[mythtv] Switched Digital Video Problem

[David Engel]

Time Warner recently rolled out switched digital video in my area.
For those not familiar with SDV, "less popular" channels are
essentially converted to on-demand.  Instead of always being on the
wire, SDV channels are put onto an unused multiplex only when an STB
is tuned to them.  As long as they don't oversubscribe, this allows TW
to offer more digital channels without without further cannibalizing
their analog offerings.  This is in contrast to how Comcast sacrificed
all of their analog channels to go fully digital.

I've run into a problem using MythTV on SDV channels that I hand't
foreseen.  In order to free up multiplexes, our STBs now automatically
switch away from SDV channels to a non-SDV channel after some period
of apparent inactivity by the user.  In my case, that period appears
to be 3 hours and it's caused me to lose the ends of 3 of the last 4
live TdF broadcasts.  Fortunately in this case, there are enough
repeats to record the parts I missed.

I'm open to other suggestions, but what I'm thinking of doing is
modifying the MythTV recorder code to optionally re-execute the
channel change script (or another one) periodically with a special
argument.  The script can then do something to make the STB think
someone is still watching so it won't switch away.  In my case, I
think simply "changing" to the same channel should be sufficient.

I haven't started looking at the recorder code yet.  Does anyone who's
already familiar with it know if there's already a nice place where
this could be added easily?  John Poet, could this fit in with your
signal monitor?

David
-- 
David Engel
david at istwok.net