[mythtv-users] input priorities?

[Michael T. Dean]

On 03/19/2009 06:21 PM, Gordon McLellan wrote:
> I'm transitioning from SD to HD on my myth box and have one HD capable
> tuner, two dedicated SD tuners and one analog capture device that is
> shared with the HD tuner for recording from a cable box.
>
> Some shows I would like to record in HD if possible, and if not,
> record in SD.  To achieve this, I have set their schedules to record
> one showing a week, filtered for new episodes only.  This also helps
> with the seemingly random timeslot changes the networks are doing to
> screw with DVR owners, like shows starting at 9:02PM either don't
> match a 9:00PM schedule, or lose 2 minutes off the end of the program.
>
> Myth doesn't seem to understand what I'm trying to do, probably
> because I'm not understanding the priorities system, or perhaps it's
> just not possible.
>
> For example I want to record the terminator drama on fox this Friday.
> It airs at 8:00pm.  Myth has it scheduled for the SD tuner because at
> 8:30 a low-priority program is scheduled to record off the cable box
> (which is part of the HD tuner's input group).  The cable box input
> has a priority of -5 in the backend setup, and the HD tuner has a
> priority of +5.  Terminator schedule has the HD tuner as the preferred
> input, and the schedule has a priority of +2.  The program that's
> bumping Terminator has a priority of -2.
>
> What do I need to change to make sure the higher priority schedules
> get to use the higher priority inputs, or at least, get to use their
> preferred inputs?
>
> Next Monday, there are two shows I would like to record in HD, and it
> seems myth is bumping the high priority schedule off the HD tuner and
> giving it to the lower priority schedule following alphabetical order.
>  The program "Chuck" is bumping the program "House", House has a
> priority of 5 and Chuck only 2.
>
> Any guidance is appreciated.

The /right/ solution is to use the capture card portion of 
http://www.gossamer-threads.com/lists/mythtv/users/264034#264034 to 
delete all capture cards and then re-create the capture cards (in any 
order you desire), and then re-connect inputs in order of preference 
(i.e. the HDTV inputs first, then the SDTV inputs).  And, finally, do 
/not/ set any priorities on any of your inputs.

While there are things you can do with input priorities to influence 
decisions made by the scheduler, few users /ever/ understand the 
consequences of making those changes (i.e. that you may be telling Myth 
/not/ to record high-priorities shows and that you may end up missing 
them due to it--basically, the kinds of things that you're seeing--which 
are exactly what you've told Myth to do).  If you feel you can't take 
the 29seconds to do it right, read /all/ of section 12.6 of the HOWTO ( 
http://www.mythtv.org/docs/mythtv-HOWTO-12.html#ss12.6 )--and, really, 
you should read all of section 12 if you really want to ensure you 
understand why the 29second approach is correct.  (In other words, after 
a half hour of reading/trying to understand, you'll figure out that you 
really want to do it the right way.)

Setting recording rule priorities is fine.  Setting channel priorities 
is not a terrible thing (though can have similar impacts to setting 
input priorities, so if you do so, you should probably understand how 
scheduling and priorities work in Myth--section 12 of the HOWTO).  
Setting input priorities is almost always the wrong thing to do--and 
setting them without fully reading and comprehending section 12.6 is 
/always/ the wrong thing to do.  :)

Mike