QAM256 HDTV local channels are available on Patriot Media's standard cable
fare, and it is probably required by law. But they omit the special
information (I forget the techincal name at the moment) that lets the
software find the channels. So I had to manually scan for and enter
that appropriate information into MythTV. So I am using cable
signals for HDTV, not off-air, and not the paid Cable HDTV channels.
The scan notes:
bring dvb-apps up-to-date
dvbscan -vv -a0 -A2 atsc/us-Cable-Standard-center-frequencies-QAM256
The channel names are not necessarily correct, and some of the channels
are useless, but this does find all the HDTV streams and sub-streams,
including numerous digital radio channels. A manual examination of each
channel using xine revealed which was which.
I let mythtv run a channel scan, which got a lot of incorrect results.
These I repaired with mysql commands such as:
select mplexid,sourceid,transportid,networkid,frequency,modulation,visible,sistandard,serviceversion from dtv_multiplex;
delete from channel where chanid=2162;
update channel set mplexid=9,serviceid=3 where chanid=2164;