another Comcast head-end goes digital

[Bill Bogstad]

On Wed, Mar 31, 2010 at 3:11 AM, Tom Metro <tmetro-blu-5a1Jt6qxUNc at public.gmane.org> wrote:
> Bill Bogstad wrote:
>>
>> Tom Metro wrote:
>>>
>>> This page:
>>> http://www.mythtv.org/wiki/Comcast_Users_And_scte65scan
>>> written in response to the Comcast transition, describes a procedure for
>>> setting up channel mapping for clear-QAM tuners...
>>
>> I basically followed that procedure to set up my system in Cambridge.
>> I currently get something like 80+ clear QAM channels.
>
> I've finally gotten around to looking into implementing this... (a rest from
> fighting domain thieves).
>
> Reading through that page above and the README for scte65scan shows that
> this process is still overly complex. Something likely to take hours of
> trial and error. It seems there are these major steps:
>
> 1. get the HDHR working with its tools and the firmware updated (done).

Have you run the hdhomerun_config_gui and verified that you have clear
QAM signals which
are viewable?

> 2. use scte65scan to find your channel mappings. (Did you build from tar
> (from last May) or from svn? I saw at least one note that the SVN version
> has some Comcast relevant fixes.)

I'm currently using the rev28 SVN version.  I just checked and there
is apparently a rev29 as well.

> 3. determine the right scte65scan command line options to get it to produce
> just the right SQL (referencing the correct tuner IDs, etc.) to load into
> MythTV's database. Sounds like there's a potential for conflicting channel
> IDs too, if you have multiple digital tuners.

The svn version has the -f n,m option which let's you specify the
source id.   That's your listing source id rather then tuner id.   All
tuners which get the same set of channels (and possibly? tune them in
the same way) will use the same source id.  I have two HDHomeRuns (4
tuners) and they all use the same set of entries in the channel table.

> 4. refine the channel lineup in MythTV. This step still is vague to me, but
> I haven't looked at it closely yet. Do you still need to enter XmltvIDs, or
> is that taken care of? Which is the best place to add/remove channels from a
> lineup? At Schedules Direct, or from within MythTV or both? I know if you
> don't do it just right, your edits can end up getting overwritten.

I THINK if the channel callsigns match up between what your listings
source (SchedulesDirect) and Comcast sends via scte65 that no extra
effort will be required.  I think I had to manually change the
callsigns in order to make them match.  I believe I did this via the
MythWeb channel editor so it wasn't so bad.  I also believe I just
downloaded the channels from SchedulesDirect and didn't do any manual
scanning.  Oh, if you don't like having lots of channels that you
can't actually tune to, you'll want to change your lineup at
SchedulesDirect so that only the channels you can actually get are
part of your lineup.  [I'm sorry about so many "I thinks".  It was all
kind of trial and error and it wasn't always clear what
made a difference and once it was all working I didn't go back and
document what was required from a fresh install.]

> At the moment I'm stuck on step #2. I know my system uses HRC frequencies,
> but I can't seem to find the us-Cable-HRC-center-frequencies-QAM256 file for
> use with scte65scan. (Scanning with
> us-Cable-Standard-center-frequencies-QAM256 produces "no lock" on all
> frequencies.)

I believe that my system is HRC as well and I have no problem using
that file for scte65 scans.  Have you tried scanning for PSIP data as
well (-p)?  That should at least show the embedded info that comes
through on OTA HD channels.  Even if Comcast isn't sending SCTE65 data
in your area you should at least be able to see PSIP data.

> The scte65scan README vaguely indicates the files are part of some other
> package, and a MythTV users list posting points to:
>
> https://sourceforge.net/projects/dvbtools/
>
> but neither of the packages published there contain the files.
> I also checked the dvbtuner and dvbstream packages in Ubuntu.
>
>
>> Things have been in steady state for me since then.
>
> Did I see a post from you more recently on MythTV users indicating that you
> had received notice from Comcast that the clear QAM was going away?

Yes.

> At the moment, using the HDHR supplied tools, I can definitely find a bunch
> of extended basic channels in the clear.
>
>
>>> 2. Anyone currently using a Comcast "Digital adapter" (bare-bones cable
>>> box) with MythTV?
>>
>> I've had no need to do so since I already can record the digital
>> signal directly with my HD HomeRuns.
>
> For now...

I've already reinstalled my PVR-150 into my backend and have a USB IR
blaster on order.  My cutoff date is April 7.

Bill Bogstad