RetroTink 4K All But Officially Announced ....

[orange808]

So, the original frame buffer is getting upscaled first and the console outputs a 1080i signal. Next, we're going to use bob field offset on the image?

These results are good? I would expect the output to appear jittery, similar to artifacts you would get from a 480i source with flicker filtering?

[SGGG2]

Results depend on the title. Some games look wrong with either offset. I was shocked at how good it can look and don't understand why it looks different than adjusting the offset with 480i. This is on an OSSC Pro, but I don't see why it wouldn't work here assuming it's the same feature.

Noninterlace restore: Displays fields one after another without any offset by default. Useful for 240p games running in 480i (e.g. classic game collections).

[ZellSF]

So, the original frame buffer is getting upscaled first and the console outputs a 1080i signal. Next, we're going to use bob field offset on the image?

These results are good? I would expect the output to appear jittery, similar to artifacts you would get from a 480i source with flicker filtering?

512x448 signal > GSM integer scales it to be windowboxed in 1920x1080 with every odd field just being a copy of the even one > bob deinterlacing displays one field at a time > since odd and even fields are offset (despite showing the same information) then you counter that with a offset to the height after bob deinterlace.

What you're left with then is a progressive 540p signal (which you need to crop down to the original 512x448).

It sometimes doesn't work, not sure why, probably some flicker filter that inserts itself at some part of the process. When it does work it looks identical to progressive output.

That said, scanlines will be wrong if you do this with the RetroTink4K.

1280x960 or 1080p is a better option for a lot of games (some do crash if output is not interlaced), however those are problematic in their own ways (1280x960 is a VGA SoG mode and 1080p isn't supported in OPL GSM).

The 2:2 pulldown on the 4K is great as well for 480i 30 fps titles with a consistent framerate. Dragon Quest VIII has never looked better.

Are there any GSM compatibility lists that are anywhere near up-to-date? 480p support was so bad I gave up on using it.

No, and I don't think there ever will be. It takes like 5 minutes per game to test. I mean if I'm going to say, spend 60 hours on Dragon Quest VIII, I'll take those 5 minutes to make sure the game looks as good as it can.

That said, there hasn't been any significant changes to GSM in ages, so even a really old list is "up-to-date". If a game requires FMV skip for earlier versions it might work with the "Emulate Field Flipping" option that was added a few years ago.

Reminder for everyone else that's more fine with wasting time: some select few games that can't be forced to 480p will look sharper if you just force them to NTSC. Well I say it's a waste of time because I think it only works with a few titles, I've yet to setup a capture setup to actually check for myself what compatibility is like.

[orange808]

I still don't understand.

Why not line double the 1080i frames if we know for sure that the fields are repeated? It's 540p, right?

Using a "double strike" (field offset adjustment) and then upscaling to eliminate underscan will create ridiculously thick scanlines, correct?

No information was lost interlacing a line doubled 540p image, so there shouldn't be any artifacts from line doubling the 1080i, unless there's a flicker filter. Of course, a flicker filter would also make a "double strike" field offset method tremble like crazy.

I would line double first, scale away overscan, and add (better looking) scanlines as postprocessing. The image will be brighter, as well. What's the benefit of adjusting the field offset?

Even if I want a final 480p output, is line doubling and scaling/cropping a deal breaker?

[SGGG2]

There's some kind of flicker filter present in certain titles when forced to 480p with GSM. It isn't present in other modes. Some games won't work with progressive modes, but will boot in 1080i.

[orange808]

There's some kind of flicker filter present in certain titles when forced to 480p with GSM. It isn't present in other modes. Some games won't work with progressive modes, but will boot in 1080i.

Yes. You have mentioned that before.

I'm not clear on how that applies to processing 1080i, though.

[ZellSF]

Why not line double the 1080i frames if we know for sure that the fields are repeated? It's 540p, right?

Using a "double strike" (field offset adjustment) and then upscaling to eliminate underscan will create ridiculously thick scanlines, correct?

Might have been a bit misleading of me to say it's 540p.

Bob deinterlacing is line doubling (takes a 240 height field and doubles it, or in the case of 1080i, takes a 540 field and doubles it).

So since the final output is 1080p, half lines which are duplicates, a scanline generator would insert a scanline between every line (it has no awareness of the duplicates). Scanlines would be 50% of the image either way, but spread out more for the 480 image, and less so for a proper 240 image. So they're thinner, but more frequent.

A scaler that's aware of what it's doing could just drop half the fields entirely, but I'm guessing bob offset has more flexible use cases? And a scaler could do scanlines properly, using the awareness that half the fields are duplicates to replace them with scanlines. The RetroTink4K currently doesn't do this (I believe the 5X can, not sure about the OSSC Pro).

[orange808]

Might have been a bit misleading of me to say it's 540p.

If the fields don't match, my first post will apply. If the fields are identical, my second post applies.

You assured me that the information was displayed properly as a "480p" image boxed inside a 540p frame with underscan, effectively line doubled, and interlaced to 1080i. Correct?

Bob deinterlacing is line doubling (takes a 240 height field and doubles it, or in the case of 1080i, takes a 540 field and doubles it).

Yes indeed, that is line doubling.

Same as it ever was.

So since the final output is 1080p, half lines which are duplicates, a scanline generator would insert a scanline between every line (it has no awareness of the duplicates). Scanlines would be 50% of the image either way, but spread out more for the 480 image, and less so for a proper 240 image. So they're thinner, but more frequent.

Do you own a RT4K? There are options for scanline configuration. I can also create a custom mask, if the menu options don't suit me. Shouldn't be any problem at all.

I know from experience that completely 100% blank (black) empty scanlines look more and more wrong as I upscale them. They also darken the image. CRT phosphors have bloom.

A scaler that's aware of what it's doing could just drop half the fields entirely, but I'm guessing bob offset has more flexible use cases? And a scaler could do scanlines properly, using the awareness that half the fields are duplicates to replace them with scanlines. The RetroTink4K currently doesn't do this (I believe the 5X can, not sure about the OSSC Pro).

In my experience, offsetting the fields is only useful for one thing: using a CRT to play a small handfull of games in proper 240p that display a progressive "240p" game as 480i without any flicker filtering. The OSSC Pro offers a "built in" DAC option, so it's probably the best tool for that.

If there's no flicker filtering and there's no missing information due to an effectively line doubled source, simple line doubling will produce a proper progressive image in the first step. I can do whatever I want after that.

If the interlaced source image has flicker filtering or the source image was upscaled/downscaled by a non-integer factor before interlacing, I need to use a proper deinterlacing algorithm to perform heavy lifting.

[ZellSF]

I'm just going to apologize, I might have thought a bit wrong and honestly thinking about it just messes with my head, and I don't really have time to organize my thoughts so I'll just say a few things:

1) I have a RetroTink4K

2) 1080i>540p restoration for PS2 games works the same as 480i>240p restoration for 240p games that are converted to 480i.

3) Scanlines are thinner when doing this. If this is fixable using the RetroTink4K's settings, I do not know since I very rarely have to rely on 1080i. I have very few games where that's a required workaround.

[orange808]

2) 1080i>540p restoration for PS2 games works the same as 480i>240p restoration for 240p games that are converted to 480i.

Here's what I'm saying:

240p is a real "standard" signal that games were displayed in. Getting 480i games back to the correct 240p standard with field offset is useful for playing a "240p game" that is improperly displayed as 480i on a CRT. That's something that makes sense to me.

On the other hand, 540p was never a thing. I can't name any home console games that displayed at 540p (to begin with). 240p was common; 540p was not. Some games had 480p. I still don't understand why I would change the field offset. I don't need to get 540p back from 1080i games for a CRT, because 540p wasn't a thing. I can get a boxed 480p inside a 540p frame on a CRT that supports it. Does all that underscan look good?

If I'm upscaling, I still don't see why I wouldn't line double in the first step, scale away underscan, and add postprocessing.

[ZellSF]

I think the thing you're hung up on is why do it in the first place?

Why convert 480p to 1080i?

It just seems to bypass some sort of flicker filter. That's it, as long as you output to 960i,1080i, 1080p or 1280x1024 then you can extract a cleaner 480p signal from that than you otherwise would.

If I'm upscaling, I still don't see why I wouldn't line double in the first step, scale away underscan, and add postprocessing.

For the same reason you can't just line double a 240p>480i converted signal. It's the same process, ignore anything I said that might be confusing and just think of it like that.

[bobrocks95]

I thought the whole point of using GSM was for improving the look of 480i games? I'm not planning on hurting myself by testing GSM all over again, I think the PS2 is just the only 480i console and we've gotta live with it.

[ZellSF]

I thought the whole point of using GSM was for improving the look of 480i games? I'm not planning on hurting myself by testing GSM all over again, I think the PS2 is just the only 480i console and we've gotta live with it.

GSM is mostly used for forcing 480i>480p. There are two scenarios where you want to use 1080i. One is some titles just have problems with FMV playback unless the output mode is interlaced, FMVs are skipped or Emulate Field Flipping is used.

The other is that for some titles, 1080i (or the other high resolutions) can give better image quality, I assume that's related to flicker filtering.

GSM can also make games that can't be forced to 480p look better by forcing NTSC/PAL. Not really sure why, bypasses some sort of internal stretching?
https://x.com/WobblingP/status/1692623170522734812

I would not recommend bothering with the two latter scenarios, since I haven't verified it works with many games myself (unlike forcing 480p, which makes a ton of PS2 games look significantly better), but for the games where they work, they do make a difference.

[orange808]

For the same reason you can't just line double a 240p>480i converted signal. It's the same process, ignore anything I said that might be confusing and just think of it like that.

But... that's the thing...

If there's no flicker filter, I CAN line double a 240p game displayed as 480i and get lovely 480p. ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯ There's no missing information. Essentially, these games we are discussing are line doubled 240p that's interlaced to 480i. Every dropped line is repeated by another field in every frame--assuming no flicker filter. (A flicker filter will make the fields unique and we need proper deinterlacing.)

I only need the field offset if I want to output 240p to a CRT.

[ZellSF]

For the same reason you can't just line double a 240p>480i converted signal. It's the same process, ignore anything I said that might be confusing and just think of it like that.

But... that's the thing...

If there's no flicker filter, I CAN line double a 240p game displayed as 480i and get lovely 480p. ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

Well;

1) How are you doing this exactly, which systems, games? I've never seen this work.

2) You don't really care about whether you get 240p or 480p, you want to bring it down to the original 240p before scaling anyway, so I'm not sure I see the point of this.

[orange808]

1) How are you doing this exactly, which systems, games? I've never seen this work.

Fantasy Zone Complete Collection is a good PS2 game for testing video. It has robust display options in the game menu. No console modifications required. You can change between 240p, 480i, and 480p seamlessly from the game menu.

[ZellSF]

1) How are you doing this exactly, which systems, games? I've never seen this work.

Fantasy Zone Complete Collection is a good PS2 game for testing video. It has robust display options in the game menu. No console modifications required. You can change between 240p, 480i, and 480p seamlessly from the game menu.

Tried this now, set it to 480i and enabled line doubling of all fields (aka: bob deinterlacing).

The result is 60 FPS, but the fields are not vertically aligned and in need of an offset.

Only way other than a bob offset I see that would work is dropping half the fields, but then you end up with a 30 FPS video, and I'm pretty sure Fantasy Zone is 60 FPS. So I wouldn't say that's a very good option.

[orange808]

1) How are you doing this exactly, which systems, games? I've never seen this work.

Fantasy Zone Complete Collection is a good PS2 game for testing video. It has robust display options in the game menu. No console modifications required. You can change between 240p, 480i, and 480p seamlessly from the game menu.

Tried this now, set it to 480i and enabled line doubling of all fields (aka: bob deinterlacing).

The result is 60 FPS, but the fields are not vertically aligned and in need of an offset.

Only way other than a bob offset I see that would work is dropping half the fields, but then you end up with a 30 FPS video, and I'm pretty sure Fantasy Zone is 60 FPS. So I wouldn't say that's a very good option.

Looks like -1 offset shifts the fields half a line? That looks like you're battling the RT4K bob deinterlacing algorithm to me. In this case, is the bob option a pure line double?

[ZellSF]

Fantasy Zone Complete Collection is a good PS2 game for testing video. It has robust display options in the game menu. No console modifications required. You can change between 240p, 480i, and 480p seamlessly from the game menu.

Tried this now, set it to 480i and enabled line doubling of all fields (aka: bob deinterlacing).

The result is 60 FPS, but the fields are not vertically aligned and in need of an offset.

Only way other than a bob offset I see that would work is dropping half the fields, but then you end up with a 30 FPS video, and I'm pretty sure Fantasy Zone is 60 FPS. So I wouldn't say that's a very good option.

Looks like -1 offset shifts the fields half a line? That looks like you're battling the RT4K bob deinterlacing algorithm to me. In this case, is the bob option a pure line double?

Not sure why you're trying to look for a more complicated explanation, rather than just think it works in the most simple and obvious way.

Never mind that though, I've explained how it works on the RetroTink4K, what device are you using that manages to recover 240p from 480i in a different way?

[orange808]

Not sure why you're trying to look for a more complicated explanation, rather than just think it works in the most simple and obvious way.

What could be more simple and obvious than clicking the remote and seeing how far the fields move?

[ZellSF]

Not sure why you're trying to look for a more complicated explanation, rather than just think it works in the most simple and obvious way.

What could be more simple and obvious than clicking the remote and seeing how far the fields move?

The RetroTink4K remote? Yeah the setting appears to shift fields by one entire row. Can't really do captures at the moment, but why on earth would it be done in a more complicated way?

Again: what device are you using to recover 240p from 480i in a different way? How's that device's behavior documented?

[orange808]

Not sure why you're trying to look for a more complicated explanation, rather than just think it works in the most simple and obvious way.

What could be more simple and obvious than clicking the remote and seeing how far the fields move?

The RetroTink4K remote? Yeah the setting appears to shift fields by one entire row. Can't really do captures at the moment, but why on earth would it be done in a more complicated way?

Again: what device are you using to recover 240p from 480i in a different way? How's that device's behavior documented?

We are recovering 240p?... Where?

I have been creating a 480p image in the buffer on the RT4K. Does field offset and prescale/decimation work together on 480i? I haven't tried it. You are getting 240p before the scaling and postprocessing? It's a 480p "canvas".

The Extron trick literally fools the CRT and hides the field offsets from the display and recovers 240p. Video scalers shift the information in the buffer during processing. The Extron RGB feeding a CRT gets you a 240p signal. That's the only way I know of to get real 240p and it won't fool a digital display.

Moving +1 or -1 doesn't fully invert the fields. I think we have a terminology disagreement. I see what you're saying now...

[ZellSF]

We are recovering 240p?... Where?

I have been creating a 480p image in the buffer on the RT4K. Does field offset and prescale/decimation work together on 480i? I haven't tried it. You are getting 240p before the scaling and postprocessing? It's a 480p "canvas".

If you bob deinterlace, then offset half the frames by one line, then pre-scale to half height, then you have 240p.

Currently, the RetroTink4K can't do pre-scale after deinterlacing, so it can't recover 240p that way no. You get 480p with wrong scanlines that way. But you do get a progressive picture out of an interlaced input.

The RetroTink5X can recover 240p that way. And from what I understand of the OSSC Pro it also can.

Pretty much my most wanted RetroTink4K feature at this point (other than a lot better serial controls).

[Austin]

Wow, no bumps since March? That's crazy. Must mean the 4K really is that good.

Got a CE a few months ago and sort of just left it as-is after updating the firmware that was available at the time. I have a couple of questions (that may have been answered already in this massive thread):

1. Retro PC capture via the VGA port: Occasionally the capture will be supremely squished vertically with massive black bars above and below the squished/garbled capture. It will only grab the signal and display properly when I go to the auto crop feature. It's not the end of the world but it is kind of annoying to have to intervene manually when this happens.

2. Another retro PC capture issue: If I try to use a Windows PC with its desktop running at 1024X768 or 1280x1024, if I run a game in a much lower resolution comparatively (like Diablo 1, which I guess is around 640x480), it can't grab it--the image just waves up and down like crazy and it's impossible to see the game itself. Note that if I put the Windows desktop resolution to 640x480, I can play games like Diablo just fine. But if it's higher, then these 640x480 games refuse to display (funny enough, switching to DOS 320x240/320x200 games from within Windows don't seem to have issues, it's just the 640x480 titles).

3. Super minor issue - The display resolution notification that automatically pops up in the top-right of the screen. Is there a way to get rid of that in settings? I should probably RTFM or dig deeper into the menu system itself, but I digress.

[Guspaz]

Documentation is available here: https://consolemods.org/wiki/AV:RetroTINK-4K

Documentation about quirks of specific systems can be found here: https://consolemods.org/wiki/AV:RetroTI ... c_Settings

Always try updating to the latest firmware before trying to troubleshoot any potential bugs, because they may already have been fixed. The latest firmware is 1.9.5, available here: https://retrotink-llc.github.io/firmware/

There's a known oddity with 1024x768, IIRC, where you may need to set the decimation factor to 2 (and remember that settings like that are stored in profiles per-resolution, or for analog, technically per linecount/refresh rate since analog video signals have no horizontal resolution), but I don't think that's what you're experiencing. I'd try playing around with the sync settings (SoG threshold, pre/post coast) to see if you can find a setting combination that avoids the problem. But you may have better luck consulting people in the RetroTINK discord's PC channel (https://discord.com/channels/9305678950 ... 0428732496) who have a lot more experience with using PCs with the RT4K than me.

Note also that higher PC resolutions may not be ideal with generic sampling on the RT4K CE, since it has a max sample count of 2048 per line (half that of the Pro), and something like 1280x1024 has 1360 to 1712 total pixels per line (depending on the timing standard), which is less than 2:1, so you may not get a very sharp image without configuring optimal sampling.

You can initiate an auto-crop directly with the remote control. AUX 1 crops just the top and bottom without adjusting the aspect ratio, AUX 2 crops the full image and scales it to 4:3, and AUX 3 crops the full image and scales it to 16:9.

You can disable the resolution change pop-up in the OSD / Firmware settings page, the "Hide Input Res" setting specifically.

[Austin]

Great info, thanks a ton!