[mythtv-users] cards vs sources vs inputs confusion, problems and possible bugs

Nick Morrott knowledgejunkie at gmail.com
Thu Dec 3 02:20:33 UTC 2009

2009/12/2 Petr Stehlik <pstehlik at sophics.cz>:
> George Mari píše v Ne 29. 11. 2009 v 10:26 -0600:
>> Assuming your two cards are both receiving from the same service
>> provider, I'm also pretty sure you should not setup two independent
>> sources, as you will run into the problems you mentioned.
>> I have 2 cards also - one receives OTA broadcasts via antenna, and
>> another receives analog video from a satellite settop box.  I have one
>> source, but I have two lineups with Schedules Direct.  Most of the OTA
>> channels are duplicated on the satellite lineup, and I just associate
>> the OTA card with the OTA lineup for my region from Schedules Direct,
>> and the Satellite lineup is linked to my old analog card.  It all just
>> seems to work fine.
>> If you post who your satellite service provider is, I'm sure someone
>> else on the list can help you out.
> It's Astra 3A but I don't think it's important. I am more interested in
> the "wiring" inside of the mythsetup (Input Connections) when one card
> is more capable than the other one so it can receive more channels. If
> there is just one video source then I don't quite see how to prevent the
> less capable card tuning to all the channels in the video source.

You will need to configure two video sources, and configure each of
the card inputs separately on the Input Connections screen.

If one input receives a subset of channels compared to another input
(even if the channels received on both inputs are transmitted using
the same method - analog/DVB-T/DVB-S/ATSC/QAM etc) you need to ensure
that you have separate video sources that contain only those channels
available for the intended tuner. This will prevent MythTV from trying
to schedule recordings or watch LiveTV on channels that are not
available on an input.

> I should try changing it to one source and see for myself but before
> I'll break all the stuff (tuning the sat channels back will take me
> several hours of manual work) I thought I would ask here.

Good idea. I comes up fairly regularly, but sitll requires a fair
amount of configuration, especially for non-Schedules Direct users.

> Anyway, I am going to buy some DVB-T tuners that will further complicate
> the setup (they can receive only a subset of the DVB-S channels).

Again, configure a new video source for just the DVB-T channels. If
all DVB-T tuners can receive the same group of channels, you only need
to configure a single video source and connect it to all of the DVB-T
tuners in mythtv-setup.

> My goal is still the same: in LiveTV pressing a certain channum should
> always find a free tuner that can tune and play that program (no matter
> if its DVB-S2, DVB-S or DVB-T). Also when browsing across all the
> channels on all tuners pressing the OK on any channel should again find
> a free tuner and tune&play that. So far it does not work that way and
> the question remains if this is a bug in configuration or in Myth
> itself.

For scheduling:

MythTV needs 'equivalent' channels (broadcasting the same station)
available on all video sources to have the same callsign in order to
make intelligent scheduling decisions across tuners. Obtaining
listings from the same source (SD/XMLTV/EIT etc) for all video
sources/channels will ensure that the scheduler uses the same
programme data during scheduling runs. Mixing listings from different
sources for 'equivalent' channels can result in unexpected behaviour.

For LiveTV browsing and EPG viewing:

Giving 'equivalent' channels on all video sources the same channel
number (channum) and name will group channels together so that MythTV
can 'find' the channel on all tuners and allocate it to the next best
LiveTV tuner if required. It will also hide multiple copies of the
'equivalent' channels which can greatly condense the EPG.


Nick Morrott

MythTV Official wiki: http://mythtv.org/wiki/
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