Thanks for the info Extrems! I've actually been trying to find a solid answer about this for awhile now: When the GCVideo is connected, does it take video before the encoder and keep it in 4:4:4, or does it pull from the video encoder in 4:2:2?
the video encoder.
So you're getting native 4:4:4 RGB with GCVideo? No 4:2:2 YCbCr is used with GCVideo?
I think theres some confusion arising here. Extrems is talking about the internal pixel format inside the GameCube GPU and how its originally RGB, but AFAIK there is no way for us to access those signals. GCVideo taps into the digital video signals between the GPU and the stock video encoder, which at that point have already been encoded into YCbCr 4:2:2.
I collected these snippets from the Nintendo SDK which might help explain:-
This is the sort of place for people who want to get the absolute very best audio/video possible from their console. Even if a mod only offers a 1% improvement in picture quality there are people who would want that.
See, that was sort of what I was trying to imply, but I did a poor job of it... The best image quality is going to be HDMI. I don't see a point in doing a gcvideo-lite in the cube because that's a middle solution in terms of output quality: it's only slightly better than the existing analog video, and not as good as the digital video, and 480p is less likely to be used on a CRT than 480i.
What I'm trying to say is, if you care about quality that much, use HDMI. If you want analog, just use the built-in component.
Its true HDMI gives you access to the pure digital video. However
the GameCube and Wii do not output a perfect 720x480 resolution, in fact its actually 640x448 - this means that GCvideo has to add black bars all around the image so that it will meet the HDMI specification:-https://www.gc-forever.com/forums/viewtopic.php?p=35025
The TV will still have to scale the image upto its native resolution (1080p/4k) and then the black bars typically cannot be defeated (Depending on your TV model it might offer a "Zoom" mode, but that usually cuts off some of the picture) This also means you cant display the game with the correct 4:3 aspect ratio.<Apparently this last sentence is incorrect, see Unseen's post below>
Using an analog signal allows the TV (Or scaler like the framemeister) to sample only the active lines/pixels, meaning we can get a full screen image with very minimal picture quality loss. In addition analog video outputs allow for easier connection to CRT TV's, for a more "authentic" retro experience.
HDMI mods for retro consoles are great and they certainly have their place, however these systems were simply designed with analog output in mind.
If that doesn't help explain why I would still like to see analog 31kHz RGB output from a Wii, then i'm not sure anything will convince you.