Re: Will F1 be on BBC HD?

On 2009-02-27, Bigbird <bigbird.usenetNOSPAM@xxxxxxxxx> wrote:

Ian Rawlings wrote:

On 2009-02-27, Bigbird <bigbird.usenetNOSPAM@xxxxxxxxx> wrote:

You don't? No I guess you get one line scan per line.

You don't even get that normally other than on professionally adjusted
video monitors used in video editing. That's one reason why modern
CRTs use screen-height vertical stripes of RGB material rather than
the older type which used small vertical stripes, it mostly removes
the issues of lining up the picture vertically.

Try this. Upscale an 8 pixel by 8 pixel chessboard to 12 pixels by
12 pixels. What size squares do you have?

An SD signal does not match the resolution of pretty much any SD
display, so you have to scale the incoming video to fit the display
anyway. A DVB signal is anything from 544x576 to 720x576 for UK-spec
DVB, and a DVD is anything from 352x576 to 720x576. LCD/plasma
displays are pretty much always square-pixel displays, but video
pixels are not square, even for 4:3 displays so you need to scale
the images whatever display you have.

You miss immediately that it is things like this that cause a problem
taking an SD source straight to an HD TV. As you point out the ratio
for TV is 1:1.094. On a CRT this will look fine. On an HDTV you
immediately have to stretch or squish the picture.

On a CRT you also have to stretch or squish the picture. You do not,
and never did have, a 1:1 mapping in either the horizontal or vertical
direction on a CRT! Did you not read anything that I wrote? You
*always* have to scale the image, scaling your chessboard from 10x10
to 12x12 (SD analogy) compared to scaling from 10x10 to 24x24 (HD
analogy) would illustrate why more pixels are better. But for SD
material you will always have to scale, no matter what your display.

A 1:1 setting is best but you never got it on CRT, won't get it on SD,
and you only ever get it on an HD source over HDMI or DVI (so no
analogue step) with the TV set to display it 1:1 on a display that
*matches the source resolution*. Only the new generation video
standards can give you the 1:1 mapping that gives the sharpest
picture. A 1080p HD-DVD/BluRay matches the resolution of a 1080p
display exactly, and over HDMI/DVI the picture is sent as individual
pixels at that resolution, so provided the TV isn't set to bugger it
up, you'll get the 1:1 mapping and it does look *very* sharp.

<load of stuff deleted>

I'm only going by what I see at my friends and families homes, many of
whom have plumped for good brandname huge LCD full HD TVs that I have
sat in front of and what smudged blurry images compared to the apparent
crystal clarity on the inherited no name CRT I am haging on to for now.

TV setup out of the box is chronically poor. As an example on my
1080p LCD, my computer desktop at 1920x1080 had the edges off the
screen and the text was blurry. Going into the setup menus and
changing the overscan setting to "1:1" made the desktop edges match
the screen sides perfectly and the text was razor sharp. The TV was
by *default* set to take a 1920x1080 input and *scale it up slightly*,
making it blurry, and put it centred on a 1920x1080 display! How ***
is that for default settings... It should have been set to 1:1 from
the start but for some odd reason, pretty much all LCD/plasma displays
I've seen have all the wrong options enabled, I'm puzzled as to why
the manufacturers take a good product and deliberately set all the
settings to the shittest possible.

Not only was the 1:1 mapping buggered up but the sharpness settings on
the TV added ringing patterns to sharp edges, softening them.
Contrast was set too high making white areas wash out, losing detail,
and black settings were so dark that dark scenes were invisible. Lots
more also needed changing, I spent about a day fiddling with it.

No doubt this is what is at the root of the OPs problem so perhaps some
advice to him on how to adjust his TV correctly may not go amiss.

Basically you have to get a good display to start with, reading the
hifi mags (not mags like "stuff", but long-standing mags not packed
with pictures of scantily clad girls caressing tellies) and paying
attention to what they say helps, they don't just cover top-end
expensive displays and you can avoid the lemons by just going for
their top-ten lists in your price range, you might not get the very
best by taking that quick route but you'll avoid the utter *** stuff.

Also bear in mind that an SD signal scaled up to a 40" display is
going to look *** no matter what as it's a low-res image being writ
large and you can really see mpeg artifacts easily on a large, sharp
display just like when you zoom in on a jpeg image. A large SD
display looks sharp-ish because it's mapped the image onto the large
screen pixels, and it's those pixels that look sharp, but you've lost
a lot of image detail, often including the mpeg artifacts! This is
not because an SD display is better, it's because you're losing
detail, some of which you're quite happy to lose with modern digital
TV signals. Just like porn stars worrying about their defects showing
up on HD, crap SD sources also get laid bare on a high-res, large
screen.

--
Blast off and strike the evil Bydo empire!
http://youtube.com/tarcus69
http://www.flickr.com/photos/tarcus/sets/
.

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