[mythtv-users] is this possible (multiple tuners and sources)

Dylan Keon dbkeon.ml at gmail.com
Wed Aug 10 22:12:54 UTC 2005


On 08/10/2005 12:01 PM, Bruce Markey wrote:
> Dylan Keon wrote:
> 
>>   My goal is to have the two PVR-250s record analog cable (already 
>> working), and the PVR-150 record OTA broadcast signals via my rooftop 
>> antenna since the reception of local channels stinks on our analog cable.
>>
>> I set up a new video source called "antenna" and configured a new 
>> "local broadcast" channel listing for my area at zap2it.  However, 
>> it's not clear to me how this will get handled in the EPG.  For 
>> example, channel 7 on analog cable is Discovery, while channel 7 on 
>> broadcast is PBS. 
> 
> The one marked "7 DSCP" and shows MythBusters is Discovery, the one
> that says "7 PBS" and has Nova is PBS. Oddly, this is the second
> time this has come up recently. If you schedule MythBusters, it won't
> bust myth and record Nova by mistake =).

Ok, good :-)

>> After running mythfilldatabase these both appear in the EPG, but where 
>> channels are the same (i.e., channel 9 is the same station on both 
>> cable and OTA), there is only one entry in the EPG.
> 
> Correct. By design. If the channel number and callsign are the same,
> it does not show both. I have NBC on 3 for analog and on 3 and 123
> digital (chanids 1003, 2003 and 2123 respectively). The EPG shows
> one line for NBC on 3 rather than two identical lines next to each
> other but does have another line for 123. If another input had
> station "KRAP" on 3 (3003), the EPG would include both channel
> 3 stations.

Nice callsign ;-)  I just took a peek via mythweb and I can see that my 
EPG is also arranged as you described.

>> I want local channels to be recorded on the PVR-150 by default, using 
>> the local broadcast channel listing unless there is a conflict, in 
>> which case they would get recorded on one of the PVR-250s.  Cable-only 
>> channels would always get recorded on the PVR-250s.  Is all of this 
>> (or any of this) possible?
> 
> This has all been solved long ago. You actually have some choices...
> 
>> I could just delete the duplicate broadcast channels from the cable 
>> lineup, but then that would eliminate the possibility of using the 
>> cable as a backup to resolve conflicts.
> 
> Myth treats two channels with the same callsign as being the same
> station and are interchangeable. Which channel is used for a show
> on that station is deterministic. If all else is equal, by default
> the scheduler will choose the lowest numbered input that has that
> station available.

Ahhh, this is good to know.

> There is also an option on the mythtv-setup Input connections page
> for "Input preference". If you set this one higher than the others,
> that tells the scheduler that it is better to record from this input
> whenever possible rather than to record from the other inputs.

Great, I think this is what I need!

> There is a subtle difference with "Input preference" vs just relying
> on the lowest input number winning. Say you have your "antenna"
> input first (probably not right now because you added it last)
> and there is a high priority show at 7 and a lower priority show
> at 7 and 10 on a channel that is available on both sources. If the
> input preference is the same, the high priority show will record at
> 7 on "antenna" and the lower will record at 7 on the channel from
> the other source. If you raise the input preference for the antenna
> input, it would record the high priority show at 7 and the lower
> priority show at 10 when it can fit it on the preferred input. If
> there was another conflict at 10 then it would again use the other
> source at 7.

When I installed the PVR-150 it appeared as /dev/video0 so I believe it 
is the lowest input number.  I had to edit the PVR-250s in mythtv-setup 
since they are now /dev/video1 and /dev/video2.

Great example.  Regarding the scenario where the same show is airing at 
7:00 and 10:00 on a channel available to both sources - how far into the 
future would myth look to make sure a show gets recorded on the 
preferred input?  How aggressively does myth do this?  For example, you 
wrote that the show wouldn't be recorded until 10:00 so that the 
preferred input could be used.  Would myth look forward as far as a week 
to find a slot when the show could be recorded on the preferred input? 
If that's the case I would rather just have it record on the other 
source so I could have it available sooner.

> So, you could redo your cards and inputs so that "antenna" is first
> but if the signal is actually better, I'd suggest leaving your card
> setup as is and just setting the input preference to "1" so that it
> will always try to get the clearest recordings for you. Way too much 
> info is at: http://www.mythtv.org/docs/mythtv-HOWTO-11.html#ss11.7

Since the PVR-150 is already the lowest input number perhaps I don't 
need to define an input preference.  I'll have to do some testing.

Bruce, thanks a million for your detailed response.  This is very 
helpful information.  Shuffling off now to read the howto....

--Dylan


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