New CRT shader from Guest + CRT Guest Advanced updates

Potential feature suggestion: separate “NTSC Chroma Scaling / Bleeding” settings for 2 phase and 3 phase “NTSC Phase”.

I have found that setting Chroma Scaling to 2.55 makes 2 phase a good match for 3 phase with Chroma Scaling at the default 1.00.

For games/systems with fixed resolutions, that is simple enough, but for games/systems that switch resolution, a compromise setting of one sort or another is currently required. It would be very nice to be able to use Auto NTSC Phase and have it automatically switch to my preferred Chroma Scaling settings for each.

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I could reproduce it with some of your presets. If I change the FPS display setting interval from default 256 frames to let’s say 15 frames (RA settings), the problem goes away. It has something to do with a single low FPS moment when the shader is loaded.

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With your latest update my issue seems to have went away since I lowered the Taps setting down to about 19 (any lower on my presets and it then starts to break/sharpen the dithering effects) but just in case, which setting exactly did you touch? “FPS display setting interval”? Where do I find that? I updated to the latest RetroArch 1.17.0 version.

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This setting is under Settings -> On-Screen Display -> On-Screen Notifications -> Notification Visibility.

Then select Framerate Update Interval (in frames).

My thoughts on this is that it’s a “false positive”, basing on a single initial shader loading frame drop, nothing to worry about. I’m certain, it’s a frame rate report issue involved. My guess is that it roots in a bit longer shader compile time because some loops need to be unrolled etc.

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Ah ok. I was looking in the video settings section getting lost lol. Ok then everything is looking good to go, I’m off to the lab to work on my next update pack, should be ready soon.

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New Release Version (2024-02-17-r1):

Notable changes:

  • Major ntsc pass 2 reformation and performance improvements (especially 2-phase and high-res content).
  • Ntsc chroma scaling has now separate parameters for 2-phase and 3-phase modes.
  • Chroma taps fall-off now only works where needed (2-phase).
  • Feedback is welcome.

Download link:

https://mega.nz/file/p4ZgACiY#0hZZbw5EzaFMI3CUN4y1nKXNtaOwNMmjn-NMz5zpP48

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I had a feeling this was coming right after I released my pack lol. I’ll take a look at it later, I have a feeling I’ll be back in the lab with this one.

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A little demonstration of the Chroma Taps Fall-Off feature. It’s very nice to clear the “weak color auras” around objects without much hassle:

Default settings:

With Chroma Taps Fall-Off:

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Beautiful work @guest.r with lots of insightful and useful input from the community. What used to be an artform in trying to find the sweetspots will have to give way to much easier automagic out of the box higher quality settings and hopefully more realism as well as you’ve given more power to the masses, much more power.

Basically everything that I’ve wished for in the NTSC shader has been implemented and even more!! This should solve the issues I was telling you about with using Mixed (phase) Mode for Turbo Duo games where some of the high res text ended up blurry when using settings designed to blend the dithering in many turbo games!

I was happily camped out on the older versions for a while now but this is the moment that I might end up making the jump to the newer versions.

I did this very willfully and deliberately however, challenging myself to squeeze the most out of the older shader before jumping on the bandwagon.

I was thinking that if I can get things to an almost perfect (for me) level using that one, I can only imagine what would happen to my presets when the new levels are switched on!

This is game changing stuff!

Thanks again!

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Which Turbo games have this issue? As much as I love the Turbo I don’t think I’ve played enough games to have noticed this before.

@guest.r so I gave this new update a spin, first thing I noticed right away was the speed. Don’t know what you did but everything is back to full speed again and I don’t get any kind of slow down when first loading up any of my ntsc presets anymore, it’s even full speed with the “ntsc taps” setting set to default which was previously giving me slow downs so that area is now perfect again.

Second thing I noticed was the separation of the chroma scaling for 2phase and 3phase, that’s a sexy feature for those who want a certain amount of bleeding/scaling for either phase. Me personally I need both of those settings maxed out for more vibrant colors and a sharper image. All in all good stuff in that department.

Third thing I noticed (this is just from my personal tweaking I was doing yesterday) was that there were weird faint barely noticeable thin almost transparent-like vertical lines that were in the background on games that I noticed in your previous pack that have completely dissapeared in this pack. I previously chalked it up to that have been either part of the composite experience or maybe something crazy I was doing in my tweaking. Now I have a completely clear composite image in this update.

Finally and this is just based on my presets alone, I think I maxed out how sharp I can get composite to look with your ntsc shader settings, bringing the ntsc taps down anything below 24-23 I notice the Sonic waterfall dithering starts to break apart. My ideal setting would be to bring that taps setting down to about 9.00 which really make 2phase games colors POP but then I lose the dithering effects and that’s a no-no lol. Same goes for the “chroma taps fall off” setting, raising that up pass .05 or .10 vertical line dithering starts to break a bit (checkerboard dithering doesn’t seem to be effected) so I may settle on just leaving chroma taps at 24 which I believe I already had it at which will make updating my pack not too much of a hassle.

The final verdict is that this release is a sexy one indeed, everything is working as intended from what I see.

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Thanks, @Cyber and @sonkun, for the nice words. The shaders needed a bit of refactoring, I also like the new features. Hopefully I won’t notice something or get ideas again too soon… :grin:

I needed to optimize texture lookups in the 2-phase loop, along with some optimizations. I’m very glad it worked out in the end.

Yeah, it’s connected with the number of taps, which basically enhance the chroma scaling feature quite a lot. With 16 “taps” and chroma scaling at 4.0 it’s the same as 8.0 with 32 “taps”. But the performance is also better, especially if you try scalefx presets in the future.

Anyway, hopefully the last release can get a good rest for a while, if you folks notice something, just mention it. :smiley:

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I feel the same way. I just released version 2 of my preset pack to go along with your latest release and I plan on letting my current pack make its rounds unless you drop another release with juicy new features. Maybe I can kick back and do a little gaming for a bit.

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What about phase 4? Do I have to raise chroma scaling for both and chorma taps fall-off?

Looks really good😃

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Very nice work! That will help make games look more colorful, I understand. Thank you :trophy:

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Quite a number of games would exhibit this issue because unlike the vast majority of SNES, many Turbo games used multiple resolutions.

So for one if you take a game like Lords of Thunder as well as Gate of Thunder or Ys IV The Dawn of Ys and try to blend some of the checkerboard dithering in order to make the waterfall transparent or to achieve additional colours through dithering the resultant NTSC Scale value would leave high resolution fonts very blurry and almost illegible.

This actually affects all Turbo Grafx-CD/PC Engine-CD games since it happens on the BIOS/Boot screen.

This is using the Mixed Phase Mode.

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Ah yes I see what you’re talking about. I always see that “m” every now and then. After reading your post I went to play around with the “mixed” phase setting in guest.r’s newest update, I admit that setting is a whole different level of tweaking to get the best “one in all” solution so I’m curious on how you plan to tackle that.

As a quick test on one of my composite presets the few settings I whipped up are:

NTSC Phase: 4.00 NTSC # of Taps (Filter Width): 6.00 Chroma Scaling (2phase): 4.00 Chroma Scaling (3phase): 2.00 Chroma Taps Fall off: 1.00

These are the results I got so far:

I get blended dithering in 3phased games:

The dreaded “m” is now gone in Turbo Duo bios start up:

But then here’s where my problems start, I get pseudo checkerboard and vertical line dithering blending in 2phase games:

So I’m stuck there trying to figure out how to blend the waterfall and bar lights properly. It’s definitely interesting taking this challenge up I’ll say.

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I’m still using a much older version of CRT-Guest-Advanced-NTSC and what I did was set the NTSC Scale to about 1.15 then cranked the Negative Adaptive Sharpness to about -8 to -9.50.

This makes the text fully readable, while preserving the blending of checkerboard dithering in Turbo games!

I only recently ran back into the"m" issue when I tried doing some RF presets with much lower NTSC Scale.

I’m hoping to resolve that by using the Auto Phase Mode and tweaking the 2 phase and 3 phase to allow blending. One of the phases is triggered while in Game for games like Lords of Thunder, while the other is triggered when in the BIOS screen. So I’ll just tweak them independently until I get the best of both worlds.

That would mean no more use of the Mixed Phase Mode though.

Most likely I will release a 2.0 version of my Megatron Preset Pack based on this new Guest, while leaving the previous version locked to the older version of Guest that it currently requires. Not sure when I’ll jump on it though. I’m still having fun with the current version and seeing some amazing things.

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Ah I see. I always keep my composite presets Negative Adaptive Sharpness at the maximum -10.00, after posting those two genesis shots I wouldn’t dare raise NTSC scale over 1.00, in fact it may need to be lowered but I don’t want to lose any sharpness at all that I already have established.

So your plan is to solve this without Mixed Phase Mode then, I thought you were going to try and get results with that mode, ok then.

Nice, you’ll get to it eventually. I’m always the guina pig when guest.r releases a new update, I usually dive right in to see what new goodies have been featured.

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That is because the Turbo switches between 2 Phase and 3 Phase in many gaming scenarios and the new independent NTSC_Scale controls for 2 Phase and 3 Phase don’t apply to the Mixed Phase Mode from what I have gathered.

Also, the Auto Phase Mode, which would be required for at least the Turbo (and possibly PSX and other similar systems which do a lot of resolution switching) doesn’t work with mixed mode.

So I see the hybrid mixed mode as a sort of compromising solution that can look better than 2 phase in systems that also do 3 phase. So it gives almost as easy blending as 2 phase, while preserving some of the sharpness and quality of 3 phase mode.

With these latest tweaks the Auto Phase Mode should now have what is needed to be the premiere NTSC Shader mode and also the most accurate/realistic implementation as well.

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Yeah Mixed Phase Mode is definitely a peculiar setting. I’ll most likely end up leaving it alone. I did go back to auto phase and saw what you mean by raising the ntsc scaling to 1.15, it got rid of that nasty looking “m” instantly. I think it looks a bit clearer even at 1.17 or 1.20. Would be nice to keep the “m” like that and still get proper vertical line dithering. I guess that’s the mission you’re facing soon.

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