Comp2RGB vs Component vs RGBs

[Virtual_Tintin]

hey !

I have all my consoles rgbs plugged (c-sync), except two : original xbox and gamecube. both are plugged in component (oem component cable for gamecube, and monster component cable for xbox).
I use a sony bvm multiformat monitor, so I can plugged either component or rgb.

as I want to have a full rgbs c-sync setup, I wonder if using a comp2rgb adapter from retrotink will allow me to have a better quality picture for 480p, and a compatibility with extron crosspoint which handle c-sync only ?

besides, how a comp2rgb compares with a "true" rgbs modification, as I did for my ps2 with this mod, to display 480p in rgbs : http://www.dansprojects.com/ps2sync.html ?

is it better to do a "true" rgbs modification on the component gamecube cable like that : https://gamesx.com/wiki/doku.php?id=av:gamecube_rgb (is it possible for xbox too ?), or it will be the same using comp2rgb ?

thanks all !

[beharius]

I highly recommend modifying that component cable for the VGA output. We modified many of them before and the image looks way sharper than the component. Back in the day It's very popular in Europe to modify them for the Scart output as these NTSC GC consoles can't output Scart RGB .
For the XBOX, I can recommend our VEDUSA VGA box which can convert to RGBHV and RGBS. If you prefer to use your Monster cable then our GARO Lite can convert it to RGBHV/RGBS too. I prefer RGB more as my display monitor handles it better.

[Josh128]

Even on a VGA monitor, I see zero difference between a PC outputting native VGA running Dolphin GC games at 480p vs a real GC with OEM component cables outputting progressive scan. Can you show some image evidence for this?


OP, to answer your original question, converting YPbPr to RGBS via a transcoder will not improve video quality in any case. Even from a native source, there is essentialy zero difference from YPbPr to RGBS signal.

[orange808]

Adding color space conversion to the chain has the potential to damage the signal. I can't think of any ways it would enhance your video quality, unless your specific display struggles with YPbPr or RGB. That would be an edge case.

[matt]

Even on a VGA monitor, I see zero difference between a PC outputting native VGA running Dolphin GC games at 480p vs a real GC with OEM component cables outputting progressive scan. Can you show some image evidence for this?

I have a modded GC component cable - I installed a switch to select between YPbPr and RGBHV modes. That was back when they were $30 each and I had no idea I'd be ruining its resale value!

I've used this cable on several monitors that are compatible with both output modes, in both 480i and 480p. There's no difference in image quality between YPbPr and RGB. Any perceived difference is most likely due to using the system on different displays.

The Gamecube itself has a 4:2:2 YCbCr frame buffer which is converted to RGB if you mod the cable. So you still get chroma artifacts either way.

[Josh128]

Even on a VGA monitor, I see zero difference between a PC outputting native VGA running Dolphin GC games at 480p vs a real GC with OEM component cables outputting progressive scan. Can you show some image evidence for this?

I have a modded GC component cable - I installed a switch to select between YPbPr and RGBHV modes. That was back when they were $30 each and I had no idea I'd be ruining its resale value!

I've used this cable on several monitors that are compatible with both output modes, in both 480i and 480p. There's no difference in image quality between YPbPr and RGB. Any perceived difference is most likely due to using the system on different displays.

The Gamecube itself has a 4:2:2 YCbCr frame buffer which is converted to RGB if you mod the cable. So you still get chroma artifacts either way.

This is correct.

[Virtual_Tintin]

first of all, thank you guys for your precise answers, that's a big help !

so, there are some conflicting opinions, but consensus says there will be no improvement in modifying oem component gamecube's cable to rgbs.

my bvm supports component as well as rgb, it's just I'm a rgbs' fan lol, so I was wondering about the only two consoles still connected in component in my setup; I supposed there was probably no better connection for these two consoles to display 480p, but I wanted to get some expert opinions. it's certain doing a whole bunch of modifications or conversions for, at best, an identical result, isn't desirable. so, for gamecube, I'll stay plugged in component

but what about xbox ? same thing as for gamecube ? there isn't anything better than direct component's connection ? and for those who have tested both, have you see a quality difference in picture between a direct plug with a premium component cable, as monster one, and a combo "official high definition av pack + premium component cable" ?

[Konsolkongen]

I can also confirm that there is no difference in picture quality between normal YPbPr and modded VGA with the official GameCube component cable.

[Gara]

I have a COMP2RGB in my own setup and I do not notice any lose in quality. I'm sure something is lost by adding this device to the video chain, but it doesn't appear to be anything that I can actually see.

My use case is similar to yours, but my main setup is gscartsw based rather than Extron. My goal is to have an all RGB automatic switching setup and I use the COMP2RGB for Gamecube and a PSPGo. I don't imagine you'd have any trouble looping the COMP2RGB in to your Extron setup. It won't be improving the video on anything, but it is much more convenient to have everything end in RGB. All my CRT's are either RGB and/or make it annoying to switch to YPbPr mode.

If I ever put an Xbox into my setup it would be with the official component cables. I'm not aware of any mod or method to increasing analog video quality. I've heard it doesn't have the best analog output, but I'm not sure it would be worth all the effort to get an HDMI mod and to pair it with an HDMI to RGB DAC to chase that tiny bit of quality.

[Virtual_Tintin]

I have a COMP2RGB in my own setup and I do not notice any lose in quality. I'm sure something is lost by adding this device to the video chain, but it doesn't appear to be anything that I can actually see.

My use case is similar to yours, but my main setup is gscartsw based rather than Extron. My goal is to have an all RGB automatic switching setup and I use the COMP2RGB for Gamecube and a PSPGo. I don't imagine you'd have any trouble looping the COMP2RGB in to your Extron setup. It won't be improving the video on anything, but it is much more convenient to have everything end in RGB. All my CRT's are either RGB and/or make it annoying to switch to YPbPr mode.

If I ever put an Xbox into my setup it would be with the official component cables. I'm not aware of any mod or method to increasing analog video quality. I've heard it doesn't have the best analog output, but I'm not sure it would be worth all the effort to get an HDMI mod and to pair it with an HDMI to RGB DAC to chase that tiny bit of quality.

thanks for your answer.

I suppose if there is no gain with comp2rgb (and even perhaps a loss by adding it to video chain ?), I won't use it. I'll leave my rgb's consoles on extron, and xbox/gamecube on bvm's optional cards (I just need to switch outputs in osd menu).

for xbox, picture is darker in some games when I display 480p, 720p a little less, but not as clean as in 480i. it's a common problem when xbox display ed/hd resolutions, even if you use premium/official component cables, as I do, and no matter console's version (1.0, 1.1, ...); I can correct brightness with bvm's settings though.
I'm really not a fan of hdmi mods for these old consoles, I prefer to stay with native video outputs and do the best with them.

[matt]

so, there are some conflicting opinions, but consensus says there will be no improvement in modifying oem component gamecube's cable to rgbs.

You can't modify a Gamecube cable to RGBS. The modded cable outputs RGBHV. To get RGBS, you have to either combine the H and V signals, or use composite video from the analog out for sync (which doesn't work in 480p). So depending on your use case, the stock YPbPr configuration may be more useful.

[Gara]

thanks for your answer.

I suppose if there is no gain with comp2rgb (and even perhaps a loss by adding it to video chain ?), I won't use it. I'll leave my rgb's consoles on extron, and xbox/gamecube on bvm's optional cards (I just need to switch outputs in osd menu).

for xbox, picture is darker in some games when I display 480p, 720p a little less, but not as clean as in 480i. it's a common problem when xbox display ed/hd resolutions, even if you use premium/official component cables, as I do, and no matter console's version (1.0, 1.1, ...); I can correct brightness with bvm's settings though.
I'm really not a fan of hdmi mods for these old consoles, I prefer to stay with native video outputs and do the best with them.

You're all set then. While I don't think the COMP2RGB is degrading my signal in any noticeable way, I wouldn't add any transcoding or unnecessary devices to your chain if you can help it. Analog video is tricky and there are no loseless conversions no matter how good the hardware is. Just remember to properly calibrate RGB and YPbPr modes on your BVM and you should get equally good results with RGB and YPbPr game consoles.

I wonder if there could ever be an Xbox mod that improves analog video. Kind of like the WiiDual mod for the Wii. I was hoping we would see a mod that supported dual output on the Xbox, but so far it's all digital mods that are HDMI only.

[Virtual_Tintin]

You can't modify a Gamecube cable to RGBS. The modded cable outputs RGBHV. To get RGBS, you have to either combine the H and V signals, or use composite video from the analog out for sync (which doesn't work in 480p). So depending on your use case, the stock YPbPr configuration may be more useful.

oh yes that's true ! is there a quality's difference between rgbhv and rgbs ?

but, there is something I don't understand then, when you say rgbs doesn't work in 480p, because the mod I had made for my ps2 (http://www.dansprojects.com/ps2sync.html) allows me to output 480p by rgbs.
or perhaps you just talk about gamecube ?

[Virtual_Tintin]

You're all set then. While I don't think the COMP2RGB is degrading my signal in any noticeable way, I wouldn't add any transcoding or unnecessary devices to your chain if you can help it. Just remember to properly calibrate RGB and YPbPr modes on your BVM and you should get equally good results with RGB and YPbPr game consoles.

yeah, I don't think you have any loss too, it's just since you talked about that, I mentioned it.

Analog video is tricky and there are no loseless conversions no matter how good the hardware is.

but I thought analog's conversions didn't cause any loss... so this isn't right ?

I wonder if there could ever be an Xbox mod that improves analog video. Kind of like the WiiDual mod for the Wii. I was hoping we would see a mod that supported dual output on the Xbox, but so far it's all digital mods that are HDMI only.

well, except this brightness "issue", which can be easily corrected with bvm's settings, picture is very good in progressive scan, and that's much more pleasant to play in 480p/720p than in 480i.


by the way, what monitors are you using in your setup ?

[Gara]

Analog video is tricky and there are no loseless conversions no matter how good the hardware is.

but I thought analog's conversions didn't cause any loss... so this isn't right ?

While I can't see any difference when using the Comp2RGB I still acknowledge that adding transcoding to my chain isn't loseless and has the potential to degrade the quality.

by the way, what monitors are you using in your setup ?

My current setup is a Sony BVM-D20F1U, Sony PVM-2530, Ikegami HTM-1990r, and a Ikegami TM20-17r. What are you using in your own setup?

[Virtual_Tintin]

My current setup is a Sony BVM-D20F1U, Sony PVM-2530, Ikegami HTM-1990r, and a Ikegami TM20-17r. What are you using in your own setup?

very sweet setup !

I have 2 consumer crt : sony trinitron kv-25fx30b/bang & olufsen mx 8000, and 5 pro monitors : sony bvm d24e1w/d20f1/20e1, sony pvm 20m2/2950q.
so, we share one monitor aha !

why don't you plug directly your gamecube in component on an additional card of your d20, as you say add conversion in video chain degrade a little bit the signal ? to have a full rgb setup ? that's my thought too, but only if there is an improvment, otherwise, I prefer to let plugged in component, as it's very simple to switch format/slot/sync mode in input configuration on bvm.

[Gara]

My current setup is a Sony BVM-D20F1U, Sony PVM-2530, Ikegami HTM-1990r, and a Ikegami TM20-17r. What are you using in your own setup?

very sweet setup !

I have 2 consumer crt : sony trinitron kv-25fx30b/bang & olufsen mx 8000, and 5 pro monitors : sony bvm d24e1w/d20f1/20e1, sony pvm 20m2/2950q.
so, we share one monitor aha !

why don't you plug directly your gamecube in component on an additional card of your d20, as you say add conversion in video chain degrade a little bit the signal ? to have a full rgb setup ? that's my thought too, but only if there is an improvment, otherwise, I prefer to let plugged in component, as it's very simple to switch format/slot/sync mode in input configuration on bvm.

Some very nice heavy hitters there. I wish I could have found a 20e1u before they went sky high in price. Do you get significantly different results on your expansion cards versus using the default board? My cards on my BVM are all a little different. I probably just need to find the calibration options on each card, but for now it's easier to run all my signals through one cable/connection.

The reasons I use the Comp2rgb is that my 2530 is RGB only, the TM20-17R requires a tiny switch flipped in the back for YPbPr, and the Ikegami htm-1990r menu system and controls are very frustratingly slow to use. Plus i also run my setup into a modern screen. With the Retrotink 5x it didn't support YPbPr over Scart. I've since replaced the 5x with the 4k and it has YPbPr over Scart support. So I now mostly keep my setup this way due to convenience. Full automatic switching and everything comes out in RGB. Maybe some day someone smarter than I am will demonstrate what (if anything) is actually lost in the transcoding process and I'll remove the Comp2rgb from my chain. For now I just like the convenience.

[matt]

oh yes that's true ! is there a quality's difference between rgbhv and rgbs ?

No, the sync type doesn't affect image quality. It's just an issue of whether your monitor accepts it or not.

but, there is something I don't understand then, when you say rgbs doesn't work in 480p, because the mod I had made for my ps2 (http://www.dansprojects.com/ps2sync.html) allows me to output 480p by rgbs.
or perhaps you just talk about gamecube ?

The Gamecube shuts off composite & S-Video in 480p mode. So using composite video or luma for sync only works in 480i.

In general, composite sync works fine at any resolution, as does sync on green.

[Virtual_Tintin]

I wish I could have found a 20e1u before they went sky high in price.

there is no difference between 20e1 and 20f1, and therefore between 20e1 and d20f1, which is basically a multiformat 20f1. I mean, no difference a non-bionic eye could see lol. sony says 20e1 is 1000tvl, while 20f1/d20f1 are 900tvl, but even if the pitch is indeed finer on 20e1, that's mainly, I think, a commercial argument, and 20e1 are in fact simply the best 20f1's tubes, some kind of "luxury" 20f1. that's absolutely not the same 1000tvl than on d24e1w, and it's a good thing, because in 240p, widescreen bvm have too thick scanlines for me. afterwards, there remains the reference's "prestige", which is much rarer than 20f1, but even 20g1, the model which is supposed to be inferior, is much rarer than 20f1.

Do you get significantly different results on your expansion cards versus using the default board? My cards on my BVM are all a little different. I probably just need to find the calibration options on each card, but for now it's easier to run all my signals through one cable/connection.

perhaps a little, indeed, but that's really negligible.
I have 21d and 42hd as additional cards, and once I calibrated with 240p test suite in all resolutions, no matter where I plug my consoles, it's fine, I just have to adjust h/v size and h/v center/phase.

the TM20-17R requires a tiny switch flipped in the back for YPbPr, and the Ikegami htm-1990r menu system and controls are very frustratingly slow to use.

I see. nothing beats sony's osd menus, and, imo, pvm/bvm are really the most "plug-and-play" monitors, in any resolution, for any kind of connection.
have you some focus' problem on the edges of image and some difficulties with 480p resolution, with your ikegami htm-1990r ?

Plus i also run my setup into a modern screen. With the Retrotink 5x it didn't support YPbPr over Scart. I've since replaced the 5x with the 4k and it has YPbPr over Scart support. So I now mostly keep my setup this way due to convenience. Full automatic switching and everything comes out in RGB. Maybe some day someone smarter than I am will demonstrate what (if anything) is actually lost in the transcoding process and I'll remove the Comp2rgb from my chain. For now I just like the convenience.

I didn't know anything about modern stuff lol.
you prefer to play on crt or on your modern screen via retrotink ? except the size, what are the advantages ?

[Virtual_Tintin]

No, the sync type doesn't affect image quality. It's just an issue of whether your monitor accepts it or not.
The Gamecube shuts off composite & S-Video in 480p mode. So using composite video or luma for sync only works in 480i.
In general, composite sync works fine at any resolution, as does sync on green.

thank you for these explanations

[Gara]

there is no difference between 20e1 and 20f1, and therefore between 20e1 and d20f1, which is basically a multiformat 20f1. I mean, no difference a non-bionic eye could see lol. sony says 20e1 is 1000tvl, while 20f1/d20f1 are 900tvl, but even if the pitch is indeed finer on 20e1, that's mainly, I think, a commercial argument, and 20e1 are in fact simply the best 20f1's tubes, some kind of "luxury" 20f1. that's absolutely not the same 1000tvl than on d24e1w, and it's a good thing, because in 240p, widescreen bvm have too thick scanlines for me. afterwards, there remains the reference's "prestige", which is much rarer than 20f1, but even 20g1, the model which is supposed to be inferior, is much rarer than 20f1.

There is a small measurable difference that I've seen demonstrated. It's usually shown with zoomed in shots of The Legend of Zelda: A Link to the Past with there being an extra line in Link's hat. It's hardly scientific, but that seems to be an indicator that there is just a tiny bit more TVL with the 20E1U. It's not something I'm going to toss my D20 for, but it's always exciting to think there is that tiny bit more you can obtain. That combined with the greater image control the 20F1U/20E1U versus the D20 sure makes it compelling for the ultimate 240p Trinitron experience. Maybe one day I'll be able to get my hands on one be able to play with it and do some fun side by sides.

perhaps a little, indeed, but that's really negligible.
I have 21d and 42hd as additional cards, and once I calibrated with 240p test suite in all resolutions, no matter where I plug my consoles, it's fine, I just have to adjust h/v size and h/v center/phase.

That's interesting to hear. I guess it's just my own 21D acting up. For whatever reason it has colors way off what I get out of the default system card. It's not something I've looked into heavily since I rarely need to run anything through it or the bkm-24n I also have installed.

I see. nothing beats sony's osd menus, and, imo, pvm/bvm are really the most "plug-and-play" monitors, in any resolution, for any kind of connection.
have you some focus' problem on the edges of image and some difficulties with 480p resolution, with your ikegami htm-1990r ?

Yeah, the Ikegami HTM series really makes you appreciate how much easier the Sony menu system is. I really romanticized the Ikegami pull out drawer in my head, but the reality is that it's a major pain to use and navigate menus. They really should have just ripped off Sony.
I get minor flagging with most 240p sources. An Extron RGB RXI device can help it a bit, but it does not eliminate the problem. So far I haven't seen anything that can completely fix this issue. Maybe one day we will get a device that can manually dial in the sync. 480p is a bit troublesome. The HTM series like to pretend 4:3 just doesnt exist. I had to set an internal jumper just to enable 480p support. I have to use 16x9 and adjust the consoles as best as I can to fit the screen. It's a very picky monitor, but it's fun to experiment with it. I sure wouldn't recommend it as primary display. If I run into random problems I have the luxury of just using a different monitor.

I didn't know anything about modern stuff lol.
you prefer to play on crt or on your modern screen via retrotink ? except the size, what are the advantages ?

I primarily play on my CRT's. Sometimes you just want that bigger screen though and the Retrotink 4k on my LG C9 OLED is pretty nice. With black frame insertion on the LG and the CRT effects from the Retrotink 4 it creates a pretty compelling alternative. I wouldn't really say it has any advantages other than size over a CRT setup, but it is very different and still fun to use. It won't have me giving up my CRT's, but it offers strong competition over what higher end CRT's are going for these days.

[Virtual_Tintin]

that's why I talked about a bionic eye lol. that's imperceptible in-game, when playing at a normal distance, while the difference between d20/20e and d24 is obvious.

d20 has a lot less image's adjustment available indeed, but I'll say image is easier to adjust on d20, with these "simplified" settings, even if you can't get absolute perfection in terms of geometry/linearity, compared to 20f or 20e (and probably 20g). there are also a lot of convergence settings which were removed on d20, but I found convergences' calibration factory on it was better than on 20e1 (not in the center of picture where it's always perfect, but in the corners). so, in the end, each monitor has their strong and weak points, and if I put my d20's convergences above those of my 20e, I'd say my 20e has better geometry and linearity.

about the difference between slots, that's strange. I don't see any difference in colors. afterwards, my monitors were calibrated with a probe, so I have reference values for each of them, and I really don't have the impression it's different according the slots. that happens I do manual contrast/brightness/color level's modifications depending on the games though, but it's very light.

p.s : indeed, ikegami's drawer is very attractive lol, as the ones on old bvm series !