GroovyUME and SNES resolution

[wilwong1971]

Hi;

Must say how awesome GroovyMAME/UME is. I was using an XBOX to CRT and thought that was excellent till I used GroovyUME on a PC through a SCART TV!

Have a quick question, probably not an issue but more me doing something wrong..when I run a SNES game GroovyUME upscales this to 512 x 240p (it also indicates the input resolution to be 512 x 226 thereabouts) it still looks great though, All other arcade games and Megadrive it seems to output native.

Is there something I could check? (though SNES native Res is 256 x 224 ?)

I am running a PC (WinXP x86) with a HD4650, through a SCART UMSA to a B&O MX4000

Thank you in adbance!

[Dr.Venom]

The 512x225 resolution is correct behaviour for mainline UME and GroovyUME. It does this because a real SNES has both a low-res (256 horizontal pixels) and a high-res mode (512 horizontal pixels). So it chooses to open the high-res mode in case a game uses this, and for the games with the low resolution it simply doubles the horizontal resolution internally. You won't notice the difference on CRT.

If you're thinking the screen is somehow stretched, then it's because the vertical resolution is 225 for the SNES driver, while it opens a 240 vertical resolution screen on your PC.  You can resolve this by installing a modeline that has the exact 512x225 resolution. Otherwise you can run it with the "-cleanstretch" option. That way it will not stretch the game vertically from 225 to 240 pixels.

[legonzo]

Hello, i'm new on the forum,
i have recently built a pc dedicated to he emulation of old console/arcade systems.
It is plugged via UMSA + crt_emudriver (15khz) on a CRT tv.

I would like to move up this topic because i'm using groovyUME and i don't understand why the chosen resolution by switchres for snes games is 512 x 225.
I understand that 512 is the double for the snes horizontal resolution (256), and that the rendering is exactly the same with 512 than 256 (pixels are doubled thus no stretching). I understand also that snes has several high resolution mod amoung them 512x224. But why shall switchres choose this 512 while it has the possibility to choose the right resolution 256x224 which is present in the list of available resolution in arcade_osd. If the games tells switch res that it is running in 256x224 shouldn't it switch to 256x224?

I have an other thing i don't understand : when i'm launching a european 50hz game, groovyUME launches it in 60hz. Is it something related with bios (snes.zip) ?

thanks in advance

[Haze]

the SNES can mix lines of 512 and 256 resolution on the same screen, you don't know this in advance, so the only way to support this is to double the 256 lines so they can be mixed properly with 512 ones, therefore the output resolution is always 512 wide.

Snes is a lucky case compared to some, things like the PC-Engine end up having to output 1280 wide resolutions just to handle this which is also unfortunately rather slow in software.

[Calamity]

Hi Haze,

It would be a godsend if eventually MAME/MESS could report all the known resolutions used by a system in its XML.

So instead of a single line like this:

Code: [Select]

<display tag="screen" type="raster" rotate="0" width="1088" height="242" refresh="59.826098" pixclock="21477270" htotal="1365" hbend="64" hbstart="1152" vtotal="263" vbend="18" vbstart="260" />
you would have an array of them. This way we could know which video modes might be required beforehand.

I think it would make for a better documentation of the systems, because accurate information on this is very difficult if not impossible to find.

At the same time I can see the difficulty of putting this information together, specially for home computer systems which programmers used all sort of video hacks to achieve non standard modes.

But for console and arcade systems that are known to switch resolutions several times it would be great to have this well documented at some point.