Path: chuka.playstation.co.uk!news From: Alex Herbert Newsgroups: scee.yaroze.beginners Subject: Re: Aspect Ratio Date: Wed, 03 Jun 1998 15:57:33 +0000 Organization: PlayStation Net Yaroze (SCEE) Lines: 44 Message-ID: <3575645D.7096AB84@ndirect.co.uk> References: <356DB143.A56CBBAB@creatron.de> Reply-To: aherbert@ndirect.co.uk NNTP-Posting-Host: dialin0-57.ndirect.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Mailer: Mozilla 4.04 [en] (Win95; I) To: Eric Bleinagel Eric Bleinagel wrote: > Hi, > > I want to port something I´ve done on the PC to the Yaroze. But on the > TV the aspect ratio of my Graphics (320x240) seems to be wrong. > > The user guide says that the possible screen modes for pal/ non > interlaced are 320x256, 384x256... and so on. So I think these modes > have aspect ratios like 1.25, 1.5... > But normal TVs and PCs have an ratio of 1.33 (4/3). > How can I get the correct aspect ratio? > > Maybe I´m totally wrong or have done something stupid, so please correct > me! > > Eric Right, I know the problem, and there's no simple answer. In NTSC modes such as 320x240, the aspect ratio is correct. In PAL, the aspect ratio is a bit messed up. Not only are there 256 lines displayed, but there are also a few extra lines at the top a bottom of the screen which are not usually writeable, so the actual screen height is >256. (Although you can write to them if you mess with the DISPENV structure, but this doesn't change the aspect ratio - just gives more lines.) The result is that a PAL picture if virtically squashed. This applies to most ports from NTSC to PAL. The program may still be running 320x240, but with those huge top and bottom borders the picture is obviously squashed. Try using the 384x256 resolution. The aspect ratio is actually much closer to what it should be. (384x288 would actually give the correct aspect ratio, but by the time you've added the extra border lines to the 256 displayable, it's not far off.) Other than that, you stuck with it. Thats what happens when you take a machine which is NTSC native and force it to work on PAL. Herbs