[mythtv-users] tuner priorities

[David Engel]

On Thu, Dec 22, 2011 at 04:51:16PM -0500, Michael T. Dean wrote:
> On 12/22/2011 04:34 PM, Tim Draper wrote:
> > i have DVB-T, and DVB-S2 tuners in my BE.
> > the DVB-T is fairly poor signal with intermittent blocking so my
> > preference is to use the DVB-S2 tuners if at all possible.
> >
> > both the DVB-T and DVB-S2 have overlapping channels (eg: BBC One), and
> > i have both inputs allowing all channels.
> >
> > i have set tuner priority of the DVB-T as -2. (DVB-S2 is 0)
> > i have also enabled 'avoid conflicts' in the FE settings.
> >
> > when i watch liveTV, it will default to the DVB-T input, which is not
> > desired behaviour.
> > the DVB-T tuner should only be used when a channel is only available
> > on the DVB-T source, OR both DVB-S2 inputs are inuse.
> >
> > i think i've asked this before (or atleast seen another thread), but i
> > cant find the info anymore. in the past i've configured it so DVB-T
> > only channels are available on that source, but i cant remember if
> > this was for convenience, or a technical reason.
> >
> > can this be done?
> 
> Input priorities ("tuner" priorities) are evil--they tell MythTV what to 
> record, not where to record it, so they don't do what people expect they 
> do.  Also, priority /never/ has any effect on capture card/input chosen 
> for Live TV.
> 
> Therefore, you probably shouldn't be using input priorities.  (Please 
> read all of http://www.mythtv.org/docs/mythtv-HOWTO-12.html for details 
> on how priorities work.)
> 
> Instead, "Delete all capture cards" (won't affect channels--but will 
> reset everything so you can configure it correctly and without input 
> priorities), then re-create capture cards and re-connect inputs.
> 
> Create capture cards in the opposite order you want them used for Live 
> TV and make sure you keep "Avoid conflicts..." enabled.  (So, sounds 
> like you want to create the DVB-S2 cards first, then DVB-T cards.)
> 
> /Then/ connect inputs in the order you want them used for recordings.
> 
> And note that the capture card order need not be the same as the input 
> order...
> 
> And don't ever set any input priorities, again.

I'm going to ignore the live TV issue for a moment.

If I understand Tim correctly, his situation is the main reason input
priorities exist.  He has an input which is less desirable than other
inputs in all cases.  Even later showings on the other inputs are
preferred over earlier showings on the undesired input.  Using a lower
priority on the undesired input will accomplish that.

Now, back to live TV.  Live TV always been an after thought in MythTV
and so it's configuration is pretty arcane.  The procedure Mike
described above is the current way to have MythTV try to avoid
conflicts on the good inputs when live TV is entered.  If you want
live TV to use the best available card, you need to configure the
tuner cards in the desired order instead of reverse order.

I'm taking off work next week and have been considering a small MythTV
project or two to work on.  Providing more explicit control of input
ordering for scheduling and live TV is one thing I've been
considering.  Is there any interest in that?

David
-- 
David Engel
david at istwok.net