[mythtv-users] Working around a lack of a IR Blaster

Nick Morrott knowledgejunkie at gmail.com
Sun Nov 22 18:30:27 UTC 2009

2009/11/22  <stefan_jones at comcast.net>:
> I don't have a working IR Blaster but want to record a few select shows.
> Shouldn't this work?
> Set up Analog video tuner card.
> Configure Input Connection to set tuner to a given channel (3).
> Connect output of STB to tuner. Set the STB to the desired channel.
> Put some dummy command in the outside tuner command line.

Using /bin/true is the recommended way to 'fool' MythTV into thinking
channel changing was successful in this scenario.

> Record anything in the appropriate time slot to make the tuner record from
> the STB for the appropriate length of time.
> Now, I tried this out this afternoon. First I tried watching Live TV on the
> Analog tuner. I saw the appropriate channel . . . the one that the STB was
> tuned to.

Expected if you have one or more tuners in the machine and (if more
than 1 tuner) you configured the analog tuner's input connection
_last_ in mythtv-setup. This gives the tuner the lowest recording
priority (as long as you have not made any other tuner/channel/LiveTV
priority changes) and will be used first for LiveTV.

> Then I tried a test record. No dice. If I'm looking at the right messages,
> another (digital) channel tried to tune in.

This is again expected if the digital tuner(s) has a higher priority
for _scheduled_ recordings. If you want to test the analog tuner for
scheduled recordings, you need to tell the scheduler to prefer to use
the analog tuner over other possibly higher-preference inputs. You can
do this in the scheduling options for each recording rule where you
want this to be the case.

> Do I need  to "scrub" the channels for the video source so they have no
> tuning information? It seems to me that the Input Connection's channels just
> need to supply a channel number . . . no tuning information that might cause
> a digital tuner to try to take over.

If you are using a video source that relies on using an external
channel change script, you need to ensure that each channel configured
on that input has a valid frequency value. In the case of controlling
an STB, it is the digits you want passed to the changer script.

A lack of tuning information will cause the recording to fail -
another tuner will not try to take over.


Nick Morrott

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