[mythtv] DVB/ATSC Signal monitoring UI (v12)

Daniel Kristjansson danielk at cat.nyu.edu
Sat Jun 4 04:54:11 UTC 2005

The latest version is available at:

As discussed earlier this patch adds a signal monitoring OSD, both
on the initial tuning to a station when starting LiveTV mode and on
subsequent channel changes. This should avoid the problem of
getting stuck on a low signal channel and not being able to either
start "LiveTV" or even change the channel once you hit a broken
channel. This also parses the ATSC tables to find the particular
channel you want, so that if the frequency is ok, but the minor
channel you are looking for is missing it will stay in the
"Partial Lock" state, and hence allow you to change to a
different channel.

The biggest difference between this and v11 which I had up earlier
today is that it is now working with the DVB drivers for HDTV cards.
How it is working is a bit of a hack, I shut down and restart the
DVBSIParser and DVBRecorder from within the SetupSignalMonitor() and 
TeardownSignalMonitor() methods. I'll try to make this neater
in the next patch.

Unlike with the pcHDTV drivers this slows down DVB tuning a little
bit. This is because I'm re-parsing the PAT and PMT is SIParser(),
after parsing them in the signal monitor, but that is relatively
easy to fix. I've also broken Channel Scanning to get the DVB tuning
working, so do any scan you need before applying this patch.

At the moment, this is a fairly large patch. But I'll be shrinking
it in the coming days by removing changes that don't belong in
this patch, and committing things like the additional documentation
I've written in the course of preparing this patch.

PS This changes the Myth Protocol, but doesn't update the protocol
number, and there is a new table, see the web page. I've commented out
the schema update code in dbcheck, this is to avoid testers missing a
schema update if another large schema updating patch makes it in before
this one... The non-updated protocol version just means you should
either apply this patch to your frontends and slave backends, or shut
them down while testing.

Daniel Kristjansson <danielk at cat.nyu.edu>

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