[mythtv-users] I got my Ceton InfiniTV 4 working in 0.24-fixes (compiled with custom code)

[Ronald Frazier]

On Thu, Jul 28, 2011 at 10:12 PM, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
> Ron, what steps are needed to get QAM working? I have a working lineup
> for my existing ClearQAM cards, I'm just wondering what I need to do
> to get the Ceton to work with them?
>
> Hopefully I'll be able to get a CableCard Aug1, but it would be neat
> to get the card working for ClearQAM before that.

First, see my reply to Tom about whether or not my patch even works
for QAM (I think it still does, but haven't tested it recently).

As far as how to setup the channels in myth, I kind of hacked things
together by hand on my dev machine when I was doing it, and it was
always a little bit of trial and error (I'd usually forget to set 1
field and wonder why things weren't working). So I don't really have a
script or step-by-step procedure to do this.

If you have a HDHR, I'm fairly certain (though not 100% positive) that
it should have all the fields you need set, so you could try just
pointing the Ceton card at the HDHR's video source and see if it
works. If it doesn't work, change the Ceton back to it's own video
source right away (I wouldn't want you to forget that it's sharing the
HDHRs source and then change it later and mess up your HDHR tuning)

If that doesn't work, then there's always the option of trying to
insert channels by hand. I'm not going to advocate doing this (not
only is it error prone, but it's time consuming to do anything more
than setting up 1 or 2 test channels). However, if you are determined
to try, then the important bits that I remember are that the serviceid
field should be set to the mpeg program number (*** see note below),
the mplexid points to a valid entry in the dtv_multiplex table, and
that the corresponding record in dtv_multiplex has the frequency and
modulation fields filled in. And of course, all of the other general
fields (chanid, channum, sourceid, callsign, etc) should be filled in
appropriately.

If you need, I can try writing a little perl script to do the scanning
and configuring of the video source tomorrow. However, I'll warn you
that I don't know a whole ton about the ins and outs of scanning QAM
frequencies. Basically, I can assume that your provider uses QAM256 as
mine does, and I can thus get a list of all the frequencies that my HD
Homerun scans for and use those as my basis for the scan. However, if
your cable provider uses one of the other modulations, I don't know a
thing about it and you'd be on your own for that bit.


*** note about the mpeg program number. Earlier on I had made an
assumption that the channel number will always match the mpeg program
number. That seemed to be true for me, but as we discovered, it's not
always true for some cable systems when using a cablecard. However,
when using QAM tuning, as far as I know, the channel number and mpeg
program numbers DO match. If that assumption is also incorrect, then
I'm not really sure where I'd get the 2 separate bits of information
from. The only place I can find it on the Ceton is in the channel map
page, and that only works in cablecard mode, not QAM mode. From my
looking at the MPEG-TS specs a while back and trying to decode the
packets, I saw no place there that the second field could be stored.
Thus if my assumption is also wrong for QAM, I'm in the dark about how
to identify which program number belongs to which channel.

-- 
Ron Frazier