[mythtv-users] What does tvformat actually do? Why is ATSC missing?

[Joel]

What does the tvformat option in the channels table actually do?  I used 
to use it to distinguish between those channels which were analog (NTSC) 
and digital (ATSC), but now the channel editor doesn't appear to have an 
option for ATSC, and the general settings don't have ATSC as a default 
option either.  Though strangely the channel scanner appears to still 
set it to ATSC for digital channels.  But if you change it to something 
else, you need to edit the database manually to get it back to ATSC.

So my question is does it even matter?  Leaving it at NTSC doesn't seem 
to break my digital channels, so it would seem tvformat has no impact on 
basic usage.  What's it for?  Does it matter at all for digital 
channels?  I see changeset 15776 for bug 4343 which removes it and seems 
to imply that the setting is only for analog channels, but there is some 
code still setting ATSC in the tvformat in the channel scanner, and some 
that appears to be reading it like recording profiles.

I'm happy to file a bug, and even provide the one-line patch to add it 
back, but I wondered if there was a reason it was removed, as I don't 
see a good one in the associated changeset and bug.

Thanks,
Joel