[mythtv] Signal Monitor UI & Channel Scanning patch update (v30)

[Daniel Kristjansson]

It's here:
  http://www.cuymedia.net/patches/

This makes the signal monitor stuff a little more robust to bad
tables. For instance if the VCT says to use program 3, but there
is only one program and it isn't program 3, we use it and complain
a little. If there are more programs and but none are the one we
need we complain a lot and don't start recording some random stream.

The channel scanning has been fixed for ATSC using the DVB drivers,
and you can now scan for ATSC channels when using the pcHDTV v4l
drivers.


There are some general improvements in channel scanning.

For one we save the full ATSC channel info, which means you can tune
to 5_1 and 9_1 on the same frequency without resorting to using the
program number ("service id" in DVB terminology) which is sometimes
changed at certain times of day by the broadcaster. This is a
problem in the New York area where most of the channels are owned
by the same guy who transmits different major channels on the same
ATSC frequency (transport in DVB terminology).

For another we try harder to update a channel rather than just
inserting another copy. This means you probably won't lose your
XMLID and hence listings will continue to work if they worked
before. I still haven't updated the datadirect stuff to try 
harder to match existing channels, but that is the plan.


This patch also changes the Channel class used by v4l drivers
to use the dtv_multiplex table if it is available. This gives
us access to additional information, such as the modulation,
after a channel scan.

After you run a channel scan on a pcHDTV using the v4l drivers,
you can now rename the channel to your hearts content. By
default the scanner preserves the current channel name, but
if you wipe your channels it will not use an underscore in
the channel name by default.

Please re-run the channel scan on all digital inputs, this
will assure that all the data is up to date. It should not
prevent you from reverting to not using the patch, but you
should back up your database just in case.

Note: You must compile with DVB support for this patch. This is
temporary, in the next patch you will be able to do channel 
scanning for the pcHDTV v4l drivers without DVB support.

-- 
Daniel Kristjansson <danielk at cat.nyu.edu>