external program?

[chris at cpr.homelinux.net]

On Sun, Aug 20, 2006 at 06:28:23PM -0400, Michael T. Dean wrote:
> On 08/20/06 16:10, chris at cpr.homelinux.net wrote:
> >On Sun, Aug 20, 2006 at 02:33:23PM -0400, Michael T. Dean wrote:
> >>On 08/20/06 09:08, Lars Kellogg-Stedman wrote:
> >>>I'm hoping that there's some way to schedule "idle time" for an
> >>>encoder
> >>You can tell Myth not to use it by not configuring it in mythtv-setup. 
> >You've missed his point.
> Well, hey, you missed my point (and I'm pretty sure you missed his, 
> too--as he seemed to want something that works with a "stock MythTV 
> build" (quoted from his post)).  My solution works with any version of 
> MythTV.

When I read "works with a stock installation" I think "a solution 
where I don't have to download patches and compile my own 
binaries".  Your solution works with a stock 0.19 install, but it 
means he can't schedule the radio recordings (which he also 
indicated he wanted to do) and use his tuner in MythTV for the rest 
of the week.  I didn't miss his point (or yours) but simply pointed 
out that there is NO current solution and that there is a lot of 
demand for this capability but it's not being taken seriously.  If 
it was taken seriously then what Lars wants to do would be 
available in a "stock MythTV installation" at some point in the 
near future.

> Where did I say, "shut down mythbackend?"  I said, "tell Myth not to use 
> it [the card] by not configuring it [the card] in mythtv-setup."

You didn't say to shutdown the backend.  On review, the Wiki FAQ 
page doesn't actually say that either.  Instead it refers to the 
"--nosched" option that allows playbacks but prevents all 
recordings (for all tuners) and breaks LiveTV.

Your solution is just as bad, though.  It would really suck if he 
had to remember to run mythtv-setup every Saturday morning and 
delete tuner 2 so that he can record a radio show and then run 
mythtv-setup every Saturday night and re-add the tuner (and 
associate it with a listing) so he'd have two tuners for the rest 
of the week.  It *would* be easier to simply use a cron job to kill 
MythTV and restart it after the radio show was over.

> That 
> means he should configure all his other cards in Myth, and--to be 
> complete--run mythbackend.  Therefore, he would have one card dedicated 
> to radio and all other cards available for TV.

That's exactly what he DOESN'T want.  He wants to be able to tell 
Myth to use both tuners for most of the week and then automatically 
know, in advance, that one specific tuner has to be excluded from 
all scheduling for a short period of time so that another program 
can record the radio.

Alternatively, he would like MythTV to tune the radio and record 
that program's audio.

> Which means as new shows "cascade" into those recording slots (from 
> previous conflicts), you'd have to insert more overrides.

I know.  That's why I didn't present it as the desired solution.  
It's *a* solution, and one that requires constant intervention by 
the user to make sure the "next day" update from mythfilldatabase 
doesn't drop something else into that timeslot to steal the tuner.

> Extending the EXECTV's support for marking a capture card as unavailable 
> would be an easier solution if you planned to write new code.  I think 
> it's pretty much as easy as sending a "FREE_TUNER" command to the backend.

I've never used EXECTV, but from the context I expect it's a
just-in-time tool and that MythTV has no way of predicting when such a
command will arrive?  If so, then that solution would cause problems for
anyone who has enabled the "reschedule higher priorities" switch as
MythTV might defer a high-priority recording only to have the tuner
stolen literally at the last minute.  Being able to specify tuner 
affinity in a recording rule and create idle-tuner recording rules 
means that MythTV can schedule around holes that are known as much 
as two weeks in advance.

Managing tuner availability through the scheduler would also allow 
a user to assign a priority to the radio timeslots and override the 
audio recording period if required.  For example, one rule might 
block the tuner during the time when the hockey game is normally on 
the radio but another rule could preempt the radio if the hockey 
game is televised that week.  It would also allow the user to override
the scheduled weekly outage and make the tuner available for video
recordings if boring teams were playing that week.

How much justification does it take to get tuner affinity and 
"no-recording" rules considered for MythTV?