So.... Some SNESes output YPbPr.....

[theclaw]

Maybe someone here can answer this question.

From what I understand, CRT televisions "natively" use Y/C signal for output. That is, every signal coming into the set is converted to Y/C for use by the tube circuitry. We all know that Y/C is what s-video provides.

So, how can someone say "s-video is overrated", when it the native signal of the television?

How can component look better than s-video on a CRT? I understand that in the case of the SNES, it is likely due to essentially outputting the raw RGB (transcoded to component by a chip on the board). However, the TV is just taking that component and converting down to Y/C. I would think that the quality difference between component and s-video from a single device going to a CRT would rely entirely on the ability of circuitry on the device to produce each signal.

s-video is lossy. By definition using it involves sending pre-degraded video to the TV. Even if the TV's native format, it may not be as high of quality as the TV uses internally.

[marvelus10]

I have read in other places of people that have trouble running 240p using s-video, now my SFC runs fine with s-video on my plasma but has a bouncing image with component. Is it possible that if the signals are out of sync then I would get this problem and by using capacitors or resistors on the outputs (as others have noted here to sync the colours properly) solve this?

[Jamisonia]

I have read in other places of people that have trouble running 240p using s-video, now my SFC runs fine with s-video on my plasma but has a bouncing image with component. Is it possible that if the signals are out of sync then I would get this problem and by using capacitors or resistors on the outputs (as others have noted here to sync the colours properly) solve this?

lets test something else. do you have a ps2? do you have ps2 component cables? play a ps1 game on your ps2 via component to your plasma and see what happens.

[marvelus10]

I have read in other places of people that have trouble running 240p using s-video, now my SFC runs fine with s-video on my plasma but has a bouncing image with component. Is it possible that if the signals are out of sync then I would get this problem and by using capacitors or resistors on the outputs (as others have noted here to sync the colours properly) solve this?

lets test something else. do you have a ps2? do you have ps2 component cables? play a ps1 game on your ps2 via component to your plasma and see what happens.

No unfortunately I do not have a PS2.

I read that new TV's are a little pickier when it comes to signals, so if the modified output of the SFC is not quite right I was thinking this could cause my issue.

My SFC has the S-ENC-B version BA6594AF I have wired mine up using pins 1 and 24 + pin 7 from A/V straight, no resistors or capacitors and it looks awesome.

When I initially did the mod I used pin 23 instead of A/V 7 and had a bright faded picture, (same issue with plasma TV also).

I have been told yes you need caps and resistors and I have been told no you don't. Which is it?

Right now my SFC works beautifully on my CRT through component but for some reason need the satisfaction of seeing it working stable on my plasma as well.

[Ziggy]

I have been told yes you need caps and resistors and I have been told no you don't. Which is it?

According to Kyuusaku, you need an amp, cap and resistor. I'm more inclined to believe him over others. He seems to really know what he's talking about. But the reason for it is that the Pr and Pb lines need to be amped a little. And from my experience with the way my picture looks, I definitely agree, they need to be amped.

I haven't had time as of late to mess around with this more, but once I find the time, I plan to try Kyuusaku's method. He seems to be on the ball about things, I wouldn't doubt that his method is correct. Or at least closer to correct than the things we've been trying.

[elmagicochrisg]

Got a link for us Ziggy?...

[Jamisonia]

Wall o Text Warning


Well man, the thing is we don't know for sure whether you need additional components. We're all amateurs here. None of us know the YPbPr spec well enough to know if the signal is "perfect", and honestly even if we did, its doubtful anybody has the tools to test to see if its in spec. You just can't simply use a multimeter. You at least need an oscilloscope, which I actually do own. I have no idea how to use it, but I own one. I know there are other tools somebody who works with video circuits all day are going to own, like a waveform generator.

Here's what I do know man. The signal has to be 75 Ohm impedance. This is not resistance, this is impedance. The further off from that we are, the more problems we're going to have with the picture.

Now you say that when you tapped the luma straight from the AV port, and straight from the chip you got an unstable picture both times? That means the TV is not accepting the sync signal. However the thing is dude the Luma signal coming from pin 7 is as close to spec as we can expect it to be.

Here is what I think the problem could be:

1. The Luma signal is 240p, and your TV simply will not accept it over component no matter what you do. The only solution is to upscale it.

2. Your TV is locked into some sort of RGB mode where its expecting to get sync either from all three signals, or from a seperate line. Solution: try another component source

The fact is you got it working on your CRT TV. Honestly I reccommend you just use that, as the picture will look better on your CRT TV than your plasma. Here is my biggest caveat to getting component out of any video game system prior to the PS2. If it works on your HDTV, consider yourself lucky. It is not guaranteed, and likely it will not work.

The fact is that these consoles output 240p. 240p was never a standard. The FCC barred broadcasters from ever using this format. Video games are the only thing that used this format. HDTV manufacturers are simply not interested in providing for legacy devices. Its in their best intersts to get you to forget about legacy devices, and buy new ones. Additionally its a matter of usefulness. I can tell you now, that TV manufacturers are not considering people modding electronics to work with newer display standards. In the history of video games there are only two official instances when one might send 240p signals over component outputs. Those are, playing PS1 games on the PS2, and playing virtual console games on the Wii. In the latter case Nintendo fixed it with a system update so that the Wii upscales all the games to 480i or 480p before output, because there were so many problems with 240p Component compatibility with HDTVs. Even in these cases if somebody ran into an issue they would just say oh well, I'll use composite.

I take shit from friends all the time over why I feel the need to modify my SNES for component, or my Genesis for s-video. They say, its still 16 bit, it won't make it HD, it won't improve your enjoyment, why waste your time. Regardless of the absurdity of this argument, it mirrors how the vast majority of people feel. Why would companies waste, time, effort, and money providing for things that the fast majority of people could care less about?

[marvelus10]

I have been told yes you need caps and resistors and I have been told no you don't. Which is it?

According to Kyuusaku, you need an amp, cap and resistor. I'm more inclined to believe him over others. He seems to really know what he's talking about. But the reason for it is that the Pr and Pb lines need to be amped a little. And from my experience with the way my picture looks, I definitely agree, they need to be amped.

I haven't had time as of late to mess around with this more, but once I find the time, I plan to try Kyuusaku's method. He seems to be on the ball about things, I wouldn't doubt that his method is correct. Or at least closer to correct than the things we've been trying.

Yes but he made that comment and referred to the data sheet, now the only data sheet in this thread is for a BA6592F. S-ENC-B or BA6594AF do we have a data sheet for that?

[Ziggy]

Yes but he made that comment and referred to the data sheet, now the only data sheet in this thread is for a BA6592F. S-ENC-B or BA6594AF do we have a data sheet for that?

Yeah, that's what I was saying before (probably quite a few times). But it's the only data we have to go on, otherwise we're just totally guessing (unless some one is actually using the appropriate instruments to measure the output). The difference between the Pr and Pb outputs on the BA6592F and the other revisions probably isn't much, if anything at all. Using his suggestions, you'll probably be closer to perfect than by any other method.

But ignoring the datasheet for second, you can see visually that the Pr and Pb lines need to be amplified. You don't need to be a video engineer to notice it. I forget if we mentioned it in this thread already, but amping those lines was idea Jam and I were already fooling around with. It's just that since we're not video engineers, we don't have a lot to go on. I'm glad Kyuusaku gave his opinion on it. I was planning on asking on NesDev myself, but you beat me to it. Anyways, next time I have the time to mess around with the SNES, I'll be trying Kyuusaku's advice.

Got a link for us Ziggy?...

http://nesdev.parodius.com/bbs/viewtopic.php?t=8979

I plan to ask a few clarifying questions, but haven't gotten around to it yet. I'd like to know if he could recommend an exact (part/model number) amp to use for it.

[theclaw]

Some HDTVs utterly refuse to accept 240p from component input, at all. Halting with a "signal not found" type error message.

Including sets that have NO immediate problems with 240p through composite and s-video!