[mythtv-users] Configuring the system - not understanding some things

[Michael T. Dean]

On 06/09/2012 04:24 AM, Alan Chandler wrote:
> In reference to an earlier thread that talked about problems with my 
> tuner, I have purchased an additional tuner and gone back to an old 
> one.  What I need to do now is properly configure them.  I tried, but 
> didn't get the result I wanted.  So I am asking here for help to 
> properly configure them
>
> I now have installed in my computer a Haupage WinTV Nova T 500.  The 
> has two DVB-T tuners - but experience of it over the past couple of 
> years is that the second tuner frequently just dies.  There are 
> multiple recipes on the internet on how to fix this, from slowing down 
> the tuner to setting values in modules.conf to prevent the inbuilt usb 
> hub being timed out.  None have worked for me.  So want I want to do 
> is only use the first tuner ( although I considered using the second 
> tuner as a lowest priority input, I would prefer a recording move to a 
> later time rather than be scheduled to record on it only to fail to 
> record - it does tend to fail silently and only a reboot will recover 
> it).  I would like make the second tuner available for live TV (until 
> it fails that is)
>
> I have just purchased a Pinnicle TV nanostick T2 290e which will give 
> me DVB T2 capability and receive the HD channels.
>
> I would like things setup so that for recordings
>
> A) If I request an HD channel recording it automatically selects the 
> Pinnicle device
> B) If I request a Non HD channel recording it gives preference to the 
> Nova T device, but if there is a conflict to choose the Pinnicle 
> Device if its free
> C) If I request an HD channel recording and the Pinnicle device is 
> scheduled to record a non HD channel, the HD channel takes priority 
> and the Non HD channel is not recorded.
> D) I would like MythTV to find an HD version of a program if possible 
> and use that, rather than a non HD version (eg make BBC 1 and BBC 1 HD 
> synonymous with BBC 1 HD higher priority)
>
> The problem is, at the moment - previously scheduled recording (from 
> before I changed the tuner) and scheduling HD channels on to the Nova 
> T, which has no capability of recording them
>
> It may be that I misunderstand what a Video source is.

A list of all the channels available on an input and their associated 
tuning information.  If the exact same list of channels is available on 
multiple inputs, they may (generally should) be connected to the same 
Video Source.

>   I have ONLY one configured which I call EIT and is the over the air 
> list of channels and their programs that I receive.
>
> In Mythtv-Setup, in input connections I have configured both my 
> capture cards to use that single source.
>
> I might also not understand what a channel scan does when I do one 
> within the input connection I have just setup the two inputs 
> connections and done a channel scan on both of them - but I am 
> suspecting that the found channels are going to a global channel list.

The channel scan needs to be done once per Video Source, and is only 
available in Input Connections to specify which input should be used for 
the scan.  Once completed for a given Video Source, there is no need to 
do additional scans using other inputs connected to that Video Source.

>
> In fact, after some thinking about it, what I am wondering is, is the 
> channel list associated with the input source, and the fact that you 
> channel scan in the input connections is just because that is where 
> there is a card associated with the source.
>
> So
>
> 1) How do I tell mythtv that a given input card can't record certain 
> channels? - Can I do this via two separate video sources (say EIT 
> without HD and EIT with HD)
> and connect the Pinnicle card to the EIT with HD source and the Nova T 
> cards (both of them) to the EIT without HD source. (and then do 
> channel scans)

Exactly.  Create 2 Video Sources that define what channels to allow on 
the inputs to which they're connected.

> 2) Should I  set the schedule priority for the second NOVA T card to 
> 0, but liveTV priority to a low none zero number?

Note that it is not a "schedule priority", but a "Schedule Order".  In 
Schedule Order or Live TV Order, low wins over high.

You use 0 to disable either recordings (via Schedule Order) or Live TV 
(via Live TV Order) on an input.

So, yes, you want to set the "Schedule Order" of the 2nd NOVA T to 0 to 
disable recordings on that input.  A non-zero Live TV Order will allow 
that input to be used for Live TV.  If the value is lower than any other 
specified Live TV Order, it will be the most-preferred input for Live 
TV.  If you want it available, but not generally used, you would want to 
make it non-zero, but higher than other Live TV Order values.

> 3) Should I set the schedule proritity for the first NOVA T card to a 
> low non zero number, set the schedule priority for the Pinnicle card 
> to a higher priority?

Again, since it's "order" and not "priority", you need to set the 
preferred inputs with lower values for Schedule Order.  So, assuming you 
want to use the Pinnacle for recordings, you could set it tuner(s) to 1 
and the NOVA T tuner to 2.

> 4) Set the liveTV priorities for the Pinnicle and First Nova T cards 
> to high priority?

I think this was answered in 2 and 3.

However, since  you said, "priority," I will say that you do /not/ want 
to change Input Priority for any of these cards.  Priority specifies 
whether or not to record shows--not where to record them.  It is simply 
an extension of recording rule priority--there is always only one 
priority in MythTV, and it just says whether or not to record a show.

If you set Input Priorities, you're basically saying, "I'd rather record 
garbage from this higher-priority input than a good show from the 
lower-priority input."  Since that's almost never what people want, 
Input Priorities are generally evil (are always evil if you set them 
without fully understanding how they're used).  Also, now that we have 
Live TV and Schedule Order settings, there's no good reason to abuse 
Input (and Channel) priorities to try to influence which inputs are 
preferred for recordings.

> 5) I have no idea how to go about achieving D
>

You may want to set the Channel Priority for the non-HDTV channels to a 
negative value (such as -1).  This says, "If an episode of a show 
matching one of my rules appears on an HDTV and non-HDTV channel, reduce 
the priority of the showing on the non-HDTV channel by one."  That is 
basically saying, "I'd rather record a lower-priority show on an HDTV 
channel than a slightly-higher-priority show on a non-HDTV channel."  By 
using a value of -1, you limit the effects of the "record garbage from 
this higher-priority channel rather than good shows from this 
lower-priority channel."  Also note that adding a negative priority to 
non-HDTV channels is /much/ better/safer than adding a positive priority 
to HDTV channels.

Also, another reply mentioned using Custom Priority to increase priority 
of HDTV shows.  However that approach is fragile as it relies on 
listings to determine what is and what is not HDTV.  Over time, as more 
and more content becomes HDTV, less and less tends to be marked as 
"HDTV"--and it's quite possible that BBC1 HD may not mark any of its 
shows as HDTV since it may be assumed that all are.  So, if you actually 
want to say, "I'd prefer to record shows from BBC1 HD rather than better 
shows on BBC1," use the Channel Priorities, as mentioned.

However, if you set your system so that the HDTV tuner(s) are used in 
preference (i.e. given a lower Schedule Order than the non-HDTV 
tuner(s)), the scheduler will probably do the right thing (unless backed 
into a corner with non-HDTV shows airing earlier than HDTV shows or 
something.  So, your best bet is to set all Channel and Input Priorities 
to 0 and specify appropriate Schedule and Live TV Order values and see 
if that does what you want.  Only use the Channel Priorities as a last 
resort because they say whether to record a show, not where/from which 
channel to record it.

Mike