[mythtv-users] Is the pchdtv card looking good?

[Brandon Beattie]

On Tue, Sep 16, 2003 at 08:11:27PM -0700, Jarod C. Wilson wrote:
> > I don't think you misunderstood.  I have saved MANY HD streams and they
> > all included 2 resolutions, 720p and 480i (this probably changes from
> > station to station)
> 
> 720p and 480i?!? Is that HD and NTSC on the same channel? From what I 
> can tell, all I'm getting over cable is 1080i HD, and those channels 
> are on different channels than normal TV (ex: 31 = ESPN, 173 = ESPN 
> HD). But of course, I have no way to capture these streams, so I can't 
> really be sure what the tuner (Motorola DCT5100; I've had it a week 
> now) is receiving. From what I understand, most HDTVs do 720p either. 
> Most are 1080i and 480p for HD and 480i for NTSC, while some do 720p, 
> and almost none do both 1080i and 720p...

A HD display device is one of the following.  1440x720 (720P), 1920x540
(1080i), 960x540 (1080i).  I have yet to see a 1920x1080 (1080/p) HD
display _being sold_.  

HD streams (ATSC) are 80% 1080i (1920x1080i), 15% 720p, 80% 480P
(720x480p or 640x480P).  Yes, this is more than 100% but this comes
because you have subchannels and 480p is often used while using a 1080i
or 720p stream.

There will be a lot of you thinking this doesn't make sense, or it's
wrong.  What you need to know is the DTV spec has about 16
"resolutions & frame rates" in it.  Your HD display will do _one_ of 
them optimally and the others it will scale and modify to fit your 
native HD resolution.

Which is better?  Depends on your viewing habbits.  If you're a sports
fan, almost all sports are recorded in 720p because motion looks better.
1080i is better for overall "quality and sharpness".  Current 1080i HD
displays cheat and alternate vertical frames (ie, 1920x1080i showing on a
1080x540(p) display.  You don't loose quality and the switching actually
makes the image loko sharper.  But yes, 1920x1080p (1920x1080) HD would
be the best video quality, but it is not in the standard.  (SO you know,
I plan to buy a 1080p (1920x1080 resolution) DLP projector in 5 years
and then de-interlace the 1080i image for "the best" image.  Until then
I use a 1024x576 DLP projector)  

All HD display units convert any signal (1080i, 720p, 540p 540i 480p
480i, etc) into the displays native resolution.  Some quality is lost
but 720p native displays actually will show the best overall image for
all DTV standards in my opinion and knowldge, but it depends on your TV
model and what type of image scaling and quality improvements it does.
-- This will change over time and be cause for upgrading your HD tv over
and over.  In the end, a 1080p display can look better if it has good
video quality improvements. 

As for SD (480i/p) on a HD display it can look terrible.  It depends on
how the upscaling is being done, and where.  480i tv shows upscaled by
the tv stations often is the worst thing I've seen being done.  However,
re-recording from film still doesn't get the clarity that exists on the
film.  a 4000x3000 stream taken from the original film will start to
look as good, but that is 20-30 years off.  (And why people shoudn't
wait to see some movies on DVD and should spend the money in the
theaters.. unless the theaters use DLP projectors and then you can wait.
(Digital is not as good as film and won't be for some years)

> 
> > I have only capped streams in Phoenix on ABC and NBC
> > and both where the same, however, on NBC... The West Wing still looked
> > like crap... Why is one of the highest nielsen numbers shows broadcast 
> > at
> > the worst possible quality (here in Phoenix)
> 
> Is it possible it is broadcast in an HD format your TV doesn't like? 
>  From what I understand, a 720p broadcast would have to be scaled by my 
> tuner to display on my TV (I have a 1080i and 480p capable one; no 
> 720p)... I'd expect the picture would still be pretty good though. Are 
> all NBC HD shows that way? Perhaps the NBC affiliate in Phoenix just 
> doesn't have all the right equipment yet...

If your HD display is one of the first, yes, some are dumb and will only
take 1 to x signals,  You'll have to buy a tuner that does the scaling
in it.  (Sorry)  Most new HD displays accept all/most.  Make sure it
supports 720p, 1080i, 480i and 480p as a minimum.  If you watch PAL
dvd's, or things of that<F3> sort, 540i/p becomes important.  

> 
> I got to watch my first Mariners game broadcast in full-out HD 
> yesterday. Un-freakin'-believable.

:)  That's just your start.. ever seen a HD DVD?  X-Men in HD is
incredible.  Oh, and as a side note, when you watch movies on
HD/broadcast ATSC, it's over twice as good of quality as that on a dvd.
It makes it hard to just say, "Oh, I have that on dvd and don't need to
wyatch it now:.


--Brandon