480i/p -> 240p Conversion to regain scanlines

Started by Fudoh, April 07, 2006, 06:41:06 PM

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Fudoh

Hi fellows,

last week I've completed this little project. It will allow you to convert games back to 240p (240 lines progressive) thus getting back real scanlines on a CRT display - no matter how messed up a conversion is (e.g. Ibara on PS2 or Forgotten Worlds on XBox).

Have a look:

http://scanlines.hazard-city.de/

Thanks for your time !

Greetings
Tobias


PS: Lawrence, I already emailed you if you'd like to give me link on your gamesx.com site to the above project...

NFG

Hi Tobias!

I haven't had time to read your page yet - I'm prepping for a Japan trip (leaving in 12 hours) and between that and work...

I had a brief look now - that's an impressive lot of screenshots.  Wow.

PS: It's not PROGRESSIVE, it's NON-INTERLACED.  Progressive is for TV salesmen and soccer moms.  =)


Fudoh

QuoteIt's not PROGRESSIVE, it's NON-INTERLACED. Progressive is for TV salesmen and soccer moms.

hehe, guess you're right. With terms like 480p and 720p being quite common nowadays, I guess for 99,9% of all readers it's just synonyms.

Tobias

Midori

Lots of fun reading there :-) Although I do not share your views on every single point there... But I don't like interlaced picture just like you and found the text very interesting and I learned a few new things... and by the way. Street Fighter Alpha 3, GigaWing and Sega's Skies of Arcadia PAL versions does support RGB, and this part doesn't make much sense:

"with a scan converter you can play those games in glorious RGB which refused to boot up before with a RGB cable connected."

How will you get a pure RGB signal from a non RGB supporting game? Or do you mean that you'll downscan the VGA signal to Low res non-interlaced?(I said it!)

Kiriko

QuoteLots of fun reading there :-) Although I do not share your views on every single point there... But I don't like interlaced picture just like you and found the text very interesting and I learned a few new things... and by the way. Street Fighter Alpha 3, GigaWing and Sega's Skies of Arcadia PAL versions does support RGB, and this part doesn't make much sense:

"with a scan converter you can play those games in glorious RGB which refused to boot up before with a RGB cable connected."

How will you get a pure RGB signal from a non RGB supporting game? Or do you mean that you'll downscan the VGA signal to Low res non-interlaced?(I said it!)
For Street Fighter Alpha 3, GigaWing and Sega's Skies of Arcadia, I believe he means the NTSC version.  Because SFA3 and Skies of Arcadia won't run in RGB for sure.  I don't have GigaWings to test it out in RGB.

Fudoh - That's some nice reading.

Midori

#5
Yes I know the NTSC versions of Skies Of Arcadia and Gigawing doesn't support RGB, didn't know SFA3 didn't do that eithor though... that is why i stated that the PAL versions did :-). So wouldn't it be easier to buy them and use a boot disc to get RGB in 15 KHz(Skies Of Arcadia doesn't support 60 Hz though)? Instead of downscanning a 31 KHz signal, or is that not hardcore enough ;)

-Martin-

No offence but doesn't redownsizing video that's already been upscaled and filtered just make it look like low resolution video that's been upscaled, filtered then downsized?

o_O

there are mods for the Xbox that let you turn the flicker filter on the actual console off - this might help a bit.

Hrm,
Also, isn't the resolution of a TV actually 720*480/576i on interlaced 15KHz?
Or does the TV simple "stretch" the image if it has a lower horizontal resolution?

I am seriously considering getting an LCD projector.
I would preffer a CRT projector but I just don't have the space for such contraptions! Now the money! LOL

Fudoh

QuoteBut I don't like interlaced picture just like you and found the text very interesting and I learned a few new things...

oh, it's not really a matter for me anymore. I play on a large LCD TV and low-res and high-res (based on low-res) will look about the same on it. You can nicely check it with Gunstar Heroes PS2 when switching throug the resolutions...

QuoteNo offence but doesn't redownsizing video that's already been upscaled and filtered just make it look like low resolution video that's been upscaled, filtered then downsized?

as said, you'll notice the difference, but it's definitely as close as it gets. We installed a scan converter in a friend's cabinet (Astro City) and the results are more than stunning. We're running a MAME PC, a PS2 and a XBox through it and it really does a lot to the picture's clarity and to give it the typical low-res arcade look.

I think Forgotten Worlds XBox is maybe is the best example of all. It's an extremely well done conversation (besides the wrong res) and using a scan converter it looks stunning.

QuoteI am seriously considering getting an LCD projector.

no need to think about low-res / scanlines then. There's no way to achieve hardware scanlines on LCD-based machines.

QuoteAlso, isn't the resolution of a TV actually 720*480/576i on interlaced 15KHz?

That's DVD resolution. Since it's usually an analogue signal you don't get a fixed horizontal resolution...

Tobias

Guest

Hmm?
You can get fixed horizontal resolutions though on analogue equipment...
VGA monitors are a perfect example... The horizontal resolution is always 640 on VGA.

So TVs just max out at 768 Horizontal (isn't that the max their capabole of displaying at?) and the TV will fil the screen horzontally if the resolution is lower?

:P  Because there has to be a maximum, regardless of analog or digital.

I take it you're only playing titles that were originally low res on this?
As I can't really see the point in playing cool high res games like OutRun 2006 in 240p when they run in 480p in arcades ;p...

Fudoh

QuoteI take it you're only playing titles that were originally low res on this?

Of course. The whole point was doing something against those wrongly ported games and shoot'em ups especially.

Tobias

Midori

#10
QuoteHmm?
You can get fixed horizontal resolutions though on analogue equipment...
VGA monitors are a perfect example... The horizontal resolution is always 640 on VGA.

Now that's not true is it? I can do 848x480 on my VGA monitor without problems. Or have I missed something(not the resolution, I can clearly see that it is 848 pixels wide)?

And is there a real horizontal resolution maximum for CRT screens? I think that 768 pixels is not the maximum but the DPI of a CRT screen(a TV in this case) makes it just silly to increase that number because you won't be able to see the difference. Of course there could be a maximum in the TVs chassis(spelling, correct word?) but not in the tube as far as I know.

Guest

Quote
QuoteHmm?
You can get fixed horizontal resolutions though on analogue equipment...
VGA monitors are a perfect example... The horizontal resolution is always 640 on VGA.

Now that's not true is it? I can do 848x480 on my VGA monitor without problems. Or have I missed something(not the resolution, I can clearly see that it is 848 pixels wide)?

And is there a real horizontal resolution maximum for CRT screens? I think that 768 pixels is not the maximum but the DPI of a CRT screen(a TV in this case) makes it just silly to increase that number because you won't be able to see the difference. Of course there could be a maximum in the TVs chassis(spelling, correct word?) but not in the tube as far as I know.
There is a maxiumum...
You can only illuminate as many pixels as your screen has before stuff goes wrong.

Electron guns themselves can only go so high >_>

Monitors HAVE a Maximum resolution that they can draw at. Most monitors can go higher than it at the expense of focus (as the electrons are blocked by the aperiure grid they dont hit the phosphaur paint).

When I said VGA, I meant standard VGA.
VGA resolution - standard is 640*480. And it stays locked at that resolution untill you change it ;)
It doesn't flick randomly from resolution to resolution.
So it's fixed at whatever you set it to.

NFG

VGA, as the video mode, is 640x480.  That's what VGA is, anything else is not technically VGA, but has another silly name attached: QVGA, SVGA, XVGA, etc etc.

Used colloquially, a VGA monitor is (nowadays) synonymous with "computer monitor", and usually refers to a monitor that supports only a computer input (no tuner) and supports multiple resolutions.

The maximum resolution for a CRT depends on the CRT.  Obviously a 21" computer monitor has higher resolution than a 12" TV.  My old Atari ST monitor did something like 1600x1200, but my much newer widescreen TV has a resolution less than half that.

viletim!

Guest,
Fudoh is saying that the horizontal 'resoultion' of analog video isn't fixed at 720 (or whatever) and he's right. A TV (or analog monitor) doesn't know what a pixel is... pixels are a product of digital video source and simply don't exist if you generate the video analogly (eg, with a camera or vcr).

*deep breath"
The maximum ammount of horizontal pixels you can display before you can't tell where one stops and another starts is mainly limited by the CRT phosphor pitch/shadow mask (in the case of a colour CRT), the video amplifiers that drive the CRT on the chassis, and if you're feeding it with something other than RGB (like composite video) then it'll limit the horiz bandwidth too.

It's possible to generate a TV compatible video signal that has a horizontal res of 1000 pixels and have it display on a TV. It'll just look shit.

Fudoh,
I like your idea and I'll try it if I can get a digital video processer on the cheap (but I don't think it's too likely).

Fudoh

QuoteI like your idea and I'll try it if I can get a digital video processer on the cheap (but I don't think it's too likely).

depends on where you live. I've snatched the cheaper one of the two Extrons for about US$90 on ebay.com. If you live in the USA it's quite ok and cheap. For other parts of the world (like me), shipping, taxes & customs add in, but it stays obtainable...

Tobias

blackevilweredragon

QuoteVGA, as the video mode, is 640x480.  That's what VGA is, anything else is not technically VGA, but has another silly name attached: QVGA, SVGA, XVGA, etc etc.

Used colloquially, a VGA monitor is (nowadays) synonymous with "computer monitor", and usually refers to a monitor that supports only a computer input (no tuner) and supports multiple resolutions.

The maximum resolution for a CRT depends on the CRT.  Obviously a 21" computer monitor has higher resolution than a 12" TV.  My old Atari ST monitor did something like 1600x1200, but my much newer widescreen TV has a resolution less than half that.
As you probably know, the regular VGA standard has only actually supports 2 resolutions..  Those are 720x400 and 640x480...

But what about 320x200 and 320x240?  Those as far as the monitor is concerned, and signal wise, is the higher-res modes, being upscaled in the video card.  (old cards DID upscale, but only by doubling the pixels, that's it..)

320x200 = 720x400  (how that is upscaled is by doubling the vertical and horizantle by x2..  and it does leave an extra black border on the left and right as it doesn't fill the 720 pixels all the way)

320x240 = 640x480  (that is perfectly multiplied by x2 with no border, as they fit perfectly together)..

320x200 was VGA's big fancy 256 color "graphics" mode..  720x400 was VGA "text" mode..  and 320x240 was used for Graphics mode also, but used more VPU power (the old game DOOM would actually chose either 320x200 or 320x240 depending on the VGA BIOS that the card had, you never saw this change unless you saw your monitors OSD)..
640x480 was the high-res graphics mode, mainly used in Windows, and some games, but only offers 16 colors...

there was a mode in VGA called 640x400, it was simply 720x400 signal wise...

As for these "borders" I speak of, this was for the real VGA monitors, the ones where brightness and contrast was the only controls you had, and the monitors already had a blank border no matter what res..

This is just something I learned while being with people that were from the days when VGA was new, and these guys are litterally experts and know all the tricks VGA did (to allow only TWO scan-rates to cut costs of monitors (remember, this was the days of fixed-frequency)..

btw, 720x400 and all of the lower modes in that res were ALWAYS 70Hz vertical refresh, and all modes in 640x480 were always 60Hz vertical refresh..

so, if you want a simple chart, for any reason, here's a simple thing to remember...

720x400 = 720x400, 640x400, 640x200 (high-res CGA), 320x200
640x480 = 640x480, 320x240....

I did not count the EGA compatibility mode 640x350, as I am not too sure how that one works.

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

Sorry, got carried away, it's that VGA is one of my expertise :P

And btw, one of my favorites were "EVGA", or "Extended VGA"..  It allowed things like 360x480, but was 640x480 signal wise.. and it was 256 colors too!  only available to VGA cards with 256KB or higher..

Guest

QuoteHi Tobias!

I haven't had time to read your page yet - I'm prepping for a Japan trip (leaving in 12 hours) and between that and work...

I had a brief look now - that's an impressive lot of screenshots.  Wow.

PS: It's not PROGRESSIVE, it's NON-INTERLACED.  Progressive is for TV salesmen and soccer moms.  =)
non-interlaced? how is that not progressive?

eastbayarb

I would like to achieve this affect using my Dreamcast/Xbox/PC/Gamecube but on a VGA monitor. I have a NEC XV29 A+ Presentation Monitor which is a 27" monitor that supports 15khz/31.5khz and it's inside my arcade cabinet.

Is there a scan converter that has VGA input AND VGA output but lets you achieve this 240p scanline effect?

Thanx!

Fudoh

QuoteIs there a scan converter that has VGA input AND VGA output but lets you achieve this 240p scanline effect?

No, not by hardware. Upscan converters like the XRGB2+ offer emulated scanlines, but they don't look good.

What you can do is use a YUV capture card (Sweetspot, PDI Deluxe. etc) and use a software filter in AVISynth. It looks very real.

Tobias

NFG

Quotenon-interlaced? how is that not progressive?
It's a terminology problem.  Progressive is a simple term used to describe the non-interlaced video from DVD players so idiots off the street don't get baffled by the Big Words.  

-martin-

QuoteGuest,
Fudoh is saying that the horizontal 'resoultion' of analog video isn't fixed at 720 (or whatever) and he's right. A TV (or analog monitor) doesn't know what a pixel is... pixels are a product of digital video source and simply don't exist if you generate the video analogly (eg, with a camera or vcr).

*deep breath"
The maximum ammount of horizontal pixels you can display before you can't tell where one stops and another starts is mainly limited by the CRT phosphor pitch/shadow mask (in the case of a colour CRT), the video amplifiers that drive the CRT on the chassis, and if you're feeding it with something other than RGB (like composite video) then it'll limit the horiz bandwidth too.

It's possible to generate a TV compatible video signal that has a horizontal res of 1000 pixels and have it display on a TV. It'll just look shit.

Fudoh,
I like your idea and I'll try it if I can get a digital video processer on the cheap (but I don't think it's too likely).
That's what I was trying to say.
Although it's not fixed it has a maximum it can go to.
=] but it came out wrong XD

Lawrence is also right about the QVGA thing.

Guest_Martin

QVGA applies to resolutions of 320*240 and lower also^

Although while it's technically VGA, they get different tags added to them to help differentiate.