Home Page Forums Archives MacMAME Full screen with correct aspect ratio

Hello
I bought a 17" LCD display for my Mac. The problem is that, due to the large screen resolution, there are a number of games which don't fill the entire screen, even if I choose the "Triple Size" option. And if I choose the Open-GL plug-in, I get an awful (in my opinion) kind of pan-scan effect that totally screws up the aspect-ratio.

Is there a way to properly stretch the displayed image on the entire screen ? I'm almost certain that Mame32 is able to perform full-screen display, preserving the correct aspect ratio. 'Seems strange to me that the Mac version is not able to do that.

Thanks for any reply.

It is already the correct aspect ratio if you use the GL plugin. If it made every game fill the screen completely, that would be the wrong aspect ratio.

One of us is on the wrong way.
When I use the the OpenGL plugin, games like Street Fighter II are stretched on the entire width AND heigth of the screen. Is this the correct aspect ratio ? Shouldn't there be big black bars up and down (letterboxed screen) ?

If I use software renderer the aspect is different (the video doesn't look vertically stretched) and most of the games got black bars on EVERY side (left, right, up, and down) instead of having only either horizontal either vertical blacks bars, ie there is no optimal use of the screen size.

Am I saying something wrong ? Maybe my memory is confused, it has been such a long time since I have seen some old arcade systems here. Which rendering is the correct one ? Software or Open GL ?

Hehehe, no. Street Fighter 2 is intended to be displayed at a 4x3 (TV-shaped) aspect ratio, so it should in fact be full height as well as width. (On a widescreen monitor it should be full height with windowboxing - black bars on the *sides*).

Well. Thanks for the replies so far.

So actually it's the Software rendering mode that is not correct. I'm a bit surprised. How can a 384*224 game be displayed full screen on a 4/3 computer monitor without deformation (well... perhaps THAT is the job of the OpenGL Plugin...) ? By the way shouldn't we see squares instead of rectangles when selecting the "Dot cloth" in the Test Switch Menu ? Is this due to technical differences between computer monitors and arcade cabinet (TV ?) display ?


Putain... je me sens vraiment stupide. J'ai l'impression de d?©couvrir la vie...
Feeling like a total newbie discovering life...

Arcade monitors work the same as your computer's CRT monitor does - you can set your PC or Mac to a variety of resolutions and they all will fill the screen fine in both directions. 320x240 on up to 1600x1200 and sometimes beyond, it'll always fill your screen. But TVs and arcade monitors usually can't display more than 640x480 clearly (they have a "dot pitch" that would make computer monitor buyers scream in terror) and so they give you a sort of free anti-aliasing effect along with your stretching. Whereas if you run a nice 320x240 MAME game on a 21" computer CRT you can pretty much count the individual pixels :-)

Arcade games usually have standard 4:3 aspect CRTs, but they do not all have square pixels. If you look at the hardware info for i.e. Street Fighter, the resolution is listed as 384x224, and the pixel aspect ratio is 7:9.

The software renderer is dumb and simply copies all pixels as if they were a 1:1 aspect ratio. On a game like Street Fighter, this leads to a "wide" window where everyone looks fat.

The GL plugin knows about the pixel aspect ratio and compensates for it when filling the screen. First it stretches the image in whichever direction will fill the most pixels, either vertically or horizontally depending on your display and the game. Then it scales the other dimension, preserving the original aspect ratio of the arcade hardware. If you have a regular 4:3 monitor, most games will fill the entire screen. If you have a widescreen monitor, you'll get black bars on the side.

Since I'm the guy who wrote this code in MacMAME, I'm probably biased, but I think it works correctly. I just tried it out again here and it looks fine, I get a 4:3 portion filled with black sidebars on my 3:2 aspect ratio 15" PowerbookG4. (I tested it on a variety of other displays when I wrote the code years ago.) If I _really_ want it to fill the entire display, I can pick a stretched display mode from System Preferences before running MacMAME. But then the aspect ratio is wrong and everyone looks fat again.

Call me an idiot, but I still prefer 3x w/scanlines in the software renderer to GL for most games. Vectors are an obvious exception (even if they were still able to display properly in software), as well as really stretched games like Blasteroids.

Unfortunately, as Jean-Phillipe mentioned, many games display too small even at 3x. Don't suppose 4x w/scanlines is ever coming our way?

I just like the "hard-edged" look you get with the software renderer; the overlays help in GL, but... I guess it's a matter of taste.

Richard: I hear what you call "windowboxing" called "pillarboxing," that is like what a 4x3 image looks like on a widescreen monitor stretched to full height with black bars on the sides. Is there a definitive term, or are we still figuring that out?

All of the home theatre and DVD-Video sites I frequent use "windowboxing", so I believe it is the correct technical usage.

Pillarboxes are very UK-specific, aren't they? Yanks have a lazy way of sending mail.