Games that look better with Composite vs RGB colors

[turboxray]

The PCE video color chip has a special matrix translation rom, that takes the RGB values (3bits each) and uses this as in index into a table of YUV values (5bits each). Two colors spaces don't convert accurately with such low YUV color resolution (15bit color), so they interesting rounding choices in the colors for composite output. It's not just a 'composite' thing; it's a digital color conversion. It makes the PCE unique in this way compared to the SNES and Genesis. It also gives it a different "ramp" on the gamut of colors. Dark colors are less saturated, and upper bright end of the range is more compressed (it has more bright color 'resolution'). Since the PCE never officially did RGB options, I always had this suspicion that developers/artists did their work matching this custom YUV set and not just simply 9bit RGB. Also, just for the record, the Luma range for Japanese NTSC TVs is full 0 to 255, while the US/NA expects 16-235 (i.e. TV's are calibrate as so, so there's a slight miss-match when running PCE systems on US/NA TVs bitd). 


 The first offender is Bonk's Adventure. I remember playing the game on emulation thinking something was seriously wrong with his skin tone. And that some of the color were just darker and more contrast-y. In RGB, his skin tone like an over done trump spray tan. The greens are darker. The volcanos in the first level have darker bands (the colors don't blend as nice).  

 Games that use primarily darker colors suffer from this too. The dark colors are too saturated and the luma steps (brightness between the levels) in RGB mode. Dungeon Explorer, IMO, looks pretty bad in RGB colors. The 'dirt' colors look have an orange or whatever saturation to them, making them look bad in RGB. Newer games like Startling Odyssey 2 also look worse in RGB. I remember when I first played it via emulation, I thought the color choices were abysmal.. it was soft look, but muted and darker faded look. Playing it on the real system with composite, the game looks pretty good (the overworld, battle screen, etc). There's even some color bands in the sky of the battle screens that don't actually show up on RGB colors (it's hard to see). Other games that use that more 'soft' look, like Xanadu 2 overhead areas. Or games with brown colors for dirt (Bloody Wolf, Valis 3), or just some shades or blue/green/purple which blend a little different with PCE YUV table.


 I mean yeah some games suffer more than others in RGB mode, and some aren't so obvious. But with everyone doing RGB mods nowadays, I can't believe that I'm the only one to have noticed this - and even unhappy with it. I'm not so much a purist that minor differences make games unplayable, but there are some glaring examples out there. I mean after all if the artist's color choices were based on this, wouldn't you want to preserve that regardless of the output type (composite, RGB, hdmi, etc)? I've mapped out the Y stepping of the VCE to match the PCE. But I don't have all the values for U and V yet. No emulator gets this correct either (mednafen allows you supply you own 9bit custom RGB palette, for this support, but doesn't native emulate this). I guess most people don't want to sample the RGB values and convert to a correct YUV table of the VCE, but you know... Y/U/V *is* available separately on every PCE console. You literally have both s-video and component video right there! And with the correct PCE colors to boot. The PCE doesn't mix the components internally and it doesn't use some generic composite encoder. 

 Anyway.. anyone else notice these differences? What games stand out to you? 

Here's some example pics:

RGB demo: Y only (real system/ composite)


RGB: Y only (RGB)

RGB: full color


 The B&W images just shows you how bright/dark the color is. That's just the Y of YUV. There's similar 'stepping' happening on the U and V channels too! But the Y is easiest to show.

[Black_Tiger]

I've noticed that many/most games are a mixed bag and most games look nice in a different way in composite vs RGB.

The Gods of Lighting stage in FX Unit Yuki looks really nice in composite and benefits more than games like SO2 and LoX2. But it was made with RGB color in mind.

Given the low effort of the pixelart and so many visual elements that just don't make sense in SO2, I don't think that they were very concerned about how things would turn out through composite.

Since I first began noticing the positive aspects of many games displayed through composite, I've made the effort to try to play each game through in both RGB and composite, or at least switch back and forth now then.

[elmer]

Dec 9, 2019 16:32:30 GMT turboxray said:

Since the PCE never officially did RGB options, I always had this suspicion that developers/artists did their work matching this custom YUV set and not just simply 9bit RGB. Also, just for the record, the Luma range for Japanese NTSC TVs is full 0 to 255, while the US/NA expects 16-235 (i.e. TV's are calibrate as so, so there's a slight miss-match when running PCE systems on US/NA TVs bitd).

Back-in-the-day most Western artists would often check their work by looking at it on a TV, and then tweak things if necessary.

The difference between what the artist was seeing on their computer, compared to the actual composite-TV output of different consoles was a well-known issue.

OTOH, almost nobody had the luxury of enough development time to try to produce "perfection", there were always compromises, even when you had a team that deeply cared about the quality of their work.


I'm really curious about how much of an effect this phenomina that you're pointing out is going to effect the LoX translations, since considerable effort was put into tweaking both the LoX2 HUD and LoX2 map graphics to make them look less garish on modern RGB/LCD displays (the main game art was not altered).

Dec 9, 2019 16:32:30 GMT turboxray said:

I guess most people don't want to sample the RGB values and convert to a correct YUV table of the VCE, but you know... Y/U/V *is* available separately on every PCE console. You literally have both s-video and component video right there! And with the correct PCE colors to boot. The PCE doesn't mix the components internally and it doesn't use some generic composite encoder.

Ahhh ... I would love to have s-video output on my PCE/SuperGrafx consoles.

I have no particular desire for RGB or a modern super-sharp LCD display on these old machines, the art just wasn't designed for it ... you actually lose the blurring that the original developers designed their art for.

[gilbot]

The developers actually did care a lot about composite output, at least initially.
In the original Hu7 development system, when the base PC was a PC-9801 at least, it was chained up with an ordinary TV for debug purposes (I think they later changed the PC to a more available IBM PC compatible, especifically for western developers, in which case they might no longer attach the system to a TV).

In the official graphics editor DF (or CE as they were the same thing, with CE lacking Famicom support), there was a feature to output the image to the TV immediately, as seen from the "OUT" function in item 7 of the screenshot of this entry. Also, as described, the TV signal would be adjusted to the low-res or mid-res modes according to whether you clicked the left- or the right-mouse button, so the designers were certainly encourged to check how stuff actually looked like on a TV. (And as noted in the article, people not working with Hu7 may not be aware of this feature. The DF tool was pirated copied and used heavily by many designers back in the "16-bit" era because of its robustness, and some people used it to develope for the Mega Drive and they asked Iwasaki in person what that "OUT" thing was for. )

Later revision of the system might use an IBM-PC instead of PC-9801, as evidence by a IBM-PC version of CE.exe extracted from the Art of Fighting disc, and they might have removed that TV output feature (I don't remember whether this CE.exe has the "OUT" function in its UI), so people (especially western developers?) might care less about composite output.

One terrible offender was Loom^TM. The graphics actually looked horrible in composite as Lucasfilm Games might only care for RGB during development (OR, quite possibly, they also decided to port it to the MD/MCD initially like Monkey Island, as evidence by the "vertical line dithering" of the images which looked good on MD but horrible on PCE; If it was made with the PCE in mind, the graphics could look much better because of the better colour capability, not just the half-arse 64-colour "improvement" in the Final product EDIT: Checking the screenshots from mobygames it doesn't seem to be the case, as there seem to be more "horizontal line dithering" than vertical ones. Anyway this game didn't looks as well on a real TV compared to the clear emulator (i.e. "RGB") shots). What's worse? The texts in the Japanese version are unreadible on an ordinary TV, as they are thin¹, coloured² Japanese text on a rich background and the game used the mid-res³. This may not be the fault of the original western developers though, as the font for the original English texts had at least 2-pixel wide lines, which made them infinitely more readible.

As far as I remember (I'm too lazy to dig up old info to verify whether I am right here), they did also considered RGB at some points though. There was a plan for a RGB booster which outputs RGB when attached to the expansion port (like the original AV booster), but the idea was scraped like many other peripherals the PCE might get in their original plan. Maybe RGB was not popular enough in Japan to warrant its release, and maybe it's also due to them hitting a road block when considering monochrome mode of the system (Compare this with the Famicom, where they indeed had revisions for RGB output, which didn't support colour empharises fully and broke some games.)

[gredler]

Gilbot thank you so much for these links in your post! I am so excited to read through these.

[elmer]

Dec 16, 2019 8:07:24 GMT gilbot said:

Later revision of the system might use an IBM-PC instead of PC-9801, as evidence by a IBM-PC version of CE.exe extracted from the Art of Fighting disc, and they might have removed that TV output feature (I don't remember whether this CE.exe has the "OUT" function in its UI), so people (especially western developers?) might care less about composite output.

The "Hu7 System2" development system for the IBM PC and Western developers definitely had the "OUT" function in CE ... it's in the documentation.

That doesn't mean Western artists in the 1990s necessarily used it a lot.

3rd-party console development teams (i.e. all Western TurboGrafx developers) have often had problems either getting access to, or affording, development hardware especially for artists (as opposed to programmers).

That didn't seem to change much until the 6th or 7th generation consoles.


I still have a box full of "Doctor V64 Jr" junior cartridges in the garage, because that mostly-used-for-piracy device was the only *affordable* way for us to lets artists see their work on an N64!

[turboxray]

I just got my PCIE-1x capture card that I ordered. So I'll post some screen shot comparisons soon.

[gredler]

Dec 16, 2019 18:24:58 GMT elmer said:

3rd-party console development teams (i.e. all Western TurboGrafx developers) have often had problems either getting access to (or affording) development hardware, especially for artists (as opposed to programmers).

That didn't seem to change much until the 6th or 7th generation consoles.

I still have a box full of "Doctor V64 Jr" junior cartridges in the garage, because that mostly-used-for-piracy device the only *affordable* way for us to lets artists see their work on an N64!

I remember lines forming behind the 3DS and PSP devkits to check our work. It looked significantly different on the consoles (especially 3DS, obviously) so we had to often go to programmer's offices to check our builds and do personal art review before going to directors who were using it constantly. I think we had 4 kits to ~50 people?

I could definitely see how western developers had it even harder the further back you go in time.


Still very interesting to read and learn about, great thread!

[Black_Tiger]

Keep in mind that while looking at their games running on a TV, most developers of games running in 256 pixel wide resolution completely ignored aspect ratio.

They were likely more concerned with how well text and visual elements read on-screen and looking things that just got lost in the overall picture through composite or RF.

It would be cool if any interviews turn up with devs specifically talking about tailoring for composite.

[turboxray]

I was messing around with the capture card today:

Left: YUV, Right: RGB




I already knew that bightness of colors has a different gamut in the VCE YUV table than RGB, but there are also some colors on the VCE YUV output that almost near invisible. I usually find them in the blue area, but was surprised to find the above (circled area). The arrow just points to the tell tale brightness gamut of the PCE compared to straight RGB. I the red range, orange is definitely subdued (one of the reason the first Bonk game appear more orange in RGB than the YUV). Orange tends to seep into some of the warm browns, making them appear more contrast-y in RGB (I'll find some games to show this off). For the record, I have the saturation set higher than default for the composite capture, so differences are easier to compare (rather than saturation itself being a distraction).

[turboxray]

Here's an example of the brightness shift; from mid way, grays are closer together, and colors in the very bright spectrum are too (it makes it so the saturation is as contrast-y). The clouds shows this off. RGB is on the right.

[samiam]

Good to see you around, Tom.

This is really interesting, and you've made a good case for the PCE's native YUV being superior to its RGB.

Xanadu 2 certainly struck me as looking better in composite, and for a game that IMHO has the best art on the system, that's a pretty remarkable thing. The overworld sections make heavy use of dithering in places, not with two-color checkerboards but with more complex speckle-patterns like the clouds in the 1941 shot you posted. When I saw it in RGB for the first time, I thought these places looked just a bit too coarse, and indeed it might actually be this RGB-YUV conversion issue that's the key difference (and not the usual fidelity loss of composite video).

Having gone down the video-quality rabbit hole myself, I've often reflected that there really is no blanket "best format" for any game system. It depends on user preferences and even individual games. Personally, I find the shimmering and dot-crawl in the PCE's native composite so distracting that I can't imagine going back to it. On that note, there is one floor in Anearth Fantasy Stories that shimmers so badly with horizontal scrolling, it makes you wonder whether anyone evaluated it on a TV during development at all. (I wish I could find a clean screenshot of it to share, but I can't at the moment.)

Is the total number of available colors still the same in the PCE's YUV colorspace? I ask because it seems to me that if two colors that are different in the system's RGB colorspace come out the same in YUV, then an artist who used both of those RGB colors at once was probably designing mostly around RGB.

Anyway, I've got a spare white PCE sitting around, and it's tempting to open it up and try a YUV mod. Has anyone ever actually done that? I wonder if the amplifier circuit would require any special considerations?

[turboxray]

Dec 21, 2019 3:51:41 GMT samiam said:

Good to see you around, Tom.

This is really interesting, and you've made a good case for the PCE's native YUV being superior to its RGB.

Xanadu 2 certainly struck me as looking better in composite, and for a game that IMHO has the best art on the system, that's a pretty remarkable thing. The overworld sections make heavy use of dithering in places, not with two-color checkerboards but with more complex speckle-patterns like the clouds in the 1941 shot you posted. When I saw it in RGB for the first time, I thought these places looked just a bit too coarse, and indeed it might actually be this RGB-YUV conversion issue that's the key difference (and not the usual fidelity loss of composite video).

Having gone down the video-quality rabbit hole myself, I've often reflected that there really is no blanket "best format" for any game system. It depends on user preferences and even individual games. Personally, I find the shimmering and dot-crawl in the PCE's native composite so distracting that I can't imagine going back to it. On that note, there is one floor in Anearth Fantasy Stories that shimmers so badly with horizontal scrolling, it makes you wonder whether anyone evaluated it on a TV during development at all. (I wish I could find a clean screenshot of it to share, but I can't at the moment.)

Is the total number of available colors still the same in the PCE's YUV colorspace? I ask because it seems to me that if two colors that are different in the system's RGB colorspace come out the same in YUV, then an artist who used both of those RGB colors at once was probably designing mostly around RGB.

Anyway, I've got a spare white PCE sitting around, and it's tempting to open it up and try a YUV mod. Has anyone ever actually done that? I wonder if the amplifier circuit would require any special considerations?

There's no duplicate colors in either set; RGB and YUV each have unique set of 512 colors. It's just that in 9bit RGB space, certain colors range from almost indistinguishable to little-more-so but pair don't pair as well with other colors. Overall, the whole palette from the VCEs YUV set is leans more cooler (towards blue/green) and a shaper brightness ramp than straight RGB space. But I can't imagine them not testing on regular units (with an NTSC) at some point (for art review).

I also realized that showing these screens shots, it's gonna look different depending on the display because I seriously doubt anyone is running color correction profiles against their monitors (I'm not haha). For instance, I use my 65" 4k TV as my monitor for my PC and it has much more saturation than my Macbook pro display (in which the above differences of Jupiter don't look so striking) - the laptop has less contrast and a softer look than my TV.

I'm also with elmer on the analog filter look. I'm not a fan for that hard-sharp pixel look. If I ended up doing an RGB mod, I'd most certainly add a couple of caps to the RGB lines to get a slight filter effect. Svideo would be perfect though; no dot crawl but you have some analog filtering on the chroma channel (you could even add a cap to the Y channel if it's too shape). I had an HDTV years ago that I used to run my systems on (rear projection), and the comb filter on that thing was so impressive that the pixels looks straight RGB square from a composite signal (but only on the PCE, not so much on the SNES and definitely not on the MD haha). Sadly, my new TV doesn't have an svideo port though.

[samiam]

Dec 21, 2019 14:00:39 GMT turboxray said:

There's no duplicate colors in either set; RGB and YUV each have unique set of 512 colors. It's just that in 9bit RGB space, certain colors range from almost indistinguishable to little-more-so but pair don't pair as well with other colors. Overall, the whole palette from the VCEs YUV set is leans more cooler (towards blue/green) and a shaper brightness ramp than straight RGB space. But I can't imagine them not testing on regular units (with an NTSC) at some point (for art review).

Gotcha. Thanks for confirming that.

With that Anearth Fantasy Stories floor, it could just be that they tested the still graphic in NTSC but didn't see how much shimmering it caused in when it moved until it was too late. Or perhaps they simply didn't mind anyway.

I also realized that showing these screens shots, it's gonna look different depending on the display because I seriously doubt anyone is running color correction profiles against their monitors (I'm not haha). For instance, I use my 65" 4k TV as my monitor for my PC and it has much more saturation than my Macbook pro display (in which the above differences of Jupiter don't look so striking) - the laptop has less contrast and a softer look than my TV.

The brightness ramp factor stands out a lot to me on the monitor I'm using. That alone makes a strong case for switching to YUV as far as I'm concerned.

If you can pin down all the values for the PCE's digital YUV colorspace, and if it's easy to plug those into Mednafen, I bet a lot of people would jump to do some comparing, myself included. For those with an AMD graphics card on their PC, there is a custom fork of Mednafen that lets you output 15kHz via CRT_Emudriver, making it possible to use SD-CRTs for the comparison.

I'm also with elmer on the analog filter look. I'm not a fan for that hard-sharp pixel look. If I ended up doing an RGB mod, I'd most certainly add a couple of caps to the RGB lines to get a slight filter effect. Svideo would be perfect though; no dot crawl but you have some analog filtering on the chroma channel (you could even add a cap to the Y channel if it's too shape). I had an HDTV years ago that I used to run my systems on (rear projection), and the comb filter on that thing was so impressive that the pixels looks straight RGB square from a composite signal (but only on the PCE, not so much on the SNES and definitely not on the MD haha). Sadly, my new TV doesn't have an svideo port though.

If you're upscaling the picture to a modern display that would turn the pixels into neat little rectangles, I'd agree about implementing a filter (although you might have better success with something digital over caps on the analog lines). On the other hand, if you're running RGB on a CRT, the screen itself does a pretty good job of softening things. Here is an enlargeable section of a shot I took some while ago of Sonic CD in RGB on a 700TVL broadcast monitor. I personally like the way the pixels look very much.

Long ago, I switched an SNES, Saturn and Playstation from s-video to YUV all at once when I bought an RGB-YUV converter. What I remember concluding at the time is that the clarity wasn't helped so much as the harmony of the colors. That's vague, I know, but the colors coming out better is why I'd prefer to do a YUV mod to an s-video mod on a PCE.

Anyway, by all means, please keep investigating this. If you or anyone else worked up a detailed article about it, I bet it would make some waves in the wider retro-gaming community.

[keithcourage]

This is why I prefer S-video. Keeps the colors looking like composite but with a sharper more clear image. JJ and Jeff looks horrible in RGB/component because their faces look super red. Pretty much any game with characters that have high amounts of skin colors look bad in RGB. Bonk looks super Red in RGB as well. Not cool.