[mythtv-users] Issues with Set Top Box and Digital Channels

Michael T. Dean mtdean at thirdcontact.com
Thu May 20 14:10:07 UTC 2010

On 05/19/2010 06:42 PM, Nick Couchman wrote:
> I'm trying to use MythTV to control a set-top converter box for digital TV.  The STB feeds via a composite input into the card, and I have an IR blaster that controls the STB.  I have a script, /usr/bin/ch_chan.pl, and I can successfully, from the command line, issue a command line "/usr/bin/ch_chan.pl 31.1" and have the IR blaster send the commands to the STB and see the channel change.
> I'm having trouble on the MythTV side...a couple of issues that I believe are related.  First, if I try to use the "Fetch Channels from Lineup" option to pull the data from my SchedulesDirect.org account, it doesn't pull any channels *unless* I happen to have one of the remaining non-DTV channels present, then it pulls only that (those) channel(s).

mythfilldatabase will never add a digital channel to a video source 
since, generally, digital channels require more information than is 
provided by listings sources (requiring an actual scan) or digital 
channels may be restricted (not part of the cable package for which 
you're paying).

However, users of analog capture who are receiving digital channels as 
tuned by a converter box will actually /want/ to add channels with 

>    For some reason, it appears to be choking on any channels that are in the digital TV format.  I'm not sure if this is because the numbers have a "." in them (e.g. 31.1), or because the call signs are longer than the traditional 4 letter call signs (e.g. KDVRDT instead of KDVR).  So, I get around this issue by manually entering the channels - name, channel number, and call sign.

Don't do that.

mythfilldatabase --help
    Normally MythTV tries to avoid adding ATSC channels
    to NTSC channel lineups. This option restores the
    behaviour of adding every channel in the downloaded
    channel lineup to MythTV's lineup, in case MythTV's
    smarts fail you.

Guess which option you need to provide?

>    This appears to work fine, until MythTV tries to go change the channel, and then nothing happens.  If I put some debugging lines in the script (ch_chan.pl), I can see that it does actually get called, but it appears to get called
>   without any argument(s) - no channel number.  This further strengthens my suspicion that MythTV is, for some reason, choking on channels with a "." in them.
> I've done some web searching and mailing list search for similar, related, or identical issues, to no avail, so I apologize in advance if this is something that's already been asked, covered, discussed, etc., but I'd appreciate some help debugging this problem.  I'm running MythTV 0.21 (tried 0.23, too) from the Packman repository on OpenSuSE 11.2

As mentioned by Rick, you need to have a proper frequency ID--which you 
will have if you use mythfilldatabase to populate your channels.

I /highly/ recommend using the video sources portion of 
http://www.gossamer-threads.com/lists/mythtv/users/264034#264034 to 
clean up what you have now, then re-create the video source, re-connect 
inputs, and use mythfilldatabase from the command line with the above 
argument to populate your channel list, then go back into mythtv-setup's 
Connect Inputs screen and set an initial channel.


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