The absolute simplest hello world...

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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

iNCEPTIONAL wrote: Tue Aug 23, 2022 6:48 amCurios, does the interlacing on say that Ranma 1/2 Chounai Gekitou Hen game have even the slightest visual effect of making the image look slightly more "high res" purely due to how the interlacing works on the human eye?
No, it doesn't.

The effect it displays here is:
  • Nothing, when the screen is still.
  • On a CRT: all motion jitters up and down, mildly unpleasantly.
  • On emulators/LCDs/upscalers: constant horizontal "mouse teeth" whenever things move.
If you want an increase in apparent resolution via interlacing it can be done, but what this game is doing is not that.
iNCEPTIONAL

Re: The absolute simplest hello world...

Post by iNCEPTIONAL »

rainwarrior wrote: Tue Aug 23, 2022 10:27 am If you want an increase in apparent resolution via interlacing it can be done, but what this game is doing is not that.
Would that be by changing the image on every field then, or something different?
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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

iNCEPTIONAL wrote: Tue Aug 23, 2022 10:19 amSo, do emulators add something else in between the pixel art to keep it all the same relative distance apart that it would be if the gaps between scanlines were there on a CRT, or is everything actually slightly squished closer together vertically on emulators then? Or, am I not quite getting what you're describing here?
Some emulators have a "scanlines" option but it darkens the overall picture because it's inserting a line of black (or at least darkness) in between each row of pixels.

For a CRT, a 240p picture is the same brightness as 480i. You don't really see the gaps between scanlines very much from a distance, unless your TV has a very sharp focus (though some people are fond of the gaps and like to emphasize the effect).

The reason a 240p picture is the same brightness as 480i is that each line of 240p is twice as bright. The same amount of light is being delivered, just spread over 1 line in 240p or 2 lines in 480i. Otherwise the main difference is 480i causes the appearance of 30hz jittering because the picture is always wiggling slightly up and down.

Hard to simulate this properly on an LCD because it doesn't deliver light in the same way. It can't make every other pixel twice as bright. It can only go darker, not brighter. So, the "scanlines" option in emulators tends to just make the image look dark.
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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

iNCEPTIONAL wrote: Tue Aug 23, 2022 10:30 amWould that be by changing the image on every field then, or something different?
Yes. It's one of the things that Mode 5 exists to do.
iNCEPTIONAL

Re: The absolute simplest hello world...

Post by iNCEPTIONAL »

rainwarrior wrote: Tue Aug 23, 2022 10:35 am
iNCEPTIONAL wrote: Tue Aug 23, 2022 10:30 amWould that be by changing the image on every field then, or something different?
Yes. It's one of the things that Mode 5 exists to do.
So, 240p is the normal SNES display mode. And 480i is interlaced in Mode 5 (and I think 6 too), correct? What's pseudo-interlaced in the other modes then, 240i?

Also, how come they're 240 and 480 when the SNES's vertical resolution in listed as 224 in normal mode and 448 in high-res mode normally (at least the sites and videos I'm looking at online)?

Edit: Oh, sorry, you were just referring to the TV resolution when talking about 240p and 480i. My bad.

So, to re-write it: 224p is the normal SNES display mode. And 448i is interlaced in Mode 5 (and I think 6 too), correct? What's pseudo-interlaced in the other modes then, 224i? And, can you do 448p in Mode 5 (and presumably 6 too) then?
Last edited by iNCEPTIONAL on Tue Aug 23, 2022 10:51 am, edited 1 time in total.
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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

There is no pseudo-interlace. There's pseudo-hires, which is about turning on the 512 pixel horizontal resolution outside of mode 5/6.

240 lines is the standard picture. SNES just happens to (by default) output black for 16 of those lines to increase its vblank time.

(Apologies for so much digression, maybe this should be its own thread.)
iNCEPTIONAL

Re: The absolute simplest hello world...

Post by iNCEPTIONAL »

rainwarrior wrote: Tue Aug 23, 2022 10:50 am There is no pseudo-interlace. There's pseudo-hires, which is about turning on the 512 pixel horizontal resolution outside of mode 5/6.

240 lines is the standard picture. SNES just happens to (by default) output black for 16 of those lines to increase its vblank time.

(Apologies for so much digression, maybe this should be its own thread.)
Yeah, sorry. If you wanna move that, go ahead (you have the power to do that right--think you did it before). Because I have a couple other things to ask regarding the way RGME explains it for the different modes.
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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

No, I'm not a moderator. I can't split threads. (I don't even like splitting threads, normally, but this is a rather large volume of stuff off topic.)
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jeffythedragonslayer
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Re: The absolute simplest hello world...

Post by jeffythedragonslayer »

Do any YouTube videos of this "mouse teeth" problem exist? I'll have to track down Chounai Gekitou Hen.
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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

Examples:
Ranma 1-2 - Chounai Gekitou Hen (Japan)_000.png
Ranma 1-2 - Chounai Gekitou Hen (Japan)_000.png (11.42 KiB) Viewed 592 times
Ranma 1-2 - Chounai Gekitou Hen (Japan)_001.png
That's how it tends to look in emulators, or on a modern TV. (Though a modern TV will often do this with non-interlaced 240p content too.)

On a CRT, mice teeth are not really a problem (because the images aren't really displayed simultaneously), but instead there is some vertical jitter to all animation because of the interlacing.
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Re: The absolute simplest hello world...

Post by turboxray »

rainwarrior wrote: Wed Aug 24, 2022 4:03 pm On a CRT, mice teeth are not really a problem (because the images aren't really displayed simultaneously), but instead there is some vertical jitter to all animation because of the interlacing.
Yeah, on consumer level CRTs it's not noticeable (back in the day). There's just soo much overlap between two fields. I.e. very little gap between the scanlines. Professional monitors, sure, but consumer CRTs in general had less of an issue with it.
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rainwarrior
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Re: The absolute simplest hello world...

Post by rainwarrior »

I'd disagree with that. I've thought jitter was quite noticeable on every CRT I've had, for any video game or other computer-generated content that is interlaced. (Live action video is excepted.) I have distinct memories of it across many points in my life, on many different TVs.

However, I had heard a lot f people say they don't see it. I do think persistence of vision varies from person to person, and maybe I'm overly sensitive.

Didn't have any interlacing games for SNES, but PS1, PS2, and PS3 all had lots of interlaced content. DVD menus. VCR and DVD player GUIs. I remember being bothered by it with all of these. From a normal couch viewing distance.

Edit: Wikipedia seems to call it interline twitter. It has an animated diagram, though it's very much over-emphasized to make it apparent (and you can't really demonstrate the severity or non-severity of it without an actual CRT TV anyway).
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jeffythedragonslayer
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Re: The absolute simplest hello world...

Post by jeffythedragonslayer »

Oh, horizontal mouse teeth. One of the Star Wars Rogue Squadron games for the Gamecube has a menu option to toggle between progressive and interlaced output, and it takes effect immediately without even needing to leave the menu. That's the only time I've ever compared the same image on a CRT like that and I didn't like the bobbing effect.
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Re: The absolute simplest hello world...

Post by bocchi »

How noticable interlace flicker is depends a lot on how much sharp vertical detail there is. Later consoles during the era 480i was common provide a "deflicker" filter that applies some vertical blur to make it less apparent. A few games like Smash Bros. Melee on Gamecube has an option to enable or disable this, but usually it'll just always be on.
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Re: The absolute simplest hello world...

Post by Pokun »

Yeah other Nintendo games for Gamecube like Pikmin 2 has that option too. If I remember correctly it only has an effect if you use interlaced mode, not on progressive with the expensive component cable. Incidentally I bought one of those official component cables for an acceptable price (I think GCVideo has lowered the demand for it somewhat, plus I bought the D-terminal version which was cheaper) some years ago, but I don't have a CRT that supports 480p. I wonder if a CRT VGA monitor would work somehow since those do 31 kHz.
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