[mythtv-users] How to configure for HD channel to get priority (Freesat/Freeview UK)?

[Michael T. Dean]

On 04/17/2013 09:16 AM, Joseph Fry wrote:
>> The issue is that in 0.26-fixes and below, channel priority doesn't do
>> what people think it does--it doesn't say, "If this show is available on
>> both channels, record it on this one."  It says, "Everything--including
>> garbage--shown on this channel is that much better than stuff shown on the
>> other channel."  That means MythTV could choose to record a show you don't
>> like as much as a different, higher-priority show that only airs on the
>> lower-priority channel, and the higher-priority show could lose out as a
>> conflict, resulting in your missing the episode.
>>
>> So, on 0.26-fixes, the best solution for saying, "I want to record on
>> these channels on this card first," is the schedule order--because it
>> doesn't mess with your specified recording priorities.  If schedule order
>> doesn't work for you because you are trying to free up the better source
>> for use with specific channels--meaning you actually want different
>> channels on the same source/input to be used with different priorities--you
>> /can/ use channel priorities, but you /must/ be careful to use sufficient
>> priority separation such that recording priority + channel priority + input
>> priority + (other priorities, such as HDTV priorities, etc.) comes out in
>> the right order all the time--basically, the problem of assigning recording
>> priorities quickly becomes intractable when you introduce too many
>> modifiers (and you end up fudging it and just fixing conflicts manually).
>>   If you're using channel priorities in 0.26-fixes or below, you may be best
>> served using negative priorities on the less-preferred channels, though, to
>> minimize the chances of something not good getting bumped way up by all the
>> positive priorities such that it gets recorded in preference to something
>> you like better.
>>
>> In unstable/development/0.27-pre, the channel priority works the way most
>> people always thought it works--it actually only affects individual shows
>> that are available on both channels (not saying that "Honey Boo Boo" (which
>> for illustrative purposes we'll say is only on Freesat) is +1 because it's
>> on BBC1 HD (which could bump it up to win out over some better (any other?)
>> show), but saying, "If Dr Who is airing on BBC1 HD and BBC1 non-HD, try to
>> record it on BBC1 HD").  So in future MythTV, you'll just use channel
>> priorities.
>>
>> That said, the OP's question--if I'm reading it right--is completely
>> different.  He's saying, "I want to record HDTV shows off the HDTV versions
>> of the channels on Freesat and not waste those channels on SDTV shows that
>> are available on other channels on other inputs"  For that, there are a
>> couple of options.  The first one--which only works if you have "good"
>> guide data--is to add a positive HDTV priority.  If you do, then any show
>> marked as HDTV in the guide data will have that positive priority.  And,
>> assuming your guide data on the non-HDTV channel does /not/ mark the show
>> as HDTV, you'll get what you want.  (But remember that means even your
>> unimportant shows that are marked as HDTV get a priority boost versus
>> better shows that are not marked as HDTV.)
>>
>> That said, since guide data may not be that precise in its identification
>> of HDTV material, the alternative option is to specifically prefer an input
>> for a given recording rule.  This way, if you know that Dr Who airs on BBC1
>> HD, you can prefer one of the Freesat inputs.  Unfortunately, the down side
>> is that this requires you to specify a particular input--so if you have
>> Freesat HDTV channels on multiple inputs (i.e. 2xFreesat inputs), you'll
>> have to be careful with shows that air at the same time on Freesat and make
>> sure that one prefers the first input and the other prefers the second.
>>
>> So, basically, there are several options, but the specifics of what you
>> want (and how often you want it) will determine which approach is best for
>> you.  Note, also, that what the responses talked about (which I don't think
>> is what you want) gets /much/ simpler in unstable/development/0.27pre and
>> will actually work like they described without the downside I tried to
>> describe.
>>
>> I hope this is a good enough (and understandable) description.  I'm sure
>> David Engel, our scheduler expert, could explain things better than I did
>> and probably correct several things I said and maybe even add another
>> method or 2 to use, but I hope this gives you enough information to play
>> around and find something that works for you.  (And if you go with channel
>> priorities, keep in mind that you may want to change them after 0.27, if
>> you actually use them with a "0.26 and before" style definition--either
>> that or just use them as if they worked like they will/like most people
>> think they work, and manually fix the problems it creates since you'll be
>> upgrading to 0.27 "soon" enough).
>
> Indeed.  I am looking at it from the perspective of having the same channel
> via two different sources and wishing to encourage the system to record
> JUST that channel on a given source.
>
> I acutally use your preferred method.  I have both a QAM and Cable Card
> tuners, and I set the QAM tuners to get used first in the recording order,
> and the cable card tuners to be used first for live tv.   This ensures that
> if a channel appears on both, it uses the QAM tuners first leaving the
> cable card tuners free since there is a lot more variety there and I want
> them free for live tv or one off recordings.
>
> However, if I wished to use the Cable Card tuner for one particular
> channel... perhaps the QAM version is lower bandwidth or something... I
> would simply LOWER the recpriority of that channel on the QAM tuner (not
> raise it on the cable card tuner).  Wouldn't that make the system favor the
> channel on the Cable Card tuner without giving preference to that channels
> shows over any other?

Right--in 0.26-fixes and below doing that actually makes shows on the 
QAM channel less preferred than shows on other channels (the exact 
opposite of what I described above).  But, the hope is that's slightly 
less likely to cause problems than artificially increasing priority of 
bad shows.

And, unfortunately, that's the only option for preferring channels 
differently across a single Video Source--but thanks to work by David 
Engel, 0.27 simplifies things to work like most people think it 
works/expect it to work.  Until then, just watch for and correct 
conflicts manually (which, really, is something you should always do 
with all versions of MythTV--it's just that you're more likely to have a 
conflict resolved incorrectly when using channel priorities in versions 
0.26-fixes and below due to its wider scope/application).

I suppose the best way to put it is that when using priority modifiers 
of any kind (channel priorities and input priorities and ...), any 
improper results of automatic conflict resolution are almost definitely 
due to the priority modifiers you used and not "MythTV scheduler is 
broken" or "strange scheduling decision" or whatever.  In other words, 
MythTV is doing exactly what you told it to do, so just make sure you 
either know what you're telling it to do and are willing to live with 
the results, or be very vigilant about manually identifying and fixing 
those conflicts before you miss a recording you really want.

Mike