720x480 On A 320x240 Screen ?

[rabbits with hats]

What do you use your smertness for in "real" life?

 

[Jarska333]

Isn't smert like, dead, in russian?

 

[EvilDragon]

What do you use your smertness for in "real" life?

​

I word in a postproduction facility for TV and cinema commercials, and my job is to do the compositing... so I should know about the different TV formats

 

[junker]

yeah, that is pretty complicated, i always get confused with that. thanks for the info, ED

 

[Tebb]

I think that it will be reduced until the width is 320, so if the movie is 720x480 it will be reduced to 320x213.

 

[Alpha2]

What we did was to create the flash file at 704x576 (576 as we're PAL here not NTSC), using graphics that were 1024x576 (16:9). Don't know why you squash the graphics down to 704x576 in flash - someone else was working on that as I was managing something else at the time. I think he said he found it in a pdf somewhere. Then we converted the swf to a 704x576 avi, then encoded the avi in tmpgenc as a 16:9 mpeg-2 which converted it to 720x576. A lot of steps, most of which don't make much sense to me, but the end result looked great

I assume it was done to increase the resolution of the art, Though I wonder if that really makes a differeance with Vector art (though youmight have been using something else i dunno)... have a sample of the project? I'm kinda curious.

720x480 is NTSC DV, the format NTSC home camcorders are recording.
It is indeed 3:2.
Why? Because they just removed a few lines which are not visible (because TV's don't show all lines of a picture) to save bandwitdh (and improve the quality, 'cause, you know, DV is compressed)

And if you add the few lines (6, to be exact), you have 720x486, which is close enough (and has 4:3).

BTW: 3:2 = 4:2,7 which is pretty close to 4:3

Oh, the Pixel Aspect Ratio also is important.
The 720x480 and 720x486 has a Pixel Aspect Ratio of 0.900, but LCD displays have a pixel Aspect Ratio of 1.
So, to have the same Frame Size 720x480 has on a television, you'd only need 720x432 pixels...

Complex? Yeah. But now you might get the idea why all emulators of TV consoles don't look the same on TFT displays - the Pixel Aspect ratio makes a bit of a difference.

​

Yeah he is indeed blessed with the smert that is 'ness.

ED, I'm clearly a moron. I have no idea what half of that means all I know is I gave Nero a 720x380 Flash file turned AVI and it gave me back a letter boxed (as planned) 704x480 (not planned) dvd. The Pixel aspect ratio was fine (nothing was squished) but I noticed a little bit of the left and right side didn't show on my 4:3 TV (NTSC BTW). I'd assume the discrepency happens in the conversion but can't clearly understand why.

aaand to keep this on topic... So the GP2X will output video in it's original/correct resolution? Can it enlarge too?

 

[EvilDragon]

aaand to keep this on topic... So the GP2X will output video in it's original/correct resolution? Can it enlarge too?

​

Well, it NEEDS to enlarge the videos, as a TV has a fixed resolution, and whatever you play with it needs to be resized to that resolution, be it be larger or smaller.

 

[Alpha2]

So I could veiw say a native 320x240 video on a larger 16:9 TV and have it fill most of the screen? (although I expect it to be full of ugly artifacts I'm just trying to be clear on it.)

The same would happen for game then a similar rez game would enlarge for a 4:3 standard TV thus making it a little fuzzy, strectched, and/or blocky but still playable, thus making a 640x480 game only neccesary if you wanted to alieviate any of those effects (or simply make it look prettier on a TV).

 

[Prophet]

So can you also make games in a little bigger size that way?

​

It's hardware video decoding. Not sure you can use it to do anything with games. Anyway, why would you want to?

Actually hardware scaling can be really useful for emulators to quickly and smoothly scale games to full screen and proper aspect ratio. This is done on emus for the Zodiac all the time and it works really nice. I'm hoping this option will be added to emus on GP2X where it makes sense.

 

[EvilDragon]

Well, the chip supports hardware scaling, so it's possible.

 

[DaveC]

So can you also make games in a little bigger size that way?

​

It's hardware video decoding. Not sure you can use it to do anything with games. Anyway, why would you want to?

Actually hardware scaling can be really useful for emulators to quickly and smoothly scale games to full screen and proper aspect ratio. This is done on emus for the Zodiac all the time and it works really nice. I'm hoping this option will be added to emus on GP2X where it makes sense.

​

I don't like scaling it makes stuff look all distorted and with smoothing blurry. That is because you can't scale 1.5:1 without some pixels doubled while others are not. 1:1, 2:1 etc look ok but not fractional scaling.

It will be ok as an option I just hope they don't make it mandatory.

 

[DaveC]

aaand to keep this on topic... So the GP2X will output video in it's original/correct resolution? Can it enlarge too?

​

Well, it NEEDS to enlarge the videos, as a TV has a fixed resolution, and whatever you play with it needs to be resized to that resolution, be it be larger or smaller.

​

But I thought CRTs can adjust a bit for slightly different resolutions. For example the MD had some games at 320 x 220 and others at 256 x 220. The first one has more square pixels, while the second more rectangular. They both fill the TV screen so the MD must output a slightly different scan rate to get it to display both fullscreen.

 

[DaveC]

Also remember that you probably won't see all of that 720 x 480 video. Some of the video will be cut off depending on how much your TV overscans.

They always made it a habit of broadcasting more video than most TVs display because all TVs are slightly different. Some cut off more than others (overscan). They didn't want you seeing a black bar on the side of the screen so that is why it is done. Plus over time a CRT will drift in picture size and position too, this overscanned video makes up for it.

 

[Esn]

Isn't smert like, dead, in russian?

​

Yeah... except that the "t" is soft at the end (smert').

Also remember that you probably won't see all of that 720 x 480 video. Some of the video will be cut off depending on how much your TV overscans.

They always made it a habit of broadcasting more video than most TVs display because all TVs are slightly different. Some cut off more than others (overscan). They didn't want you seeing a black bar on the side of the screen so that is why it is done. Plus over time a CRT will drift in picture size and position too, this overscanned video makes up for it.

​

What about digital tvs, though? Don't they display the entire image, without cutting the sides off? Also, how does that whole NTSC/PAL thing work on digital displays?

 

[DaveC]

Isn't smert like, dead, in russian?

​

Yeah... except that the "t" is soft at the end (smert').

Also remember that you probably won't see all of that 720 x 480 video.  Some of the video will be cut off depending on how much your TV overscans.

They always made it a habit of broadcasting more video than most TVs display because all TVs are slightly different.  Some cut off more than others (overscan).  They didn't want you seeing a black bar on the side of the screen so that is why it is done.  Plus over time a CRT will drift in picture size and position too, this overscanned video makes up for it.

​

What about digital tvs, though? Don't they display the entire image, without cutting the sides off? Also, how does that whole NTSC/PAL thing work on digital displays?

​

HDTVs? They scale up the image to fit. For some reason they overscan them still resulting in some being cropped off in the overscan area. TV manufacturers are real paranoid about you seeing a black bar somewhere so they crop instead. You can adjust overscan on some TVs if you go into the technician service menu though. You can set overscan, color bias, RGB cutoff levels, convergence etc. That is risky as you can really botch up the settings if you don't know what you are doing there. There are many in depth FAQs on service menus on the 'net so I am not going to go into those.

I went into my Sony PVM 2030 RGB monitor (I have my PS2, Xbox etc on that using RGB cables that I hacked together) and adjusted the pots for overscan, position, and pincushion. The set still has a bit of a red push but I couldn't find that adjustment. The geometry and overscan was set terrible from the factory. Most sets that I have seen are pretty messed up from the factory and need major tweaking.

Even many LCD panels have major overscan. They scale up the image and to me it looks crappy. I would prefer a small border but at 1:1 and no scaling or smoothing. I think it is possible with a VGA connection on some though.

 

[woogal]

Well, the chip supports hardware scaling, so it's possible.

​

Yes, but I think the hardware scaling might be part of the video post processor, which is why I'm not sure if it can be used for games.

 

[Squidge]

I think it can scale from video memory as well, but the image data might have to be in 2D format, rather than 1D.

Still, if that's a problem, we can just take the frames from the emu, mpeg encode them, and then decode and rescale them

 

[Vimacs]

lol, that solution sounds.... do ms have anything to do with gp2x?

 

[DaveC]

I think it can scale from video memory as well, but the image data might have to be in 2D format, rather than 1D.

Still, if that's a problem, we can just take the frames from the emu, mpeg encode them, and then decode and rescale them

​

But why would you want to do all that? Almost all emus are close enough to full screen. Any that have a small border it is not that bad. That awful looking, image distorting stretching looks far worse than any small border. Plus if you are using the chip to do all of that converting you can't be using it as much for important stuff like speeding up emulation.

One of the main advantages of the GP2X screen res was that it matched emulated games so well without distortion. Why would we want to bypass that?

 

[Jarska333]

Isn't smert like, dead, in russian?

​

Yeah... except that the "t" is soft at the end (smert').

"Ogibaya virazhi, obgonyaya smyert' i zhizn'" Should there be y in there, I wonder... :huh: