WiiDual / GCVideo discussion

[strygo]

I've found the Wii via component through OSSC to be quite soft on my display. Is that just the system itself? Does the WiiDual help? If GCVideo could output in 720p or 1080p would that improve things? When I contrast that with say the N64 via UltraHDMI, the N64 is much crisper in either of those display modes.

[nmalinoski]

I've found the Wii via component through OSSC to be quite soft on my display. Is that just the system itself? Does the WiiDual help? If GCVideo could output in 720p or 1080p would that improve things? When I contrast that with say the N64 via UltraHDMI, the N64 is much crisper in either of those display modes.

To begin with, there is a stark difference in quality between the YPbPr component out of a stock Wii and the UltraHDMI, because the Wii's video output necessarily needs to be converted to analogue and then redigitized and scaled by the display, and the UltraHDMI is a fully digital-to-digital solution, so the UltraHDMI is always going to look better in that comparison.

With that in mind, I imagine the HDMI output of the WiiDual is going to be on-par with the UltraHDMI (at 480p), in that it'll look better than YPbPr component out of a stock Wii, because it's also a digital-to-digital solution. With the added benefit of bypassing the stock DAC, the component output from the WiiDual should also be better than stock.

I think the only scenario where GCVideo potentially being able to scale to 720p and 1080p like the UltraHDMI is where the connected display sucks at digitizing and/or scaling 480p.

[Lawfer]

Does the WiiDual help?

For what use exactly? If it's for use on a 16:9 1080p TV, then yes both HDMI and YPbPr from WiiDual improves the picture compared to what you would get from an unmodded Wii through YPbPr.

If planning to use an OSSC, of course with the OSSC lacking an HDMI input you'll have to use instead component or a scart anyways.

[bobrocks95]

I've found the Wii via component through OSSC to be quite soft on my display. Is that just the system itself? Does the WiiDual help? If GCVideo could output in 720p or 1080p would that improve things? When I contrast that with say the N64 via UltraHDMI, the N64 is much crisper in either of those display modes.

To begin with, there is a stark difference in quality between the YPbPr component out of a stock Wii and the UltraHDMI, because the Wii's video output necessarily needs to be converted to analogue and then redigitized and scaled by the display, and the UltraHDMI is a fully digital-to-digital solution, so the UltraHDMI is always going to look better in that comparison.

With that in mind, I imagine the HDMI output of the WiiDual is going to be on-par with the UltraHDMI (at 480p), in that it'll look better than YPbPr component out of a stock Wii, because it's also a digital-to-digital solution. With the added benefit of bypassing the stock DAC, the component output from the WiiDual should also be better than stock.

I think the only scenario where GCVideo potentially being able to scale to 720p and 1080p like the UltraHDMI is where the connected display sucks at digitizing and/or scaling 480p.

Unfortunately the Gamecube and Wii both use 4:2:2 chroma subsampling, so they're unlikely to ever be quite as sharp as the UltraHDMI's output.
For the WiiDual, the DAC bypass for analog output and all-digital signal path for HDMI output will both offer improvements over the stock Wii output however.

[strygo]

I'm interested in getting the most out of GC/Wii on a modern display. I have a Vizio P series 4K display that I use. Upgrading the GC from component cables to an Eon GCHD helped, but still leaves me a bit dissatisfied. I was hoping the WiiDual could be the answer for the Wii.

I only mention the UltraHDMI because I got one this week. I was struck by two things: it is an improvement over the N64RGB+OSSC and also - its default 480p output looks a fair amount worse than when I switch it to 720p/1080p on this display. It's possible this display could just stink at scaling 480p.

So I've been curious as to whether my display just stinks at this (it may) and then if 720p/1080p output was in the cards with GCVideo or if it isn't feasible with the current FPGA.

[bobrocks95]

I'm interested in getting the most out of GC/Wii on a modern display. I have a Vizio P series 4K display that I use. Upgrading the GC from component cables to an Eon GCHD helped, but still leaves me a bit dissatisfied. I was hoping the WiiDual could be the answer for the Wii.

I only mention the UltraHDMI because I got one this week. I was struck by two things: it is an improvement over the N64RGB+OSSC and also - its default 480p output looks a fair amount worse than when I switch it to 720p/1080p on this display. It's possible this display could just stink at scaling 480p.

So I've been curious as to whether my display just stinks at this (it may) and then if 720p/1080p output was in the cards with GCVideo or if it isn't feasible with the current FPGA.

Since you have an OSSC, have you tried either of the 480px2 modes with any consoles? You could get a cheap HDMI to component/VGA transcoder to give it a try with your Eon before committing to a WiiDual.
The HDMI output on the WiiDual should look exactly the same as the Eon's output. There was that chroma bug in earlier GCVideo versions but it's not going to have a very dramatic impact on image quality.

I don't believe the current FPGA could handle 720p scaling and output.

[Lawfer]

I have a Vizio P series 4K display that I use.

So I've been curious as to whether my display just stinks at this (it may)

It's 480p, if you want 4K you're gonna have to invest in a 4K upscaler.

Such as the followings:

Extron DSC HD HD 4K Plus A

Crestron HD-WP-4K-401-C

Brompton SX40

[strygo]

If I recall, 480px2 doesn't work with this display.

For this display - I think 720p/1080p would suffice. The display seems to be able to scale both of those to 4K without issues.

[Lawfer]

If I recall, 480px2 doesn't work with this display.

For this display - I think 720p/1080p would suffice. The display seems to be able to scale both of those to 4K without issues.

In both case if you don't want 480p you will have to either use the OSSC to linedouble 480p to 1440x960 (which does not work on my display and apparently doesn't work on yours either), or get an upscaler. I think WiiDual also allows you to linedouble 240p and 480i to a higher resolution, but 480p does not have this feature I think.

WiiDual HDMI 480p > Upscaled to my TV native resolution:

[Lawfer]

Yep 240p and 480i can indeed be linedoubled:

The WiiDual outputs analog video and HDMI simultaneously. It can output 240p/480i/480p in all video modes. 240p/480i and can be line doubled to display 480p.

So if you have a game that is 240p only (virtual console I assume as I never seen a GameCube or Wii game that is only 240p) or 480i only such as MadWorld, Little King's Story, Mega Man 9 and 10 and many GameCube games WiiDual allows you to linedouble that to 480p, however like I said if someone wants a resolution higher than that you will need a 1080p or 2160p upscaler.

[Unseen]

Color bleed test however can tell us objectively, in bit values, if we actually alternate between full black and full red/green/blue as the pattern is meant to be conveyed.

I think we don't even get that on the input side. I hacked up a way to capture the raw input data from a single video line and asked citrus3000psi to grab the same data from one of his modded Wiis which he did insanely fast - at first glance both his Wii and my Cube seem to output identical raw data in the 240p test suite, so I wonder why there were no color shift reports for the GC except for the Cb->green thing extrems reported.

One pixel per line, left column is Y, right column is color (Cb or Cr), ninth bit of color is the CSel line, only one instance of the repeating pattern shown

Color bleed red pattern, in 240p mode:

Code: Select all

52 063
52 1d4
10 076
10 19c

same, green:

Code: Select all

90 048
90 139
10 06d
10 168

same, blue:

Code: Select all

29 0d4
29 172
10 09c
10 17b

Even though the test suite outputs pairs of pixels of the same color, on the digital AV port each pixel in these groups has a different color. For the black pixels, the Y value is "digital black", but the color is not neutral (80). It is a pure black/white output for the white color bleed pattern though:

Code: Select all

eb 080
eb 180
10 080
10 180

In 480p 1:1 mode, the source pattern is just one pixel color and one pixel black and the digital AV output also shows a repeated 2-pixel pattern.

Red:

Code: Select all

52 06d
10 1b8

Green:

Code: Select all

90 05b
10 151

Blue:

Code: Select all

29 0b8
10 177

White:

Code: Select all

eb 080
10 180

citrus' raw capture from the SMPTE color bars test pattern is here for 240p mode and here for 480p mode in case someone wants to do calculations with it. The data includes blanking (Y=00) and is captured at 54MHz even for the 240p mode, so that one shows each byte twice.

[Extrems]

As expected for co-sited chroma, and as described in the patent.

Nothing new here.

[Unseen]

As expected for co-sited chroma, and as described in the patent.

Nothing new here.

One interesting thing is that this patent specifies linear interpolation for 422 to 444 conversion (page 40, column 19, lines 57+), but people here claim that the real hardware just replicates the previous value.

[DatMonkey]

So does this mean that the chroma shift issue is the same for both the WiiDual and GCDual? So the output is identical for both?

[Extrems]

One interesting thing is that this patent specifies linear interpolation for 422 to 444 conversion (page 40, column 19, lines 57+), but people here claim that the real hardware just replicates the previous value.

The patent doesn't cover the video encoder.

[paulb_nl]

Here is a comparison between the 240p raw data on top and Gamecube component cables OSSC at the bottom.

Edit:
Fixed comparison is below

The raw data only went up to part of the magenta color. I hope I converted the raw data correctly but it looks good to me.

So it looks like the raw data has been interpolated by the GPU and it looks quite bad without some magic from the component cables

[Extrems]

You screwed up the conversion and ended up with fully shifted Cr, ironically.

[paulb_nl]

Woops yea I figured out what I did wrong.

Here is the new comparison. No difference now.
https://i.imgur.com/QruKRVs.png

[awe444]

As expected for co-sited chroma, and as described in the patent.

Nothing new here.

Right, so it looks like there was discussion of this exact “issue” almost 2 years ago:
viewtopic.php?p=1232367#p1232367

So does the HDMI mod circumvent the 4:2:2 YCbCR framebuffer?

Of course not. GCVideo can only take what the Gamecube provides and that is a 4:2:2 YCbCr video signal. If you want existing software rendered in 4:4:4 RGB, Dolphin might work.

Fair enough. So have you seen any need for a deblur function like on the N64, or do the pixels look digitally sharp as is with the mod?

Acknowledging in full that the console is delivering a raw 4:2:2 signal and that the above screenshots are thus expected output for this spec video, FBX’s question still stands: can a “chroma deblur” feature ever be possible?

[Extrems]

The best you could do is have a sharp transition in chroma following a sharp transition in luma.

There's no "deblur". You're in image reconstruction territory. This is why passing through YCbCr 4:2:2 is so important.

[awe444]

The best you could do is have a sharp transition in chroma following a sharp transition in luma.

There's no "deblur". You're in image reconstruction territory. This is why passing through YCbCr 4:2:2 is so important.

Understood, thanks for the clear answer there. I’d been holding out on buying a WiiDual with the hopes that a new firmware might eventually be able to “fix” these 4:2:2 YCbCr artifacts and I’d rather have waited for that than have to flash an update myself. Now that you’ve convinced me there’s nothing that can (or should) be done, I’m down to buy one in the next available batch and just appreciate it for the incredible feat of open source engineering that it is!

[fernan1234]

Would there be an appreciable gain going from a PAL Wii, which has excellent RGB output IMO, to the WiiDual's analogue output?

Like most here I love the idea of getting "the best" picture quality, so I'm interested in this kit, but I would have no use for the HDMI output. I plan to play Wii/Gamecube games exclusively through analogue output on a BVM through 480i. My monitor can do 480p, but invariably I feel every time that at least on the BVM 480i looks much better to my eye than 480p, more vibrant and sharp. That's why I'm a bit on the fence. Any opinions on this would be greatly appreciated.

[nmalinoski]

Would there be an appreciable gain going from a PAL Wii, which has excellent RGB output IMO, to the WiiDual's analogue output?

Like most here I love the idea of getting "the best" picture quality, so I'm interested in this kit, but I would have no use for the HDMI output. I plan to play Wii/Gamecube games exclusively through analogue output on a BVM through 480i. My monitor can do 480p, but invariably I feel every time that at least on the BVM 480i looks much better to my eye than 480p, more vibrant and sharp. That's why I'm a bit on the fence. Any opinions on this would be greatly appreciated.

If it already looks good to you, why spend the money?

[fernan1234]

Would there be an appreciable gain going from a PAL Wii, which has excellent RGB output IMO, to the WiiDual's analogue output?

Like most here I love the idea of getting "the best" picture quality, so I'm interested in this kit, but I would have no use for the HDMI output. I plan to play Wii/Gamecube games exclusively through analogue output on a BVM through 480i. My monitor can do 480p, but invariably I feel every time that at least on the BVM 480i looks much better to my eye than 480p, more vibrant and sharp. That's why I'm a bit on the fence. Any opinions on this would be greatly appreciated.

If it already looks good to you, why spend the money?

As I mentioned, I appreciate efforts to achieve the best picture possible, but it would be good to know the extent of the difference. I haven't looked too much into the Wii's output, but from cursory reading I have the sense that the Wii's analogue output (maybe even RGB?) is not as good as the Gamecube's component output, for example, though I'm not sure exactly in what ways or under what measurements.

[Extrems]

Would there be an appreciable gain going from a PAL Wii, which has excellent RGB output IMO, to the WiiDual's analogue output?

I'd say no.

As I mentioned, I appreciate efforts to achieve the best picture possible, but it would be good to know the extent of the difference. I haven't looked too much into the Wii's output, but from cursory reading I have the sense that the Wii's analogue output (maybe even RGB?) is not as good as the Gamecube's component output, for example, though I'm not sure exactly in what ways or under what measurements.

Apparently your cursory reading doesn't include this very thread.

[andykara2003]

I have the sense that the Wii's analogue output (maybe even RGB?) is not as good as the Gamecube's component output

As far as I know, for analogue it's just the component element of the Wii's output that's substandard. The native RGB output is very good for 240p, but 480i games tend to have a flicker filter that adds a level of blur:

https://gbatemp.net/threads/possible-to ... er.477163/

[fernan1234]

I have the sense that the Wii's analogue output (maybe even RGB?) is not as good as the Gamecube's component output

As far as I know, for analogue it's just the component element of the Wii's output that's substandard. The native RGB output is very good for 240p, but 480i games tend to have a flicker filter that adds a level of blur:

https://gbatemp.net/threads/possible-to ... er.477163/

This is pretty interesting, and probably explains why I always ended up preferring 480i over 480p on my CRT monitor if the Wii/Gamecube is applying a softening filter on 480p. I wonder if removing the flicker filter would be for the better or for the worse on a CRT display--it sounds like it is definitely for the better on a flat display.

And to Extrems, sorry if I missed something obvious on this thread, but here I only found posts about the Wii's YPbPr component output and how it would compare to this solution, but not really a comparison to a PAL console's RGB output through a SCART cable (which may be the same as YPbPr in effect? That's what I'm not sure of).

[nmalinoski]

I have the sense that the Wii's analogue output (maybe even RGB?) is not as good as the Gamecube's component output

As far as I know, for analogue it's just the component element of the Wii's output that's substandard. The native RGB output is very good for 240p, but 480i games tend to have a flicker filter that adds a level of blur:

https://gbatemp.net/threads/possible-to ... er.477163/

This is pretty interesting, and probably explains why I always ended up preferring 480i over 480p on my CRT monitor if the Wii/Gamecube is applying a softening filter on 480p. I wonder if removing the flicker filter would be for the better or for the worse on a CRT display--it sounds like it is definitely for the better on a flat display.

It says that filter is applied to 480i, not 480p; which means 480i should have a softer image than 480p, no?

[Extrems]

It gets murky with the analog bandwidth limiting in 480p on earlier video encoders, but this digital filter is generally only applied in 480i.

[fernan1234]

According to that GBATemp post, 480p has a separate filter of its own:

"Now with a progessive signal (480p) the flicker filter should always be disabled, since there are no interlaced lines to flicker. However Nintendo did something odd - they instead created a new video mode that deliberately 'softens' the picture when in progressive scan mode."