crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come)

[Riverstorm]

@dankcushions said in crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come):

Questioning of my ability as a programmer.

Correct.

And this:

https://retropie.org.uk/forum/topic/14257/correcting-scaling-artifacts-in-lr-mame2003

[dankcushions]

we are almost ready to release the new .zips with @AndrewH's improved algorithm!

a check has been added to make sure that the scanline shader is NOT used in situations where the screen does not have sufficient resolution for the game. i forget the official figure from @davej, but I believe it was 3 or 4 pixels per scanline for good results. you can see an extreme example of the problem when you use the shader in games like darius, which has a very wide, high resolution image. the scanlines just appear like a grey haze... not ideal!

so, **a question for 720p users! **
following this change, the following games will NOT have the crt-pi shader applied for your resolution:

• nba jam
• mortal kombat (all)
• smash tv
• r-type
• donpachi
  (this isn't the complete list, which is 100s, just some popular games)

can you check these out on your screen with the crt-pi shader on? do the scanlines look acceptable? if so, maybe we could reduce the threshold, or make it optional or something like that.

[Darksavior]

@dankcushions Will this update fix or reduce rainbow banding issues? I only get them on an old Samsung 720p tv when using any emulator with the crt pi shader. It might be an isolated issue with these old TVs being 1366x768 or whatever res it is when using the vga port, but the hdmi ports only output 720p.

[dankcushions]

@darksavior said in crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come):

@dankcushions Will this update fix or reduce rainbow banding issues? I only get them on an old Samsung 720p tv when using any emulator with the crt pi shader.

are you already use the script's configs?

[Darksavior]

@dankcushions Not in a while. It’s a problem I’ve had forever and given up on it. If the scripts have been updated recently, I’ll give them a try when I can. It might be a combo of the shader itself with the tv...

[dankcushions]

@darksavior said in crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come):

@dankcushions Not in a while. It’s a problem I’ve had forever and given up on it. If the scripts have been updated recently, I’ll give them a try when I can.

eliminating the rainbow effect is exactly the script's function :) that part of things hasn't changed a great deal. i wonder which ones you see the effect?

following the next update it will not bother applying shaders to certain higher resolution games on lower resolution screens, but for the majority of games you will still get the shader on a 1366x768 display.

[Clyde]

Hi folks,
I have a native 1600x1200 TFT. Although I read most of the posts about this resolution here, I don't really understand what I should do for the best results with this resolution or if the latest version is "4:3 ready" by now. Could someone please enlighten me in a few words? Thanks.

[dankcushions]

@clyde You would have to generate the configs using the script yourself, since I have not created a set for that resolution in the initial post. However, I am probably going to re-generate all the configs soon using a different shader, and could do you a 1600x1200 pack then. this probably won't be soon, though!

[Clyde]

@dankcushions Thanks, that would be very kind of you. I can wait, it's not an urgent issue for me, as the rainbow effect is not more than a little nuisance. In addition, I'm testing @ghogan42's curved shader at the moment, which seems to have no rainbow effect in vertical games – or at least none that's noticeable to me.

Which different shader will you be using for the new configs?

[dankcushions]

@clyde curved shaders won't have the issue since they don't 'line up' with the pixels on your TV anyway. my plan is to use @ghogan42's non-curved shaders :)

[Clyde]

@dankcushions said in crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come):

my plan is to use @ghogan42's non-curved shaders :)

I'm looking forward to that. :)

Thanks for the clarification about curved shaders.

edit: Repaired the quote. :*)

[AndrewH]

@clyde : it's pretty simple stuff to use @dankcushions's script to generate the files you need. Definitely worth a try, and the results are really nice (one of the systems I have is 1600 x 1200, as mentioned above somewhere).
You can get the current version here : https://github.com/dankcushions/crt-pi-configs
..and it's got full instructions, so even if you're not a Linux command-line wizard, you should be fine.

If you do run into problems, let us know and we'll either lend a hand, or I'll see if I can post some zip files at that resolution somewhere public.

[Clyde]

@andrewh Thanks very much for your offer. I'm using Linux for more than eleven years now, so that should be no problem. :) I'll look into it in the next few days. Alas, my free time at workdays is very limited.

[Clyde]

@andrewh Okay, I've used the script with the command python crt_pi_configs.py mame2003 1600 1200 to create a folder MAME 2003 full of .cfg files for all of MAME 2003's games. I then put this folder into /opt/retropie/configs/all/retroarch/config so that the full path is /opt/retropie/configs/all/retroarch/config/MAME 2003. But vertical games in lr-mame2003 still have the shader crt-pi.glsl, not crt-pi-vertical.glsl.

Before doing that, I used @ghogan42's shader zfast_crt_curve.glslp. To test @dankcushions' script, I changed it back to crt-pi.glslp and chose "Save Core Preset" in the Shaders menu of retroarch.

What am I missing or doing wrong?

[AndrewH]

@clyde said in crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come):

@andrewh Okay, I've used the script with the command python crt_pi_configs.py mame2003 1600 1200 to create a folder MAME 2003 full of .cfg files for all of MAME 2003's games. I then put this folder into /opt/retropie/configs/all/retroarch/config so that the full path is /opt/retropie/configs/all/retroarch/config/MAME 2003. But vertical games in lr-mame2003 still have the shader crt-pi.glsl, not crt-pi-vertical.glsl.

Before doing that, I used @ghogan42's shader zfast_crt_curve.glslp. To test @dankcushions' script, I changed it back to crt-pi.glslp and chose "Save Core Preset" in the Shaders menu of retroarch.

What am I missing or doing wrong?

It looks like saving the core preset overrides the game-specific configuration, which isn't what I'd have expected to happen.

Navigate to /opt/retropie/configs/all/retroarch/shaders/presets , and delete the MAME 2003 folder you'll find there.

[Clyde]

@andrewh

It looks like saving the core preset overrides the game-specific configuration, which isn't what I'd have expected to happen.

Then we both have learned something today. :)

Navigate to /opt/retropie/configs/all/retroarch/shaders/presets , and delete the MAME 2003 folder you'll find there.

Now it works and looks beautiful, thanks! Alas, now I'm having a hard time to choose between this and @ghogan42's also beautiful curved shader … maybe I'll switch between them from time to time. :)

[AndrewH]

@clyde said in crt-pi shader users - reduce scaling artifacts with these configs in lr-mame2003, lr-fbalpha, lr-nestopia (and more to come):

Now it works and looks beautiful, thanks! Alas, now I'm having a hard time to choose between this and @ghogan42's also beautiful curved shader … maybe I'll switch between them from time to time.

It's always good to have options :-)

[thelostsoul]

I recently upgraded from LCD 1080p monitor to CRT VGA. And it may sound strange, but even on my crt monitor I would like to use the crt-pi filter, as it looks so good. The problem is, the sweet spot on my system is 640*480 pixel and I can't use these files then. If I would understand these concepts here, I could write my own simple script and convert them probably. Do anyone have an idea?

[caver01]

@thelostsoul At that low resolution, you won't be able to see the full effect of the shader. Think about it. If the shader draws a dark line inbetween each bright line to simulate scanlines/shadow mask, that only leaves you with 480/2 = 240 pixels vertically, with every other line used for the scanlines. The reason the shader looks good is because it is able to use a few surrounding lines on a high resolution display to give the appearance of CRT scanlines (that your CRT display already has).

Now, I am pretty sure the best use of CRT-PI comes with a high resolution display (but not so high it slows down) with enough extra lines to render the proper effect.

[thelostsoul]

@caver01 Yeah. I was using them on my 1080p monitor. But on CRT without shader, I can just barely see the monitors own scanlines. The effect is very low and with added shader, it looks better to me, at least on systems like snes.