[mythtv] Has anyone tested channel scanning in a us-cable Clear QAM environment?
Klaas de Waal
klaas.de.waal at gmail.com
Mon Feb 10 19:53:32 UTC 2020
Hi faginbagin,
On Mon, 10 Feb 2020 at 03:15, faginbagin <mythtv at hbuus.com> wrote:
> On 2/8/2020 3:52 AM, Klaas de Waal wrote:
> > Hi faginbagin,
> >
> > On Sat, 8 Feb 2020 at 02:39, faginbagin <mythtv at hbuus.com <mailto:
> mythtv at hbuus.com>> wrote:
> >
> > On 2/7/2020 1:55 PM, Klaas de Waal wrote:
> > > On Fri, 7 Feb 2020 at 08:00, faginbagin <mythtv at hbuus.com <mailto:
> mythtv at hbuus.com> <mailto:mythtv at hbuus.com <mailto:mythtv at hbuus.com>>>
> wrote:
> > >
> > > I ask because I can't get mythtv-setup to find any channels. I
> first
> > > tried a scan before running mythfilldatabase as mentioned in
> this email
> > > thread on mythtv-users:
> > >
> http://lists.mythtv.org/pipermail/mythtv-users/2020-January/402291.html
> > >
> > > I just tried another channel scan after running
> mythfilldatabase.
> > > mythfilldatabase added lots of channels and listings to the
> database,
> > > but the channel data looked incomplete. So I did a full
> channel scan,
> > > which said it was scanning for ATSC channels, not QAM, and
> found no
> > > channels. I can't find any channel scan settings that
> distinguish
> > > between ATSC and QAM.
> > >
> > > Not surprisingly, the channel data still looks wrong. For
> example, all
> > > of the channel records have a NULL mplexid and the
> dtv_multiplex table
> > > is empty. Has tuning a clear qam channel changed so much that
> channel
> > > records don't need to point to valid dtv_multiplex records any
> more?
> > >
> > > FWIW, both "General -> Locale Settings -> Channel frequency
> table" and
> > > "Video Sources -> MyVideoSource -> Channel frequency table"
> are set to
> > > us-cable and the listings grabber is "Multinational (Schedules
> Direct
> > > JSON web services w..." and the listings data looks correct.
> > >
> > >
> > > It is interesting to know which version of MythTV you are running.
> There are lots of changes in the latest master / v31 compared with previous
> versions.
> > > You might have missed the Scan Type/ Full Scan settings, see the
> end of this thread:
> > > https://forum.mythtv.org/viewtopic.php?f=36&t=3567
> > > Also described here:
> > > https://www.mythtv.org/wiki/Channel_Scanning#Scan_Type_2
> > >
> > >
> > >
> > > _______________________________________________
> > > mythtv-dev mailing list
> > > mythtv-dev at mythtv.org <mailto:mythtv-dev at mythtv.org>
> > > http://lists.mythtv.org/mailman/listinfo/mythtv-dev
> > > http://wiki.mythtv.org/Mailing_List_etiquette
> > > MythTV Forums: https://forum.mythtv.org
> > >
> >
> > Hi Klaas,
> >
> > My apologies for not mentioning the version, it's v31 from the
> ubuntu PPA, 2:31.0~master.202002051824.e81d4cc~ubuntu19.10.1 and the distro
> is lubuntu 19.10 with the lxqt desktop.
> >
> > Both the forum thread and images got me on the right track. Instead
> of scanning 51 ATSC channels, I'm now scanning 130+ QAM-256 channels. It's
> still in progress. I'll report back once I've done further testing.
> >
> > But I must say the new settings UI is quite confusing and a
> departure from how other parts of mythtv's UI work. It hadn't occurred to
> me that right arrow would do something different than OK. Also, that left
> arrow behaves differently than ESC.
> >
> > Another point of confusion: after navigating to the scan type page
> and changing the frequency table and modulation to cable and qam-256,
> followed by pressing ESC and being asked if I want to save my changes, and
> saying yes, why am I kicked out of not only the scan type page, but also
> out of the channel scan page? And when I go back into the scan type page,
> why are the frequency table and modulation settings back to the original
> broadcast and 8-vsb settings? Maybe something can be done to explain these
> points in the help text and the wiki?
> >
> > And, if I've specified us-cable as the channel frequency table in
> the channel scan page and also in the Global -> Locale page, why does the
> frequency table in the scan type page always revert to Broadcast, not to
> mention 8-vsb modulation? Seems to me there's room for improvement in
> setting more reasonable defaults based on the us-cable setting as well as
> saving the settings the user specifies?
> >
> > Food for thought?
> >
> >
> > I am glad that the scanning does work for you now.
> > About your painful experiences with the GUI, you have made a good
> summary of what can be improved. It is largely in line with what I have in
> mind. For the time being I have documented the way it works in the WIki in
> https://www.mythtv.org/wiki/Channel_Scanning but I do not expect people
> to actually read all of this, But it is there for when desperation sets
> in....
> > Interesting is also that most of the changes in v31 are "under the
> hood", the GUI is not really changed since v30 except for a few new options.
>
> Hi Klaas,
>
> I haven't used mythtv-setup to do channel scans in years. My cable company
> has only made incremental changes over the years, most of which haven't
> been important to me. When they do make a change I care about, I've used
> hdhomerun_config to scan for changes, then crafted sql inserts and updates
> to the channel and dtv_multiplex tables. I tend to upgrade mythtv with
> every other release, e.g. 0.27 to 29 and now to 31. And I didn't need to
> spend much time in mythtv-setup to get 29 configured for my needs.
>
> Now I'm getting ready to upgrade to 31 and find it necessary to re-learn
> how to setup a video source because of the elimination of the DataDirect
> video source. So, I figured it was also time to see how channel scanning
> works these days. I had hoped, since the channel table was populated by the
> new Schedules Direct video source, that maybe the channel scan would be
> able to update those channel records. But it didn't happen, at least not in
> my case. Instead, it just added all new channel records for those found in
> the scan.
>
> In my case, the channel scan only found 68 channels when there are
> actually just over 100 channels. Maybe increasing timeouts would help. But
> if I've still got to populate the xmltvid columns, then I think I'm better
> off starting with my production system's channel and dtv_multiplex tables
> and using the switch_to_json.py script Bill Meek sent me to automate
> conversion from the old to the new xmltvids.
>
> Many Thanks for your help in getting channel scanning working.
> _______________________________________________
>
Thanks for testing on USA cable. I appreciate getting feedback on this
since I can test only on DVB sources. I have made changes over time that
also can influence the ATSC behaviour but there has no serious regression
testing been done on this.
About finding only 68 channels when there are actually just over 100
channels.
Could you try with larger timeouts to see if that makes a difference? In
v31 the default timeout values have increased from 1000/3000 to 3000/6000
but maybe even bigger timeouts are needed. Note that this new default is
only for new capture cards, the timeout values of existing capture card
entries are not changed.
It could also be that there are frequencies used that are not being tested
with a channel scan. The way it works is that a predefined list of
frequencies is scanned but maybe that does not cover all frequencies.
To figure this out, could you provide me with a list of channels as found
by hdhomerun_config and also the output of a mythtv-setup channel scan with
the "-v chanscan" option? E.g. "mythtv-setup -v chanscan 2>&1 | tee
ms-20200210-2033.log".
About creating new channels vs. updating existing channels.
The v31 code does try to update existing channels more than before so that
non-scanned channel information like xmltvid is preserved across scans.
If I understand you correct then you have tested with a channel list
created by/from Schedules Direct and then do a mythtv-setup channel scan.
The expected/wanted behaviour is that the channels in the database are
updated, but the actual behaviour is that mythtv-setup creates new channels.
Correct?
To figure if the expected behaviour can be realized I need a dump of the
tables channel and dtv_multiplex as created by/from SchedulesDirect and
also as created by mythtv-setup.
N.B. the default Channel frequency table for ATSC "Full Scan" is now
obtained from the Video Source table value or, if that is "default", from
the General / Locale settings table value, in master and in fixes/31. Of
course it might take a few days before this is in a repository near you.
Thanks,
Klaas.
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