GROOVYMAME GRAPHICS ISSUE

[mikehaggar]

Hi all, I bought an Astro City Cab which came with a pc that I'm not sure how its hooked up as I'm not technical but its not using groovymame as there is screen tearing.
Then I have this custom made jamma pc using groovymame but the picture isn't very good. The scanlines are huge and the games look blocky. I used to own pcbs and I was recently at arcade club and saw many original boards running on arcade monitors and none of them had huge scanlines with blocky pictures.
Attached is a screenshot of the pictures on the two pcs. The left one is groovymame and the right one is whatever this other pc is using. Excuse the blurryness of the right picture. (The camera wouldn't focus, it doesn't look like that in real life)
How do I get groovymame to output a picture without the blockyness and scanlines like the right picture (which looks more like a proper board). Bare in mind in not technical. Thanks!

[SailorSat]

I'd call the left one the better picture.

Back to your question: You can't - different tubes.
The only thing you could try is to turn the focus know on your screen to get the sharpnes down.

I experienced that "problem" years ago - same source, different tubes:
old tv, broadcast monitor, vga monitor

[mikehaggar]

It isnt different tubes though. Both pics are the same monitor different pc set ups. Ones groovymame the others just mame.

[SailorSat]

It isnt different tubes though. Both pics are the same monitor different pc set ups. Ones groovymame the others just mame.

The non-groovymame setup is most likely not running the games in native resolution - and applying a bilinear filter as it stretches the image.

Like I commented earlier, your left picture is correct - the right is not.

I am sure you can turn of native resolutions in groovymame, though it most likely was not designed for it.

[mikehaggar]

The picture on the left is not correct though. I used to own pcbs and you never could see giant scanlines. I was also just in an arcade seeing old school monitors of various sizes running original pcbs. You couldnt see the scanlines and there was no blocky edges. The colors are more faded on the left pic also. More noticeable in person than in the pictures.

[SailorSat]

I don't want to start a discussion on which of the two images is "correct". (I happen to own enough arcades myself)

That being said, you need to tell groovymame to use a fixed resultion (640x480 as example), stretch the image to full screen, and enable bilinear filtering to get the look of the right image.

[Paradroid]

The picture on the left is not correct though.

It is, actually. Not to start a pissing contest but my range of SCART TVs, RGB hacked TVs, arcade monitors, PCBs and GroovyMAME setups will attest to it. Besides which, you can take SailorSat's word on anything related to CRTs and image quality.

GroovyMAME is showing the image true to the original. The problem for you is that you seem to prefer a distorted, softer image than the original RGB progressive scan image. It's a personal taste thing. Some people like the razor sharp look of a Sony PVM. For me, it's too harsh. I prefer a consumer grade TV or arcade monitor because they're softer and have more image artifacts. It seems that you prefer something even softer than that.

If you never noticed the scanlines before, you were probably too busy playing the games or were playing on a smaller tube than the one you have currently. Larger tubes have more pronounced scanlines as do multi-sync monitors that need the ability to resolve more lines.

Honestly, the left side images look great! I would be very happy with that. I guess you can learn to love it or do something like scale your image or defocus your monitor to destroy your picture quality a little.

[butanebob]

I was also just in an arcade seeing old school monitors of various sizes running original pcbs. You couldnt see the scanlines and there was no blocky edges.

Try to get yourself a shadow mask screen. Most arcade cabs had them back in the day, they're a lot softer than the other type and the scanlines are nowhere near as noticeable. I actually prefer them to the sony style aperture grill screens coz those are extremely sharp.

[mikehaggar]

I don't want to start a discussion on which of the two images is "correct". (I happen to own enough arcades myself)

That being said, you need to tell groovymame to use a fixed resultion (640x480 as example), stretch the image to full screen, and enable bilinear filtering to get the look of the right image.

I set resolution to 640x480 and filter 1 but it only seems to have worked on capcom games for some reason. Everything else still looks blocky. What do I need to change so it works on everything?