[mythtv-users] ASTC~NSTC

[Joseph Fry]

>> >>>> The wiki covering general back end set up (written at the time of
>> >>>> .21)
>> >>>> says "TV format" options include ASTC, NSTC, etc... In the distro I'm
>> >>>> using, .25, "TV Format" options start at NSTC with many other options
>> >>>> except ASTC. My set up is functional, so I'm not complaining, just
>> >>>> curious,
>> >>>> Why can't I select ASTC? I'm using one analog card and one digital
>> >>>> card
>> >>>> at
>> >>>> the moment so any insights would be appreciated.
>> >>>>
>> >>>
>> >>> You would set it to NTSC for an ATSC system.  The setting isn't really
>> >>> used too much for ATSC, but choosing NTSC would allow you to use other
>> >>> things you might see in an ATSC area, such as NTSC via
>> >>> S-Video/Composite/... outputs from your old VCR or whatever.
>> >>>
>> >>
>> >> Agreed, that is what I selected, I just wondered why, if a wiki from a
>> >> 0.21
>> >> distro professed an ATSC option, 0.25 doesn't offer one.
>> >> If I upgrade to 0.26 will I get an ATSC option? Would it even be useful
>> >> when I receive only 25 digital channels and some 75 analog channels?
>> >>
>> > Where are you in the world that can receive ATSC yet still receives so
>> > many
>> > analog channels?
>>
>> It's technically impossible.  NTSC broadcast standard only defines 69
>> channels.
>>
>> I think he's on cable... he has 75 analog NTSC CATV cable channels and
>> 25 digital **QAM** channels.  He's not using ATSC at all.
>
> I have two sources, FTA antenna, 25 digital and STB cable, 75 analog, a
> digital signal comes in on the coax and Cogeco mashes it through a DCT700
> and it comes out analog. I can get digital channels from the coax without
> the box, but not the encrypted channels, and I only have two cards .
>

I stand corrected... sorta.

As previously stated, ATSC is an independent standard that requires an
ATSC tuner... so if your using an ATSC tuner there is no reason you
would need to specify a source format as it can only supply an ATSC
signal and mythtv is smart enough to know that.  However analog is a
different beast, for example, S-Video and composite video can both
carry PAL signals, so mythtv relies on that setting to know which type
of signal to expect from a given source.