[mythtv-users] Channel scan on both tuners (hybrid system) not possible? (setup)

A. F. Cano afc at shibaya.lonestar.org
Mon Jan 19 06:16:36 UTC 2009

Please be patient, I'm slowly getting there...

This applies to the OnAir Creator, accessed through the pvrusb2 driver,
although I suspect other cards or usb devices with hybrid tuners should
work the same, and mythtv 0.20-svn20 that comes with Debian Lenny.

This usb device has a hybrid tuner (analog and digital) with parts in
common, so it's not possible to use both at the same time.  It also has
a composite input and an S-video input (as well as a hardware encoder).

In mythtv-setup I set it up as an mpeg 2 device (/dev/video0) based on
reports I found of configuring a Hauppauge device which is apparently
very similar (it uses the same firmware).  The 3 inputs are correctly
recognized: television, composite and S-video.  When configuring the
video source television, I tell it to use the EIT scan on us-bcast
frequency table.

When going to input connections, the 3 video sources are there, so
I associate input Television to the video source Television.  A
channel scan at this point only scans (apparently) the analog channels.
In the next screen, I set up two input groups, which is, I gather,
mythtv's way of dealing with the two tuners: HDTV and Analog.

So far so good, but there doesn't seem to be a way to do a digital
channel scan.  What am I missing?

Of course, in mythfrontend, I can only watch the analog channels.
How can I switch to the digital tuner?  I have found that 'c' changes
the input, so I can go from 'television' to 'composite' (I have connected
a camera to the composite input), but I get a blank screen on 'composite'.
The same camera connected to the tv or vcr works just fine.

I have tried all kinds of combinations: as 2 capture cards, but then
there are 2 composite inputs and 2 s-video inputs, which is clearly
not the case; manually putting in the /sys/adapter0/* devices supplied
by pvrusb2 - mythtv-setup didn't like that at all; as a DVB-DTV card -
but then I can't get to the analog part and trying to watch tv with this
setup I can't get a signal lock on any of the ATSC channels the scan found.
The channel scan locks but says "no tables".  I presume this has to do
with the lack of channel information in the database?  In any case, if
the scan detected a channel, shouldn't it be viewable in the frontend?

Is DVB DTV card the proper setting for this device?  What am I missing?
Any hints or (especially!) experience with this device (am I the only
one usint it?) would be greatly appreciated.


PS: Before flaming me for not doing my homework, consider that I've spent
the better part of 2 days reading docs and doing google searches.  Most
of what I found is about 2 years old and not one thing applies directly
to this device.  The low level setup seems to work: the pvrusb2 creates
the device files, the firware gets loaded, mythtv connects to the backend
and the database configuration seems to be correct.

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