Sony Megatron Colour Video Monitor

[Azurfel]

For the sake of a more direct comparison, i have made an edited version of 5.6 that uses the old linear transfer function from 4.1.

These comparisons are all made using crt-sony-megatron-default-hdr.slangp with all settings on default aside from hcrt_max_nits = “790.000000”/hcrt_lcd_subpixel = “1.000000” to match my C1, and hcrt_colour_system = “2.000000” because D93 would potentially complicate the intended comparison.

Video driver is set to d3d12 to avoid any potential issues with vulkan in recent versions of retroarch, black frame insertion is disabled, and the core is Mesen-S (note: while checking other cores for the sake of comparison, i noticed that snes9x currently has broken color output with a tinted grey ramp on every PC i tested across multiple versions of retroarch, as did Genesis Plus GX, and VBA-M. So that’s troubling…).

old transfer function in 5.6

5.6 default/current transfer function

old

current

old

current

[MajorPainTheCactus]

Hmm yes so the ramp in ‘old transfer function in 5.6’ looks like its tailing off too fast - we should just about see the second to last bar and it looks like the fourth bar is that - its hard to tell from photos though. Just to rule out issues what is your monitors gamma set to in its settings? Weve certainly got a bug somewhere though and you might be on to something with the ordering. Can you get some screen shots? Ill try my end but Im on SDR monitor at the moment.

[Azurfel]

@MajorPainTheCactus

Hmm yes so the ramp in ‘old transfer function in 5.6’ looks like its tailing off too fast - we should just about see the second to last bar and it looks like the fourth bar is that - its hard to tell from photos though.

Yeah, i don’t think the pictures captured it well. In-person you can just barely see the second to last bar with 4.1/‘old transfer function in 5.6’, and even bar 0 looks massively overbright with 5.6 proper.

(That said i’m not convinced i hacked the old transfer function into 5.6 100% correctly, and i’m going to continue using 4.1 for actual games for the time being. The hack just seemed useful for the comparison even if it wasn’t 100% right, due to significant changes to settings making direct comparisons between 4.1 and 5.6 complicated.)

@MajorPainTheCactus

Just to rule out issues what is your monitors gamma set to in its settings?

Locked SMPTE ST 2084, which displays as greyed out 2.2 in the menus. (LG OLEDs don’t have adjustable gamma settings in HDR, or at least their “TVs” don’t.)

@MajorPainTheCactus

Can you get some screen shots? Ill try my end but Im on SDR monitor at the moment.

I’ve never gotten around to getting HDR screenshots working on this system, so i guess it’s time to do that/i’ll see what i can do. (Assuming they even work with retroarch? I’ve heard conflicting noise on the subject.)

[MajorPainTheCactus]

No I mean normal screenshots rather than photos so I can see the actual values myself - RA has a screenshot keyboard shortcut that I now cant remember what it is. Only if its not much bother - Ive got enough to work off above.

[Cyber]

@MajorPainTheCactus

RA has a screenshot keyboard shortcut that I now cant remember what it is.

It’s F8 but it seems to be horribly broken for anything other than Mega Bezel at the moment. If I press it while using Megatron, I’ll definitely get a soft crash and it might just capture an all black screenshot at best or a corrupt 0 byte file at worst. Same goes for CRT-Royale and CRT-Guest-Advanced.

I use GeForce experience for screenshots when using those shaders.

[Cyber]

@Azurfel

At least on my system

Not trying to discredit you or anything but Super Ghouls and Ghosts looks perfect to me (at least on my system using my settings).

As a matter of fact, I’d say it looks impeccable!

@MajorPainTheCactus, notice I no longer have any complaints about colours or anything of the sort after spending some days tweaking my way around things.

[Azurfel]

I managed to get some mangled HDR as SDR screens so far, but they at least somewhat show the issue

Raw image from Mesen-S

4.1 transfer function hacked into 5.6

5.6 default/current transfer function

[Azurfel]

Interesting. Mind sharing your settings so i can see what they do on my end?

[Cyber]

@Azurfel

Mind sharing your settings so i can see what they do on my end?

Sure, here they are:

Sony Megatron Colour Video Monitor

If it’s too dirty or hacky, maybe you can just stick to the leaner, lighter version @GPDP1 isolated first, at least for now. After spending more time tweaking, I doubt I even need the other filtering and sharpening stuff anymore. I would even argue that it’s a separate module from the NTSC stuff. Just the Super-XBR stuff plus the 5 pass NTSC stuff should work wonders. I’ve finished with my first release of my CyberLab Megatron Death To Pixels 4K HDR Preset Pack by the way! Just to upload an…

By the way, you should really update your shaders. That Vulkan bug has been squashed.

I’m currently doing some work on my Turbo Duo_Dreamcast preset using the newest CRT-Guest-Advanced-NTSC module so you might want to get that as well from his thread. Things should still look good using the version currently in the Repo though but for my next release you’ll definitely want to have the updated version.

@Azurfel

4.1 transfer function hacked into 5.6

5.6 default/current transfer function

Yeah, something definitely looks off there. Probably HDR isn’t being enabled properly or your Paperwhite setting might be way too low. Also, you can try Mask Accurate mode if you’re using an LG OLED TV.

[Azurfel]

This is what “CyberLab Megatron 4K HDR.slangp” looks like for me with the latest RA nightly, no reused cfg files from any old versions, and freshly downloaded shaders:

So that’s extremely weird given that the transfer function appears to be what makes the difference, and i’m not sure what could possibly cause such divergent results in that case.

@Cyber

By the way, you should really update your shaders. That Vulkan bug has been squashed.

I was erring on the side of caution. All tests were performed with the most recent shaders (or modifications made from the most recent shaders) unless i specified that it was Megatron 4.1.

@Cyber

Yeah, something definitely looks off there. Probably HDR isn’t being enabled properly or your Paperwhite setting might be way too low. Also, you can try Mask Accurate mode if you’re using an LG OLED TV.

That isn’t what it looks like on my end, that is a mangled SDR screenshot Windows spat out. It’s just somewhat illustrative of the difference in the darkest bars.

[rancid]

Did you try setting your drivers to DX12 and also disable HDR and then re-enable HDR after the shader is loaded? You look like your having the “washout” problem everyone has been complaining about before we discovered the fix.

[Cyber]

@Azurfel

“CyberLab Megatron 4K HDR.slangp”

And what do you get when you use the SNES preset for SNES games?

Also, please take a photo.

My Megatron preset pack is still in the early stages so it’s advisable to stick to the console specific presets.

Different consoles have differently tuned output circuitry and I try to optimize for this in my presets.

@rancid

Did you try setting your drivers to DX12 and also disable HDR and then re-enable HDR after the shader is loaded? You look like your having the “washout” problem everyone has been complaining about before we discovered the fix.

That bug has been squashed and the new version of the shader uploaded to the repo.

Also the night sky in Super Ghouls and Ghosts isn’t jet black in many shaders that I have used for a while now. It looks blacker than it is in my photos compared to in real life. The title screen is jet black though and also many of the backgrounds in game.

Also, you still need to tweak your Peak and Paperwhite Luminance settings for your TV.

What model TV are you using?

If it’s an LG OLED make sure that your HDMI input is labeled PC, you turn on HDMI Ultra Deep Color, and you’re using the HDR Game Picture Setting.

Lastly, be sure you graphics card is outputting in RGB 4:4:4 Full colour.

[Azurfel]

So it gets weirder. Its not the transfer function as such, but a related change that was made at the same time. Specifically, in colour_grade.h:

const vec3 linear = r601r709ToLinear(white_point); //pow(white_point, vec3(HCRT_GAMMA_IN));

If i change that to

const vec3 linear = pow(white_point, vec3(HCRT_GAMMA_IN));

(which is what it was prior to 4.2), then the weird blending issues in dark colors vanish. How bizarre…

@Cyber

And what do you get when you use the SNES preset for SNES games?

Displayed the same issue without the const vec3 linear alteration.

[Cyber]

@Azurfel

Displayed the same issue without the const vec3 linear alteration.

Do you have a camera or cell phone with Manual/Pro mode/controls that you can use to take and share some more representative photos?

Why is this affecting your system and not mine? Any theories?

[Azurfel]

@Cyber

Do you have a camera or cell phone with Manual/Pro mode/controls that you can use to take and share some more representative photos?

Not on hand, nope.

@Cyber

Why is this affecting your system and not mine? Any theories?

Possibilities off the top of my head:

• Windows version (I’m on Windows 10 Pro 22H2, it could be some weird Win10 HDR issue if you are all on Win11.)
• GPU (A Gigabyte RTX 2080. Not sure why that would be the cause, but who knows.)
• GPU driver (I’m on 472.12 right now because that’s easier to downgrade from, but i’ve observed the issue on more recent drivers as well, so i don’t think it’s this. I may check whatever drivers you are using later tho to make certain.)
• Exact display model (seems unlikely, but as mentioned i have a C1 specifically)

[Cyber]

@Azurfel

Windows version

Yes, I’m on Windows 11.

@Azurfel

GPU

I’m using a Gigabyte GeForce GTX 1070.

@Azurfel

GPU driver

I’m on the second to latest one. I see there’s a new one available today. I tend to keep things as up to date as possible.

@Azurfel

Exact display model

Probably not this but you have a C1 and I have an E6P.

@Azurfel

with the latest RA nightly

Just noticed this. I don’t use nightlies. Strictly Latest Stable versions but I do update my Shaders and Installed Cores from time to time.

[Azurfel]

I’m guessing it’s either Win10 or drivers then. I’ll double check the newest drivers when i have the time to mess with that unless the cause has already been determined by then.

Win11 will have to wait until i have a drive free, as i want to keep both my Win7 and Win10 installs for compatibility reasons, so hopefully i’m not literally the only one using Win10 xD (Tho if i am, it becomes more likely that is the cause i suppose.)

@Cyber

Just noticed this. I don’t use nightlies. Strictly Latest Stable versions but I do update my Shaders and Installed Cores from time to time.

The nightly was specifically a testing thing i did for your preset to rule out version issues. I think my regular version is 1.15.0 stable, but i’m reasonably certain it’s not caused by RA version anyway since i checked my old 1.11.1 install earlier, and that shows the same problem.

[MajorPainTheCactus]

Sorry just catching up. This is all rather odd. Hmm. Have you got the modified sony_megatron.slangp file that hunterk kindly modified for me that removes the scale vieport line at the end. This stopped it working on vulkan. Actually does this happen in vulkan? Might be an RA driver issue.

[Azurfel]

@MajorPainTheCactus

Have you got the modified sony_megatron.slangp file that hunterk kindly modified for me that removes the scale vieport line at the end.

That line was added after your v5.5 and removed before your v5.6, so none of my testing involved versions with the bug.

I have seen what the viewport bug looks like tho, and that’s a very different sort of broken.

[mas]

Thats all I could make of CyberLab Megatron 4K HDR.slangp on my cheap 4k hdr TV.

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