[mythtv] schema for manually adding channels

[Michael T. Dean]

On 01/14/2016 10:38 AM, Matt Zagrabelny wrote:
> On Thu, Jan 14, 2016 at 8:04 AM, Michael T. Dean wrote:
>> On 01/14/2016 08:12 AM, Matt Zagrabelny wrote:
>>> Hi Mike,
>>>
>>> Thanks for the reply!
>>>
>>> On Thu, Jan 14, 2016 at 6:39 AM, Michael T. Dean wrote:
>>>> On 01/13/2016 05:37 PM, Matt Zagrabelny wrote:
>>>>> Greetings,
>>>>>
>>>>> I've grepped the -dev archives and didn't find an answer to the question
>>>>> of:
>>>>>
>>>>> What tables do I need to add records to in order to manually add an
>>>>> ATSC DTV channel?
>>>>>
>>>>> It looks like: channel and dtv_multiplex. Any other tables?
>>>>>
>>>>> I have a channels.conf file that works with mplayer:
>>>>>
>>>>> 3.1:587000000:8VSB:49:52:1
>>>>> 3.2:587000000:8VSB:65:68:2
>>>>> 6.1:503000000:8VSB:49:52:1
>>>>> 6.2:503000000:8VSB:65:68:2
>>>>> 8.1:183000000:8VSB:49:52:1
>>>>> 8.2:183000000:8VSB:65:68:2
>>>>> 8.3:183000000:8VSB:81:84:3
>>>>> 8.4:183000000:8VSB:97:100:4
>>>>> 10.1:195000000:8VSB:49:52:3
>>>>> 10.2:195000000:8VSB:81:84:5
>>>>> 21.1:491000000:8VSB:49:52:3
>>>>>
>>>>> Any hints about manually adding channels will be much appreciated.
>>>>>
>>>>> Thanks!
>>>>
>>>> Digital channels, especially, really need to be scanned using
>>>> mythtv-setup's
>>>> channel scanner.  We don't support importing channels.conf anymore
>>>> because
>>>> there are many formats used by different channels.conf files and--more
>>>> importantly--channels.conf doesn't contain all the information MythTV
>>>> needs
>>>> for its channels.
>>>>
>>>> So, why not just scan with MythTV's channel scanner?
>>> Using the scan for channels feature of mythtv-setup doesn't find the
>>> channels. Originally after installing Myth, the scan didn't find *any*
>>> channels - that was a few weeks/months ago. I just reran the scan
>>> about a week ago and it found *one* channel - with four subchannels:
>>> 8.1 - 8.4.
>>>
>>> The issue doesn't seem to be unique to myth either. I have run a
>>> separate scan utility:
>>>
>>> w_scan -A1 -X -c US -fa -t3
>>>
>>> and it doesn't find all the channels, but it did find more than the
>>> myth scan did.
>>>
>>> I have a friend who lives on the other side of town and his w_scan
>>> found all the channels. I've used that channels.conf file with mplayer
>>> and verified that all of the channels in it "work".
>>>
>>> Any ideas of where to proceed from here?
>>>
>>> Thanks for the help!
>>
>> Sounds like poor signal issues coupled with too-short tuning and/or signal
>> timeouts.  Try increasing (possibly significantly--like to the maximum
>> allowed) the "Signal timeout (ms)" and "Tuning timeout (ms)" in Capture Card
>> setup, then "Delete all Video Sources", then reconfigure your video sources
>> and redo your channel scan.
> Thanks for the advice, Mike. I upped the timeouts to 15 seconds, I
> could have kept increasing it, but I didn't want the scan to take all
> day.
>
> The scan got almost all the channels - there is one channel left. So
> either I need to rescan with a timeout longer than 15 seconds or
> manually insert that last channel.
>
> What do you think?

I'd recommend, for the short term, rescanning with higher timeouts to 
see if that gets your last channel (and/or rescanning at a different 
time of day and/or day--with different atmospheric conditions (wind, 
etc.) and/or different radio usage conditions--like morning, afternoon, 
evening, vs night and/or weekday vs weekend and/or dry week vs rainy 
week and/or--though this is getting to more long term--winter vs spring 
vs summer vs fall for different foliage/weather/... conditions :).  You 
can keep what you have now and do a tuned scan, where you specify the 
frequency, to try to get the one more channel without having to wait for 
timeouts on all the other frequencies.  Once done, you can decrease your 
timeouts, as desired--just make sure to test that MythTV is 
(reliably--at different times of day and on different days) still able 
to tune the channels in /both/ Live TV and scheduled recordings (since 
the 2 are often tuned with different constraints).  Or, at the least, 
after reducing the timeouts, if you see failed recordings or failed Live 
TV/channel changes in Live TV, go back in and increase the timeouts 
slightly until you find a good value.

For the long term (and for maximum satisfaction with your TV setup), I 
highly recommend attempting to improve your signal quality--by improving 
your antenna, antenna positioning/height, cabling, amplifiers, 
splitters, ... (assuming OTA) or by contacting your cable company (if 
cable).  I'd recommend posting on the mythtv-users mailing list for more 
information--you'll be sure to find a lot of people who can give a lot 
of good advice on the subject--and it's likely to be things you can do 
for little or no cost.

Mike