New CRT shader from Guest + CRT Guest Advanced updates

[ynnad4]

Proof I could get about the Rainbow banding in Sega Genesis games: (@sonkun)

1. Real hardware Sega Genesis (model 1) VS RetroArch Genesis Plus GX (my rainbow sega preset v2.7)

2. Real console proof by HunterK vs some fast tweak I did to replicate with mame_hlsl for GenesisPlusGX core

https://www.chrismcovell.com/gotRGB/screenshots.html

Rainbow sega preset available in here: Rainbow with composite - MOD preset for Sega Genesis Games

3. More serious dithering + rainbow effect exposure from real Genesis console:

Dithering on the Sega Genesis with Composite Video

4. This is some old preset named rainbow sega v3.0 which gets some Rainbow comparison to real Genesis console:

Rainbow with composite - MOD preset for Sega Genesis Games

Rainbow v3.0 for Sega genesis this time buddies. Ok so this time took another Composite sample to make another variant… This one looks almost the same to me but can’t manage to turn blue a bit lighter. If you got any ideas about another shader to incorporate, I’d appreciate it. left side is cutted video from real sega genesis composite connection vs Genesis plus GX rainbow danny v3.0. Source video is: https://www.youtube.com/watch?v=j-G02cjXpZ0 >> Thanks to it’s author for this sample. v3.0…

2021-10-14 21-51-43.mkv

5. Some other video comparison from rainbow sega v4.0 and 4.1 presets I did to compare Rainbow effect with original Genesis console model 2

Rainbow with composite - MOD preset for Sega Genesis Games

I’m happy to release now Rainbow for sega v4.0(+v4.1). It looks very similar to the video samble. Hope you enjoy them guys. Preset is for genesis plus gx and not blastem (rainbow will be unacurrate). Big thanks to it’s original author for uploading the sample: [Sonic 2 -Genesis Test Capture] Left side is a Genesis console model 2 and right side is Genesis Plus GX You can see the beautiful rainbow colors around the letters on first picture from Sonic & Tails text presentation. [4…

Rainbow sega danny v4.0 video comparison demostration.mkv

some other video samples for the original Rainbow looking:

https://youtu.be/SwotQNShPvs?t=380 (model 2)

Sonic the Hedgehog 2 (Sega Genesis - Composite VS. S-Video)

7. some of my attempts to replicate this source video sample with my preset v6.291

https://youtu.be/EtNjgW5RtyI?t=365 (Genesis Model 1 VA6.8 )

Rainbow with composite - MOD preset for Sega Genesis Games

hello there again. Just sharing some experimental presets left aiming to give some similar results from available samples: Rainbow sega v6.26 is intended to work either for BlastEm OR Genesis Plus GX with core options >> borders (overscan) = Full OR left/right being set available. video sample: Sonic the Hedgehog 2 (Sega Genesis - Composite VS. S-Video) - YouTube Also, a video available as a proof for v6.26 in Sonic waterfall to expose dithering + rainbow effect. Left side is Genesis cons…

8. All the NTSC-Rainbow intended shaders available I have tested around with the exception of mame_hlsl, actually have delivered to me a wrong Rainbow banding in Streets of Rage 2 for the Genesis console. Which the results are somehow similar to this:

Rainbow with composite - MOD preset for Sega Genesis Games

This is a very recent sample. Big thanks to the guy who made it possible. [Streets of Rage 2 ( Sega Genesis - Composite VS. S-Video)] So there it seems to match pretty well what is done with the rainbow sega v6.26 preset. This is how it looks to me with that version in streets of rage 2: I will look if can give a bit more accurate rainbow with your 8-16bits preset, however I may really appreciate if this effect can be combined with OTHER composite-blurry looking shader/presets. …

Big thanks to the author from this video that delivers such a wonderful Streets of Rage 2 gameplay demostration to check the proper Rainbow:

https://youtu.be/bpqmPjpfN1k?t=342 (Genesis Model 2 with Composite-video)

This is a little proof of how the same game look like with my preset rainbow sega v6.26:

2022-03-02 15-38-30.mkv

…

Many thanks to all the nice people who recorded all of these great classic games and served for this case situation.

[sonkun]

Got it, no problem at all. In that case I’ll just post up my shaders as is, like you said I can still get the look by just adding in that pass.

[guest.r]

@guest.r

Probably i’ll tweak the existing ntsc shaders for a bit more sharpness though.

I report a nice success with new ntsc-sharpness implementation. More info in the release notes.

New Release Version (2022-05-21-r1):

Notable changes:

• only ntsc-based changes with this version
• new ntsc-sharpness implementation, nice new looks are possible
• sharpness and de-dithering are mutually exclusive at some point, so a pair of great gdapt shaders are now included with the preset, which was updated, de-dithering has to be enabled with a parameter though
• ntsc-sharpness shader is no longer needed, so it was removed from the preset
• with testing the shader performance is about the same
• new sharpness feature works great with 3-phase mode, just mentioning

Download link:

https://mega.nz/file/4gY0gJZR#t0or-vPntGVn3li_nnVYwA2iKO5RYbGpnXGe7q4S6jg

Screenie:

[RealNC]

Thanks. Will try it out when I get the chance. Also forgot to say thanks for the luma noise. It’s great! No more ruined black level!

Though there’s something odd about the randomness of the noise. It doesn’t seem very… random. Can’t quite put my finger on it. (Not specifically luma noise. Both types give the impression of a repeating pattern. Kind of…)

[Syh]

Ik exactly what you’re meaning by the noise feels like it’s on a patterned/loop. I’m not sure what’s going on but I experience a seemingly similar situation.

[hunterk]

Randomness in shaders is a tough nut to crack. There’s no way to get truly random values, and the built-in “noise” value has apparently never been implemented in a useful way (it always returns 0.0, which is arguably technically correct, since the values it returns are supposed to average out to 0.0…).

The alternative is to generate pseudo-random numbers inside the shader, but this is computationally expensive and has performance vs quality (i.e., visible patterns/looping) tradeoffs, as well as GPU/driver-dependent quirks. For example, there’s a famous one-liner PRNG that relies on inconsistencies in fract-ing certain floating point values, but it falls apart on mobile GPUs.

Similarly, many of the common PRNGs you can find online fall apart (or get out of hand, computationally) when the seed value–usually FrameCount in our case, so it moves around each frame–gets too high, so you have to modulo the value to keep it in a usable range, but whenever it loops, you get a sort of “reset” back to the minimum value, which is often visually noticeable and is exacerbated by happening at consistent intervals (every 783 frames or whatever is hardcoded in the mod() function).

One option here may be to sample a robust noise LUT using a pseudo-random texture coordinate, so you get the visual benefit of random-on-random without having to generate both of them on each frame.

[sonkun]

This update just had to come after I updated my presets lol. Adding in that gdapt shader definitely was unexpected, I tested it out a little and for some reason I’m just not getting good results with it, seems buggy actually unless I’m just not tweaking it right. I get a nice sharper clearer picture when using the jinc2-dedither shader in my shader chain since it comes with it own sharpness setting as well (I played around with every dithering shader in that dithering shader folder even sgenpt-mix and none of them produced the same kind of image as jinc), kind of wish you had used that shader instead. Still a nice feature though and that updated sharpness is nice as well. Should be simple to update my presets with this new release since I plan on sticking with the jinc2-dedither shader that I ended up using in my last update.

[BendBombBoom]

Hello, I’m trying to get a bigger slot mask. One image is from the Master System’s Psycho Fox, and the other NES Legendary Wings, both with integer scaling on. (NES has banding while SMS does not.) I’m assuming the slot mask is resolution dependent and there is now way to have it work on both without changing the numbers?

shaders = "12"
shader0 = "shaders_slang/crt/shaders/guest/advanced/stock.slang"
filter_linear0 = "false"
wrap_mode0 = "clamp_to_border"
mipmap_input0 = "false"
alias0 = ""
float_framebuffer0 = "false"
srgb_framebuffer0 = "false"
scale_type_x0 = "source"
scale_x0 = "1.000000"
scale_type_y0 = "source"
scale_y0 = "1.000000"
shader1 = "shaders_slang/crt/shaders/guest/advanced/stock.slang"
filter_linear1 = "false"
wrap_mode1 = "clamp_to_border"
mipmap_input1 = "false"
alias1 = "StockPass"
float_framebuffer1 = "false"
srgb_framebuffer1 = "false"
scale_type_x1 = "source"
scale_x1 = "1.000000"
scale_type_y1 = "source"
scale_y1 = "1.000000"
shader2 = "shaders_slang/crt/shaders/guest/advanced/afterglow0.slang"
filter_linear2 = "false"
wrap_mode2 = "clamp_to_border"
mipmap_input2 = "false"
alias2 = "AfterglowPass"
float_framebuffer2 = "false"
srgb_framebuffer2 = "false"
scale_type_x2 = "source"
scale_x2 = "1.000000"
scale_type_y2 = "source"
scale_y2 = "1.000000"
shader3 = "shaders_slang/crt/shaders/guest/advanced/pre-shaders-afterglow.slang"
filter_linear3 = "false"
wrap_mode3 = "clamp_to_border"
mipmap_input3 = "true"
alias3 = "PrePass"
float_framebuffer3 = "false"
srgb_framebuffer3 = "false"
scale_type_x3 = "source"
scale_x3 = "1.000000"
scale_type_y3 = "source"
scale_y3 = "1.000000"
shader4 = "shaders_slang/crt/shaders/guest/advanced/avg-lum.slang"
filter_linear4 = "true"
wrap_mode4 = "clamp_to_border"
mipmap_input4 = "true"
alias4 = "AvgLumPass"
float_framebuffer4 = "false"
srgb_framebuffer4 = "false"
scale_type_x4 = "source"
scale_x4 = "1.000000"
scale_type_y4 = "source"
scale_y4 = "1.000000"
shader5 = "shaders_slang/crt/shaders/guest/advanced/linearize.slang"
filter_linear5 = "true"
wrap_mode5 = "clamp_to_border"
mipmap_input5 = "false"
alias5 = "LinearizePass"
float_framebuffer5 = "true"
srgb_framebuffer5 = "false"
scale_type_x5 = "source"
scale_x5 = "1.000000"
scale_type_y5 = "source"
scale_y5 = "1.000000"
shader6 = "shaders_slang/crt/shaders/guest/advanced/gaussian_horizontal.slang"
filter_linear6 = "true"
wrap_mode6 = "clamp_to_border"
mipmap_input6 = "false"
alias6 = ""
float_framebuffer6 = "true"
srgb_framebuffer6 = "false"
scale_type_x6 = "absolute"
scale_x6 = "800"
scale_type_y6 = "source"
scale_y6 = "1.000000"
shader7 = "shaders_slang/crt/shaders/guest/advanced/gaussian_vertical.slang"
filter_linear7 = "true"
wrap_mode7 = "clamp_to_border"
mipmap_input7 = "false"
alias7 = "GlowPass"
float_framebuffer7 = "true"
srgb_framebuffer7 = "false"
scale_type_x7 = "absolute"
scale_x7 = "800"
scale_type_y7 = "absolute"
scale_y7 = "600"
shader8 = "shaders_slang/crt/shaders/guest/advanced/bloom_horizontal.slang"
filter_linear8 = "true"
wrap_mode8 = "clamp_to_border"
mipmap_input8 = "false"
alias8 = ""
float_framebuffer8 = "true"
srgb_framebuffer8 = "false"
scale_type_x8 = "absolute"
scale_x8 = "800"
scale_type_y8 = "absolute"
scale_y8 = "600"
shader9 = "shaders_slang/crt/shaders/guest/advanced/bloom_vertical.slang"
filter_linear9 = "true"
wrap_mode9 = "clamp_to_border"
mipmap_input9 = "false"
alias9 = "BloomPass"
float_framebuffer9 = "true"
srgb_framebuffer9 = "false"
scale_type_x9 = "source"
scale_x9 = "1.000000"
scale_type_y9 = "source"
scale_y9 = "1.000000"
shader10 = "shaders_slang/crt/shaders/guest/advanced/crt-guest-advanced.slang"
filter_linear10 = "true"
wrap_mode10 = "clamp_to_border"
mipmap_input10 = "false"
alias10 = ""
float_framebuffer10 = "true"
srgb_framebuffer10 = "false"
scale_type_x10 = "viewport"
scale_x10 = "1.000000"
scale_type_y10 = "viewport"
scale_y10 = "1.000000"
shader11 = "shaders_slang/crt/shaders/guest/advanced/deconvergence.slang"
filter_linear11 = "true"
wrap_mode11 = "clamp_to_border"
mipmap_input11 = "false"
alias11 = ""
float_framebuffer11 = "false"
srgb_framebuffer11 = "false"
scale_type_x11 = "viewport"
scale_x11 = "1.000000"
scale_type_y11 = "viewport"
scale_y11 = "1.000000"
beam_max = "1.300000"
shadowMask = "13.000000"
maskstr = "0.800000"
slotmask = "0.800000"
slotmask1 = "0.800000"
double_slot = "3.000000"
slotms = "3.000000"
post_br = "1.200000"
textures = "SamplerLUT1;SamplerLUT2;SamplerLUT3;SamplerLUT4"
SamplerLUT1 = "shaders_slang/crt/shaders/guest/advanced/lut/trinitron-lut.png"
SamplerLUT1_linear = "true"
SamplerLUT1_wrap_mode = "clamp_to_border"
SamplerLUT1_mipmap = "false"
SamplerLUT2 = "shaders_slang/crt/shaders/guest/advanced/lut/inv-trinitron-lut.png"
SamplerLUT2_linear = "true"
SamplerLUT2_wrap_mode = "clamp_to_border"
SamplerLUT2_mipmap = "false"
SamplerLUT3 = "shaders_slang/crt/shaders/guest/advanced/lut/nec-lut.png"
SamplerLUT3_linear = "true"
SamplerLUT3_wrap_mode = "clamp_to_border"
SamplerLUT3_mipmap = "false"
SamplerLUT4 = "shaders_slang/crt/shaders/guest/advanced/lut/ntsc-lut.png"
SamplerLUT4_linear = "true"
SamplerLUT4_wrap_mode = "clamp_to_border"
SamplerLUT4_mipmap = "false"

[Syh]

Add " ``` " at the top and bottom of your preset without the " ". If you want I mean

[RealNC]

Well, the new NTSC sharpness setting certainly does sharpen. You can make it so sharp your eyes will bleed if you want…

[guest.r]

@RealNC

Well, the new NTSC sharpness setting certainly does sharpen. You can make it so sharp your eyes will bleed if you want

I think i can re-balance it for even better results, maybe new noise implementation is also around the corner, will probably post an update soon.

[Cyber]

@guest.r

maybe new noise implementation is also around the corner, will probably post an update soon.

I don’t have any issue with the current implementation and I use it in all my presets. Will the new implementation resemble more closely something that goes on in a real CRT?

I use noise very subtly in most of my presets just to simulate a scanning effect of the scanlines. They don’t necessarily have to scan in the direction or manner as on a CRT but just by not not being static it certainly adds something to the image.

I’m hoping this new implementation isn’t going to take away from the way things are right now, which I feel are in a very good place.

I certainly don’t mind improvements though.

[guest.r]

@Cyber

I don’t have any issue with the current implementation and I use it in all my presets. Will the new implementation resemble more closely something that goes on in a real CRT?

I compared it with an other popular noise function and current implementation was way better, so i optimized it a bit for a more random feel, in general, it’s a bit more ‘random’ and nicer.

[guest.r]

New Release Version (2022-05-22-r1):

Notable changes:

• ntsc sharpness feature greatly improved
• small noise function optimization
• small cleanup

Download link:

https://mega.nz/file/w1hCmSAD#SlOcEN_vk4RDzim8dSZLip3A1vUy-W-_AupT2pAcw7A

Edit: small improvement to the ntsc-shaders, ntsc-fast blend mode default is now 2.0.

[RealNC]

Thanks for the noise.

For people using luma-type noise, make sure to increase “post brightness” slightly, as the image gets darker with noise. For example for DOS, I use a noise value of 0.28 with noise resolution 1.0, and I have to edit the saved preset to set post_br = "1.035000" to maintain the same overall brightness. (The menu control for post brightness is too coarse and the smallest available step of 0.05 makes the image too bright.)

As for the sharpness setting, it does appear to be much cleaner now. Not sure what the terminology is, but previously the image would look like it was hacked by a saw at high sharpness levels.

[guest.r]

@RealNC

For people using luma-type noise, make sure to increase “post brightness” slightly, as the image gets darker with noise.

Yep, that’s correct, there is already a small compensation implemented, but increasing post brightness does also help. Didn’t want to go full scale since some very bright colors would clip and go darker in average regardless.

@RealNC

As for the sharpness setting, it does appear to be much cleaner now. Not sure what the terminology is, but previously the image would look like it was hacked by a saw at high sharpness levels.

I guess i had to sleep over it. There is still a notch of substractive sharpness (causes shading/ringing) involved, but the main focus is now on adjusting the interpolation weights for ‘normal’ sharpness.

[BendBombBoom]

I had not idea the images didn’t post from from several days ago. Here they are:

“Hello, I’m trying to get a bigger slot mask. One image is from the Master System’s Psycho Fox, and the other NES Legendary Wings, both with integer scaling on. (NES has banding while SMS does not.) I’m assuming the slot mask is resolution dependent and there is now way to have it work on both without changing the numbers?”

[guest.r]

Slotmask horizontal width shouldn’t be an issue for banding, it’s more or less to be aligned with crt mask width.

Actual vertical spacing comes in steps of two (must be an even number). As it can be seen the most problematic part is the interaction with scanlines. Quick cure for this is to use a smaller height or less pronounced scanlines.

Integer scaling can help, as it comes with two ‘flavors’ with the shaders, one bringing odd and the other even vertical original resolution scaling.

Ofc. does a display with higher resolution help a lot.

[guest.r]

New Release Version (2022-05-24-r1):

Notable changes:

• post brightness parameter step is now 0.01
• gamma bug with scanline gamma and interlace modes fixed (ntsc, hd versions)
• small cleanup
• ntsc shaders register usage reduced (unused parameter cleanup)
• nicer artifacting with ntsc-sharpness
• ntsc-fast shaders filtering reworked, not compatible with older version preset/parameter wise
• ntsc-fast version blending modes reworked (no longer needed, made obsolete by new features)
• edit: ntsc-fast preset also changed

Download link:

https://mega.nz/file/Ulo3WIpT#w17zeDk4yOBGrQ__nXp8SbYpaUS1pL3LarJwtiiRzb0

[RealNC]

Just noticed that ntsc-fast produces a ghost image when using horizontal overscan. Vertical overscan doesn’t do that.

Examples:

(Visible at the sides of the image.)

(Visible in the text in the upper-left corner. There’s ghost images of the yellow and white letters.)