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Why is the composite video so crappy on Sega consoles?


MaximRecoil
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I'm very disappointed with the composite video from both of my Sega Genesis Model 1 consoles; it is not significantly better than RF from the same consoles. It doesn't have the slight RF interference patterns, but it isn't noticeably sharper/clearer than RF. Both of my Sega Dreamcasts are the same way, but since it has far more advanced graphics, it isn't as noticeable. In fact, the poor composite video quality isn't terribly noticeable even with the Genesis' typical "16-bit" graphics games, but it is very noticeable with e.g., Frogger (which has the same primitive graphics as the 1981 arcade game).

 

I have an NES emulator disc (NesterDC) for the Dreamcast, and when playing that, the bad composite sticks out like a sore thumb. Here is a comparison:

 

Super Mario Bros. on the Dreamcast (composite video):

 

tGqLJqo.jpg

 

VyqpGeN.jpg

 

Super Mario Bros. on the NES (front-loader, composite video):

 

YpAfRDf.jpg

 

Wylcgyk.jpg

 

The composite video from my Nintendo consoles (I have a few NES front-loaders and a couple of first-generation SNESes) is excellent, so good that I don't really feel the need to try to improve it (such as with RGB or component video modifications).

 

Come to think of it, the composite video from both of my Sony PlayStations is crappy too, and like the Dreamcast, it is only really noticeable when playing games with primitive graphics (such as Namco Museum). Was Nintendo the only console manufacturer to get composite video right?

Edited by MaximRecoil
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Yeah, something like an NES emulator in 480i with bilinear filtering is bound to look a bit blurry on the DC =)

 

There's a handful of 240i (or p?) 2D games on the DC that look really sharp, with scanlines and everything. Most of them are Capcom games (I think Street Fighter Alpha 3 and SF III Third Strike support it), but there are a few others, like Bangai-O.

 

I've never compared RF to composite on the Genny, but I know composite video on the model 1 looks way better than on the model 2.

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Funny, I always found the Sony PS1 and PS2 composite to be really solid (and it come from someone who have RGB SCART on all systems that support it, so it dos say something) but maybe PAL composite encoders in Sony console were better than their US counterparts.

The GameCube also have excellent composite... but the N64, gosh! blurry madness! I can't even play a N64 game just for that.

 

On the Sega systems, I can't say anything - I never had a composite cable for my Dreamcast, and to save money (I assume), the French Master Systems and Megadrive model 1 doesn't even have composite encoders - that's right, I have no choice but to use RGB :D

 

SMS%20switch_zpsfpilsqah.jpg

 

The existing RF hole is obtured with a thick stiky paper, making it the ideal place for a 50/60htz switch, as pictured here. Only on French SMS :D

 

(BTW, the SMS II French model also have RVB out, no RF or composite as well - seems we were the only country where they did that)

 

KMD_Back.jpg

(this is apparently the back of a Korean unit, but this is looking the same on my console - explains me how Sega made it tho, as designing a shell for only one market would have been too costly, apparently the Japanese systems had no RF either, but a separare RF transcoder could be obtained).

 

I remember trying the composite out on a Super Nintendo because I had nothing but a N64 cable.. It was okayish but nothing outstanding either. Maybe on the other hand Super NES PAL encoders weren't extraordinary, or once you tasted RGB on such systems you can't go back :D

Edited by CatPix
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Yeah, something like an NES emulator in 480i with bilinear filtering is bound to look a bit blurry on the DC =)

 

Are you sure it's 480i? Interlaced vs. progressive doesn't make a difference in the context (i.e., blurriness, which is a matter of color separation), but the Dreamcast can output ~240p (though it usually didn't). Whoever wrote the emulator should be using 240p. And are you sure it is scaled (bilinear filter)? There's certainly no need for scaling; the native resolution of NES games is already in the 15 kHz range, which is what the Dreamcast outputs by default (though it can also output "VGA", i.e., ~31 kHz, but not over composite of course). If this emulator is written in such a way that it is scaling the NES games telling the Dreamcast to send a 480i video signal, then that's ridiculous.

 

Edit: I just turned on the NesterDC disc again to check, and it is definitely interlaced (480i), both the menus and the gameplay (which are equally bad). That sucks, and there's no need of it. I doubt anything's being scaled/filtered though.

 

 

There's a handful of 240i (or p?) 2D games on the DC that look really sharp, with scanlines and everything. Most of them are Capcom games (I think Street Fighter Alpha 3 and SF III Third Strike support it), but there are a few others, like Bangai-O.

 

I have SFIII: Third Strike, and I never knew about the 240p option. There are instructions for enabling it here. I'll have to give that a try. As for "240i", there's no such thing, at least not as a standard. A standard resolution TV wouldn't be able to sync to 240i. They are designed to sync to a roughly 15 kHz signal, which is roughly 240p or 480i. 240i would be about an 8 kHz signal.

 

Edit 2: Those instructions work, and it is a definite improvement. I didn't think it worked at first, because I was holding the two buttons down before I turned on the Dreamcast, and when I got to the game, it was still interlaced as usual. You have to press and hold the buttons just after turning the Dreamcast on. Also, if you make a save on the memory card after doing it, it saves 240p mode so you don't have to hold those two buttons down every time you start the game.

 

I've never compared RF to composite on the Genny, but I know composite video on the model 1 looks way better than on the model 2.

 

The model 2 must look horrible then. One of my model 1s has a VA7 motherboard, which supposedly has the best video output of any of the revisions (and the worst audio). It is passable with a typical Genesis game (but not nearly as good as the SNES's composite video), but it is utter crap with Frogger. The simpler the graphics, the more obvious bad color separation (blurriness) becomes. I have some games with primitive graphics for the SNES too (Williams Arcade's Greatest Hits with Defender, Stargate, Joust, etc.), and those look good over composite. I have an S-video cable for the SNES too, and while it is an improvement over composite, I have to get up really close to the TV to see the difference.

 

or once you tasted RGB on such systems you can't go back :D

 

I love RGB. I have 4 arcade machines, 3 of which have monitors that I bought brand new (and they are still like brand new). Like all (or practically all) color arcade monitors from the '70s to the mid '00s, these are 15 kHz RGB CRT monitors, and they are beautiful. However, RGB isn't as important to me for a console, because I'm 11 feet away from the TV as opposed to right up close when playing an arcade game. Good composite like from the NES and SNES is perfectly acceptable, though it would never cut the mustard in an arcade machine. These other consoles on the other hand, are pretty bad. I'd have to be so far away that I could barely see what's happening on the screen before I wouldn't be able to notice the blurriness of the Genesis' composite video.

 

As for the PlayStation, have you ever played e.g. Namco Museum on it? Pac-Man and other games from that era are rather blurry over composite, at least it is on my U.S. NTSC models.

Edited by MaximRecoil
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As for the PlayStation, have you ever played e.g. Namco Museum on it? Pac-Man and other games from that era are rather blurry over composite, at least it is on my U.S. NTSC models.

Not on PS1, I only found those kind of compilations for PS2. And those days my PS2 in on component, and from day one when I got my PS2 new back in 2001, I hooked it up with RGB so can't tell you much about.

To me, I can tel lthe difference between composite, as the picture is definitively brighter and also more "shaky" (as the color always blur a bit on the edges ov vertical lines on menus).

Tho I more play like 1.5/2 meters away from my TVs, and they are 43 and 54cm TV, not small 36cm where is would be less noticeable.

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Why is the composite video so crappy on Sega consoles?

 

 

This question implies that all Sega consoles have crappy composite video. I disagree with that premise. I own several Sega consoles and the composite video is no worse on them as a whole than any other system.

 

My experience is that individual consoles sometimes have not aged well.

  • The video on both SMS consoles I currently own is good and there is no discernable difference between them.
  • Out of the 4 Genesis consoles I currently own, one has video that is screwed up via both RF and composite. The other 3 look the same. I bought the system with crappy video in 2008 so I don't know if it was always that way or simply got worse with age.
  • Out of the 5 Dreamcast consoles I currently own, one of the consoles has distorted, almost weak video. This is also deterioration from age because that same console looked great several years ago.

My experience with Sega consoles isn't different from my experience with other console manufacurers. I've had just as many Nintendo consoles display bad video with age. Aging or bad capacitors are usually the problem.

 

It is also my experience that video adapters are far more likely to be a problem than the consoles. The Dreamcast specifially suffers from bad adapters, especially the Mad Catz which I've had several bad ones.

 

Admittedly my experience is anecdotal, however I still don't think it valid to say that a majority of Sega consoles have bad composite video.

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Your running a Emulator ..Run a DC Game

 

I do run DC games, which I've already mentioned in this thread. I've also mentioned that bad composite is more noticeable with primitive graphics, which NES games have and DC games don't have. The emulator is also the only way to compare it directly to the composite video of the NES, since I can run the same game. Whether or not it is an emulator doesn't matter; it uses the same video output hardware either way. It would make a difference if the emulator is applying a bilinear filter to the game, but I highly doubt that it is. Not only would doing so require more resources, but there would be no need for it, because NES games are already SD, just like the DC is. Scaling with a bilinear or similar smoothing filter is often used by emulators running on a PC because they are being output to a high resolution display, and if they didn't scale the output, it wouldn't even come close to filling the screen. Most emulators allow you to scale with or without a smoothing filter.

 

 

 

This question implies that all Sega consoles have crappy composite video. I disagree with that premise. I own several Sega consoles and the composite video is no worse on them as a whole than any other system.

 

My experience is that individual consoles sometimes have not aged well.

  • The video on both SMS consoles I currently own is good and there is no discernable difference between them.
  • Out of the 4 Genesis consoles I currently own, one has video that is screwed up via both RF and composite. The other 3 look the same. I bought the system with crappy video in 2008 so I don't know if it was always that way or simply got worse with age.
  • Out of the 5 Dreamcast consoles I currently own, one of the consoles has distorted, almost weak video. This is also deterioration from age because that same console looked great several years ago.

My experience with Sega consoles isn't different from my experience with other console manufacurers. I've had just as many Nintendo consoles display bad video with age. Aging or bad capacitors are usually the problem.

 

It is also my experience that video adapters are far more likely to be a problem than the consoles. The Dreamcast specifially suffers from bad adapters, especially the Mad Catz which I've had several bad ones.

 

Admittedly my experience is anecdotal, however I still don't think it valid to say that a majority of Sega consoles have bad composite video.

 

I'm not talking about screwed up composite video; I'm talking about low quality composite video, i.e., there's nothing wrong with the consoles, but the composite video isn't as "sharp" as it could be (the NES and SNES being examples of how good composite video can be).

 

Here's Frogger on my VA7 Genesis, composite video:

 

zvjH72v.jpg

 

Note the general indistinctness of sprites / graphical objects. The large home base frogs look like indistinct lumps, as does the "lady frog" on the log.

 

Here's the same Genesis, RF video:

 

iXo7CKP.jpg

 

There's very little difference. The main difference I can see in person (which doesn't show up in the picture) is that the RF video has slight constant random-motion RF interference patterns noticeable in the lighter colored areas (especially blue), which is always present to one degree or another in RF video. The composite video doesn't have any RF interference at all of course.

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Funny, I always found the Sony PS1 and PS2 composite to be really solid...

On my PSX, the colors are way oversaturated, especially reds. I have to turn down the "color" setting on my TV.

I have a PSone and the colors are just fine.

 

Maybe I just have a defective unit? I tried searching online and couldn't find any other mention of this issue.

 

There's certainly no need for scaling; the native resolution of NES games is already in the 15 kHz range...

Except NES's resolution isn't 640x480 =) Or even 4:3, so it has to be scaled.

 

As for "240i", there's no such thing...

Yeah, I remember someone mentioning before that it's 240p, but I wasn't certain.

 

The model 2 must look horrible then. One of my model 1s has a VA7 motherboard, which supposedly has the best video output of any of the revisions (and the worst audio). It is passable with a typical Genesis game (but not nearly as good as the SNES's composite video), but it is utter crap with Frogger.

Do you mean the horizontal blurring?

 

In a lot of games, it doesn't look that great, but there are some games that take advantage of it. They use it like "artifacting", to create the illusion of there being more colors than the Genesis palette allows. Or to fake translucent effects.

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Except NES's resolution isn't 640x480 =) Or even 4:3, so it has to be scaled.

 

That isn't how it works with an analog video signal. A digital resolution such as 640 x 480 or 256 x 240 only exists in the digital domain. An analog video signal doesn't consist of a grid of pixels, nor pixels at all. A composite video signal has to conform to the NTSC standard (or be compatible with it), and a device can form an NTSC [compatible] video signal from any digital resolution, no scaling involved. This is why a typical DVD player can properly display a DVD (720 x 480) or a VCD (352 x 240) on the same TV. No scaling/filters are used. Note that neither of those resolutions seem to be 4:3, but they actually are, because they don't use square pixels (i.e., their pixel aspect ratio [PAR] is not 1:1). The same applies to the NES and plenty of other platforms.

 

I have a little box made by Western Digital which can display video of any resolution of 1920 x 1080 or less ("widescreen" resolutions display as letterboxed on a 4:3 TV), and it doesn't scale anything either, it just gets directly converted to an NTSC composite video signal regardless of what its original digital resolution was.

 

With that said, I don't know the specifics of the Dreamcast's digital-to-analog video converter. It may be made in such a way that it is only expecting a digital input resolution of 640 x 480, in which case NES games would have to be scaled before being sent to it, though bilinear isn't necessary. "Nearest neighbor" type scaling could be used, which doesn't affect the "sharpness" at all, like bilinear, lanczos, etc., does, because it is just pixel duplication, nothing more (no anti-aliasing/smoothing filters are used). For example, this is the raw 256 x 240 NES digital video:

 

jtvVfaE.png

 

This is what it looks like resampled ("scaled") to 640 x 480, without any anti-aliasing/smoothing filter (i.e., "nearest neighbor"). You'll have to click on it to see at the full 640 x 480 resolution, because, annoyingly, the forum software here automatically resizes images down to 600 pixels wide, and it uses a bilinear or bicubic filter to do so, thus ruining what I'm trying to show. 600 pixels wide is a ridiculous limitation; it should be at least 640, since 640 is a standard, and 600 is not, and it is not as if the extra 40 pixels are a big deal to display, especially these days. In fact, a better limit would be 800 or even 1024 pixels wide, because practically everyone runs a high enough desktop resolution now to accommodate it without having to scroll side to side.

 

oTNohJf.png

 

This is what it looks like resampled to 640 x 480 with a bilinear filter:

 

mJPKBjl.png

 

As you can see, bilinear gives it a "Gaussian blur" effect, while "nearest neighbor" doesn't add any effects at all; it is no different than looking through a magnifying glass. If scaling has to be used on for NES games on a Dreamcast (and I'm not sure that it does), then it should be using "nearest neighbor" type scaling, because that uses less resources and looks better when displayed on a TV.

 

Edit: This is interesting. Based on that thread, it looks like it does resize to 640 x 480 and use bilinear filtering to do so, but apparently, the bilinear filtering can be turned off (though I don't know how to do so [Edit 2: I found the option to do so; it looks a little better but still not nearly as good as the NES; 240p would help a bit more, but the DC's composite video simply isn't as good as the NES's]). Also from that thread:

 

Thanks for the link! Someone says that, in theory, DC should be capable of pushing the real native NES resolution. I really wish the NesterDC author would look into it. It would make the games look exactly like they do on a real NES. No ugly stretching, flickering, or blurring.

 

Ah well...

 

I agree with that guy.

Edited by MaximRecoil
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Someone says that, in theory, DC should be capable of pushing the real native NES resolution. I really wish the NesterDC author would look into it.

The only homebrew I know of that actually does that is on the Wii.

 

I know there was a thread at the NESDev forums where they were discussing how to do it on the DC, and trying to figure out how to do it on the XBox, but nothing much came of it.

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  • 4 weeks later...

I agree that Genesis / MD have really bad composite video output. And I think it is actually the same signal used for RF out too, hence the similar quality. For instance on my Mega Drive II VA0 there is Fujitsu MB3514 video encoder and... nothing else than RGB is acceptable.

 

Also, that Dreamcast emlator seems to be outputting an interlaced image hence the totally wrong visual experience. Old school gaming need 240p video modes. That's why running emulators on Xbox (which cannot output 240p at all) does not make real sence to me.

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Sega used off the shelf parts and farmed out manufacturing, leading to sub par video and audio encoders on many units.

 

There's a detailed thread at Sega-16 showing the difference between the various board revisions and models: http://www.sega-16.com/forum/showthread.php?7796-GUIDE-Telling-apart-good-Genesis-1s-and-Genesis-2s-from-bad-ones

Edited by Gentlegamer
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I agree that Genesis / MD have really bad composite video output. And I think it is actually the same signal used for RF out too, hence the similar quality. For instance on my Mega Drive II VA0 there is Fujitsu MB3514 video encoder and... nothing else than RGB is acceptable.

 

Also, that Dreamcast emlator seems to be outputting an interlaced image hence the totally wrong visual experience. Old school gaming need 240p video modes. That's why running emulators on Xbox (which cannot output 240p at all) does not make real sence to me.

 

The Xbox can output 480p (and even 720p with a modded interface I think) so while a 240p mode isn't possible, a progressive display is.

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I do not need 480p to play 15 kHz 240p games. Absolutely not.

 

Also, it's ridiculous to think I am going to collect dozens of console revisions to match someone's "recommendations" to find out I have a different view. Sega did what they did. I still find my VA0 board pretty much OK and have no need to hunt for another one. It plays, looks and sounds authentic and exactly like it should.

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The good thing about the main models of the Genesis, the Model 1 and 2, is that RGB is at the port without any mod. If you want your RGB, then go grab a Genesis SCART cable and (1) your SCART-input capable TV, (2) your SCART-to-Component converter and your 240p Component capable TV, or (3) your Framemeister and your HDTV with HDMI connector.

 

The Sega Genesis is well known for artifact composite color, and many companies took advantage of this to ease the palette restrictions. The waterfalls in Sonic look much more like water than columns of alternating blue-white pixels. The palm leaves in Sonic 2 have a translucent appearance where they would be just alternating lines. Earthworm Jim uses the effect extensively to smooth the backgrounds. The Genesis is nowhere near as sharp as the NES, otherwise these effects just would not work. So you have a tradeoff.

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The good thing about the main models of the Genesis, the Model 1 and 2, is that RGB is at the port without any mod. If you want your RGB, then go grab a Genesis SCART cable and (1) your SCART-input capable TV, (2) your SCART-to-Component converter and your 240p Component capable TV, or (3) your Framemeister and your HDTV with HDMI connector.

 

The Sega Genesis is well known for artifact composite color, and many companies took advantage of this to ease the palette restrictions. The waterfalls in Sonic look much more like water than columns of alternating blue-white pixels. The palm leaves in Sonic 2 have a translucent appearance where they would be just alternating lines. Earthworm Jim uses the effect extensively to smooth the backgrounds. The Genesis is nowhere near as sharp as the NES, otherwise these effects just would not work. So you have a tradeoff.

 

Pretty much this.

 

Sega used cheap composite encoders for the SMS and Genesis, and the original Japanese systems as well. I have no idea how well it looks in PAL land, but for NTSC land composite encoder has this nasty artifact when scrolling (and I'm not talking about the rainbow artifacts either). It's apparent on certain colors than others, because the TVs can't pull out the color detail from the signal properly. Later on, developers started relying on the crappy composite chip to pull off color blending. You don't see this in first generatio titles. I guess said developers just ignored people with RGB setups (games that go overboard look like a terrible mess of dithering and alternating lines on RGB setups).

 

To the original poster; get your Sega 16bitter modifed for s-video or a different encoder chip. It's worth it.

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Another example, check out the tubes in the Chemical Zone in Sonic 2. In composite, they look like a glass tube, with a nice transparency effect when Sonic spins through them in a ball. With S-Video (mod) or RGB, they look like alternating light gray lines.

post-4291-0-83014800-1446126024_thumb.png

Edited by Great Hierophant
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Another example, check out the tubes in the Chemical Zone in Sonic 2. In composite, they look like a glass tube, with a nice transparency effect when Sonic spins through them in a ball. With S-Video (mod) or RGB, they look like alternating light gray lines.

That's cause they are light gray lines

 

I agree that color artifacting on the genesis is a big deal, drives me knuts when I play genny games on xbox with component output and running 720p (or the PC for that matter)

Edited by Osgeld
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Interesting example. Make me better understand some design choices on some games. Here, Megadrive model 1 were shipped without composite chip encorders, so we were "forced" (oh the tragedy :D) to use RVB.

Edited by CatPix
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Another example, check out the tubes in the Chemical Zone in Sonic 2. In composite, they look like a glass tube, with a nice transparency effect when Sonic spins through them in a ball. With S-Video (mod) or RGB, they look like alternating light gray lines.

 

That's a good example of how crappy the Genesis' composite video is. A good composite signal is close in quality to S-video (with my SNES I have to look very closely to tell the difference between composite and S-video; they are both excellent), whereas with the Genesis, you can see a drastic difference between the two, and the difference is not just in the glass tube effect.

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That's a good example of how crappy the Genesis' composite video is. A good composite signal is close in quality to S-video (with my SNES I have to look very closely to tell the difference between composite and S-video; they are both excellent), whereas with the Genesis, you can see a drastic difference between the two, and the difference is not just in the glass tube effect.

 

Even though the composite video from the Genesis is generally poorer than the SNES, still it can be useful as demonstrated with that screenshot. Don't forget that the Genesis is using a 320x224 resolution here and most Genesis games use that resolution, almost all SNES games use 256x224. When 256 pixel modes are used, whether on the NES, SMS, Genesis, TG16 or SNES, this artifact color is usually not seen. When the SNES uses a higher resolution mode like 512x224, a similar transparency effect is present. Look at the screenshots of Kirby's Dreamland 3 here for examples : http://nerdlypleasures.blogspot.com/2015/03/the-case-for-composite.html

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