How to use the whole TV display area?

[BDB]

I have a pc with an Asus ATI 4850 hooked up via HDMI cable to my
Panasonic plasma TV. Everything is great except that the desktop
display area is slighly smaller than the TV display area, leaving
black bars of approx a quarter to a half an inch all around. When
the TV source is my cable box (via component connection) the whole
screen gets used. Any ideas how to fix this? I didn't see any
way to fix it in the catalyst control center.

 

[Bob Myers]

I have a pc with an Asus ATI 4850 hooked up via HDMI cable to my
Panasonic plasma TV. Everything is great except that the desktop
display area is slighly smaller than the TV display area, leaving
black bars of approx a quarter to a half an inch all around. When
the TV source is my cable box (via component connection) the whole
screen gets used. Any ideas how to fix this? I didn't see any
way to fix it in the catalyst control center.

You didn't mention what model TV you're using, so it's going
to be hard to be specific - but keep in mind that a widescreen
TV has a 16:9 aspect ratio, while standard widescreen PC
formats are currently 16:10. You SHOULD have some black
areas to the left and right of the PC image, if it is to be
displayed without distortion (i.e., it would need to be stretched
slightly horizontally to fill the screen).

The other thing to keep in mind here - "TV" video is very
commonly shown as "overscanned," meaning the edges of the
active image extend slightly beyond the visible screen. This
is not the typical mode for PC video; if you can find a setting
on the TV which is labelled "overscan," "full-screen," or
some such, this may affect this behavior. The other alternative
is to use a "TV standard" timing for the PC video, when
connected to the TV (e.g., use the common "720p" or
"1080i" timings). If this is done, the TV will likely default to
a "TV mode" and again overscan the video slightly.

Bob M.

 

[BDB]

You didn't mention what model TV you're using, so it's going
to be hard to be specific

It's a Panasonic TH-50PX77U 50" 720p plasma.

The other thing to keep in mind here - "TV" video is very
commonly shown as "overscanned," meaning the edges of the
active image extend slightly beyond the visible screen. This
is not the typical mode for PC video; if you can find a setting
on the TV which is labelled "overscan," "full-screen," or
some such, this may affect this behavior. The other alternative
is to use a "TV standard" timing for the PC video, when
connected to the TV (e.g., use the common "720p" or
"1080i" timings). If this is done, the TV will likely default to
a "TV mode" and again overscan the video slightly.

When you say "TV standard timing" what do you mean, resolution?
A little overscanning would be fine, I'm only using the pc for playing
videos and games.

Thanks for the ideas, I'll try them out tonight.

 

[Bob Myers]

When you say "TV standard timing" what do you mean, resolution?

Yes - set up the PC to provide either a standard 720p/60Hz or
1080i/60 Hz output. The TV will likely consider this to be
"TV video" (esp. if you can feed it via, say, an HDMI input) and
will overscan or fill the screen.

Bob M.

 

[Bob Myers]

Why would they ever overscan an LCD or plasma, when fed a digital/HD
signal?

It makes no sense to me, either, but it IS a quite
common practice in the TV industry. I keep asking
my friends on the various standards groups - the ones
from the broadcast side of the industry - if, say,
Samsung knows that there's really no sense in their
making 1920 x 1080 panels...

Really, it's more tradition driven than anything else.
The TV industry, up to about 10 years ago, could
barely spell "pixel," and simply was not based on thinking
of images in "digital" terms. You still hear talk of
"clean" and "safe" apertures which have nothing to
do with the defined active area of the image.

Bob M.