[mythtv-users] Guidance for phase 9

Tom Dexter digitalaudiorock at gmail.com
Tue Aug 13 16:51:04 UTC 2019


On 8/13/19, Allen Edwards <allen.p.edwards at gmail.com> wrote:
> On Tue, Aug 13, 2019 at 8:07 AM Tom Dexter <digitalaudiorock at gmail.com>
> wrote:
>
>> On 8/13/19, Tom Dexter <digitalaudiorock at gmail.com> wrote:
>> > On 8/12/19, Allen Edwards <allen.p.edwards at gmail.com> wrote:
>> >> On Mon, Aug 12, 2019 at 1:26 PM Tom Dexter
>> >> <digitalaudiorock at gmail.com>
>> >> wrote:
>> >>
>> >>> On 8/12/19, Allen Edwards <allen.p.edwards at gmail.com> wrote:
>> >>> > In planning for Phase 9 channel reassignments scheduled for next
>> >>> > year
>> >>> > I
>> >>> > found this quote (paraphrase):
>> >>> >
>> >>> > "MythTV rescan is just too difficult so I did it manually and it
>> >>> > only
>> >>> took
>> >>> > 4 hours"
>> >>> >
>> >>> > Not what I wanted to find. Can someone point me to how this should
>> >>> > be
>> >>> done.
>> >>> > Specifically, I find four possibilities on how this might be done
>> >>> > in
>> >>> > two
>> >>> > menus:
>> >>> > In Connect Source to Inputs
>> >>> > 1) Scan for Channels
>> >>> > 2) Fetch channels from Listing Source
>> >>> >
>> >>> > In Channel Editor
>> >>> > 1) Channel Scan
>> >>> > 2) Edit Transports
>> >>> >
>> >>> > I have learned the hard way not to just experiment so I am asking
>> >>> > for
>> >>> > guidance.
>> >>> >
>> >>> > I have two HD Homerun dual tuners (first generation) so I have four
>> >>> capture
>> >>> > cards listed and connected to a single Video Source called "Antenna
>> >>> North"
>> >>> > which is linked to Schedules Direct. All the capture cards are
>> >>> > apparently
>> >>> > set up as MPEG2TS.
>> >>> >
>> >>> > My system is Mythbuntu 14.04.1 LTS and MythTV fixes/0.28
>> >>> >
>> >>> > Is there some documentation or can someone give me some specific
>> >>> > guidance
>> >>> > for doing the required rescan or other channel reassignment
>> >>> > process.
>> >>> >
>> >>> > Allen
>> >>> >
>> >>>
>> >>> I just replied to a thread from James Abernathy with the subject "USA
>> >>> OTA FCC frequency rescan?" that you may want to check out. As far as
>> >>> I
>> >>> know, the biggest pitfall of the channel rescan in mythtv-setup is
>> >>> the
>> >>> possibility of new channels getting created when you really want to
>> >>> just change the frequency of existing channels. This (also as far as
>> >>> I
>> >>> know) is caused by the station changing the callsign that gets
>> >>> reported from the signal itself.
>> >>>
>> >>> Assuming you have something that can be used to just scan channels to
>> >>> a file as I describe in that reply, you should be able to use the
>> >>> channel editor to change and callsigns to the new ones before doing
>> >>> the rescan to prevent that.
>> >>>
>> >>> I'm actually one of those who's written utilities of my own to
>> >>> manually change frequencies surgically, but again, I believe those
>> >>> callsign changes are the main source of unwanted results.
>> >>>
>> >>> Tom
>> >>>
>> >>>
>> >> I am not sure I understand the call signs of these stations. Let me
>> >> give
>> >> an
>> >> example.  Channel 7_3 in MythTV Channel infor is LAFFTV.  In HDHomeRun
>> >> (under windows) it is also LAFFTV. In Schedules Direct it is KGODT3
>> >> and
>> >> the channel that overwrites it is KGOLD3. I think I should ignore the
>> >> SD
>> >> name.
>> >>
>> >> I did hdhomerun_config 10126134 scan /tuner1 filescan and for the
>> >> above
>> >> channel I get two listings
>> >> Channel 35 Program 5 7.3 LAFFTV
>> >> Channel 7 Program 5 7.3 LAFFTV
>> >>
>> >> That is the problem I always have with scan. I end up with channel 35
>> and
>> >> I
>> >> want channel 7. According the the repack guidance I am seeing, 7 will
>> >> move
>> >> to 12 and 35 stays put. This will still give ma a problem when I scan.
>> >> I
>> >> think I just rescanned and interrupted it before the overwrite but I
>> >> am
>> >> not
>> >> sure.
>> >>
>> >> So just to clarify, you are suggesting checking that LAFFTV and all
>> >> the
>> >> other channels to check for name changes then just do a rescan and
>> figure
>> >> out how to deal with channel 7.
>> >>
>> >> It looks like the repack will move 4 stations we watch.
>> >>
>> >> Channel 35 comes to the back of my antenna and is weak. It has the
>> >> same
>> >> program information as channel 7.
>> >>
>> >> Allen
>> >>
>> >
>> > Wow...I'm a bit confused as to what you're saying. Here's an example
>> > what my output from the scan looks like:
>> >
>> > SCANNING: 599000000 (us-bcast:35)
>> > LOCK: 8vsb (ss=92 snq=98 seq=100)
>> > TSID: 0x07D5
>> > PROGRAM 1: 4.1 WNBC
>> > PROGRAM 2: 4.2 COZI-TV
>> > PROGRAM 3: 47.1 WNJU-HD
>> > PROGRAM 4: 47.2 TeleX
>> >
>> > That PROGRAM reported there (stored as the serviceid on the channels
>> > table) is always unique for the specific frequency and defines the
>> > specific channel on the multiplex. What's the exact output you're
>> > getting? It sounds like you're saying you get the same channel and
>> > callsign (7.3  LAFFTV) on two completely different frequencies. If so
>> > that's pretty ugly and I have no clue how or if the channel scan would
>> > deal with that.
>> >
>> > As to the callsign reported by SD that should have no affect on
>> > anything related to the scan. As mentioned above, the only connection
>> > between the MythTV channels and XMLTV is the xmltvid on the channel.
>> >
>> > Tom
>> >
>>
>> Sorry...clearly didn't read you're reply carefully enough. It sounds
>> like that's exactly what you're saying. I assume  that when you refer
>> to channel 7 and 35 you mean the VHF channel 7 and UHF channel 35.
>>
>> Wow, yea that's a tough one, and I've never encountered that. Maybe
>> someone else here knows what might happen in that case.
>>
>> Tom
>> _______________________________________________
>>
>
> Yes, I am referring to transmitter channel 7 and 35.  After the repack they
> will be transmitter channel 12 from San Francisco and transmitter channel
> 35 from San Jose. I live between the two.  They both carry the same
> programming and both are virtual channel 7. What happens is that you end up
> with transmitter channel 35 and nothing for channel 7.
>
> What I remember for sure is that it was a problem because I want
> transmitter 7 and after the scan I got transmitte 35, which is weak.  I
> think I repeated the scan to clear it.  I don't recall if the scan started
> at the high end, got 35 and then ignored 7 or if it started at the low end
> and when it got to 35 it overwrote 7. My forensics indicate that I started
> the final scan on 7.1 so once I know which way the scan works, I will know
> what I did.
>
> Perhaps I could have renamed the channels from transmitter 35 to something
> other than 7 and then deleted them after the second scan. But I dealt with
> it before so I guess I can deal with it again. It is just too bad I can't
> just edit something or fetch channels from listing source and have that
> work and avoid the scan.
>
> Two questions remain unanswered (or perhaps unasked):
> 1) Does "Fetch channels from listing source" work? If so, what does it do?
> 2) Is there documentation on "Edit Transport" beyond don't use it unless
> you know what you are doing?
>
> I only need to change 4 channels although that represents a larger number
> of sub channels.
>
> Allen
>

First of all, you probably want to read the list thread with the
subject "USA OTA FCC frequency rescan?", as it seems I was wildly
wrong about the importance of the callsign in the scan. Based on
replies there, new frequencies apparently WILL cause a new channel to
get created. That was news to me for sure. I was probably confusing
that with the roll of callsigns with recording rules, which is where
they become important.

To be honest I can't answer either of those questions. If I ever used
that "fetch channels" it would have been 12 years ago when I first
built my system. I've never used the edit transport either and am not
even clear what it attempts to do.

Tom


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