240p via HDMI on Raspberry Pi to RGBS, no need for RGB hats!

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vol.2
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

Fudoh wrote:A question about these quadrupled CEA modes. The original idea behind these is to raise the pixel clock above a certain compatibility threshold, right?
Yes. I dug up the information on what and why it's an issue:

"The PLL supports abitrrary frequencies from 600MHz to 2.4GHz and the pixel clock is generated from this with an integer divisor.
The maximum divisor is limited, so when a frequency is too low to be generated we switch to using the OSC (19.2MHz) as the source with an integer divisor.
That probably explains the limited low frequencies available."

So, basically, in order to hit a specific resolution, you have to deal with the pixel clock limitations of the Pi 3. Any modeline you create (say for a specific system or arcade game) has to conform to the 19.2MHz auxiliary oscillator as an integer divisor.

For example, an R-Type cab is 8.2MHz. That's not going to work. You want R-Type, you have to crank things up past the limitation of the PLL divisor. I can't remember what the limit is anymore, but let's say it's around 13MHz, I think that's about right.

Does Retroarch internally see this kind of resolution? I mean, if you go into the video settings and chose a custom AR setting, where you can set the pixel count for both axis manually, what number does RA see here as fullscreen ? Can't try it right now with my Pi connected to a HD screen, which doesn't take any of the 240p resolutions through HDMI.
Retroarch (RA) is "aware" of the global resolution. If you set config.txt on the boot to be 3840x240, you have to tell Retroarch to expand all the way to 3840 to get a full raster. It's *razor* sharp and amazing looking. It also eliminates artifacting and gives you plenty of horizontal resolution to play with insofar as tweaking the sides goes.

I'm not sure about the interaction between RA and RetroPie (RP). I have a lot of bad experiences with too many config files in RP, so I can't confirm for you if it behaves the same as plain old RA on a Pi. When you start RA through RP, it should be the same, because RA takes over, but the GUI browsing experience might work differently. Kittykats probably has better info on that.

Regarding Retropie: here you can set the ES resolution globally through the config.txt, while you set the resolution for each emulator videomodes.cfg. This is where run command saves its settings. The run command option screen doesn't give you all the CEA modes for selection through the menu though, but you can easily edit the .cfg file by hand and just change the CEA mode to 8 or 12.
Ok. Thanks for that info. I'll try to figure it out as I go.
I'll grab one of my HDMI to component boxes over the next days and give this a try on a small BVM.
Sounds good. I'll let you know if I make any progress.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by fernan1234 »

vol.2 wrote:Retroarch (RA) is "aware" of the global resolution. If you set config.txt on the boot to be 3840x240, you have to tell Retroarch to expand all the way to 3840 to get a full raster. It's *razor* sharp and amazing looking. It also eliminates artifacting and gives you plenty of horizontal resolution to play with insofar as tweaking the sides goes.
Which CEA mode is 3840x240? If it's a custom resolution rather than a CEA mode, I was never able to set one successfully for HDMI output.

And as I mentioned before, none of the 240p CEA modes looks any different, at least in my setup. I did manage to use CRTSwitchres for this kind of super resolution, but it actually looked no better or worse than the standard CEA 8 mode, which is 720x240p.

The issue I did find, going back to Fudoh's AR question, is that with the CEA modes the ideal is to set 2x integer scale for the horizontal resolution, which will work well for most content except that with 256 horizontal resolution, which when doubled will be 512 and look too narrow, while 3x will be too wide and not fit within the 720 width. My workaround was to turn on the widescreen preset on my BVM to make it look closer to how it should. Using the CRTSwitchres super resolution does simplify this, but I gave up on it after finding that using it somehow leads to audio and vsync issues with CD-based cores, at least on the image I use.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

but it actually looked no better or worse than the standard CEA 8 mode, which is 720x240p.
I think technically CEA 8 is 1440px wide. So I assume that running the emus in Recalbox using CEA mode 8 makes Retroarch see a 720px wide resolution "only"? If that was the case, a custom resolution might make sense after all. It should still be possible to run global mode 480i and then just call up DMT 87 for the cores and the specified custom res.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

Fudoh wrote:
but it actually looked no better or worse than the standard CEA 8 mode, which is 720x240p.
I think technically CEA 8 is 1440px wide. So I assume that running the emus in Recalbox using CEA mode 8 makes Retroarch see a 720px wide resolution "only"? If that was the case, a custom resolution might make sense after all. It should still be possible to run global mode 480i and then just call up DMT 87 for the cores and the specified custom res.

According to Unseen, "on the wire they are indeed [CEA modes 8,9] 1440x240, but the actual source resolution is just 720x240 with each pixel sent twice."

So it's 720. Let's call it pixel doubling, not to be confused with line doubling. I think the whole point is because it's more convenient and stable in digital-land to run at a higher clock.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

yes, I know, but the disadvantages within retroarch (because of the horizontal scrolling issues) are huge.

On the other hand you stated that custom resolutions are shown in RA 1:1, so creating a custom res with - let's say 1440x240 - might give the obvious advantage over using the preset CEA mode 8 for that exact reason.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

PS: What's the difference between using HDMI_CVT=... and HDMI_TIMINGS=... in the config.txt for creating a custom mode 87 ?
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

Fudoh wrote:PS: What's the difference between using HDMI_CVT=... and HDMI_TIMINGS=... in the config.txt for creating a custom mode 87 ?
The HDMI_CVT call is supposed to be an easier way to do timings, but it relies on the monitor being able to do things with CVT (in our case it will be the HDMI-VGA adapter). It should be setting a modeline that adheres to Coordinated Video Timings. I don't have all the details, but it's outlined on the config page:
Raspberry Pi Docs wrote: hdmi_cvt=<width> <height> <framerate> <aspect> <margins> <interlace> <rb>
Value Default Description
width (required) width in pixels
height (required) height in pixels
framerate (required) framerate in Hz
aspect 3 aspect ratio 1=4:3, 2=14:9, 3=16:9, 4=5:4, 5=16:10, 6=15:9
margins 0 0=margins disabled, 1=margins enabled
interlace 0 0=progressive, 1=interlaced
rb 0 0=normal, 1=reduced blanking
Fields at the end can be omitted to use the default values.

Note that this simply creates the mode (group 2 mode 87). In order to make the Pi use this by default, you must add some additional settings. For example, the following selects an 800 × 480 resolution and enables audio drive:

hdmi_cvt=800 480 60 6
hdmi_group=2
hdmi_mode=87
hdmi_drive=2
The wikipedia page on CVT: https://en.wikipedia.org/wiki/Coordinated_Video_Timings


Fernan is correct that the custom modes may not work over HDMI out, which is why people use CEA/DMT settings. I tried it myself a couple years ago with fernan as well, and I think neither one of us got that right. However, I think mode 12 worked for me, which is what I think is the best option for the Pi 3.

I just threw up Mode 8 on my monitor, and it looks okay, but it's a little too big to fit on my screen. I haven't tried any games yet though. Fernan is totally correct that interlaced would be better, BTW. 240p the menus look bad.

I can confirm that mode 12 doesn't change the display resolution at all. I am assuming that it's doing the same thing as mode 8, but just increasing to 2880.

Also I can confirm that mode 8 and 12 do not give you added horizontal resolution in game via RetroArch inside of Retropie. There is no shimmering or dot crawl though, it looks similar to what I would see if I was just outputting at 640x240 via an RGB hat.

It look fine, good even, but it doesn't look anywhere nearly as good as 3540x240p.
Last edited by vol.2 on Thu Jan 14, 2021 12:28 am, edited 1 time in total.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

I haven’t really encountered any horizontal scrolling issues...

Here is a clip of GBA... as usual, I went to scaling, set to 1:1 PAR and keep integer scaling ON, then switch it to “custom”. From there, 480 width 160 height pixel perfecto. Only takes up ~33% of the screen area however :o

https://media.discordapp.net/attachment ... video0.mov

Another thing to remember is going into the options for certain cores and make sure the AR is set to uncorrected!!
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

Hmm, but don't you get a problem with the horizontal fill ratio being too low, if you limit 256x224px games to 512x224px on a 720x240p output signal ?
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

It look fine, good even, but it doesn't look anywhere nearly as good as 3540x240p.
thanks! Makes sense.

With "weirder" custom resolutions not working for HDMI, it might still be worth a try to mimic the CEA timings as a custom mode. This should (could?) keep the Pi itself running at known working timings while enabling a higher resolution for retroarch to work with.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

Fudoh wrote: With "weirder" custom resolutions not working for HDMI, it might still be worth a try to mimic the CEA timings as a custom mode. This should (could?) keep the Pi itself running at known working timings while enabling a higher resolution for retroarch to work with.
It doesn't seem that the kernel compiled by the Retropie people works that way. It seems to be "stuck" at 720x240, no matter what. Custom defined modes seem to fail.


The only positive progress I can report is that interlaced stuff seems to look good. I loaded up Castlesvania Legacy of Darkness in Hi res mode and the quality is perfect. The screen is off-center though. That's where everything seems to fall apart. Fixing something small and stupid like that seems practically impossible.

However, because I want something for interlaced stuff, maybe it's okay? The Pi3 is pretty slow for the stuff though. My Pi4 is just barely good enough.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

vol.2 wrote:
Fudoh wrote: With "weirder" custom resolutions not working for HDMI, it might still be worth a try to mimic the CEA timings as a custom mode. This should (could?) keep the Pi itself running at known working timings while enabling a higher resolution for retroarch to work with.
It doesn't seem that the kernel compiled by the Retropie people works that way. It seems to be "stuck" at 720x240, no matter what. Custom defined modes seem to fail.


The only positive progress I can report is that interlaced stuff seems to look good. I loaded up Castlesvania Legacy of Darkness in Hi res mode and the quality is perfect. The screen is off-center though. That's where everything seems to fall apart. Fixing something small and stupid like that seems practically impossible.

However, because I want something for interlaced stuff, maybe it's okay? The Pi3 is pretty slow for the stuff though. My Pi4 is just barely good enough.
Can you not shift games left and right when they are interlaced...? For certain off-center titles (some ROM Hacks etc) I just do my usual steps that end at 'custom' in scaling, which leaves it properly integer scaled, then turn OFF the integer scaling and use X and Y adjustment to center the image but not change the height or width at all. Then simply save a game-specific config for said title!
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

kitty666cats wrote:
Can you not shift games left and right when they are interlaced...? For certain off-center titles (some ROM Hacks etc) I just do my usual steps that end at 'custom' in scaling, which leaves it properly integer scaled, then turn OFF the integer scaling and use X and Y adjustment to center the image but not change the height or width at all. Then simply save a game-specific config for said title!
I don't know. I couldn't figure out how to enter settings for the emulator on that level of detail. I'm not used to RetroPie.

Sure, I know how to do that with RetroArch, it's easy, but when you open the RA settings in Retropie, it doesn't save them, even if you save the config file.

I'm sure they are buried somewhere in the labyrinthine menus somewhere, but I'm not sure how worth it is to me to figure it out. If I try again, it will be just for Retroarch alone, and only for interlaced games (which isn't very many).

Anything 240p looks significantly better using a 24 bit VGA hat and a super resolution.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

vol.2 wrote:
kitty666cats wrote:
Can you not shift games left and right when they are interlaced...? For certain off-center titles (some ROM Hacks etc) I just do my usual steps that end at 'custom' in scaling, which leaves it properly integer scaled, then turn OFF the integer scaling and use X and Y adjustment to center the image but not change the height or width at all. Then simply save a game-specific config for said title!
I don't know. I couldn't figure out how to enter settings for the emulator on that level of detail. I'm not used to RetroPie.

Sure, I know how to do that with RetroArch, it's easy, but when you open the RA settings in Retropie, it doesn't save them, even if you save the config file.

I'm sure they are buried somewhere in the labyrinthine menus somewhere, but I'm not sure how worth it is to me to figure it out. If I try again, it will be just for Retroarch alone, and only for interlaced games (which isn't very many).

Anything 240p looks significantly better using a 24 bit VGA hat and a super resolution.
...if you enable “save configuration on exit” your first time setting up a libretro emu in RetroPie (after setting to your liking) you are all good to go with my prior instructions. Then you are good for almost all games on said console, from then on (The cores seem to pull from a massive resolution database or something). Just gotta set separate per-game configs for ones you wanna set to 480i (mash “A” on the gray window before ROM boots)
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

@vol.2

I just gave it a try and the first custom mode I tried works for me. Can't say anything about D/A compatibility, since I currently can only test it with an Extron scaler between the Pi and the display.

I added hdmi_cvt=1440 240 60 1 to the config.txt and changed the output resolution for the emu in question to DMT-87. After that Retroarch is running in 1440x240 and I can use the full pixel width to add scaling, e.g. setting a 5x horizontal scale. This is using a fresh Retropie install from a few months back, so RP 4.6.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

Fudoh wrote:@vol.2

I just gave it a try and the first custom mode I tried works for me. Can't say anything about D/A compatibility, since I currently can only test it with an Extron scaler between the Pi and the display.

I added hdmi_cvt=1440 240 60 1 to the config.txt and changed the output resolution for the emu in question to DMT-87. After that Retroarch is running in 1440x240 and I can use the full pixel width to add scaling, e.g. setting a 5x horizontal scale. This is using a fresh Retropie install from a few months back, so RP 4.6.

Ok. That's a good thing to know. It looks like Coordinated Video Timings is the way to go. Technically speaking, I don't think that counts as custom, because you are just giving it a suggestion and guidelines which must adhere to some know video standard. In order to generate the porches and the sync pulse length, it must be comparing your CVT entry to some database of modelines and filling in the blanks, or performing some CVT algorithm that does it automatically.

Thanks for letting me know. If I can get CVT working and it gives me extra resolution, that would be great.

When you say "extron scaler," do you mean that you are pre-scaling the 1440x240? I'm using an 203 RXI just to combine my sync because it's the most convenient way for me to do so, but it's not performing any scaling.

If you are pre-scaling things, that makes me think that the CVT 1440x240 is still coming out of the pi at 720x240. That's what it should be anyway, right?

kitty666cats wrote: ...if you enable “save configuration on exit” your first time setting up a libretro emu in RetroPie
I didn't see that anywhere. I guess I'll look again.

(mash “A” on the gray window before ROM boots)


I found that screen, it's the only thing that seems to change the resolution settings.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

vol.2 wrote:
I found that screen, it's the only thing that seems to change the resolution settings.
Yeah, you make per-game configs in there for my group 1 mode 8 forays (should not have to make many game specific configs) and simply otherwise leave everything untouched, with RetroArch output set to 'config'. Or maybe it was render res? Whichever one has config in parentheses already... I just leave 'er alone.

For getting correct pixel perfect scaling and whatnot you sometimes must go to 'Options' in the RetroArch menu for the specific core, 'uncorrected' is usually best for any potential forced aspect ratio. For NES, I get torn between cropping H and V overscan or not, heh. I think I may make some talkie videos explaining my setup a bit more, in addition to posting a image :3
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

In order to generate the porches and the sync pulse length, it must be comparing your CVT entry to some database of modelines and filling in the blanks, or performing some CVT algorithm that does it automatically.
It was just a quick test. I assume the same timing using a complete set of pixel values would work as well.
When you say "extron scaler," do you mean that you are pre-scaling the 1440x240?
I mentioned it above. I can currently only test in on my HDTV and there the 240p timings don't work via HDMI. Using the extra scaler I can give all the timings a try, since the Extron scaler understands them all and allows me to display them on the HDTV set.
If you are pre-scaling things, that makes me think that the CVT 1440x240 is still coming out of the pi at 720x240. That's what it should be anyway, right?
I compared CEA8 and CEA12 to the CVT timing and while the Extron sees both as "wide", I can tell from Retroarch, that the CEA modes are actually 720px wide internally, while the CVT mode is truely as wide as the pixel count suggests.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by fernan1234 »

I wouldn't make any conclusions based on scaled output to an HDTV though. Ideally you want to see how things work out directly on a CRT.

Regarding settings saving, for some images the only way to make permanent per-game or per-core changes for some of the settings is to use one of the "override" options in the quick menu.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

I wouldn't make any conclusions based on scaled output to an HDTV though. Ideally you want to see how things work out directly on a CRT.
of course. As said, I'll try this on a small BVM these days.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

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I've been playing with 240p output a little more. Still haven't got my small BVM from storage, but I'm running Pi > DAC > OSSC > LCD right now to fine tune the settings.

A few quick questions - maybe kitty666cats has a comment or two ?

- What's the recommend horizontal fill factor for generic 4:3 240p output using the CEA-8 mode ? 660px seems like a good viewport width.

- I'm using a cheap HDMI to YUV converter right now. Probably the same that Mike Chi demonstrated in his Retrotink > OSSC demonstration video. When I first boot the Pi with hdmi_mode=6 set in the config.txt, the converter outputs nonsense. The OSSC goes crazy and my TV on its own just displays a flickering mess. If I start a game (which puts the Pi into CEA-8 mode) and quit back out of it, Emulationstation returns back to 480i, but this time the converter and OSSC have no problems processing and showing it. Any idea what might be causing this ? What DACs are you guys using for a similar setup ?

- Does anybody know if disabling shaders (false setting in the cfg file) results in the same CPU usage as using the stock.glsl filter? The shader is basically made, so you cycle through other shaders and back to a Next Neighbour scaling option. To do "nothing" the glsl file seems rather complex, so I'm wondering if the later might have more excessive CPU usage.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by fernan1234 »

Fudoh wrote:- I'm using a cheap HDMI to YUV converter right now. Probably the same that Mike Chi demonstrated in his Retrotink > OSSC demonstration video. When I first boot the Pi with hdmi_mode=6 set in the config.txt, the converter outputs nonsense. The OSSC goes crazy and my TV on its own just displays a flickering mess. If I start a game (which puts the Pi into CEA-8 mode) and quit back out of it, Emulationstation returns back to 480i, but this time the converter and OSSC have no problems processing and showing it. Any idea what might be causing this ? What DACs are you guys using for a similar setup ?
Never encountered this problem. I guess 480i via HDMI is relatively non-standard, so something in your chain may just have problems initializing properly with it. I've been using an HDFury, specifically an HDF3.
Fudoh wrote:- Does anybody know if disabling shaders (false setting in the cfg file) results in the same CPU usage as using the stock.glsl filter? The shader is basically made, so you cycle through other shaders and back to a Next Neighbour scaling option. To do "nothing" the glsl file seems rather complex, so I'm wondering if the later might have more excessive CPU usage.
From what I remember, libretro-based images for RBPi (at least the 3) only supported a limited set of shaders, mainly those that only run on potato computers. Anything that actually runs on a Pi should be fine.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

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Fudoh wrote:I've been playing with 240p output a little more. Still haven't got my small BVM from storage, but I'm running Pi > DAC > OSSC > LCD right now to fine tune the settings.

A few quick questions - maybe kitty666cats has a comment or two ?

- What's the recommend horizontal fill factor for generic 4:3 240p output using the CEA-8 mode ? 660px seems like a good viewport width.

- I'm using a cheap HDMI to YUV converter right now. Probably the same that Mike Chi demonstrated in his Retrotink > OSSC demonstration video. When I first boot the Pi with hdmi_mode=6 set in the config.txt, the converter outputs nonsense. The OSSC goes crazy and my TV on its own just displays a flickering mess. If I start a game (which puts the Pi into CEA-8 mode) and quit back out of it, Emulationstation returns back to 480i, but this time the converter and OSSC have no problems processing and showing it. Any idea what might be causing this ? What DACs are you guys using for a similar setup ?

- Does anybody know if disabling shaders (false setting in the cfg file) results in the same CPU usage as using the stock.glsl filter? The shader is basically made, so you cycle through other shaders and back to a Next Neighbour scaling option. To do "nothing" the glsl file seems rather complex, so I'm wondering if the later might have more excessive CPU usage.
I usually set to 640. Here is a video showing my process for when I first boot up a core (disregard the FULL video, it was part of a Discord chat where I was asking opinions comparing the core's aspect ratio options of '4:3' versus 'Uncorrected'. I didn't seem to notice a difference in this particular game, but YMMV... if a game ever looks odd, try altering the core-specific options too!)

https://cdn.discordapp.com/attachments/ ... video0.mov

I boot a core, immediately go to scaling, make sure integer scaling is ON, go to 1:1 PAR, then leave integer scaling on and switch to custom. From there, I resize to 640 width and leave vertical untouched. Some consoles may vary...

I have the same HDMI to YPbPr DAC (with the rounded 'roof'), and have not run into any wonky issues. Granted, I just leave the main menu alone @ 720x240... with this particular theme, it doesn't bother me at all.
Spoiler
Image
I also never use that DAC unless bringing my Pi to a buddy's house who only has a consumer CRT. I personally use a Portta HDMI to VGA and combine sync.

I also don't use any shaders for any console. I disable "shaders", "on-screen overlay", "video layout".

I'm actually in the midst of setting my image to 2560x240 to see how things go for me. I'm perfectly content with what I have dialed-in with 720x240, but I am in the mood for some experimentation right now!
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

kitty666cats wrote: I'm actually in the midst of setting my image to 2560x240 to see how things go for me. I'm perfectly content with what I have dialed-in with 720x240, but I am in the mood for some experimentation right now!
I will be very interested if you can get that to work, and confirm that it's outputting at that resolution. As fernan mentioned previously, it seemed that setting anything to a 240p resolution simply output at 720x240 no matter what. It seems though that Fudoh noticed that he got a different resolution to happen by using the CVT modes instead.
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

vol.2 wrote:
kitty666cats wrote: I'm actually in the midst of setting my image to 2560x240 to see how things go for me. I'm perfectly content with what I have dialed-in with 720x240, but I am in the mood for some experimentation right now!
I will be very interested if you can get that to work, and confirm that it's outputting at that resolution. As fernan mentioned previously, it seemed that setting anything to a 240p resolution simply output at 720x240 no matter what. It seems though that Fudoh noticed that he got a different resolution to happen by using the CVT modes instead.
Yeah, I was trying something via modes 2 + 87, couldn't get a custom timing quite right - things looked fine vertically but horizontally all wonky.

I didn't try very hard, though - these are what I tried:
hdmi_cvt=2560 240 60 6
hdmi_cvt=2560 240 60 1 1 0 0

...then I got sick of it and went back to what I already have goin', heh. I will try any suggested timing people ask of me, but I am plenty content with what I have configured now!
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Fudoh
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by Fudoh »

...then I got sick of it and went back to what I already have goin', heh
on the video you linked to above, that output resolution did you run there ?
things looked fine vertically but horizontally all wonky.
with the lower resolution (CEA8/12) you need a horizontal interpolation filter, otherwise scrolling will be terrible.

Only the "super-resolutions" allow you to get away without any shaders.

When I tried CVT 1440 240 60 I noticed that the refresh rate wasn't exactly right. I think it dropped to something like 58Hz, so I guess that the "full timing spec" method is required to get better results.
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kitty666cats
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

Fudoh wrote:
...then I got sick of it and went back to what I already have goin', heh
on the video you linked to above, that output resolution did you run there ?
things looked fine vertically but horizontally all wonky.
with the lower resolution (CEA8/12) you need a horizontal interpolation filter, otherwise scrolling will be terrible.

Only the "super-resolutions" allow you to get away without any shaders.

When I tried CVT 1440 240 60 I noticed that the refresh rate wasn't exactly right. I think it dropped to something like 58Hz, so I guess that the "full timing spec" method is required to get better results.
The video is good ol' modes 1 & 8, CEA 720x240p.
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fernan1234
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by fernan1234 »

Fudoh wrote:with the lower resolution (CEA8/12) you need a horizontal interpolation filter, otherwise scrolling will be terrible.
This is not the case if you use integer scaling.
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kitty666cats
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by kitty666cats »

I wish I had picture perfect integer scaling fully worked out, but as you can see in the images it’s not quite there - I’m not too bothered as things look pretty good and there’s no scrolling distortion, but the OCD never fails to get me... :(
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vol.2
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Re: 240p via HDMI on Raspberry Pi to RGBS, no need for RGB h

Post by vol.2 »

kitty666cats wrote:I wish I had picture perfect integer scaling fully worked out, but as you can see in the images it’s not quite there - I’m not too bothered as things look pretty good and there’s no scrolling distortion, but the OCD never fails to get me... :(

I swear that this whole mess is 1000% easier if you just use RetroArch instead of messing with Retropie. RA let's you lock integer scaling from the video settings menu and all of your settings are controlled in one place. (outside of the config.txt)

It's really not that big of a deal to compile. I'll try to make separate post giving a blow-by-blow here at some point.
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