- How uncommon is Nestopia's "15° Canonical" encoder in consumer TVs? Is it uncommon enough to be generally less accurate to the TV experience than "Consumer" encoders?
- Nestopia's "Alternative" encoder boosts yellow, which I have read to be an effect from NTSC-J, so is it supposed to represent a general NTSC-J encoder? If so, why is the yellow boost much stronger than Sega Li's "Sony CXA2025AS/J" and "Sony CXA2095S/J" encoders? Perhaps they were made for different monitor color temperatures?
- I am assuming that Sega Li's "industrial" encoder is supposed to be canonical to NTSC standards (correct me if I'm wrong), as is Nestopia's "canonical" encoder, but why are they different? If it could be found out, which is more accurate?
In Sega Li, the only decoder properties I use are R-Y/G-Y/B-Y angles and gains, obtained from sources online, no adjustable black level or "yellow boost" (which is probably artificial in Nestopia). I convert these properties to a matrix and feed them to blargg's nes_ntsc.
Point 3: Yes, the industrial decoder is standard NTSC, the gain levels were guessed though. Anyone knows the correct values?
Point 3: Yes, the industrial decoder is standard NTSC, the gain levels were guessed though. Anyone knows the correct values?
Code:
R-Y angle: 90.0, gain: 0.6
G-Y angle: 246.0, gain: 0.3
B-Y angle: 0.0, gain: 1.0
*edit*, I did some fiddling, G-Y angle is probably 236 even..
G-Y angle: 246.0, gain: 0.3
B-Y angle: 0.0, gain: 1.0
*edit*, I did some fiddling, G-Y angle is probably 236 even..
Quote:
How uncommon is Nestopia's "15° Canonical" encoder in consumer TVs? Is it uncommon enough to be generally less accurate to the TV experience than "Consumer" encoders?
In the U.S. until the late 90s, certainly. Japan is different.Quote:
Nestopia's "Alternative" encoder boosts yellow, which I have read to be an effect from NTSC-J, so is it supposed to represent a general NTSC-J encoder?
The only by-the-book difference between American NTSC and Japanese NTSC is the setup (7.5% U.S., 0% Japan) and the white point (D65 U.S. since the 1970s, D93 Japan). Any boosting business will be at a TV manufacturer's discretion. Best forget about it.Quote:
Anyone knows the correct values?
Code:
R-Y: 90°, 0.570
G-Y: 236°, 0.351
B-Y: 0°, 1.016
Actually, the gains should be twice as high, but for some reason Nestopia requires them at half value.G-Y: 236°, 0.351
B-Y: 0°, 1.016
This thread is a little confusing.
Could someone please explain what "*-Y", "angle", and "gain" exactly means?
Could someone please explain what "*-Y", "angle", and "gain" exactly means?
NewRisingSun wrote:
Quote:
Anyone knows the correct values?
Code:
R-Y: 90°, 0.570
G-Y: 236°, 0.351
B-Y: 0°, 1.016
Actually, the gains should be twice as high, but for some reason Nestopia requires them at half value.G-Y: 236°, 0.351
B-Y: 0°, 1.016
When I tried to enter in the doubled gain values into Nestopia's settings, B-Y's doubled gain of 2.032 was clipped to 2, which seems to be Nestopia's color decoder limit for angle gains. The luminance ranges across the different hues became oversaturated and disproportionate of each other after doubling the gains, which might also be why Nestopia halves the gains.
- How close to (or far from) Japanese TV yellow boost is Nestopia's yellow boost? Is the yellow boost in Nestopia generally typical or atypical to most of these TVs?
- Why does Nestopia's yellow boost differentiate colors 20h and 30h in red, green, and yellow emphasis? Could this be a bug, or does this actually happen on Japanese TVs? I don't see why it should happen, since those two colors are supposed to be the same.
- What is the most common color temperature for American CRT TVs - specifically those around the NES era? On modern websites, I've read 7100K or even 9300K, like Japanese TVs.
Quote:
How close to (or far from) Japanese TV yellow boost is Nestopia's yellow boost? Is the yellow boost in Nestopia generally typical or atypical to most of these TVs?
Atypical. Just forget about it.Quote:
What is the most common color temperature for American CRT TVs - specifically those around the NES era? On modern websites, I've read 7100K or even 9300K, like Japanese TVs.
Most Japanese and American TVs of the 1980s use a white point of 9300K+27MPCD, meaning the same. The most common decoding characteristics seem to be something like 120°/246°/-10° with gains of 0.75/0.33/1.00 (roughly). (This will look too "red" on an sRGB monitor.)
With gains that high, most TVs will use a "relative colorimetric" rendering intent, whereas Nestopia's decoder seems to use a "saturation" rendering intent.
Not atypical at the time.
Compare the RGB NES palette with the yellow boosted palette, and you will find they are VERY similar. this is evidence that the RGB NES PPUs were designed to replicate that amount of yellow boost.
MANY japanese developed games look right with that yellow boost, and look wrong with any other setting.
Compare the RGB NES palette with the yellow boosted palette, and you will find they are VERY similar. this is evidence that the RGB NES PPUs were designed to replicate that amount of yellow boost.
MANY japanese developed games look right with that yellow boost, and look wrong with any other setting.
_Zaphod_ wrote:
Compare the RGB NES palette with the yellow boosted palette, and you will find they are VERY similar. this is evidence that the RGB NES PPUs were designed to replicate that amount of yellow boost
Maybe some of the yellow boosted hues (5-A) may look similar in hue, but the luminances look very warped in the RGB palette in comparison to a yellow boosted NTSC palette in Nestopia, especially hues 3 and 4. So I don't think the RGB palette is a good standard here.
Also, as mentioned in this thread, I found a bug in Nestopia's yellow boost that differentiate colors 0x20 and 0x30 in red, green, and yellow emphasis settings. Someone else reported this in Nestopia's bug tracker, concluding that Nestopia was calculating yellow boost based on the NES's palette values and not on the PPU's output values. Yellow boost is supposed to be directly a TV effect, not a Famicom PPU effect; if you play with the hue slider, you'll see that colors the TV should yellow boost are not boosted anymore. So Nestopia's yellow boost is probably not reliable regardless.
The fact that Nintendo changed the color numbers used in Playchoice 10 games for the RGB PPU is proof that the RGB palette is not authoritative.
Given that no one has ever named a television model that actually works this way, I still think the yellow boost business is a dud. I once mentioned the idea based on a single untrustworthy source and had it as experimental code in my algorithm when blargg created his library, and that's why it's still there after all that time, unfortunately.
Given that no one has ever named a television model that actually works this way, I still think the yellow boost business is a dud. I once mentioned the idea based on a single untrustworthy source and had it as experimental code in my algorithm when blargg created his library, and that's why it's still there after all that time, unfortunately.
NewRisingSun wrote:
Given that no one has ever named a television model that actually works this way, I still think the yellow boost business is a dud. I once mentioned the idea based on a single untrustworthy source and had it as experimental code in my algorithm when blargg created his library, and that's why it's still there after all that time, unfortunately.
I removed "hue warping" from nes_ntsc in version 0.2.1 in 2006. I thought Nestopia always had its own extended color algorithms, which this yellow boost came from.
NewRisingSun wrote:
Given that no one has ever named a television model that actually works this way, I still think the yellow boost business is a dud.
So does that mean that yellow boost is just a myth after all? According to _Zaphod_, on certain Japanese TVs, yellow colors look like they are indeed boosted; he cited Fire Mario's bright-yellow clothes as an example:
_Zaphod wrote:
Many games were developed for consumer Ntsc on the NEs/Famicom.
WHat this means is that many games orginally developed in japan were made for a yellow boosted palette, which was common on JP tvs at the time...
On a JP consumer TV, fire mario wears yellow clothes instead of white. Ths is replicated in the arcade version. ON US tvs, he wears white instead. Luigi wears white on either, though.
WHat this means is that many games orginally developed in japan were made for a yellow boosted palette, which was common on JP tvs at the time...
On a JP consumer TV, fire mario wears yellow clothes instead of white. Ths is replicated in the arcade version. ON US tvs, he wears white instead. Luigi wears white on either, though.
Maybe _Zaphod_, if he has one of these JP consumer TVs, could tell us the model of that TV to see for sure if JP TVs indeed boost yellow or not.
Quote:
So does that mean that yellow boost is just a myth after all?
Yes, or "dud", as I phrased it.Quote:
According to _Zaphod_, on certain Japanese TVs, yellow colors look like they are indeed boosted
Manufacturer and model, please. Make sure you set the saturation knob to the center position when trying.Quote:
On a JP consumer TV, fire mario wears yellow clothes instead of white. Ths is replicated in the arcade version. ON US tvs, he wears white instead.
No, he doesn't; it's just a rather pale yellow. If it appears white on your monitor, your monitor is maladjusted.I did PM _Zaphod_ if he had any of those TVs, and he said he didn't. Yeah, I could see how oversaturation could produce an illusion of this yellow boost...could it be that Japanese TVs are simply set to be more saturated than American TVs? I personally think that might be the case, because yellow does "boost" if you increase saturation in Nestopia. Naturally, since the yellowish hues are generally the most saturated hues in the NES, a saturation increase would be noticable on the brighter colors of yellowish hues, which are 7 and 8 in the NES under normal emphasis settings.
Quote:
could it be that Japanese TVs are simply set to be more saturated than American TVs?
Not by default, but many people I know just turn saturation all the way up on their TV, Japanese or otherwise. This over-saturating the picture only works however if your TV sets doesn't clip colors. Here's an example of what I mean:
left: saturation at 100% (default). Accurate hues, but pale color 0x37.
middle: saturation at 200% with simple RGB clipping, as used in cheap TVs. Yellow "boosted" color 0x37, but the browns drift to red because of the RGB clipping.
right: saturation at 200% with hue preservation, as used in better TVs; boosted yellows while still accurate browns.
I have at home an old (?) japanese tv, 1998 toshiba if my memory is good that my brother in law lend us when we moved to japan.
I could always try to put the default setting and take some screen shots if that could help.
I just need to know a list of games that the issue is more obvious. As long as I have the game, I can test it. But a 1998 tv is still not a tv from the famicom era so I don't know if the test would be conclusive or not.
I could always try to put the default setting and take some screen shots if that could help.
I just need to know a list of games that the issue is more obvious. As long as I have the game, I can test it. But a 1998 tv is still not a tv from the famicom era so I don't know if the test would be conclusive or not.
Banshaku wrote:
I just need to know a list of games that the issue is more obvious.
Any game that starts out with title screens or first areas that use yellowish colors (of hues $7 and $8 especially, but $6 and $9 are also affected) or bright skin tones are good test games. Here's a small list of such, by their Japanese names first, then American names if different:
- Double Dragon (the Kanji characters in the title screen are yellowish, and the first level uses yellowish BGs and skin tones for some enemies)
- Double Dragon II (the "II" in the title screen is yellowish, and skin tones)
- Gimmick! (yellow stripes in the title screen and the first level)
- Senjou no Ookami {戦場の狼} (aka Commando, the skin tone of the gray enemy soldiers)
- Hitler no Fukkatsu: Top Secret {ヒットラーの復活: Top Secret} (aka Bionic Commando, the yellowish bricks of area 1 and the skin tones of the playfield characters)
- Gun-Dec (aka Vice: Project Doom, skin tones and some colors in the first level)
- Crisis Force (skin tones in the intro, yellow land in the first level)
Actually, I doubt you'd even need a list - probably any and all of the games you have can be good test games.
This is a good starting list. Once I have a chance (i.e. my kid is sleeping..), I will try to take some pictures of them.
But I do remember that some of them did seems more yellowish than what I remembered when I had them on my original nes. I will try to reset the settings of the tv just to make sure that it doesn't compromise the tests, but I guess we never changed them once we received it so it should be in it's normal position already.
But I do remember that some of them did seems more yellowish than what I remembered when I had them on my original nes. I will try to reset the settings of the tv just to make sure that it doesn't compromise the tests, but I guess we never changed them once we received it so it should be in it's normal position already.
Banshaku, have you been able to take the pictures yet? If for some reason you're not able to, then maybe you could just tell what the model number of your TV is, and that could be looked up to see if it does any yellow boost or oversaturation.
I wanted to do it but my kid is sick and we had to go to the hospital in the middle of the night. Once things get back to normal, I should be able to take the pictures.
If I have a chance, I will try to get the model # tonight once I return from work.
Edit:
I just came back and I had a chance to check the model. It's a 1997 Toshiba 21R77. This is the only information on the back for the model number. No specific series or anything. In brief, a very basic tv.
If I have a chance, I will try to get the model # tonight once I return from work.
Edit:
I just came back and I had a chance to check the model. It's a 1997 Toshiba 21R77. This is the only information on the back for the model number. No specific series or anything. In brief, a very basic tv.
Here the images I could take tonight:
Senjou no ookami
This one, the picture is not great. Cannot see. Not that yellowish.
Double dragon
The yellow tone is a little bit more obvious
Double dragon 2
This one, not really.
Hilter no fukkatsu: top secret
You cannot pause the damn game and see the game play so it was a hard one to take.
Crisis force
Seems a little bit yellowish
Gun-dec
These batch doesn't comes out as clear as I expected. The building are yellowish. The enemies a little bit.
I still have the originals pictures. At 2 megs each, I couldn't put them online and I don't think my ISP would like it since I put them on my personal page.
I had to do them very fast, the battery of the digital camera was dying. I don't know how long I will be able to keep them online.
But my setting was very improvised. Dark room to avoid light, basic digital camera, my hand where shaking even on a chair+box so it was not the ideal setting.
The settings of the TV are all reset to zero, except for one called "unicolor" in japanese. If you increase it, it boots the color. In that case, the yellowish tone becomes more obvious but it must be because the colors becomes over saturated.
I hope these pictures will help you. I can take more someday if I can find the time to do it.
Senjou no ookami
This one, the picture is not great. Cannot see. Not that yellowish.
Double dragon
The yellow tone is a little bit more obvious
Double dragon 2
This one, not really.
Hilter no fukkatsu: top secret
You cannot pause the damn game and see the game play so it was a hard one to take.
Crisis force
Seems a little bit yellowish
Gun-dec
These batch doesn't comes out as clear as I expected. The building are yellowish. The enemies a little bit.
I still have the originals pictures. At 2 megs each, I couldn't put them online and I don't think my ISP would like it since I put them on my personal page.
I had to do them very fast, the battery of the digital camera was dying. I don't know how long I will be able to keep them online.
But my setting was very improvised. Dark room to avoid light, basic digital camera, my hand where shaking even on a chair+box so it was not the ideal setting.
The settings of the TV are all reset to zero, except for one called "unicolor" in japanese. If you increase it, it boots the color. In that case, the yellowish tone becomes more obvious but it must be because the colors becomes over saturated.
I hope these pictures will help you. I can take more someday if I can find the time to do it.
I hope your kid's getting better, but thank you for taking the pictures anyway; they're good enough for me. :) I don't think your TV, at default settings, doesn't do any yellow boost at all; any over-yellowishness is probably something that's different between individual TV sets, so I guess it probably is a myth.
We do have to take into consideration that this tv is post famicom era but I would be very surprised if all of a sudden they would have changed the standard about that.
edit:
If we want to keep those pictures for future reference, where could I host them? Like I said, I don't know how much my ISP will like me to keep them on my personal web page (even thought for now I don't really take care of that site). It would be a shame to lose them if someone want to see that specific information again.
edit:
If we want to keep those pictures for future reference, where could I host them? Like I said, I don't know how much my ISP will like me to keep them on my personal web page (even thought for now I don't really take care of that site). It would be a shame to lose them if someone want to see that specific information again.
Just make a quick photobucket account:
http://photobucket.com
Free and easy : ) I've had mine for years, and still have images all over the place haha
http://photobucket.com
Free and easy : ) I've had mine for years, and still have images all over the place haha
Roth wrote:
Just make a quick photobucket account:
http://photobucket.com
Free and easy : ) I've had mine for years, and still have images all over the place haha
http://photobucket.com
Free and easy : ) I've had mine for years, and still have images all over the place haha
I followed your advice and updated the message. Thanks for the tip. Still, my concern is if this site goes down, we lose the content.
strangenesfreak wrote:
I don't think your TV, at default settings, doesn't do any yellow boost at all;
Huh?banshaku wrote:
We do have to take into consideration that this tv is post famicom era but I would be very surprised if all of a sudden they would have changed the standard about that.
No, but way until the 1980s, manufacturers still assumed (for whatever reason) that the transmitted NTSC signal encoded RGB values for the 1953 FCC reference receiver, even though as early as 1968, broadcasters were recommended to send out a signal encoded for less-saturated SMPTE-C monitors. Depending on when TV set manufacturers started taking that into account, their color decoding will "suddenly" change.
Based on those pictures, I don't think the TV boosts anything at all:
- If red boost was active, the yellows wouldn't look as greenish as they do in the pictures.
- If yellow boost was active, color 0x36 would look orange instead of pinkish. In the Double Dragon I title screen shot, the fire above the "© 1988 Technos Japan Corp" looks orange for 0x26, but then pinkish for 0x36, a clear sign of no "yellow boost".