xBRZ... shaders for FS-UAE

[Photon]

All right, thanks for the setting, I will try it. What is Retroarch? And where do I type the snippets I see in the thread and make them active? Is there a saturation or black point tweak in the shader?

[guest.r]

Retroarch (RA) is a frontend for libretro, covers a lot of emulator cores and comes with tons of very good shaders, some of them made exclusively for RA (ehem libretro) as it offers the most advanced shader platform for retro gaming. Very popular and with active development.

The snippets are from the shaders itself, just grab a text editor. The viable tweaking options are declared as defines (#define saturation 1.2 for example) and changing a number to a new usable value should produce the desired change.

I have included the saturation option in some of my shaders as they compensate for the higher output gamma. Dunno about the black point tweak though...

[Photon]

Originally Posted by guest.r

Sorry about the instructions, the authors (Lottes, Easymode, Hyllian...) left us to discover the options mostly by ourselves and this isn't too hard in Retroarch since we can use the shader adjustment interface. (my shaders have most setting "hardcoded" lol). But the default settings are nice and if someone gets into the altering process, can be very interesting. I want only to let folks know that they can get geeky on this CRT thing.

About the scanline options in WinUAE. Yea basicly you can use masks or shaders for this and WinUAE favors some shaders more (gaussian scanlines for example - higher the scale, the better they look). So i wouldn't use a CRT shader for 720x568, because masks/scanlines makes a better job here.

In a 1080p situation shaders become a reasonable option since we usually want the image to have pixel-aligned scanlines. Masks also become viable, someone could perhaps create nicer 4x or 5x pixel perfect scanlines with manual integer scaling option.

I'm adding a gaussian scanline shader with some options to tweak and basic guidance to use, in fullscreen of course.

I put the .fx file in the shader folder, used a default configuration and switched it to 1920x1080 fullscreen, and set the settings as per your screenshot, , and got this. It also flickers.

Something different in our setups maybe?

WinUAE64.exe, Win7 x64, DX11 if it makes a difference.

[Retro-Nerd]

Enable the bilinear filter = Pull the slider to the right (1) in the Filter Tab. If some shader still don't look right then make sure you set the marked option in the below screenshot to "2x". I forgot what this option really does, but it works.

[Photon]

That looks like this - I think I matched it perfectly? Filter pane over the 1080p picture. The flickering is gone, I think Auto Integer Scaling is what caused it before. I've tried 1x, 1.5x, 2x instead of 4x for horiz/vert size, but the scanlines are too wide or too thin compared to the pixels.

[Retro-Nerd]

Strange. I use Windows 7 32bit, with an old ATI HD5570 card. Are you sure you've set resolution = Lores and Linemode = Single?

[guest.r]

The scanlines should look acceptable. I'm posting my results also.

Here is also the FS-UAE version (for reference).

[Photon]

Originally Posted by Retro-Nerd

Strange. I use Windows 7 32bit, with an old ATI HD5570 card. Are you sure you've set resolution = Lores and Linemode = Single?

Nope, from default configuration so I know what does what. Default means hires and double, and if it's for full-screen, Native, 32-bit color, and 100Hz.

If I change to lores it works but I get a horizontal jitter of 1 lores pixel left and right of the disk hand and text, about twice per second.

Ideally, I would like to turn my head from my high-end PC monitor to my 1084S-P and not notice a difference.

To make CRT on LCD I need global desaturation to not have to lower the contrast, exponential subpixel blur that I can adjust (or better, neighboring-pixels contrast-based color mixing), raise the black point on odd lines (as in pixel lines, not scanlines "between" pixel lines), and then a mask (edit: for scanlines) can be applied that is as good as the monitor resolution is larger than the Amiga resolution.

After that, there's a point in adjusting the gamma (which should be 2.2 for CRTs on LCDs but, you know, mileage varies).

This is the recipe. Can you give me some pointers in the right direction to code that guest.r?

[Retro-Nerd]

Well, it's a lores shader. I'm sure guest can do a hires version too.

[guest.r]

Well, it's a lores shader. I'm sure guest can do a hires version too.

Well, it's lores with a good reason. I would need to use a slower interpolation algorithm for a hires version and the sound could/would crackle. Amiga emulation is special regarding this matter and classic crt shaders can't do a perfect job where hires makes sense (Lionheart etc.). But it's not that bad at all in general, though it/they (lores shaders) might require an extra startup configuration as it changes the default settings.

If I change to lores it works but I get a horizontal jitter of 1 lores pixel left and right of the disk hand and text, about twice per second.

Yeah such things can happen, jittering happens to me also with various CRT shaders if i include a mask on the WB screen. I can report it clean with the games i tested though.

To make CRT on LCD I need global desaturation to not have to lower the contrast

I understand this as a shift towards grayscale. There are some ways to achieve this, shouldn't be a hurdle.

exponential subpixel blur that I can adjust

The PD CRT-Lottes uses exponential blur which is adjustable. Worth taking a look.

raise the black point on odd lines (as in pixel lines, not scanlines "between" pixel lines), and then a mask (edit: for scanlines) can be applied that is as good as the monitor resolution is larger than the Amiga resolution.

Black point could be something new, didn't see it with popular CRT shaders. Scanline masks can be also tricky, they might require to use a constant vertical integer scale factor and could be applied in linear (not 2.2 gamma) space from my observations.

After that, there's a point in adjusting the gamma (which should be 2.2 for CRTs on LCDs but, you know, mileage varies).

Yea this shouldn't be a problem to code.

I left this as an option in the CRT-Scanline shader, it's a bendable rule and it didn't appeal to me in this case since i wanted a specific scanline look. Interpolation looks better with higher gamma and solid scanlines with lower. There is tiny bit of interpolation and a strong scanline presence so the scanlines won.

This is the recipe. Can you give me some pointers in the right direction to code that guest.r?

Sure, np. I guess you are more a WinUAE user. HiRes/LoRes doesn't matter too much, you can have both versions. You could start with a horizontal exponential subpixel filter, make lookups gamma correct, apply desaturation etc. You'll see WinUAE is quite specific, looking forward for that.

[Photon]

WinUAE doesn't hand over a bitmap to post-process freely? (Along the lines of, asking like a child gives results).

If a shader causes jitter, how is it a visual improvement? (Again with the offensively stupid questions ) It didn't get past the disk hand, and I didn't use a mask.

Well any shader that I can use should display the same picture, just with scanline emulation.

I'm not a heavy WinUAE user, I think it's just a difference between game eyecandy and something usable for text, creative use, etc. Different expectations. Game screenshots here are certainly not as intended/drawn. Which is kind of the point; everything looks better.

[nobody]

Originally Posted by guest.r

I'm adding a gaussian scanline shader with some options to tweak and basic guidance to use, in fullscreen of course.

I like the clean look like a BVM monitor. It works for me if i set 3x instead of 2x (the scanlines look uneven). Maybe because resolution on my laptop is 1366x768 not 1080p

[nobody]

A quick comparison i did in WinUAE:

CRT-D3D


CRT-Geom-flat


CRT-Hyllian (guest.r port)


CRT-Scanlines-low res (guest.r)


From all of these i prefer hyllian, the colors and light almost match a CRT, but scanlines are a bit too subtle.

[guest.r]

WinUAE doesn't hand over a bitmap to post-process freely? (Along the lines of, asking like a child gives results).

If a shader causes jitter, how is it a visual improvement? (Again with the offensively stupid questions ) It didn't get past the disk hand, and I didn't use a mask.

Not too freely. You see you have to use the same algorithm which makes sense here to handle different circumstances.

Shaders can't officially cause jitter without a timer/frame counter uniform variable. Forcing progressive solutions to an interlaced platform with fixed refresh rates and trying to enhance the whole process requires to take exclusive decisions. So people notice a flickering last line, 1 pixel shifted masks, missing lines/columns after scaling etc. NPOT buffers could also contribute their share...

I'm not a heavy WinUAE user, I think it's just a difference between game eyecandy and something usable for text, creative use, etc. Different expectations. Game screenshots here are certainly not as intended/drawn. Which is kind of the point; everything looks better.

You should embrace the common thought that (crt) shaders are for low resolution games only, at least with 1080p. For text and creative use for example it's best to install this OS 4.1 thingie, get your net working, download nicer fonts etc.

I read about per-game configurations folks use and that's the spirit.

Originally Posted by nobody

I like the clean look like a BVM monitor. It works for me if i set 3x instead of 2x (the scanlines look uneven). Maybe because resolution on my laptop is 1366x768 not 1080p

Yea WinUAE can resize the image after filters are applied (cool for scaling shaders) and scanlines are a bit sensitive to that. The 768 vertical resolution also doesn't look as good as 1080p for example.

I'll include a reference sample of crt-scanline @1080p.

[Photon]

Well, a lores shader makes the Amiga useless outside games. I guess you'd even have to have a "MAME" type KG etc menu to not have to navigate Workbench.

I definitely see a need for an accurate hires shader that allows creative use of WinUAE, just as if you were using a normal Amiga with a CRT.

If it can be done I would try it, but it seems you're saying it can't be done?

[Retro-Nerd]

CRT-Hyllian Hires looks pretty good to me in WinUAE. Have you tried it? It's attached here:

http://eab.abime.net/showpost.php?p=...9&postcount=52

[guest.r]

Indeed we have some HiRes CRT shaders already (WinUAE), people were also content with a crt guest hires shader for FS-UAE so you can give it a try also, though the sound might crackle and slowdowns can happen with WinUAE.

I also made two scanline masks. I think each deserves it's own configuration.

Some tips for 5xScanlines...hires, double line mode, no scaling, 2.5xsize, vertical shift etc.

[Retro-Nerd]

And if you want a nearly 100% authentic look you would need multi-pass shaders, like the ones in Libretro/Retroarch. And probably a 1440p or 2160p capable monitor. 1080p looks nice enough though.

http://emulation.gametechwiki.com/index.php/CRT-Royale

https://forums.libretro.com/t/crt-ro...tion-help/3909

[guest.r]

Sometimes we don't need a shader at all. They are smarter though.

I guess this sub-thread (nr. 5) is more about WinUAE, np.

I'll throw in some crt masks, the results are not bad at all. Folks with decent WinUAE and game lore could manage to drive them operational.

The good is the HW requirements could be very low.

[Retro-Nerd]

Sure, a mask only works too. But doesn't add much for a really authentic CRT look (amount of blur, general "glow" etc.). I don't like the xxx-halation shader versions though, they tend to overdo the glowing effect of a CRT.