[mythtv-users] Beginner - Practical HDTV and Comcast Questions

Kevin Kuphal kuphal at dls.net
Mon Jan 8 22:14:34 UTC 2007

Greg Kettmann wrote:
> My TV is capable of 1080i and if I'm going to "upgrade" then I'd 
> probably like to enable HDTV.  I really dislike the "cable boxes".  I 
> believe that means I'm watching only analog signals and certainly no HDTV. 
> If I get one of the "listed" HD tuners will I get all of the Comcast 
> HDTV content or only the "local" stations which they are passing 
> through?  I'm very confused about which stations I can and can't pick up 
> and in which quality.  For that matter someday I think they're going to 
> discontinue analog.  What will be the impact to PVR's at that point?  I 
> don't want to even think about the broadcast flag. 
I have Comcast cable (Basic service only) near Chicago and I only get 
the HD versions of the broadcast channels (ABC, NBC, etc), I do not get 
the HD version of Discovery which I do get on the analog side.  You 
really won't know what you can pick up until you connect an HD tuner 
(either from your TV, standalone, or a card like the AverMedia A180).   
I've heard of some Comcast outfits dumping everything in unencrypted QAM 
and others putting out nothing.  And for reference, a firewire-enabled 
cable box is another option with the same caveats on what you can tune 
or not.
> One disadvantage of the HDTV cards is that they have no on card 
> compression.  HDTV is apparently digital already and so is already 
> MPEG-2 encoded, thus there is no need for on card encoding.  What about 
> all of the "standard" channels?  Can the HDTV cards do analog and 
> digital (or is it even needed based on the questions above)?  Also, HDTV 
> playback apparently requires a rather substantial machine, not just some 
> old junker lying around, so, is it worth it?
Most HDTV cards cannot do analog and if they can, they cannot switch 
between them on the fly.  The LinuxTV website for DVB has a good chart 
of which do and which don't.  I have three SD tuners (one PVR-150 and 
one PVR-500) for recording SD content as well as my two HD tuners 
(AverMedia A180). 

A good option is to look at the HD HomeRun units which are two tuner 
units.  Each tuner can do either QAM (digital) or NTSC (analog) and 
since they are external to your MythTV box, make for very easy to set up 
and expandable units (or so I have read from this list).

I'm still using an SD set with my HD content and I totally think it is 
worth it.  90% of what I watch is broadcast in HD on the broadcast 
channels and it looks glorious on my SD set compared to the SD content 
so I can only imagine it will look even better on a HD set.  As long as 
you understand you won't be getting HD HBO, ESPN, etc and can live with 
that, it is very nice.


More information about the mythtv-users mailing list