GBA in 240p...ALMOST there, but something's not right

[theredeye]

Like others on this forum have in the past, I'm trying to play Game Boy Advance games over RGB in 240p. I'm following what looks to be the de facto method - forcing Game Boy Player to 480p and piping it through a scan converter - but something is off.

Here is my current chain:

GameCube > component cables > Monoprice component to VGA converter > VGA cable > Extron Super Emotia > RetroGamingCables BNC to SCART > RetroGamingCables SCART to PVM > Sony PVM-2530

Game Boy Player settings are on Sharp, image is NOT stretched. Emotia is set at non-interlace NTSC with overscan, which works absolutely perfectly when I play emulators through VGA.

Here are the results I get:



Notice the ghosting on top of the characters' heads? That's not right. Here's an even better example:



The same letters in different locations look different.

It's hard to describe, but basically, some sections of the screen look perfect, and some look strange...like when the Emotia is merging the wrong lines, and they look "blurry." Except it's just some of them, not all.

So...what could the problem be? My running theory is that the Game Boy Player does NOT spit out a perfect 2x image of the GBA window...I would expect a 480x320 window with all of the pixels doubled, but I'm guessing that the GBP spits out something a little bigger than that. If so, I guess getting a nice 240p image is hopeless, unless someone writes custom software.

Any other theories? Could my VGA converter box have something to do with this?

[SunJammer]

I'm guessing it's the emotia, since instead of "deleting" every other line from the original 480p image it instead averages every other line together. (fudoh does a much better job of explaining this here on his site)

short story, try feeding your video through an Extron RGB interface before the emotia to shift the image up or down a line

and let us know if it works! i've wanted to try something like this for awhile

[theredeye]

I'm guessing it's the emotia, since instead of "deleting" every other line from the original 480p image it instead averages every other line together. (fudoh does a much better job of explaining this here on his site)

short story, try feeding your video through an Extron RGB interface before the emotia to shift the image up or down a line

and let us know if it works! i've wanted to try something like this for awhile

Does anyone else agree with this? That was my first thought as well, but in my experience, if it's off by one line, EVERYTHING is blurry. This happened to me running a PC through my Emotia: the entire picture was blurry, but as soon as I shifted everything up one pixel in Windows, everything was instantly clear. With the Game Boy Player, it seems like some parts of the screen are blurred in that way, and some are perfect. It's almost like 4:1 right lines vs. wrong lines.

[Fudoh]

Got any other 480p component source to verify your Monoprice converter ? I've seen similar with other cheap and "not real" transcoders, where the pixel mapping was off in certain areas of the screen, but spot on in others.

[robneal81]

The Swiss team seems to be getting closer to forcing 240p from the Game Boy Player. They've already added 240p support from their launcher and it works great for most games. I suggest posting over there, so they know more people are interested:

http://www.gc-forever.com/forums/viewto ... 1&start=36

[theredeye]

Got any other 480p component source to verify your Monoprice converter ? I've seen similar with other cheap and "not real" transcoders, where the pixel mapping was off in certain areas of the screen, but spot on in others.

I'll take a look through my PS2 library and see if I can find a good test case (Mega Man Anniversary, maybe?). That's a great idea.

[theredeye]

The Swiss team seems to be getting closer to forcing 240p from the Game Boy Player. They've already added 240p support from their launcher and it works great for most games. I suggest posting over there, so they know more people are interested:

http://www.gc-forever.com/forums/viewto ... 1&start=36

Great idea, maybe these images will illustrate why a solution is needed.