GBI setup for use with OSSC and GCDual on 4K TV

[thebigcheese]

The options offered by GBI are very confusing to me and I'm struggling to figure out what the best options for me are. I use it with the Action Replay/SD Media Launcher and set it to boot automatically whenever I put it in so that I don't have to go through a bunch of menus. The downside of this is that it means I have to code all the options I want into the file on the SD card since I don't even have Swiss to be able to fiddle with them. This makes it... kind of a pain to test.

I am not one that likes to fiddle with the OSSC's settings for every system. I have it set basically at the default settings with a few exceptions:
-240p is set to 5x scaling at 1600x1200 (which looks amazing on my TV)
-480p is set to 2x scaling

For the GCDual, I have it set to not do any line doubling on any formats (so that the OSSC can take care of it instead). My TV is set to "Direct" for picture size so that it doesn't do much in the way of interpolation.

For GBI, I thought it made the most sense to use the OSSC-optimized preset, but this resulted in an image that was squished horizontally rather than matching the aspect ratio of the GBA. I made a few tweaks and now have it outputting at 240p and giving me what appears to be basically the same aspect ratio as a real GBA, but it fills only a tiny portion of the screen. I suspect this is partly because the OSSC is outputting a 4:3 image, but the result is that it fills only the center 4:3 space horizontally and probably only half the screen vertically (though it is centered). I could live with that, honestly, except that the pixels aren't even particularly sharp - there is clearly some interpolation going on whereas there is almost none when playing, say, SNES or Genesis through the OSSC. Surely there is a happy medium here? Ideally, I would not change any settings on the OSSC. I would much rather have all the configuration happen with GBI even if it means some small concessions.

[SavagePencil]

Can you provide some photographs, as well as the current GBI parameters you’re using?

[thebigcheese]

Won't be able to get a picture until later, but these are the settings I'm using for GBI:
--vfilter-even=.5:.5
--vfilter-odd=.5:.0:.5
--format=hd60,offset=0
--scan-mode=non-interlace,no-clock2x,no-size2x
--volume=.3:.3
--enhance

This is a mashup of the OSSC optimizations and other settings that seemed to get me close to the right aspect ratio. Plus turning enhancements on and lowering the volume because the default is crazy loud.

[Extrems]

HD60 isn't supported in GBISR, or with GCVideo DVI for that matter.

[thebigcheese]

I suppose I should clarify that I am using RGBs output to the OSSC. I would use high fidelity, but my PVM doesn't work well with the off-spec refresh, so I've stuck with SR. I don't use any borders, so I'd rather have the low input lag of SR.

[Extrems]

The GCDual uses GCVideo DVI, it doesn't matter which output you're using. GBISR also support borders.

GBISR also use the same video format as GBIHF with digital AV, so I don't know what you're going on about.

[thebigcheese]

The GCDual uses GCVideo DVI, it doesn't matter which output you're using. GBISR also support borders.

GBISR also use the same video format as GBIHF with digital AV, so I don't know what you're going on about.

I'm not using digital AV, I'm using the multi-out for analog RGBs. Unless you are saying those are the same, in which case it would really help to be more clear about that. This part that is only in HF as far as I can tell: 59.7276 Hz refresh rate. I get horrible tearing on my PVM with it (though the last time I tested was when it was still ULL) that I don't get when using the other versions. If that's been changed, then I'd happily switch to HF, but I've been sticking with SR since previously it did not work well for me using ULL.

In any case, with the settings I have, I get picture, so it works. In regards to borders, yes, I know it supports them, I just don't want them so I don't have any of them loaded. I was just clarifying that my preference is for low input lag hence why I do not use the standard edition.

I'm sure there are many things about GBI that make sense to you since you created it, but make absolutely no sense to me or, I suspect, to many other people. For example, the default "matrix" for HF is "identity." What does that mean? What is "identity?" What's the difference between progressive, non-interlace, and quasi-interlace (which, in my years studying video production, I've never even heard of "quasi-interlace")? What does format=custom mean? Like, what IS "custom"? I'd have a much easier time playing with settings myself if I had any idea what any of these things actually turn on. NTSC and PAL I understand, but I'm not aware of any standard known as "custom." If it's something I can specify, then how do I specify it? What does "vfilter" do? All I can do is pick and choose from settings that you or others recommend and hope they help, but I'm really just picking blindly here. I've come here hoping someone has some more specific suggestions since I've given up hope of ever being able to translate any of these things myself.

[Extrems]

This part that is only in HF as far as I can tell: 59.7276 Hz refresh rate.

It's available in all editions.

I get horrible tearing on my PVM with it (though the last time I tested was when it was still ULL) that I don't get when using the other versions.

GBIHF is not GBI ULL.

For example, the default "matrix" for HF is "identity." What does that mean? What is "identity?"

https://en.wikipedia.org/wiki/Identity_matrix

What's the difference between progressive, non-interlace, and quasi-interlace (which, in my years studying video production, I've never even heard of "quasi-interlace")?

Have you heard of Progressive segmented Frame? That's what it is.

What does format=custom mean? Like, what IS "custom"?

It's what produces 59.7276 Hz video.

What does "vfilter" do?

It controls the vertical filter. It can be used for black frame insertion, deflickering, 2:1 downsampling, and scanlines. 2:1 downsampling is used in the OSSC/XRGB presets.

[thebigcheese]

So GBIHF would not have the same tearing even with that refresh rate? I don't believe you ever actually said that. There are a lot of new features introduced all the time that are not really explained. I would be happy to do the explaining except that I don't understand them.

If I might offer some suggestions for your future wiki updates based on what you have just said:
-Regarding the matrix, "identity" is a math term while all the others are console names. Would be good to clarify what is meant by that for non-math people (it's been a while since I learned about matrices).
-Regarding progressive/non-interlace/quasi etc, would be useful to specify why one might be beneficial over the others.
-Regarding the formats, that's the first I have ever seen it actually specified anywhere that that's what "custom" means. It also looks like it's not possible to specify a different format with GBIHF, is that correct? Hence why I have steered away from it.
-Regarding the downsampling - okay, but what does that mean in terms of performance? Is that why I'm not getting sharp pixels? When I think downsampling, I think about basically taking an image and shrinking it down by 50% (which would be 2 to 1 downsampling in, say, Photoshop). Why would this be useful? If that's not what is meant, then what is meant by it?

I want to be clear that I really appreciate the software you have made for the community. I am not trying to be rude or whatever, I just want to understand so I can actually use it. I am usually pretty good at understanding engineer speak and translating it to English, but in this case I don't even know where to begin.

[Harrumph]

To get it to fill more of the screen, you can reduce active area on the ossc. Unfortunately it can not be lowered below 200, ideal setting would be h.active 240, v.active 180 (to preserve aspect, displaying the 3:2 inside a 4:3 frame). The lowest integer you can set for exact 4:3 frame is h.active 272, v.active 204.

There is a feature request already at vgp forums to be able to reduce v.active below 200, not sure it caught Marqs attention though.

Edit: the above is when using OSSC optimized 320x240 settings. Fixed typo.

[Extrems]

So GBIHF would not have the same tearing even with that refresh rate?

GBIHF has smarter buffering. It's a bit buggy at the moment though.

Regarding progressive/non-interlace/quasi etc, would be useful to specify why one might be beneficial over the others.

I don't think I need to specify why 480p might be beneficial over 240p. I don't expect anyone to use 480sf.

It also looks like it's not possible to specify a different format with GBIHF, is that correct?

Currently, yes. It'll support all modes supported by the standard edition.

Is that why I'm not getting sharp pixels?

No, that's from the horizontal scaling for aspect correction.

When I think downsampling, I think about basically taking an image and shrinking it down by 50% (which would be 2 to 1 downsampling in, say, Photoshop). Why would this be useful?

If you did use borders, it would flicker in 240p without it.

There is a feature request already at vgp forums to be able to reduce v.active below 200, not sure it caught Marqs attention though.

Not so relevant anymore with 360p.

[Harrumph]

There is a feature request already at vgp forums to be able to reduce v.active below 200, not sure it caught Marqs attention though.

Not so relevant anymore with 360p.

Oh, interesting! And that works with the regular RGB cable?

[thebigcheese]

There is a feature request already at vgp forums to be able to reduce v.active below 200, not sure it caught Marqs attention though.

Not so relevant anymore with 360p.

Oh, interesting! And that works with the regular RGB cable?

If I understand his earlier post, it won't work at all with GCDual because it's one of the HD60 modes which are not supported by the GCDual for some reason.

[Harrumph]

I don’t use gcdual, I have an unmodded PAL gamecube.

[Extrems]

It should work on a PAL GameCube with SCART RGB.

If I understand his earlier post, it won't work at all with GCDual because it's one of the HD60 modes which are not supported by the GCDual for some reason.

It's because of GCVideo DVI's blanking regeneration.

[thebigcheese]

What does the HD60 work with then? Official component cables only? Eon HD? I had got the Dual because it gives me RGBs, component, and HDMI output, so it seemed the best and most flexible option. And also because I wanted the RGBs output to work with my switcher setup.

[Extrems]

AVE P-DOL, CMPV-DOL, GCVideo Lite, and BadAssConsoles GCVideoX. EON GCHD is GCVideo DVI.

[Harrumph]

Cool, I just saw paulb_nls post in the gc-forever thread, looks like we’ll soon get x3 on the OSSC for this mode then! GBI in x6 into 1080p frame, who would have thought!

[maxtherabbit]

AVE P-DOL, CMPV-DOL, GCVideo Lite, and BadAssConsoles GCVideoX. EON GCHD is GCVideo DVI.

what is gcvideox running on then? if not the DVI firmware what is it

[Extrems]

A fork of GCVideo DVI.

[maxtherabbit]

A fork of GCVideo DVI.

damn must be private then? the only fork on github that had any commits ahead of master was citrus3000psi's and they were unrelated

[citrus3000psi]

I’ve been meaning to send a GCDual to fbx to let him play around with it. That will probably be the sharpest it will get, unless extrems shares his changes.

[Extrems]

I'm not working directly on GCVideoX. I don't know FPGA programming or electrical engineering.

[thebigcheese]

Okay, so back on topic to the "what settings to use" portion, here are the pictures.
In this picture, you can see the portion of the screen filled by GBA games. You can also see the resolution GCDual is outputting: https://photos.app.goo.gl/wm9oWZsgkVdIhPiP2.

And here is a close-up of Metroid Fusion's title screen so you can see the interpolation. Not horrible, but if it's gonna be so tiny, I'd rather have it be better: https://photos.app.goo.gl/oXoYtUg58MBK6F7y2.

Game Boy Color games take up even less of the screen: https://photos.app.goo.gl/C9Auay1pGek5xGMu2

And a close-up of Crystalis for more comparison: https://photos.app.goo.gl/Etq05tDfWhaeAe4C3.

From what I can tell, it seems to be mostly in the horizontal direction. Vertical is pretty sharp. This is with it set as described above, though, since HD60 shouldn't work with my setup, I am not sure if it defaults to something else or what. All I know is I get picture and sound, so... it's doing something. I'd prefer to use GBIHF if it'll work, but I haven't tested it yet. GBISR is what I have been using.

[Extrems]

The setting simply isn't taking effect and it's staying on custom. GBISR doesn't recognize HD60, HD50 or HD48 at all.

[thebigcheese]

The setting simply isn't taking effect and it's staying on custom. GBISR doesn't recognize HD60, HD50 or HD48 at all.

Is it just regular GBI that supports it then? Or also GBIHF?

[Extrems]

I don't understand. It was clearly specified this was added only to the standard edition, and they're only listed as options in the standard edition.