Path: chuka.playstation.co.uk!news
From: "Alex Herbert" <aherbert@ndirect.co.uk>
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: Re: PAL & NTSC resolutions
Date: Sat, 5 Jun 1999 13:21:32 +0100
Organization: PlayStation Net Yaroze (SCEE)
Lines: 46
Message-ID: <7jb4ve$9666@chuka.playstation.co.uk>
References: <7hrf3p$4u56@chuka.playstation.co.uk>
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Rad wrote in message <7hrf3p$4u56@chuka.playstation.co.uk>...
>Can anyone explain the relationships between the screen resolutions and the
>output signal?
>
>For example 320x240 is an NTSC resolution but I use it with PAL and it
still
>works, although I know you get (16?) unused lines at the bottom.
>
>I use 320x240 because it's a 1:1 ratio but having thought about it I'm not
>sure it is with a PAL screen. If not what about 320x256?
>
>Thanks,
>
>Rad.
>rad@cyberdude.com
>http://www.netyaroze-europe.com/~radpsx
>
>

Hi Rad,

320x240 has a 1:1 pixel aspect ratio ONLY when displayed in NTSC.  The PAL
standard uses more lines than NTSC, so the resulting display ends up
vertically squashed.

Using 320x256 will allow the display of 16 more lines, but this does NOT
affect the pixel aspect ratio.  But, 256 lines still does not fill a PAL
picture, so there are black lines at the top/bottom of the screen.  The PS
can be made to display the full 288 lines, but I wouldn't recommend it.
(It's not standard, and it doesn't fit into VRAM very nicely.)

Theoretically, a horizontal resolution of 384 pixels should give a 1:1 pixel
aspect ratio in PAL.  In practice though, it's still not perfect - don't
know why.

BTW, the pixel aspect ratio only really matters for 2D stuff like sprites.
The 3D functions include aspect ratio correction, so no worries there.

Hope this helps,


Herbs