Best way to output SCART (RGB) from Pi 3?

aTg

You know RGB-Pi? This is the web of the project rgb-pi.com is ready to work with RetroPie

Dochartaigh

So I FINALLY had a chance to mess with this some more and it's a total mess this time around... See this photo showing PiSCART on the left, and a regular SNES console (hooked up to a PVM via RGB cables). Notice the blue and white lines on the Pi2SCART being all wavy (along with the rest of the photo as well - and not being as clear - and the colors not popping quite as nicely).

I was told on the Arcade Forge Facebook page that I had to go into the RetroArch menu and disable all video filters and set the aspect ratio, res and integer scaling (because RetroPie's default settings are made for HDMI TV's and wreck the image on a CRT). On the several topics about this here, unless I missed it, I haven't seen any reference to this causing problems....but I don't see how in the world it wouldn't as these settings are on by default in RetroPie...

Nobody has replied past that above info on Facebook so I thought I'd get your guys input. From this good post on Lakka Optimal Video Settings, I saw these things to tweak, but don't know if I'm on the right track or not:

Pixel Perfect mode (says best picture quality but "Image is square for some systems (i.e NES and SNES), which results in little black bars to the left and right of the image on a 4:3 TV Screen").

Aspect ratio Index 1:1 (PAR 4:3)
Windowed scale 1.0
Integer scale ON
HW Bilinear Filtering OFF
Threaded Video ON
Vsync ON

Or this mode is for "Full Screen Mode" (little more blurry but should fit to screen for every system).

Aspect ratio Index Core Provided
Windowed scale 3.0
Integer scale OFF
HW Bilinear Filtering ON
Threaded Video ON
Vsync OFF

What would you all suggest? Is this the right track? The most common problem is while I'm flipping through all these options it keeps on changing the Custom viewport size? (or something like that...I really should have taken photos...) - but I know it jumps from like 240p (or native 244p? NES/SNES size) I have the /boot/config.txt set as, to something WAY larger, and doesn't seem to shrink back to that smaller size even if I change the ""Aspect Ratio Index" to "Config" (which should change that back to the config.txt's 256x244 or whatnot).

maxriptide

@Dochartaigh it looks like scaling artifacts, do you have overscan enabled in config.txt?

Dochartaigh

@maxriptide said in Best way to output SCART (RGB) from Pi 3?:

@Dochartaigh it looks like scaling artifacts, do you have overscan enabled in config.txt?

I did have overscan settings on to shrink the image - but something else was also messed up so I started with a fresh /boot/config.txt). I just tried the "Pixel Perfect" settings, versus the "Full Screen" and the Pixel Perfect is definitely more clear.

My problem, in part, is definitely the overscan. With it turned on (which I was using to shrink the image since it was way too large) the image gets all blurry. Is there any other way to shrink the image besides tweaking the overscan settings in /boot/config.txt? (or besides changing the settings on the monitors themselves - which are set perfect for the actual consoles hooked up to them)

edmaul69

@Dochartaigh the correct way to shrink and expand is to use the overscan up, down, left, and right. Adjust those until you get the right size and position. You can use positive and negative numbers (ie: 5, -5) to get it shrunk to the size you need.

maxriptide

@edmaul69 using overscan with such small resolution (320x240) always lead to scaling artifacts which are what Dochartaigh is experiencing

maxriptide

@Dochartaigh said in Best way to output SCART (RGB) from Pi 3?:
Is there any other way to shrink the image besides tweaking the overscan settings in /boot/config.txt?

@Dochartaigh you can try the settings I suggested to you in this thread and try to center the image following the method suggested by Molhoy in this thread: https://retropie.org.uk/forum/topic/8673/how-to-center-image-of-retroarch-with-pi-outputing-240p-rgb-via-hat-board-gert-666-to-pvm/14

Dochartaigh

Hi Gents, so if I'm hearing you both correctly (please let me know if I'm not!), there is NO other way to SHRINK the image via software settings BESIDES overscan, right?

Overscan, like Max said, totally ruins the image quality, so I'm hoping there's something else to try. Centering is perfect (thanks to that post - even tested it with the 240p Test Suite on NES, SNES, and Genesis!).

mikechi2

You guys might want to check out this:

https://discord.gg/gCvP6

Kevin has been doing some great work getting the scaling settings right using a high horizontal resolution (1600 x 240) which eliminates non-integer scaling artifacts.

He using my component video output to a TV but the same theory should apply if you're using SCART on a PVM.

maxriptide

@mikechi2 Thanks mikechi, I have to try it!

riggles

I'm really interested in a solution to this as well, got my raspberry pi + pi2scart today and can't get it to look nice without having to use black bars at 240p, is it possible to resolve these issues with a future update or modification to retropie+retroarch? Or is it a limitation inherent to the Raspberry Pi ( 3 model B ) itself? If it's not, would it be possible that we can change resolutions on the fly in the future like when using retroarch on a modded wii with rgb scart? That would be the dream!

@mikechi2 Would love to check the discord out, the invite ran out.

On a side note, NES scrolling backgrounds with any of the cores stutters for me, both through hdmi (720 and 1080p )or on a crt in 1:1 240p. Is this due to me using an ipad power supply? It's rated 2.4A. It says I'm getting a solid 60fps (60.2) but it's noticeably lagging compared to the same game on a wii which is buttery smooth. Settings seem optimal, no shader, smoothing etc, messed with both vsync and threaded video, if I apply a 2x phosphor shader when playing in 720p performance still stays exactly the same, also the backgrounds stutter irregularly.
Should I wait for my 3A micro usb psu or install an older version of retropie, surely there's no need to overclock for NES is there?

edmaul69

@riggles phone chargers are terrible to use because they dont run a constant voltage. The way fast charging works is it runs at a high voltage and the drops and runs at a slower voltage then goes back up to higher voltage. Buy a power supply made for the pi 3.

mikechi2

@riggles

Take a look at the second half of the video when super metroid starts. We figured out a good solution that matches the original console without introducing scaling artifacts. It should work on all the various DPI based adaptors.

I'm planning on making another video this weekend with some detailed instructions. Stayed tuned...

riggles

@mikechi2 Looks amazing and big thanks for sharing, going to wait until then to mess around with the pi2scart in that case :D

A Former User

Hi folks, 1st post here...

I just received my Pi2SCART. Connected everything and unfortunately the IQ is abysmal - it looks like RF, lots of noise. I suspect that it might be a fault of the RGB cable I bought - its awful, the clamps that secure connector casing to the cable both fell off instantly and now its all wobbly, colours change when the cable is moved. I bought it as a bundle with the Pi2SCART from Arcade Forge so Im surprised it`s so shoddy.

Now, Im an experienced PC user but this is my first time with the Pi, hence Id appreciate if you had a look at my checklist and see if I maybe missed a step or detail. I`ll get another cable anyway of course.
I followed the most common guides from RGBCables, HiScoreBob, Pi2Jamma, Arcade Forge and RPi homepage. What I did:

-assembled the unit (Pi + Pi2SCART)
-formatted a MicroSD, wrote images (RetroPie, later tried Lakka and the one from Arcade Forge)
-edited the config.txt adding the settings from Arcade Forge page
-connected power (original charger), Dualshock 3 via USB, RGB cable to my SONY Trinitron CRT, got the MicroSD in

The image is stable however extremely noisy - just like an RF connection. I have PS1 and Wii connected via RGB to this TV and IQ is superb, so its not the TVs fault. I havent tried any actual roms or emulators yet - however I suspect that even the frontend should be noise-free.

Any help/comments appreciated. Apart from the cable, I was thinking, maybe I need to update the firmware (though I just got this Pi from PiHut). Or maybe I missed something obvious.

EDIT: some bizarre highlights in red in the above post - not sure how that happened :/

Dochartaigh

Can you post some photos of the image so we can see exactly what you're talking about? You might also be better off on their FaceBook page for troubleshooting info - they're very well versed in their own product and offer great help (RetroPie, while great, is very much geared towards HDMI TV's).

mikechi2

@arkive Double check your power supply - are you getting the yellow low voltage warning? When I designed my adapter I had a lot of issues with picture noise and dimming due to lower supply problems.

Dalton69

@mikechi2 Arcadeforge settings are for 320x240 so the GUI will not look any good at all at that resolution. You can try the pixel theme it works a little bit better but we really lack a low resolution theme.

A Former User

Thanks for replies folks,

@Dochartaigh - I decided to post here because I saw posters who might have Pi2SCART & CRTs and some experience with it - and maybe could see if I missed some obvious step. I'm not on Facebook, but will try to pester AF's customer support if this is unresolved. Can't post pics because the damned cable actually fell apart completely after I pulled it out from the Pi yesterday - ridiculous :) But, the "noise" is akin to static you see on hardware connected through RF socket...think "film grain" filter you get in some modern games (not sure if it`d be even possible to capture on camera, these things are rather tricky)

I`ve just ordered a new cable anyway, will see if this problem persists. Hopefully not...if yes, it means that either Pi2Scart or the Pi itself is borked :/

@mikechi2 - " the yellow low voltage warning"? Hmm, not sure, but don't think so - I read somewhere the warning manifests itself as a square in the top right corner...can't recall seeing anything like that (can't test again because that damn cable is busted). Do you mean yellow LED? I see the green-ish LED (next to the red) blinking, but it looks like it`s reading from SD (maybe). Also, I got the original Pi power thingy, so hopefully this is not the case...though the symptoms (noise/dimness) match.

@Dalton69 - yes, I'm aware of that GUI theme limitation but that's something to be expected when outputting to a CRT (got similar "problems" on Wii emus) - however I don't think the noise I describe above should be present at all, even in the frontend GUI.

Will wait for the new cable, see what happens then. Thanks again.

Dochartaigh

@arkive said in Best way to output SCART (RGB) from Pi 3?:
the "noise" is akin to static you see on hardware connected through RF socket...think "film grain" filter you get in some modern games

This topic isn't letting me scroll up (I might have posted this before), and without a picture I still really don't know exactly what you're seeing, but try these settings for the Pixel Perfect mode. You can either do it by hitting Select+X in a game to enter the RetroArch settings (remember to save if they work for you), or through the RetroPie menu, RetroArch settings.

Before doing the above settings, mine was kinda muddy, blurry almost, some diagonal lines were a little wavy, just not as clean as my actual video game consoles were at all. After trying those above settings it's razor sharp on my BVM's (actually too sharp almost!).