[mythtv-users] dtv_multiplex table for US OTA ATSC

[Tom Dexter]

After the last go-around I had with channel re-scanning (when the NY
WNBC network moved to a new frequency), especially thing like channels
getting new ids etc, I decided that going forward, I'd make any such
changes manually based on information from information I can get from
manual scans using hdhomerun_config. I understand the changes needed
around the channel table, and it's dtv_multiplex assignments etc. It
doesn't appear that it'll be too tough at all.

The only part I'm unclear on are a few details regarding cases where I
may need to create a new dtv_multiplex record for a frequency that was
never used before...specifically around several columns that may have
no affect at all on US ATSC broadcasts.

The mplexid is obviously just the auto assigned id. The critical
database columns that I'm aware of, and understand how to correctly
set, are these:

sourceid		<my-source>
transportid		<transport-id-from-scan>
frequency		<frequency-from-scan>
modulation		8vsb
sistandard		atsc

It appears that, in existing records, the following fields...while
they have no default defined for the table itself, always appear to
have these values (though I have no idea if they matter, and some
arbitrarily seem to have a NULL networkid):

networkid		0
mod_sys		1

The one's I'm primarily curious about are the following. While these
have table defaults, many of my existing records accumulated over the
years for very similar stations vary between having NULL values, or
the table defaults (for example values like 'a', 'auto' etc). That
tends to make me suspect that these may be totally moot for US ATSC:

inversion
fec
bandwidth
lp_code_rate
transmission_mode
guard_interval
constellation
hierarchy
hp_code_rate

Does anyone know if any of those even matter for US ATSC?

Thanks in advance.
Tom