[mythtv] Tuning problems with V3.1 DVB patch

[David J. Fiddes]

Hi,

> So questions that arise are :
> a) Are there any frequencies in the list ( I think there are judging by
> the debug)

Yes. I think so. The code in the "Updating Transports" part of
SIScan::StartScanner() seems to work fine. I put code to dump out the
contents of NIT after it has finished. This data seems to mostly make
sense.

The main frequency matches that of the main transmitter on the network
and the extra frequencies match those quoted on www.dtg.org.uk for the
other transmitters including the one my aerial is pointed at. The order
of the frequencies is consistent between multiplexes but I guess that
this can't always be relied on.

> b) If there are some, do we manage to tune to any ? (Apparently not)

CheckNIT seems to have no issues in tuning into the other frequencies
(because of the order it only checks the main one then the correct one).

What goes wrong is the next step in the scanning process where it is
looking for services on each transport. This seems quite disconnected
from the initial transport scanning phase with all of the tuning data
coming from the database? I think the database doesn't seem to store
nearly enough information. It needs to store all of the frequncies that
CheckNIT is able to glean from the transport scan otherwise how can it
get back to rescan in the future? Also DVBChannel::GetTransportOptions()
and DVBChannel::TuneTransport() would have to know how to deal with a
DVB-T multiplex with multiple frequencies. Probably need to store the
favoured frequency otherwise changing multiplexes would take
forever...maybe a simple metric like: "I got signal lock therefore it
must be OK to keep using" would be sufficient to start with?

I'm quite happy to have a hack at getting this running but I'm not sure
about the codebase or the big picture of where it is going yet. Assuming
I've got the right end of the stick ;)

Dave
-- 
David J. Fiddes <D.J at fiddes.net>