[mdlug] Building a Linux PVR

[Raymond McLaughlin]

Ron Blanchett wrote:

> High Definition Video only refers to the resolution of the
> video.

> There are several different resolutions that qualify as being HD.
> They are 720i, 720p, 1080i, 1080p. Don't be fooled by these numbers
> though because 1080i is really no better than 720p. Why you ask?
> Because when your TV receives a 1080i signal it has to down convert it
> to 720p. Why you ask? Because most TV's are incapable of displaying an 
> Interlaced signal and that is what the I stands for in 720i and 1080i.

> So when your TV receives that 1080i signal it has to down convert it to
> a 720p signal to display it as a Progressive Scan signal.
> So if you own one of those great new HD TV's and you bought it because
> the guy/gal in the store up sold you on the idea that 1080i is way
> better than 720p, you where taken for a ride. Just about every none tube
> based TV is Progressive Scan and said TV has to Down Convert 1080i (if
> that is the highest resolution it can display) to 720p to be able to
> display it on the screen. And 720p has a resolution of 1280 x 720, hence
> the 720p.

> So to answer your question, if your DVI LCD monitor can display 1280x720
> without a problem you don't need a new one for HD content as long as
> that content is output at the equivalent of 720p (which in case you
> missed it is 1280x720). And since your display is an LCD monitor it
> should be Progressive Scan.

Maybe you can shine some light here. I had the impression that 'scan',
progressive vs. interlace, was a CRT thing. With progressive meaning
that the whole screen was repainted, line by line, top to bottom, by the
electron gun with each pass. And interlaced essentially meant that every
other horizontal line was painted with each pass, thus requiring two
passes to repaint the whole screen.

Is this over simplified to the point of being wrong, or just plain
wrong, or what?

In such a scheme how does a device like an LCD have a 'scan' pattern?
Aren't all the pixels refreshed more or less simultaneously?

> Oh one more thing, 720i is the equivalent of 480p which is the
> progressive scan equivalent of Standard-definition TV.
> 
> Any more questions?????



> Is any of this a little confusing?
> I hate to say it but the TV industry wants you to be confused about all
> of this. It helps them sell TV's.
> Also those new "HD" monitors are just something else the industry is
> doing to try to get you to upgrade your equipment and guess what M$ is
> in the boat with them as far as the forced upgrade cycle goes, Vista
> will not display all of its new eye candy if you are not using an HDMI
> HD Monitor as your display. Forget buying into needing an HD Monitor to
> display HD video, as long as your monitor can display a minimum of
> 1280x720 you are already capable of displaying HD video on it.
>