VGA to component converter for PC to SDTV (pixel perfect)?

[dogman91]

Hey; new to the forums... thought I would ask my question on this forum as you all seem to be very knowledgeable on video signals and such from what I've read in the past. So here's a copy-paste from my post on Racketboy:

I've been looking into a VGA to Component converter to output 480i to my TV for ScummVM and other emulators like for the Amiga... the problem is I'm not sure what kind of scaling and other things (like flicker filtering) would arise that I won't be able to disable. Anyone know of a well-reviewed (by other gamers) known pixel perfect and non-filtering/no video signal degradation solution, kind of like the RGB to component converter on eBay? I want try something similar that I'm doing with that for RGB 240p consoles except with my PC, and disabling the interlacing in the TV service menu. Thanks.

(For example, I'm not sure I trust this (http://www.ebay.com/itm/VGA-PC-to-Compo ... 1e6a7cca9d) on eBay because of it's "all resolutions scaled" and "flicker filter! (which blurs everything)" )

Thanks for any help!

[Fudoh]

all your choices: http://scanlines.hazard-city.de/

If you're ok with 480i output, just grab an Extron VSC unit, for the example the VSC 150 listed for $65 buy it now on ebay.com right now. I know, it's more money than the $38 you linked to, but the Extron was a $2500 machine and it shows - really!

[dogman91]

Thanks... seems like just what I'm looking for. Just to clarify: with a video card that doesn't interlace, will the Extron VSC processing interlace the image? I'm assuming it does (especially with the fact it has flicker options) but just want to make extra sure!

[Fudoh]

Thanks... seems like just what I'm looking for. Just to clarify: with a video card that doesn't interlace, will the Extron VSC processing interlace the image? I'm assuming it does (especially with the fact it has flicker options) but just want to make extra sure!

I don't have the specs of the VSC 150 on hand. You check it's maximum input resolution on the Extron website. Let's assume it takes anything up to SXGA (1280x1024). The VSC is completely independent of the source. So you input VGA, SVGA, XGA (or anything else) from your PC through VGA and the Extron will output 480i either through video, s-video, RGBs or component (you just need three cheap RCA to BNC adapter plugs to use standard component cables).

[Fudoh]

PS: On the lowest filter levels you get a very sharp, pixel perfect output - great quality all around!

[dogman91]

Thanks a lot; bought it! I really appreciate it. The link you linked to is awesome as well; very informative... this is perfect for my needs though as I can disable interlacing in my TV service menu and this has component outputs. Hit the nail right on the head!

[Fudoh]

this is perfect for my needs though as I can disable interlacing in my TV service menu

eventually the result will depend on what TV does when you disable the interlacing. I would expect the TV to just shift the line offset and display all the fields on the same height. This will look nice in real low-res material, but if you have true hi-res material (full VGA games like Broken Sword), then this would cause flicker.

Report back and let us know how it worked out !

[dogman91]

So the VSC is supposed to arrive tomorrow and to prepare I've been toying around with MAME on PC for the first time. Side question in case you or anyone else are up to it: I'm curious about Capcom CPS games with their resolution of 384x224. If I can get my video card (NVIDIA Geforce 6200) to somehow output a resolution at exactly double or slightly above a doubling of that (768x448), will the thing accept the resolution and not scale it down to a 640x480 or so resolution? Would be pretty great if I can somehow get a pixel-accurate display of CPS games if turning off interlacing doesn't cause flicker with those.

[Fudoh]

The Extron will always scale to 720x480i. And it will only accept 480p, but you can try if it might accept 854x480 (that's 16:9 480p). If you can set MAME to linedouble to 448p and just pad the remaining lines with black, then the result will be pretty nice. Don't worry about the horizontal resolution too much. As long as you display on a CRT and not on a LCD, it doesn't really matter.

Easiest way to get MAME to linedouble is to set the processing to DirectDraw instead of Direct3D.

The Extron you bought can only output interlaced. The other units I reviewed (linked earlier) will output in 240p instead. That's what you usually want for arcade games.

[dogman91]

Doesn't seem to be pixel accurate so far as every "simple 2x" scaled thing (tried at 720x480 and 640x480) I throw at it has flickering with the interlacing off... size and position controls I think have something to do with it but I have no idea how to set those to be exactly right (if that is possible) as they are just knobs. Might have to resell and look into a more expensive option with true 240p output if this doesn't work out.

[Fudoh]

Don't panic! The VSC150 brings excellent results if set correctly. You can spend $1000 on a scan converter the results would hardly be any better.

The correct vertical size is easily set if you use a test pattern (e.g. a white grid on a black ground). This way you can set the pixel mapping perfectly. You can adjust the vertical filtering to get rid of the flicker so a certain degree. Medium is usually the best setting.

240p on the other hand isn't a good idea for you. It's good for MAME/arcade use, but the 200p to 240p mapping (DOS games to 240p) doesn't work, so you have to go 480i instead.

Take a digicam snapshot and post it if you're not sure about the settings !

[dogman91]

Thanks for your help so far... fairly new to all this and trying to get a grasp on it so I have a ton of questions if you don't mind me asking! Researched a bit more and everything I've found seems to be written by you; kick ass job I have to say with the wealth of information you've put out there.

I would think DOS games and others would be fine if I simply letterbox it in 240p (not try to output some kind of doubling of 200p, but rather 480p as usual).

Anyway, for question #1, does the horizontal sizing options on the VSC have to be set correctly as well with the vertical one to achieve pixel accurate output, or is it only the vertical that matters? Tried every vertical option and the screen still flickers with all of them (interlacing is off in the service menu of course).

Question 2; seems to be kind of blurry compared to my RGB to component consoles as well so something tells me there might be some kind of bilinear filter you can't turn off unless I'm mistaken. I've selected what looks like the sharpest settings on the filter settings (encoder = 2; everything else is '1'). If a built-in bilinear filter that can't be turned off is indeed the case, does this make pixel-perfect output impossible? If this isn't case at all I'm guessing my troubles might have to do with the VSC sizing options or the PC video card output side of things (and how the VSC handles that) too. Can you confirm any of this?

Question 3; would not inputting a 720x480 resolution to the VSC 150 (as you say the scan converter always converts to [it's native res output?]) have possible troubles with pixel accuracy of simple 2x stuff? Or is it as you said and the horizontal side of things doesn't matter? Just trying to get a grip on where that statement applies or is not relevant! My basic understanding is that the CRT NTSC lines are fixed (480) but the horizontal pixels res could be anything due to how CRT phosphors draw the lines, so I'm trying to base my thinking on that with regard to getting a pixel perfect output, but I'm not quite sure how the VSC handles things in this regard as it's digital.

Question 4, 5, etc... I might have to look into that MIMO Genius II you were talking about if everything is as razor sharp as you put it with true 240p output and if none of the above works out. Did your usual resolutions or custom ones work out for pixel accuracy on SD CRT displays with downscaling 640x480 or even odd resolutions like the doubled Capcom 768x448 ones with the Genius (no anomalies; just as if you connected a real arcade board or such to the display with scanlines etc)? Can the MIMO Genius II or any other scan converter out there output a direct halving of any resolution you input as long as the vertical is compatible (like 480)? For example, 768x480 input converts to 384x240 out and 640x480 to 320x240 out, or is it only set to locked resolutions like 320x240 or 256x224 etc (and would that effect pixel accuracy?). As you say this requires a lot of extra accessories to get going, due to my limited knowledge if I go with this can you possibly mention what I would need to input computer VGA and have a SCART RGB male output for a RGB to component transcoder and have everything work perfectly as I intend (15khz low res pixel accurate output from a VGA resolution)? Would want to know for sure if a such a setup would work before I would pull the trigger.

Again thanks for everything and I really appreciate all the info you've provided so far.

[Fudoh]

I would think DOS games and others would be fine if I simply letterbox it in 240p (not try to output some kind of doubling of 200p, but rather 480p as usual).

but then again this would kill your aspect ratio. Essentially you would output a letterbox signal, while 320x200 on a PC monitor is supposed to be fullscreen.

does the horizontal sizing options on the VSC have to be set correctly as well with the vertical one to achieve pixel accurate output, or is it only the vertical that matters?

only vertical. Horizontal doesn't matter, since the horizontal resolution isn't changed from the input. The way analogue video works, there is no clear definition of horizontal resolution.

Tried every vertical option and the screen still flickers with all of them (interlacing is off in the service menu of course).

a bit hard to image what you mean by flicker. Also you can't switch of the interlacing, since the whole purpose of the unit is to interlace your 480p PC output.

Question 2; seems to be kind of blurry compared to my RGB to component consoles

which consoles for example ? Not really fair to compare a 240p console output to a 480i signal.

as well so something tells me there might be some kind of bilinear filter you can't turn off

the signal is running through a filter, but with the right input resolution, the processor just has nothing left to do. It's a matter of finding the sweet spot using the zoom controls. With the pure analogue controls on the 150 it might be more complex than on a VSC 700 (I've got one) with digital controls.

A big problem is certainly your TV. If you say that you disable the interlacing on the TV set, your TV throws out the line-offset in every second field the Extron produces. This usually only works on a very certain type of game and it's certainly not a good idea to turn it off in general.

to do with the VSC sizing options or the PC video card output side of things (and how the VSC handles that) too. Can you confirm any of this?

What's your source right now ? Which software is running on your PC ? If you have MAME ruin your scaling beforehand, the scan converter won't be able to do anything about that.

would not inputting a 720x480 resolution to the VSC 150 (as you say the scan converter always converts to [it's native res output?]) have possible troubles with pixel accuracy of simple 2x stuff?

Even if the Extron works with 720x480 on it's input, it's likely sampled as 640x480 or - likely - the horizontal resolution is simply left untouched.

Just trying to get a grip on where that statement applies or is not relevant!

a vertical match is much more important. Horizontal usually doesn't matter - or at least I can't imagine any in case in which it would matter.

basic understanding is that the CRT NTSC lines are fixed (480) but the horizontal pixels res could be anything due to how CRT phosphors draw the lines

that's right. And that's why, as long as you input 480p, the VSC doesn't scale the horizontal resolution. Not until you force it by adjusting the hor. zoom.

I might have to look into that MIMO Genius II you were talking about if everything is as razor sharp as you put it with true 240p output and if none of the above works out.

you can do that, but you have to realize that you're then limited to low-res material.

or is it only set to locked resolutions like 320x240

The Mimo ALWAYS does output 320x240. No matter what you input. You can take care of the vertical padding (e.g. 448 to 480p) in the software you run. You can't do anything about the horizontal resolution. Other converters like the Extron Emotias keep the full horizontal resolution and only reduce on the vertical.

If you need it "more sophisticated" than this, you have to go with an ArcadeVGA card.

Fagin recently posted about this MAME + Emotia experiences. Maybe you should read up on this !!

[dogman91]

Going to answer your responses in bold to make it easier:

Tried every vertical option and the screen still flickers with all of them (interlacing is off in the service menu of course).

a bit hard to image what you mean by flicker. Also you can't switch of the interlacing, since the whole purpose of the unit is to interlace your 480p PC output.
I meant that with interlacing off in the TV service menu, whenever the pixels don't align vertically it flickers. I notice when adjusting it some lines get right and others don't with each alignment.

Question 2; seems to be kind of blurry compared to my RGB to component consoles

which consoles for example ? Not really fair to compare a 240p console output to a 480i signal.
I think it was just the non-aligned pixels causing it to flicker between scanlines that was throwing me off compared to the solid 240p signal.
A big problem is certainly your TV. If you say that you disable the interlacing on the TV set, your TV throws out the line-offset in every second field the Extron produces. This usually only works on a very certain type of game and it's certainly not a good idea to turn it off in general.
I just assumed it throws out every second line, which would mean 2x would appear as "1x" basically for emulated 240p games that appears as 240p with scanlines in 480i. It's worked with emulators on consoles that only have 480i output like the original Xbox and others so I assumed the same would apply with PC if the Extron outputs a perfectly aligned 480i signal from 640x480.

to do with the VSC sizing options or the PC video card output side of things (and how the VSC handles that) too. Can you confirm any of this?

What's your source right now ? Which software is running on your PC ? If you have MAME ruin your scaling beforehand, the scan converter won't be able to do anything about that.
I tried ScummVM with 2x graphic rendering with Secret of Monkey Island (don't have "force aspect ratio" enabled as it stretches it) outputting in 640x480. I also tried Magician Lord with "keep pixel ratio" in the Screen menu of MAMEUI, DirectDraw on without hardware scaling, force aspect ratio on, non-windowed and outputting in 640x480 60hz to the Extron. Seems to do a 2x with fullscreen.

Thanks for your help

[Fudoh]

It's worked with emulators on consoles that only have 480i output like the original Xbox and others so I assumed the same would apply with PC if the Extron outputs a perfectly aligned 480i signal from 640x480.

you have to differentiate between 30Hz and 60Hz games. What you describe only works on 30Hz/fps games on which two adjacent interlaced fields don't show any difference.

Your TV certainly does not throw out every second field, but it removes the offset, displaying the two fields on the same height.

[dogman91]

So is there an alternative to this then if this effectively can't be done with what I have? Would the Genius II be up to it or would an Extron RGB take care of the 60hz/fps problem while retaining pixel accuracy and sharpness?

Edit: reading your link about the Extron RGB interfaces tells me the flickering isn't gone completely in the 240p mode. I guess I will look into it.

Edit2: Seems like Soft15Khz w/ Powerstrip might do the trick with a simple VGA to component transcoder (http://www.crescendo-systems.com/transcoder.html).

[Fudoh]

So is there an alternative to this then if this effectively can't be done with what I have? Would the Genius II be up to it or would an Extron RGB take care of the 60hz/fps problem while retaining pixel accuracy and sharpness?

a conversion to 240p won't neccessarily look sharper than one to 480i. It depends on your source (low-res vs. hi-res ScummVM) what looks better.

Edit: reading your link about the Extron RGB interfaces tells me the flickering isn't gone completely in the 240p mode. I guess I will look into it.

The Extron RGB interfaces do exactly what your TV does.

Edit2: Seems like Soft15Khz w/ Powerstrip might do the trick with a simple VGA to component transcoder

soft15k is limited to very few output resolutions, depending on the graphic card you have. You also have the problem with the PC booting in 31khz which can/will damage your TV, so you have to be quite careful.

[screamingtrees]

Thanks... seems like just what I'm looking for. Just to clarify: with a video card that doesn't interlace, will the Extron VSC processing interlace the image? I'm assuming it does (especially with the fact it has flicker options) but just want to make extra sure!

I don't have the specs of the VSC 150 on hand. You check it's maximum input resolution on the Extron website. Let's assume it takes anything up to SXGA (1280x1024). The VSC is completely independent of the source. So you input VGA, SVGA, XGA (or anything else) from your PC through VGA and the Extron will output 480i either through video, s-video, RGBs or component (you just need three cheap RCA to BNC adapter plugs to use standard component cables).

Crap, I think I went too far off this advice and bought a VSC 150 w/ BNC to RCA plugs when I should have gotten a 100gx. Because doesnt rgb to component require that $80 jrok encoder?

[Fudoh]

The VSC 150 can output in 15khz component as well. You just need to set the output switch accordingly. The switch is on the back between the s-video and the BNC ports.

[screamingtrees]

Oh, ok cool.

[Classicgamer]

I recently picked up an extron VSC 200 to play mame games on a Sony Trinitron through S-video and I had a problem with blurry images until I figured out how to set it up correctly.

Conventional wisdom would say that of you output 480p from your gpu, then the VSC's conversion to 480i should be optimal due to less scaling being necessary. I didn't find this to be the case though and I don't really know why exactly.

My gpu recognizes the extron device as "analogue display" and it is convinced that it's native resolution is 1024 x 768. In fact, it offers no lower resolutions than that, even when I tried custom resolutions. It does allow 480p at 120hz but not 60hz. The other thing that it allows is lower resolutions to be enabled in custom resolutions (but not selected for windows). The lower resolutions can be selected in mame's preferences. For example, I selected 320 x 240 for street fighter 2. With hardware scaling turned off in direct draw, this produces a decent image that fills about half of the screen. The Extrons horizontal and vertical stretch settings can then be used to make it fill the screen.

I found that every game's resolution needs to be set differently to look it's best and it took a lot of trial and error to find the right ones. If the resolution is set too high or too low in either the gpu or mame's settings, the image looks blurry, either at the edges or for the entire screen. The good news is that once you find the right resolution combination, games look amazing. The extron devices do a really nice job of the conversion.

I turn off direct 3d, hardware stretching, bilinear filtering, tripple buffering etc. The only one I leave selected is "wait for vertical sync". I do all of the scaling on the extron device. Each game needs different filter settings too for reduced flickering. I find the flickering problem in games to be exaggerated most of the time, unless I sit too close to the screen. My Sony tv is 27" and from 4 feet away, games look good enough to use only the lowest level flicker control.

A lower desktop resolution makes windows text easier to read but oddly, it seems to make games blurry. I would set your gpu to whatever it thinks is "native" to start with and then select all of the custom resolutions through the emulator.

[tcancian]

I don't want to get in the way of the thread, but dogman91 have you considered using a PC CRT coupled with a hardware scan-line generator or MAME filters? I take your SDTV is likely bigger than any CRT VGA Monitor you'll be able to find, but if you set a PC monitor to 640x480 at VGA and then use a scan-line generator to cut in half the vertical resolution you'll have something that looks very good and it's all very easy to set-up and it get up and running. For DOS, Amiga and Apple-II gaming this is a great setup as you can use 200p no problem (I assume), just disable scaling, you'll have black bars on top and bottom.

If you have, let's say, a 21" SDTV you won't loose much if you look around for a 19" PC Monitor, PC Monitors also have the advantage of multiple resolutions, I don't know if you're into W95-WXP era gaming, but all those games will look great on 640x480, 800x600 and 1024x768 and you can increase the refresh rate so you'll barely notice any flickering. I'm not sure if a higher refresh-rate messes up the scrolling on MAME games though, I'm talking this from my Counter-Strike 1.6 days where 100 hz was king. I have a setup where I can send the same signal to three devices: a 29" SDTV (RGB, Emotia), a 17" PC Monitor and a 42" FPD Plasma TV (1024x768 native resolution).

When I'm playing with other people or I want a more relaxed experience, I use the 29" but for 480p and WXP era games I use the 17" Monitor and I've set up as I told you (with a Toodles Scanline Generator) and it looks just as good as the 29" SDTV, it flickers less (once you get to play at 100, 110, 120 or 144 hz, you'll have a hard time at 60 hz, even if it's progressive), the quality of the tube is better thus making the scan-lines more noticiable and you can mess around with various setups you usually don't have access to in a SDTV. Bigger SDTVs also won't look very good up close due to pixel dot pitch being bigger. Most PC CRTs have squared plastic casing, if you're interested in TATE this makes it a lot easier but you need to take in account the structure of the CRT as most of these displays are made to be standing upwards. Just my two cents on this subject.