[mythtv-users] overscan problems with nvidia 8400 GS
Simon Hobson
linux at thehobsons.co.uk
Mon Jul 13 06:55:07 UTC 2009
Matthew Harrison wrote:
>I wonder how consistent modern sets are. I've not dug out the
>relevant standards to check, but Wikipedia has this interesting
>nugget on the following page.
>
>http://en.wikipedia.org/wiki/Overscan
>
>"With the accuracy attainable with digital type displays (e.g.
>plasma <http://en.wikipedia.org/wiki/Plasma>, LCD
><http://en.wikipedia.org/wiki/LCD> etc.), the area presented to the
>viewer is precisely defined. For 1080i or 1080p material only the
>central 1776x1000 pixels are presented to the viewer. For 720p
>material it is only the central 1152x648 pixels."
>
>I hope that doesn't mean that I have to scale HD video up in order
>to correctly display it on my 1920x1080 LCD.
I think it means exactly that ! How completely f***ing crazy can it
be to define a standard where the source can supply a high quality
digital signal that's been scaled to the right size in the decoding
section (ie where it will create the least artifacts) - and then
resample it to guarantee some distortion of the picture !
Though to be fair, I suspect the standard doesn't specify how many
pixels the panel itself has - in which case, it seems crazy that
manufacturers produce panels with 'non native' resolutions. Why not
produce a 1776x1000 panel for a 1080 set and avoid the rescaling
altogether ? I guess I can answer that myself - our less educated
brothers (and sisters) would probably then refuse to buy it as not
being "full 1080" :(
The more I find out, the more I think we've been sold a pup here. On
digital signals, why any need for overscan at all ?
--
Simon Hobson
Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.
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