Remaining N64RGB Noise - Inherent to the console?

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bobrocks95
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Remaining N64RGB Noise - Inherent to the console?

Post by bobrocks95 »

I have Tim's N64RGB board with borti's voltage regulator installed to clean up the 3.3V signal and remove flickering horizontal lines.

But my N64 remains the noisiest/least clean system I have hooked up. I don't know if it's software-related/inherent to the console or what. The worst I've seen is on Star Fox 64 so I was testing with that.

So I looked to Youtube for UltraHDMI footage and found some mixed results. Some were poorly compressed but looked like they had the noise, others had a black so clean I wonder if they had an RGB Limited/Full mismatch, mainly because when I was capturing with OBS it kept crushing the blacks, which hid all the noise I was seeing.

This is what my N64 looks like. Watch at 4K for the most details of course.
Full processing chain is N64 -> Retro-Access coax RGB cable -> OSSC with optimized sampling at Line 5x 1600x1200p -> Datapath E1S capture card -> 2x nearest-neighbor upscale to 3200x2400 -> VirtualDub 2 lossless FFV1 encoding -> Youtube compression. Very accurate to what I'm seeing on my display.

Note the grainy near-gray noise on the solid black backgrounds. I think it's easiest to see after the level select with just text and the characters talking, and then right after during the level title card. You can also see the same sort of noise on a more colorful background as the ships fade in right before I skip the cutscene (34-35 seconds).
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Blair
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Blair »

thats strange, I've never noticed that on my N64 (I have the old style RGB mod) does it look that way if you use s-video or composite? some games have a color and brightness test pattern that might be useful. (resident evil 2?)
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Syntax
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Syntax »

You are used to the solid blacks that an emulator produces for the background.

They do this by removing software level dithering/anti aliasing.

If you want solid blacks apply the ips/aps patch for that game with an everdrive.
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Josh128
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Josh128 »

Star Fox 64 renders colors differently than most N64 titles. Transitions to and from black and black itself has a sparkly dithering effect. I always thought it was a strange way of rendering graphics compared to every other N64 game, but it may be a technique to help keep fps up vs other N64 games is what I always assumed. I see nothing wrong at all in the video you posted.

If you pop in SM64 you will see no such issue on the blacks. 100% certain of this.
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bobrocks95
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by bobrocks95 »

Syntax wrote:You are used to the solid blacks that an emulator produces for the background.

They do this by removing software level dithering/anti aliasing.

If you want solid blacks apply the ips/aps patch for that game with an everdrive.
I haven't regularly used emulators in over a decade, and I'm not seeing anything like that with other consoles, so dunno.

I've found an IPS and APS patch set, and tried the generic command line patching tool from I believe Assembler, and I can't get Star Fox 64 to run after patching for the life of me. No signal on real hardware with a RetroBlaster flash cart and Project64 gives an Infinite Loop error, closes, and says to check my ROM. Works fine before patching of course. If anyone has another IPS link or wants to DM me, feel free.

Does the UltraHDMI look like this too? If I got a $200+ mod back from an installer and saw that I would assume something was wrong lol.
Blair wrote:thats strange, I've never noticed that on my N64 (I have the old style RGB mod) does it look that way if you use s-video or composite? some games have a color and brightness test pattern that might be useful. (resident evil 2?)
Mark this down as officially the first time I've really wanted an S-Video input on the OSSC. I could fish my power cable out of my entertainment cabinet and try S-Video on my CRT, but it won't exactly be an apples to apples comparison on a different display. We'll see if I'm able to test anything else first.
Josh128 wrote:Star Fox 64 renders colors differently than most N64 titles. Transitions to and from black and black itself has a sparkly dithering effect. I always thought it was a strange way of rendering graphics compared to every other N64 game, but it may be a technique to help keep fps up vs other N64 games is what I always assumed. I see nothing wrong at all in the video you posted.

If you pop in SM64 you will see no such issue on the blacks. 100% certain of this.
Not just the blacks, plenty of color transitions as well. I've seen similar-looking "noise" on colored patches in other titles too, Star Fox just looked the worst. Pretty sure I've seen evidence of it in SM64 too, but I'll play some today to look.

It may all be AA/dithering, but I get a bit confused there because what I would have previously called "dithering" on older consoles would just be something like the Genesis/Saturn with static checkerboard patterns to reduce color banding or simulate transparencies once blurred by composite video. Star Fox 64 has some of this in the clouds and looks like what I'm used to. I don't see what adding flickering gray pixels to a black background is doing for aliasing, color banding, or transparencies.
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TooBeaucoup
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by TooBeaucoup »

I have a standard Voultar RGB board in my N64 and Star Fox looks a bit noisy for me as well. None of my other N64 games seem to have an issue.
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NoAffinity
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by NoAffinity »

It's a particular layer that some n64 games utilize. Check backgrounds on ki2 and the character select screen on fighting force 64.

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Syntax
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Syntax »

I don't know why it's so hard to apply the ips aps patch and have this thread done and dusted.

Its been awhile but don't you just put them in a folder, and before you start a game go into the options and select ips on?
I'll dust off the n64 and take a look.
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Syntax
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Syntax »

Well that was a PITA, my matrix decided to just not output anything to anything, then when it was working none of my IPS APS patches would work.

Something must of changed in a firmware update but now to patch on an x7 you can only do it auto, I cant seem to find a way to do it manually.

So you have to have the IPS APS patch in crc hi name format in the patcher folder, or named the same as its respective rom in that roms folder.
Then Z and options/ auto patcher on.

Here's a full collection minus the unused IPS doubles, but some of the redump names dont match my HDB packs.

Tested the crc auto ones with Superman, took that golden noise away and left me with nice solid black backgrounds for the intros.

https://drive.google.com/file/d/1u9PpRm ... sp=sharing
Last edited by Syntax on Wed Jun 16, 2021 3:55 am, edited 2 times in total.
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bobrocks95
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by bobrocks95 »

Syntax wrote:I don't know why it's so hard to apply the ips aps patch and have this thread done and dusted.

Its been awhile but don't you just put them in a folder, and before you start a game go into the options and select ips on?
I'll dust off the n64 and take a look.
On an everdrive, yeah, but I don't have one. I'm manually applying the IPS patch and the ROM no longer works. Emulator or console.

EDIT: I'll try the patches you linked and see what happens.
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bobrocks95
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by bobrocks95 »

Those don't work either. For whatever reason these AA patches can only be applied at runtime, or are specific to the Everdrive or something.

EDIT: Got it, those IPS patches break the ROM checksum, so you have to use a program (n64crc.exe) to fix it. I guess the Everdrive is bypassing the checksum or repairing it on the fly. Either way the patch authors can and should fix that, that's ridiculous. I've run plenty of ROM hacks that never broke the checksum...

So the near black noise is gone and looks much better. Wild that that's part of the game- still curious how it looks with proper capture on an UltraHDMI or N64Digital. Again I would fully assume something was wrong if I saw that.

I still have some noise on solid colors though that I'd like to clean up. I figure this has to be mod-related. I'll try and get some capture of it tomorrow or later tonight.
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Josh128
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Josh128 »

So someone patched the ROM to remove the color noise it was programmed with? Is performance affected?
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Syntax
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Syntax »

Poregon hosted the patches ages ago.

They just remove AA/Dithering.

No performance hits.

Here's a wayback link to the old site. Grab them while you can I guess.

https://web.archive.org/web/20191113074 ... index.html

Kinda funny the comparison game used is Star Fox.
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Josh128
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by Josh128 »

Hmm. The Star Fox 64 black /dark color noise is something different from just AA though. Its one of the only titles I can think of that does that on N64. Hardware AA only affects edges of polygons and (possibly) sprites if implemented that way, and it has nothing to do with affecting solid colors on backgrounds or textures.

Regardless though, AA is a bit hit on fillrate, and the N64 is notoriously fill rate limited, so actually removing the AA processing from the GPU workload should significantly increase performance (just a guess, but I'd say at least by 10-20% on average). In fact, there are titles that definitely dont employ AA to help with performance, the most high profile being FZero X and MK4, but there are others as well.

Now that I have an ED64, Im very interested in patching some roms to see if there is a difference, but there may not be depending on how the hack is actually done. If the GPU is still performing the calcs but somehow just omits writing the resulting image to the frame buffer, then there wouldnt be a performance difference.
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Re: Remaining N64RGB Noise - Inherent to the console?

Post by NewSchoolBoxer »

bobrocks95 wrote: Note the grainy near-gray noise on the solid black backgrounds. I think it's easiest to see after the level select with just text and the characters talking, and then right after during the level title card. You can also see the same sort of noise on a more colorful background as the ships fade in right before I skip the cutscene (34-35 seconds).
I was about to say the grey horizontal dots are supposed to be stars XD but the ships fade in scene, I see it. Doesn't look like dithering to me and kid me would have noticed on Composite + CRT.

Can you see any static snow on the screen with power on and cabled hooked up but no game inserted?

So you're seeing noise because black is low voltage and bright colors are high voltage. Signal to noise ratio is power of signal / power of noise. Lower the number, the more you see the noise that is fairly constant. Probably a strong filter in the TV or OSSC below true black level so no noise in true black backgrounds.

Retro-Access makes respected cables but you're using SCART yes? Small jacket forces the 6 wires of R, G, B, S, L and R audio to be even smaller and generate EMI on each other. I'm doing a test next week of SNES -> VGA female Multiout + 3.5mm audio -> BNC breakout vs my existing JP-21 setup. See if RGB looks better with more shielding, distance and separation of audio.

That said, the entire problem could be in the N64 installed DAC -> ADC of OSSC. If you can do 480p or at least 720p, see if noise is reduced. Lower frequency encoding is effectively a LPF because 1080p high frequency range isn't used.
Full processing chain is N64 -> Retro-Access coax RGB cable -> OSSC with optimized sampling at Line 5x 1600x1200p -> Datapath E1S capture card -> 2x nearest-neighbor upscale to 3200x2400 -> VirtualDub 2 lossless FFV1 encoding -> Youtube compression
Why don't you capture from RGB cable -> Datapath E1S and then 5X scale in OBS or something? Every device in the chain adds some noise and a LPF isn't going to cut anything out inside the color carrier bandwidth. OSSC is outputting best RGB or 4:4:4 YCbCr too? Digital RGB would be better coming from analog RGB.
with borti's voltage regulator
I know borti4938 is a prominent modder and I see board for sale from prominent modder Arthrimus. On picture in shop is a GH272G voltage regulator. Issue I have is, I can only see it being sold from counterfeit chip makers in China. Not saying Arthrimus didn't buy 1000 when/if they were sold from US or European vendors. What I see available is the apparent replacement, the < $1 AZ1117EH-3.3TRG1. You can probably get a free sample from Diodes Incorporated if you ask and swap it in.

Can you ask Arthrimus where the GH272G was sourced and what exact capacitors are used? Someone ask borti4938 on Twitter why the capacitor values were chosen? I'm serious. I'm used to seeing datasheets of crap I install in my computer but we take things in retro world with no proof. I do respect Tim W's work he publicized so not a knock against the mod itself. This is copied from the AZ1117E datasheet:
The AZ1117E is compatible with Low ESR ceramic capacitor.
A minimum of 1.0μF input and output capacitors are required.
The ESR of the output capacitors must be less than 1.5Ω.
Close to the OUTPUT pin, it is not recommended to use a capacitor smaller than 0.68μF in parallel with output capacitor.
When the output capacitor parallels 0.1µF capacitor, the 0.1µF capacitor must be away from the OUTPUT pin, the distance is no less than 5mm.
The borti addition uses 3 capacitors but I can't be certain it's C1 and C2 on the input and C3 on the output because only Tim W posted a circuit diagram. 1 μF is 1000 nF and capacitors in series form an equivalent capacitance of (a*b) / (a+b) like resistors do in parallel.
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