480i vs 480p Q.

Just a quick question I can't seem to google up....

When I play my games on my no-frills 480i CRT, simple things like an anti-aliased lines have a "crawling" effect along the perimeter of the aliased portion of the line...

Is that due to the nature of an interlaced display or something?

If so, I'm tempted to grab a 480p TV (too cheap to afford a game-ready ED/HDTV still) if that would solve that problem for a more clearer display on my gaming systems, cause that (and the fact my current 21" has its display warp slightly with bright colors) bugs the crap out of me.

yes

Yes,... the problem is really lack of resolution to draw the lines cleanly.

480i is really only 240 lines of resolution for each image. These are displayed 60 times per second alternating between upper and lower fields. (30 fps, 2 fields per frame = 60 fps)

a 480p display will update the entire 480 lines of resolution 60 times per second, so you will get twice the vertical resolution.

So I take it then 1080i would have the same problem, unless said TVs have some sort of optional filter built-in since they're usually displayed via non-SDTV methods?
(read: the big-ass tube behind the screen)

Wonder how the alternating thing works hardware wise, I take it the gfx card is really rendering it out in 480p, but interlaces the display each frame for displaying on older setups?
(would explain why some games have a "filter" you can toggle on which in essense jiggles the screen up/down 1px each frame which removes the line-crawling on fine-text, usually in RPGs)

yes, although not as bad.

this is why 720p is a higher resolution than 1080i
720p = 1280x720 60fps
1080i = 1920x1080 30 fps interlaced (in other words 1920x540 60fps)

Different hardware uses different methods to "up-res" things (I hate this terminology, btw) These are usually either duplicating the lines or using an interpolation method to create the missing info.

Anyways, this is more true for video signals,...a game system should not have to do this anyways, and should be able to send the full appropriate resolution. (assuming your tv supports it.)

The term I see mainly regarding TVs "up-res"'ing is upscaling, which appears more appropriate/recognizable.

Anyways, thanks for the info, just a matter of finding a company who knows how to clearly define the technical TV specs on the box rather than the usual "Clear, fast image! Supports S-Video!" crap.

Or possibly I should wait a bit and reconsider getting an HDTV & 360 together when the time comes (read: that even Joe Anonymous can afford it) so my could-be 480p system wouldn't be rendered unsatisfactory at that time.
(since the 360 can easily output 720p it appears, and that would bug me knowing I aint getting the most out of a $499'ish system {CDN currency, Microsoft screwed Canadians over})

Umm, s-video or component will both remove the crawling noise caused by interference due to color and brightness being combined in the same composite signal. If it's really bad try turning down the saturation setting on your tv.

480i and 480p isn't the same resolution?
one is interlaced and other is progressive, but the same resolution. 480pixels height

480i is 240lines per field, so 240+240=480lines but only 240lines viewed at one time.
480p show always 480lines on screen.

Yeah they're both 480 lines, but interlaced only has to update 240 of those each frame. The jaggedy edges come from the fact that you're viewing 2 frames in each image, so if the edges are moving, you will see 2 offset edges interlaced.

yup to the last few posts.

It gets even worse when you go looking for an HDTV set. Just because a TV SUPPORTS 1080 does not mean it DISPLAYS 1080 lines! Actually, it's possible to have an HDTV that only displays a resolution slightly better than NTSC.

They do this a lot with LCD displays,... take a look at the native resolutions of these monitors and you will see you're missing half the pixels in a lot of models.

All about deceiving the consumers I take it then in the TV market.

I miss the good ol' SDTV days when every TV had the same RF adapter, same composite cable input (well ok, not all of them had ones built-in, but thats what VCR/Modulators are for >.>), and all that mainly mattered was the size of the thing, not the refresh-rate, or "true" resolutions, aspect-ratios, or all that crap.


I'll take a look at adjusting my TV Skid, possibly make it less obvious on specific things (my eyes have a natural tendency to look for faults in things).

Bip part is antialiasing resolution/quality. And motion blur. Just look DVD or TV programs, not much lines crawling (except when looking 480i :) )