Odd screen size with game supporting widescreen

[Quzar]

I have a pal, pre-production version of wacky races, which I ripped to GDI (and have made sure it wasn't a problem with the rip). Using the default configs, nullDC beta1 displays only about half of the screen. I suspect it may have to do with wacky races being one of the DC games that supports widescreen output. It has no errors (apparent errors) but only displays a portion of the screen.

It is noteworthy that it will display the full screen during the loading portion of the game, up until you get to the main start screen.

[KanedA]

maybe that's emulator problem? Let's wait for coders answer

[drkIIRaziel]

It most likely uses progressive scan :).Progressive scan has half the resolution...

[iamp]

Hm. Progressive scan? Why half resolution? it's must be full resolution frame each cycle.oO

[drkIIRaziel]

TV's can do either 480i , either 240p.They don't have the bandwidth for 480p.
Dc outputs 480i/240p when connected to tv , and 480p when connected to vga

[iamp]

Hm. Is that so? Strange.
But regular tv cannot handle progressive scan. Don't it?
DC supports progressive output only when using vga box.
Other connection types used on DC doesn't support P-scan.

But how it is working on emulator :eyemove:
Only drkIIRaziel knows it. oO

[PsyMan]

Regular TVs support both progressive and interlaced mode.

[iamp]

How? 8)
Composite video, Scart - only interlaced **** %)

[hushypushy]

Most "regular" TVs don't support progressive scan. That's one of the things that makes them "regular" ;)

[Quzar]

Actually many normal TVs will accept a progressive version of the normally interlaced one at half the refresh rate. 240p30 is rare, but many SDTVs can handle it.

[PsyMan]

Exactly. "Regular" TVs support progressive scan but only at 30Hz (or 24Hz for PAL).
Some DC games do progressive scan on "regular" TVs but their resolution is often changed either to 640x240 or even to 320x240. They draw half the resolution and then the screen is stretched using the frame buffer... Don't ask details on how DC manages that on "regular" TVs cause I have no clue). On the other hand, some other games might use other non 4:3 resolutions (and use the frame buffer to stretch the image) but still use interlaced scan.

When using the VGA adapter you achieve progressive scan at 60Hz instead of interlaced at 60Hz which is the best possibility. :)

[iamp]

Understood. thankz =)
And which DC game are using that crap? =)

[Cid Highwind]

Well waddaya know, it's Quzar :D

And I'm interested on knowing about these games as well. Also 320x480 in progressive scan mode sounds rather odd to me. I always thought interlacing was done on horizontal lines, hence the scanlines?

[PsyMan]

It is odd... cause I messed the post. It's a fact I mess up when I post sometimes... but sometimes I really overdo it.

* PsyMan edits previous post...

[hushypushy]

You're contradicting yourself. First you say that regular TVs can support progressive, then only some TVs, then only some modes.

No. Please, spare me.

Like I already commented on IRC, I think one of the conditions for it to be called a "regular" TV is the fact that it doesn't support progressive. Let's see, I have a 20" Sony "regular" TV sitting around, that doesn't do progressive. My sister's old TV doesn't support progressive, my girlfriend's TV doesn't support progressive....even my parents' brand new 24" and 27" CRT TV's don't even support progressive. I checked, the 27" even has component input but no progressive scan. It'll do 480i nicely though.

So what does "regular" mean to you, then? No system is outputting 480p (which I consider progressive...240p is the same as 480i) through composite. And even some TV's (such as the aforementioned example) support component but only do 480i (SDTV). Real progressive, which is what we're talking about, begins with EDTV and HDTV.

[PsyMan]

Ehh... no?

Interlaced scan results in blurring effect and even artifacts (due to skipping each line every time the screen is updated) but the motion is more smooth.

On Progressive scan the lines are drawn at the same time, thus eliminating blurring and such but since "Normal" TVs cannot co-op with the bandwidth needed to achieve HRESx480p either the VRES or the Hz must be cut to half.
This results in HRESx480p at 30Hz (24Hz for PAL) or HRESx240p at 60Hz (50Hz for PAL) and "normal" TVs can do that. ;)

[drkIIRaziel]

All tv's (should ?) support progressive scan , at 50/60 hz.The difference on it is that we send frames in one field (640x240) , instead of two fields.Thats why the resolution is half.

Interlace signal is like :

frame 0:
sync
field0 (640x239.5)
sync
field1 (640x239.5)
frame 1:
...
Progressive is :

frame 0:
sync
field0 (640x240)
frame 1:
....

Before dc , many consoles used progressive scan , because its hard to do it flicker free (that includes amiga & older stuff ;) )

[hushypushy]

Progressive scan, to me, is 480p. You're showing a full frame EVERY time. Not half of a progressive field, and not a full interlaced field. Every frame has every bit of resolution.

And I have several TV's that will attest to not supporting this, believe me, I have tried.

That's not to mention the hardware limitation...I've never seen anything that will send 480p over a composite cable.

[drkIIRaziel]

Uhh , well progressive means no interlace .. but it doesnt have to be 640x480.Yes , it sends full frames.But they are half the size ;)

[Quzar]

um. the video in the game shows at 1/4 the size, not half. Have you tried it yourself yet? ... maybe I should get some screenshots up.

[hushypushy]

Uhh , well progressive means no interlace .. but it doesnt have to be 640x480.Yes , it sends full frames.But they are half the size ;)

Yeah, you're right, it does. So if you want to "weasel" around it like that, then fine. But for real progressive scan, which to me is 480p (EDTV), no, it's not gonna be supported.

Unless the game runs in 640x240 by some chance (very widescreen).

[PsyMan]

Ehh... A game running at 640x240 does not have to be widescreen. The image can be stretched you know. Why do you think some games running on nullDC take only a quarter or half of the screen? Cause they use small resolutions but the "stretching" part is not implemented. :p

[Quzar]

Ehh... A game running at 640x240 does not have to be widescreen. The image can be stretched you know. Why do you think some games running on nullDC take only a quarter or half of the screen? Cause they use small resolutions but the "stretching" part is not implemented. :p

What I've been trying to explain is that it doesn't show up as 1/4 the size. It shows only 1/4 of what should be on the screen stretched onto the entire screen.

edit: added screenshots (please excuse the window in the corner, i forgot it would capture that). The first shot is in the game menu. The second is before that, in the loading portions.

[drkIIRaziel]

Ahh , thats different then , most likely it uses AA .. Support for it is missing too =P

[Quzar]

Yea, that's what I was talking about the other day. Doing AA by having the screen be four times larger and shrunk back down to get higher quality.