Sony Megatron Colour Video Monitor

[Cyber]

@Azurfel

I need to know how we want to integrate the Downsample Pseudo Hi-Res feature into Megatron.

@Azurfel

Should I put in a PR on the slang-shaders repository with my own implementation merged into Megatron for you to review?

I think you should keep these derivative works separate. So you could PR it but probably give it a new folder name which describes and differentiates it from the main, core, pure Sony Megatron Colour Video Monitor.

It would be similar to how we have the original CRT-Royale or CRT-Geom while still having access to derivative works which integrate and add different features or just pull features from the original.

One consideration is that by keeping things lean and modular, Sony Megatron’s original design scope and performance goals can be maintained and respected and others who might possibly want to integrate slightly similar features but maybe in a different way or for example using a different specific version of the decoupled CRT-Guest-Advanced can still tap into the Sony Megatron core shader functionality unhindered.

An example of this is when you originally released an updated decoupled CRT-Guest-Advanced-NTSC section, I also did my own decoupling experiments and shared a couple of them. You hadn’t figured out how to exclude the AfterGlow pass (yet) and you set the defaults to be as transparent as possible. I had (eventually) figured out how to remove that AfterGlow pass and was thinking about basing my next preset pack on that setup but I ended up using the one with the AfterGlow pass instead, just in case I might have wanted to play around with AfterGlow in the future and I eventually did.

[Cyber]

This should be the ultimate TV for Sony Megatron Colour Video Monitor and other shaders and presets which focus on Accurate CRT Emulation!

List of recommended TVs for emulation

TCL X11L 11,000+ Nits Peak Brightness, RGB Subpixel Layout, the closest LCD has come to OLED according to RTINGS and many other review outlets.

Here are some excerpts from RTINGS’ review of the set.

Note: Due to the high peak brightness of the TV, we had to use different measuring equipment for many of our tests, as the TV exceeds the peak luminance of our <a href="https://www.colorimetryresearch.com/products/cr-100">Colorimetry Research CR-100</a>, which we normally use.…

[Azurfel]

I’ve put in the pull request for decoupled-guest-advanced-ntsc and decoupled-guest-advanced-pal. Whether i add a Megatron fork for compatibility with Downsample Pseudo Hi-Res or it gets added to Megatron itself can be decided later. Ultimately, it only really effects sfc/snes games with pseudo hi-res material running on Mesen-S anyway, which is a fairly limited category (albeit one that includes several of the most notable titles for the system.)

[Azurfel]

decoupled-guest-advanced-ntsc and decoupled-guest-advanced-pal have now been merged, and can be found in the ntsc and pal directories respectively once you have updated your shaders.

I’m sure turnkey Megatron presets will follow in time, but in the meantime, prepending is of course an option. Note that there are additional presets in the “decoupled-guest” folders in the shader directories.

[cybermat]

I own a LG C5 48" , is it compatible with this shader? I see the screen red when i apply this, i tried to change some subpixel settings but i cannot solve. I also tried the nightly because i read there were issues fixed

[Azurfel]

When you say “screen red”, do you mean it has a reddish cast, or is, like, solid red?

Either way, ensure that you have 444 chroma working correctly using a test pattern: https://www.rtings.com/tv/learn/chroma-subsampling

And try the version linked here: Sony Megatron Colour Video Monitor

[cybermat]

The version linked works. I had this issue

Test pattern says that i’m on 4:4:4

[Azurfel]

Was that with Megatron v1 or Megatron v2? And if so, are you using an AMD GPU?

Megatron v1 was known to have that issue with certain AMD drivers, but it was my understanding that v2 resolved that.

(The version i linked is derived from v2, but has certain differences. Nothing i would expect to effect this.)

[cybermat]

Red picture is of the version 1, with version 2 no issue

I have amd rx 6400 videocard

Is there a way to fix the version 1? With an old version of amd drivers? I dug in this thread in the meantime

[Azurfel]

@cybermat

Is there a way to fix the version 1? With an old version of amd drivers? I dug in this thread in the meantime

May i ask why you want to use v1 over v2?

The current v2 does have color accuracy issues in my experience, but the AzMods version i linked is based on a version of v2 that predates those issues. (And that is the version i still personally use, tho i have since made some additional updates and improvements to decoupled-guest-advanced-ntsc and decoupled-guest-advanced-pal, previously called ~crt-guest-advanced-ntsc-decoupled and ~crt-guest-advanced-pal-decoupled.)

AzMods also includes modifications that (seem to) make v2 work on older, non-nightly builds, if that is a concern. (Tho i would strongly encourage using a nightly build if at all possible. There have been gobs of HDR quality of life improvements, like the UI brightness setting.)

Other than that, the only substantial difference i can think of is the old tone mapping. I should be able to quickly and easily roll up a modded version of v2 with the old tone mapping if that is something you really want, but i think that the v2 tone mapping is strictly better in terms of results.

[cybermat]

Ok i understood now. There are V1 and V2 version, so i stick with V2, i don’t need to use V1. Since i tried your derived V2 and they seem working, i tried also V2 present under shaders preset folder and some works some not.

I read a post of Cyber user, that stated troubles with RX 6600, since i own RX 6400 maybe there are drivers issue with V2. If i well remember PVM shaders are “red”. Now i remove drivers and try again and then i install older version in order to see if old drivers fix this.

I jumped into these new shaders (for me) because now i own an OLED LG (48") and i can try a lot of beatiful hdr shaders. Unfortunately RX 6400 is not so powerful for reflection, but at this time i would be happy with working drivers and no reflection

thanks for your support

[Cyber]

@cybermat

Unfortunately RX 6400 is not so powerful for reflection,

Within Mega Bezel there are several performance tiers, try them all before giving up on reflections. There’s also a Sony Megatron Mega Bezel Base preset that you can try as well.

Besides Mega Bezel, there are other more efficient reflective Bezel Shaders like Koko-AIO and uBorder.

I almost forgot about that Radeon bug. Strangely enough it doesn’t seem to affect CRT-Guest-Advanced which is a shader that you can coax into having very similar output characteristics to Sony Megatron Video Monitor.

Also, Sony Megatron Colour Video Monitor has never been a requirement to use CRT Shaders in HDR mode since HDR is built into RetroArch so it could be applied to any shader.

From what I remember, the Radeon red screen bug only affects certain Mask Type so you can work around it and it also only affects the Vulkan video renderer, so you can just switch to DX11/12 and you should be fine.

Running DX11/12 requires you to enable HDR in Windows as well as RetroArch.

[Wilch1]

@Azurfel

Megatron v1 was known to have that issue with certain AMD drivers, but it was my understanding that v2 resolved that

The issue was resolved briefly before returning after a nightly update and remains still.

@Cyber

Running DX11/12 requires you to enable HDR in Windows as well as RetroArch

So does Vulkan and has for a couple of years now for me at least. I remember HDR used to engage without having to enable it in Windows first, it was quite convenient

[bigretrofan]

Red color issues with V1 for Amd Rx 6000 series started after driver 24.5.1 and is broken ever since then. V2 was working fine at the beginning but recent updates broke it again. Red color issue is only for aperture mask, slot and shadow are working as intended.

[Azurfel]

@Wilch1 @bigretrofan

If you have time, please do a completely fresh install of the latest nightly, enable HDR, extract this archive to the shaders_slang folder, and check which presets in the base “megatron red tint bug bisection” directory exhibit the red tint issue.

https://www.mediafire.com/file/mr9qwo8cap4kodg/megatron_red_tint_bug_bisection.zip/file

[Azurfel]

@cybermat Whoops, missed tagging you. Please see previous post.

[Wilch1]

Both hdr158x files have the bug. All hdr26x/27x versions don’t have the bug. All hdr28x versions have the bug.

So hdr261-1 fixed the bug and hdr280-20260227 reintroduced it?

[Azurfel]

Yep.

Technically it was probably hdr260 that fixed it, but hdr260 had broken, dimmed output even on release, so i excluded it from the test.

Just to be fully upfront: i’m not going to make an attempt to fix this myself at this time. hdr280 radically overhauled the shader in ways i have not even begun to investigate, and i don’t really have much interest in doing so given that hdr265 onward all have inaccurate color (on at least my setup) anyway.

[Wilch1]

What about hdr27x? Same colour inaccuracy? I’d like to stick with vulkan as dx11/12 has some graphical glitches when using shaders

[Azurfel]

Yep, all variants of hdr265, hdr266, hdr267, hdr271, and hdr280 have inaccurate color (again, at least on my setup, but i’ve seen no reason to think it isn’t universal to at least all modern RWBG WOLEDs.) Everything is a smidge desaturated and has a slight reddish tinge. The tinge is particularly noticeable on a grey ramp test pattern.

Compare shaders off, hdr261/hdr262, and hdr271-20260225 for yourself using the test suite and see what you think.

I also use Vulkan, and i have personally continued using my modded version of hdr261, a slightly older version of which is linked here. I should probably post an update to that soon with the decoupled-guest-advanced-ntsc/pal updates.