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Oh my, so much nonsense in one thread.

Originally Posted By "BootGod"
an NTSC emulator was developed by a guy named Blargg
It was developed by me, then optimized for speed and distributed without my explicit permission by Blargg, and obviously without credit, not that anyone cares.
Originally Posted By "R. Belmont"
Here's your problem: the exact colors generated by an NES/Famicom *are* NTSC artifacts. (..) The artists for NES (and SNES and Genesis) games drew the graphics to look good *with* NTSC artifacts.
That's a bunch of crap. The NES does NOT primarily work on "artifact color". The Apple II and CGA with some games do, but NOT the NES. There are THREE (3) differences between a "NTSC-filtered" and an RGB picture made from a "palette":

1. Chroma subresolution: the color has a lower resolution than the brightness. This is ONLY relevant on one- or two-pixel-wide colored areas, where transitory colors appear. This effect also happens with S-Video.
2. Cross-color artifacts: some of the luminance information is incorrectly interpreted as color, causing "rainbow swirls". What this artifact color looks like depends on the phase of the chroma subcarrier relative to the pixel clock, which is not only changing from pixel to pixel, but also UNDEFINED on power-up. On the Famicom, I can reset a game, and the cross-color artifacts on the title screen, are sometimes the opposite from before resetting. You don't see that on the U.S. NES because the reset button also resets the PPU. But obviously, this makes it impossible to use this kind of artifact by an artist for effect.
3.- Cross-luma artifacts: some of the chrominance information is incorrectly interpreted as brightness, causing "jaggy edges". I know of no game that uses this to any effect, for the same reason as 2.

2. and 3. only appear with composite video, not S-Video. Only 1. is used for effect on *some* games, and is annoying on many others. SMB1 and others scroll at a fractional pixel speed to avoid 3. becoming too visible, but 2. and 3. are impossible to be used for effect.

In other words: A "palette" will be sufficient for any game that does not heavily rely on chroma subsampling, which by my count are most games. The "Composite/S-Video" setting buttons in NEStopia are nonsensical, as "Composite" looks more like RF, and S-Video looks like a well-comb-filtered RF signal. I can't tell you why that is, because I have no clue what picture processing operations lie behind phenomenological terms such as "Sharpness" and "Resolution".

And whether you use a NTSC filter or a palette does NOT answer the question of how greenish or brownish color x8 should look, or how blueish or purplish color x3 should look. That depends on the TV set that the graphics artist/programmers used; precisely speaking, the result is precisely defined by the TV's:

1. signal amplification and clamping. Some TVs use the color burst as an amplitude reference, others don't.
2. chroma decoding angles and gains
3. phosphor chromaticities and white point.

All these can be precisely emulated if you know the values. NEStopia by default assumes standard NTSC chroma decoding angles and gains, which no real non-studio TV set uses. It allows for user-adjument of these settings, but those are worthless without simultaneous emulation of different phosphor chromaticities and white point, also known as "Color Management".

Unless you want to Turing-successfully emulate the look of a particular TV set, the best solution is to just use an idealized PALETTE designed to make COMBINATIONS of colors look sensible, and activate chroma subsampling only on those games that use it for effect. There's no good reason to emulate actual chross-color/-luma artifacts, and YUV-derived *color values* don't get you anything useful that a palette can't, unless you care about having a "Hue" and "Saturation" slider to play with.

Last edited by NewRisingSun; 01/25/08 01:04 PM.
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I can assure you that every piece of art for 8 and 16-bit games was hand-tuned using NTSC televisions and composite monitors. Even if the artifacts weren't used specifically for effect, they did influence things like color choice and thus with the artifacts is the way the games were intended to be seen. Period. (This is also why PAL ports were so half-assed most of the time).

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Sounds like someone's all pissed because he didn't get any credit and is now trying to discredit the usefulness of it because of that.

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Quote:
I can assure you (...) Period.
Well, I doubted you before, but NOW I am convinced. :P

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(This is also why PAL ports were so half-assed most of the time).
Which PAL "ports" are "half-assed" and what does this have to do with artifacts? I find PAL versions to be identical to NTSC versions, except that the picture is letterboxed and they play slower.

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Sounds like someone's all pissed because he didn't get any credit and is now trying to discredit the usefulness of it because of that.
Sounds like you couldn't be bothered to read and understand the full post and are now trying to churn out a smartass remark.

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the picture is letterboxed and they play slower.


Exactly. Native PAL games were not letterboxed and played the right speed.

Anyway, if you're so down on NTSC, why did you create the filter? It certainly looks pretty sour-grapey.

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Native PAL games were not letterboxed and played the right speed.
But what does this have to do with artifacts and color choice? That's the context in which you brought it up, which is why I ask for clarification.

Creators may have avoided particular color combinations because of artifacting as you claim, but that doesn't make a lack of artifacts look worse. Speculating about what is "intended" amounts to palm reading, because you can't know what the creators intended, or how much artifacting their particular TV set had.

There are two possible goals for emulator authors:
1. increasing game enjoyment, and
2. 100% accurately looking like a particular TV set.

For game enjoyment, you want a clear picture with nice colors. "Nice colors" requires a palette that makes color combinations, such as light brown (0x27) and bright brownish-red (0x36), look proper. For some games, you also want chroma subsampling for transitory colors. But you don't want nasty edges or rainbow swirls around objects.

To 100% emulate a particular TV set's look on the other hand, the critera are different. You need all the extra things I talked about, in addition to NTSC artifacting and filtering. It's an interesting challenge, but not neccessarily good for game enjoyment, as there are some nasty-looking TV sets out there. smile
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Anyway, if you're so down on NTSC, why did you create the filter?
For Apple II and CGA, which you should know.
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It certainly looks pretty sour-grapey.
That's MooglyGuy's incorrect contention. I bother writing ~40 lines of post not to descredit but to inform.

NEStopia brings RF quality to "composite" and "RF" settings, and lacks proper Color Management to make adjustable YUV decoding angles/gains meaningful. It also gives people the false impression that using an NTSC filter makes for more accurate colors than palettes, as evidenced in one of MooglyGuy's posts some time ago, when actually except for the chroma subsampling for small-area colors, one has nothing to do with the other.

All these are legitimate points, so stop the psychobabble please, if you could be so kind.

Last edited by NewRisingSun; 01/25/08 04:16 PM.
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My point about PAL was simply that NTSC was so ingrained in the design process (at least in the US) that a) it hurt ports to other systems and b) clinically clean RGB output is not how the games were designed, so on some level it's not right.

Emulators are at least in part about nostalgia. I don't get that feeling from perfect sharp pixels. I need the fringed text, the dot crawl, the smearing on scrolling dither patterns, and the bleeding reds. That's what it actually looked like on real hardware (in the 80s, I played NES on a good quality 1985 model GE TV so it had a decent comb filter and so on). You can easily prove that no possible settings are "perfect", and it doesn't matter. The defaults in NEStopia with the NTSC filter compare quite favorably to real-world hardware, even if they're provably not exactly right.

Feel free to make your own emulator that's perfect by your standards (with color management and whatnot), and I'll probably switch to it when it comes out (assuming I can build it on Linux). Or make your own filter and Marty will probably add it. Either way, everyone wins.

Last edited by R. Belmont; 01/25/08 04:44 PM.
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Well, look at that. I can't edit my first post. I'll just have to post some answers to my original questions here.

By the way, the discussion in this thread got too technical for me, so I'm just going to try to keep this basic.

Originally Posted By Josh7289
Questions about video and sound on Nestopia and on real NES/Famicom hardware

I've recently begun to get into NES/Famicom emulation, and I have a bunch of questions that I haven't found clear answers to, so I created this thread with the intention of finding some of these answers, and to help others who have similar questions to find answers for themselves.

VIDEO

Color Palette -- Every emulator I have tried so far has rendered games with different colors. Furthermore, there are people out there who are striving to make the perfect color palette (like AspiringSquire -> Link 1 Link 2). Doesn't the NES/Famicom, when rendering an image, render a pixel with an exact color? Why don't emulators just look to that for the correct color palette?

The NES/Famicom only renders video in the NTSC colorspace -- not in RGB. What this means is that there is no possible way to get the colors of NES/Famicom games on an RGB emulator/platform/monitor (like a PC) the exact same as they are on actual hardware. It just has to do with the inherent differences between the NTSC colorspace and the RGB colorspace.

Quote:
Aspect Ratio -- The TV Aspect option doesn't work exactly right in Nestopia. This can be tested with either Kirby's Adventure (the circle drawn in the game's opening) or tvpassfail. To clarify, it does work properly for 1X and 2X screen sizes, but not 3X, 4X, Max, or Fullscreen for any resolution over 640 x 480 (but I'm not sure if it works for resolutions lower than 640 x 480). Does anyone know if this option will be fixed?

This is still an issue.

Quote:
SOUND

Sound Effect (specific instance) -- So far, my video questions are much more pressing. Regardless, I've noticed that the sound effect for throwing fireballs in Super Mario Bros. is off in Nestopia, but sounds correct in FCE Ultra. I find it hard to believe this problem could have gone unnoticed for such a popular game, so what am I doing wrong? My sound settings are all at their defaults.

It turns out Nestopia is the correct one. The fireball sound effect is still "off" most of the time, but I recently played the game on actual hardware, and I heard the same thing as I heard in Nestopia. FCE Ultra wasn't emulating the hardware as accurately as Nestopia, it seems.

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--------------------

If any other questions pop up, I'll add them here. I'll also throw any answers I get up here for people to see.

I have come up with one other question:

VIDEO

Actual NES/Famicom hardware can be modded to have RGB color rendering and output with any of the following PPUs:

-- Any of the Rx2C03x PPUs (available from Vs. Tennis, Vs. Duck Hunt, Vs. Ice Climber (JP), PlayChoice-10, and the Sharp C1 Television)

-- And the RC2C05-99 PPU (available from the Sharp Famicom Titler)

Because these are RGB PPUs, the colors are not the exact same as the regular PPUs of actual NES/Famicom hardware. However, in all Nintendo promotional material, screenshots of games were always taken with these RGB colors, making the color palette on these PPUs (which is the same between all of them) the "official" NES/Famicom RGB color palette.

My question is: Has anyone exactly replicated this color palette in an emulator? Alternatively, does anyone know where I can find exactly which colors are in this "official" palette so I can make a custom palette to use in an emulator myself?

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Quote:
Because these are RGB PPUs, the colors are not the exact same as the regular PPUs of actual NES/Famicom hardware. However, in all Nintendo promotional material, screenshots of games were always taken with these RGB colors, making the color palette on these PPUs (which is the same between all of them) the "official" NES/Famicom RGB color palette.


The RGB PPU's palette is not "official" in any way. First, several Playchoice 10 games (Punch-Out, Volleyball) actually select different colors to look better on the RGB PPU. If the RGB PPU were the official palette, there would not be a difference in the colors that the regular NES version uses (for NTSC output) versus the PC10 version.

Second: yes, the American "Nintendo Power" and the German "Club Nintendo" since 1990 used the RGB PPU to take screenshots, but those screenshots were then "corrected". For example, Metroid's Brinstar stage looks very greenish in the RGB PPU's palette, but was made to look bluer in most screenshots, because that's what the NTSC PPU outputs. They forgot to do that in a few pictures however, revealing the original rather ugly RGB PPU's palette.

Also, in Japanese television commercials, the game display is almost always visibily filmed off a composite TV.

There is no "official" palette, because every developer just chose the colors to look good on his TV, and there was a lot of variation in NTSC televisions in the 1980s, more than now. There just is not one palette OR setting for the NTSC filter that will make all games look right.

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Has anyone exactly replicated this color palette in an emulator?


Yes. Select "RGB" in Nestopia, that IS the RGB PPU's palette. smile

Beware though that it is designed for a monitor with a 9300K color temperature, so select that setting on your monitor if you can, otherwise the reds and browns will jump in your face.

If it then still looks different from that promotional shot you saw keep in mind what I told you about them being retouched.

Last edited by NewRisingSun; 04/02/08 10:03 PM.
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For games developed in the US, *the* developer monitor for NTSC-output games (including PS1/N64/Saturn) was the Commodore 1084/1084S and/or the Phillips equivalent, with the controls all set to the detents. So if you can find schematics for one, you can have a "what the developer saw" setting. (I would imagine for European-developed PAL games the PAL version of the 1084 was also popular, but I can't prove it).

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