RMD: Wii Component Cable

[Fuseball]

Interesting. I've been on the lookout for an official one for my 42" plasma, but I might leave it if there isn't that much difference. You've obviously switched to 480p in the options on the Wii?

Yes. Admittedly I'm only playing Zelda on it, but I couldn't discern any difference in picture quality, even when smoothly panning around. I'm not saying that component is rubbish or anything, just that the Wii's output doesn't require or make use of that extra signal bandwidth.

[Dio]

As far as I know, neither RGB or component have any PAL/NTSC type encoding on them.

Sure it does - the sync signals conform to the correct timing for one or the other. The question is, can it accept other timings (as component obviously can)?

[Dio]

I don't want to sound like I'm teaching people to suck eggs, but with RGB you have an equal amount of bandwidth available to each primary colour (red, green and blue), which is inefficient in itself *and* you're also having to cram the luminance information for each colour down each of the three wires. With a YCbCr component system you get one wire carrying nothing but luminance (the most important) then another two wires for the blue and red colour component with no overhead for their respective luminance. It's this higher bandwidth efficiency that makes it capable of carrying HD signals.

That doesn't make too much sense to me. Assuming the same quality of cable, the bandwidth of the three RGB wires and the three YBR wires is the same; both SCART and component use ground wires rather than differential encoding AFAIK.

Colourspace conversion is a lossy process, and both the source signal (the RGB framebuffer inside the console) and the destination screen are RGB colourspaces. No colourspace conversion == more information. Sure, there might be a colour gamut remapping operation, but that's a lot less lossy than transferring to any luminance space. And if the remap is analogue, then it's likely to cause colour shifts. (That said, even a luminance space conversion isn't a very lossy process, but it is still a lossy process.)

Are you arguing that a SCART cable doesn't have the bandwidth of a triple RCA (phono) jack system? That could well be true I suppose. Anyone know?

[WiteWulf]

That doesn't make too much sense to me. Assuming the same quality of cable, the bandwidth of the three RGB wires and the three YBR wires is the same; both SCART and component use ground wires rather than differential encoding AFAIK.

Quite right, the bandwidth available on the wire is the same in both cases but on the Red wire of an RGB connection you're carrying the chrominance and luminance for the red component of the image (and the same for the green and blue wires) whereas with YBR component the Y wire has all that wire's bandwidth to itself for the luminance component and the B and R wired only carry chrominance information.

Colourspace conversion is a lossy process, and both the source signal (the RGB framebuffer inside the console) and the destination screen are RGB colourspaces. No colourspace conversion == more information. Sure, there might be a colour gamut remapping operation, but that's a lot less lossy than transferring to any luminance space. And if the remap is analogue, then it's likely to cause colour shifts. (That said, even a luminance space conversion isn't a very lossy process, but it is still a lossy process.)

Very true, good point.

Are you arguing that a SCART cable doesn't have the bandwidth of a triple RCA (phono) jack system? That could well be true I suppose. Anyone know?

Nope, just that use of the total bandwidth available over the three wires in a YBR setup is far more efficient than with RGB. This efficiency is the main reason why YBR component can carry HD signals and RGB can't. There's no difference, bandwidth-wise, between the three wires being present in a SCART cable or triple RCA jack (although the SCART standard doesn't actually allow for YBR it's available on some equipment).

Going off ona tangent for a moment: I've just discovered my cable STB can output component but the TV only has one component input (now reserved for the Wii). Can anyone recommend a good, cheap, component switcher with 2 or 3 inputs?

[Deckard]

I got one for sale -B Tech audio video switcher - 80 quid new , 45 quid with 3 hours use - got a Denon 1930 same afternoon which made my Panny hard drive with component redunadant - comes with remote and all packaging.

http://www.hificables.co.uk/ProductDeta ... tID/11416/

[Wudzi]

Interesting. I've been on the lookout for an official one for my 42" plasma, but I might leave it if there isn't that much difference. You've obviously switched to 480p in the options on the Wii?

Yes. Admittedly I'm only playing Zelda on it, but I couldn't discern any difference in picture quality, even when smoothly panning around. I'm not saying that component is rubbish or anything, just that the Wii's output doesn't require or make use of that extra signal bandwidth.

How does the Opera browser look in it? I think that would be the best was to make a comparison.

[Kelloggs]

on the Red wire of an RGB connection you're carrying the chrominance and luminance for the red component of the image

Pardon me for quoting with a scalpel here, but there appears to be a misunderstanding somewhere, and if it rests with me I'd like to clear it up before I make any stupid mistakes in the future.

My understanding of an RGB cable (well, RGBHV if you've got sync as well, and it certainly helps me that way) was that the Red, Green and Blue wires carried nothing more than a monochrome image each. The phosphors/pixels in screens being red, green and blue, combined with our retinas having red(ish), green(ish) and blue(ish) colour-sensitive cone cells are what converts these three independant (but optically-mixed) monochrome images into what we perceive to be full(ish) colour.

If this is not the case, then I stand corrected, and I am missing a piece of information. If it is, however, I would have to ask what a (Red, in this example) monochrome image is doing needing a chrominance component? It is, after all, just brightness in red-space, which I would happily have called luminance, and certainly wouldn't have thought needed both.

Please note, if my typing style is ambiguous, I am not trying to take the piss; I'm just seeking a little personal clarity.

[Dio]

Err. Yes. R carries just R. It's a single component, just as Y is a single component.

use of the total bandwidth available over the three wires in a YBR setup is far more efficient than with RGB.

One can argue that Y is more useful than R, but its existence in the TV signal chain is partly as a holdover from the days when a single signal had to be interpreted as RGB and partly for reasons of encoding efficiency. In terms of transmission down a wire, YCrCb hardly has any efficiency advantages over RGB. The reason YCrCb is more efficient on a DVD or in a TV signal is because the Cr and Cb components are transmitted / stored at far lower bandwidths than the Y signal (about 4:1, typically).

You can make arguments either way, but I would say that in a purely analogue system, if you have three identical wires, you get higher quality from RGB - in YCrCb you clearly need far more bandwidth and S/N on the Y channel than the other two, which is less true in RGB, so you're 'wasting' the capacity of the Cr and Cb wires. Of course, you can argue you need more on the green wire in RGB too, but that's both a lesser effect and I've seen arguments against (e.g. the human eye actually can have more resolving power for blues than any other colours under certain circumstances).

Component is certainly a valuable thing when connecting a DVD player to a TV. The MPEG images on DVD are stored in YCrCb format, and so allowing the TV to do the conversion from component to RGB allows potentially higher quality (for example, it may be possible to map the YCrCb more accurately to the image gamut available, which may be different depending on the screen type). One colourspace conversion maximum is definitely a good thing.

With consoles, the situation is completely different; they generate their images in RGB, so the 'component' conversion throws information away (for any number of bits per channel, the YCrCb signal doesn't map 1:1 to RGB).

This efficiency is the main reason why YBR component can carry HD signals and RGB can't.

I really doubt this by analogy; VGA cables handle 2048x1536 60Hz no problem, and they're analogue RGB with similar signalling characteristics to SCART and much crappier connectors...

[WiteWulf]

My understanding of an RGB cable (well, RGBHV if you've got sync as well, and it certainly helps me that way) was that the Red, Green and Blue wires carried nothing more than a monochrome image each. The phosphors/pixels in screens being red, green and blue, combined with our retinas having red(ish), green(ish) and blue(ish) colour-sensitive cone cells are what converts these three independant (but optically-mixed) monochrome images into what we perceive to be full(ish) colour.

If this is not the case, then I stand corrected, and I am missing a piece of information. If it is, however, I would have to ask what a (Red, in this example) monochrome image is doing needing a chrominance component? It is, after all, just brightness in red-space, which I would happily have called luminance, and certainly wouldn't have thought needed both.

Yeah, I guess that's another way of describing it...the red wire carries a full red 'image' but I was under the impression that the red chrominance signal in a YBR system has more bandwidth for that red component due to one wire being given over entirely to whole, full colour, image's luminance. This is called chroma subsampling and takes advantage of the fact that the human eye is most sensitive to brightness.

I'm no optical scientist so check out the wikipedia entries, they'll explain it far better than me:
http://en.wikipedia.org/wiki/Chroma_subsampling
http://en.wikipedia.org/wiki/Component_video

[Dio]

That's what I described above about DVD and TV broadcasts. It isn't used on an analogue component cable, and would be useless were it.

[WiteWulf]

Component is certainly a valuable thing when connecting a DVD player to a TV. The MPEG images on DVD are stored in YCrCb format, and so allowing the TV to do the conversion from component to RGB allows potentially higher quality (for example, it may be possible to map the YCrCb more accurately to the image gamut available, which may be different depending on the screen type). One colourspace conversion maximum is definitely a good thing.

With consoles, the situation is completely different; they generate their images in RGB, so the 'component' conversion throws information away (for any number of bits per channel, the YCrCb signal doesn't map 1:1 to RGB).

Ah, yeah...that makes a lot more sense.

This efficiency is the main reason why YBR component can carry HD signals and RGB can't.

I really doubt this by analogy; VGA cables handle 2048x1536 60Hz no problem, and they're analogue RGB with similar signalling characteristics to SCART and much crappier connectors...

So why does no TV accept an HD signal an anything other than component or HDMI (which is essentially tarted-up DVI) and why does no HD capable console output an HD signal on anything other than HDMI, VGA or component?

[disciple]

These things seem to range in price from £15 up to £35 depending on the manufacturer and where you look. The official Nintendo one is most expensive and the Blaze one looks cheapest. Anyone tried any of these and can recommend something and where to buy?

To be honest I tend to think all the comments, looks fine, no problem here, no issues here etc.. are pretty useless since WiteWulf is wondering if there's any visible difference in the component cables from the different manufacturers. Even the one comparative comment isn't particularly helpful since it was done in Zelda where there's bugger all contrast and is intentionally blurred to hide the GC assets! To be honest I think the only decent comparison were gonna get is if someone actually posts up some direct comparison pictures.

Saying that I have read elsewhere from a few people that there's bugger all difference between the madcatz, the game home brand and the official one in terms of clarity. But that the official has slightly richer colours but again there's are just a few peoples opinion and I've heard people say they can't see any difference therefore without pictures to back any of it up I don't think we're gonna get a decent answer.

[Dio]

So why does no TV accept an HD signal an anything other than component or HDMI (which is essentially tarted-up DVI) and why does no HD capable console output an HD signal on anything other than HDMI, VGA or component?

That was my question above, as to whether there's a technical reason or if TV's just won't accept unusual syncs on SCART. Why they should choose to block this baffles me, but I can't think of any technical reason why, and it's certainly not the colourspace.

[Deckard]

Still there is this comparison for Twilight -

http://www.gizmodo.com/gadgets/home-ent ... 217054.php

[Fuseball]

Even the one comparative comment isn't particularly helpful since it was done in Zelda where there's bugger all contrast and is intentionally blurred to hide the GC assets! To be honest I think the only decent comparison were gonna get is if someone actually posts up some direct comparison pictures.

Saying that I have read elsewhere from a few people that there's bugger all difference between the madcatz, the game home brand and the official one in terms of clarity. But that the official has slightly richer colours but again there's are just a few peoples opinion and I've heard people say they can't see any difference therefore without pictures to back any of it up I don't think we're gonna get a decent answer.

Sorry, haven't got the facilities to do any decent pictures. To my eyes I couldn't see any discernable difference between the official RGB cable, official component cable and a third-party component cable. That was in the menus, other wii channels and VC games as well as Zelda. Spent ages this morning swapping between RGB and official component trying to justify the component cable and couldn't. The progressive scan 480p mode didn't make much difference to Zelda and, if anything, seemed fractionally softer in the menus than 480i. Of course, this could also be greatly affected by the screen (and any upscaling) it's being sent to.

Obviously both RGB and component look loads better than composite, which is what that gizmodo article is showing.