About PAL Artifacting

[José Pereira]

When I saw this image of Menace's Amiga version with the scanlines showed I started to think in something but have to study this PAL Artifacting better.

As I don't have a real Machine I would like to know if ALTIRRA Standard Pal Artifacting choosed it's what you see on real machines?

 

Also, last night with some tries with G2F and then loaded into ALTIRRA it seems that this thing works in 2x1 also (although less luminances because only PF0->PF4). Is this right?

 

The main idea is what? Having always the second scanline all way with a darker luminance?

 

My idea is to use something like:

-> PF0/PF2 as one colour and two luminances

-> PF1/PF3 another colour and two luminances

Background all scanlines as Black

(Like here the two colours would be Red and Green)

 

But, here, for example to have the greens and the Reds what colours/luminances I have to set (trying to get more luminances? more colours? Possible?)?

 

 

 

Then the PAL Artifacting on the gfxs but ships would be 'clean' and seen because they would be solid (no darker scanlines between) using Background, PF0 and PF1.

 

 

Edited August 28, 2012 by José Pereira

[Rybags]

I doubt that's using Pal artifacting.

 

I don't think much if anything ever done on Amiga would rely on any type of artifacting - Pal colour mixing doesn't work in RGB, it only works if you're using a TV or monitor with Composite or S-Video input. NTSC artifacting only works if using RF or composite input.

 

Besides that, the Amiga can put 32 colours onscreen in any screen mode before you have to resort to any Copper or HAM tricks.

 

There's just no real point - Pal colour mixing means you effectively halve the vertical pixel resolution. NTSC artifacting means you halve the horizontal pixel resolution.

Edited August 28, 2012 by Rybags

[Mclaneinc]

Trivia Fact: Menace on the Amiga was called Draconius before it was released, some damn handsome reviewer spoke to them when he got his review copy and told them there was already a game currently with the same name out there, so it was changed.

 

The damn handsome reviewer was of course me

[Lazarus]

There's just no real point - Pal colour mixing means you effectively halve the vertical pixel resolution. NTSC artifacting means you halve the horizontal pixel resolution.

Actually it's more 1/4th of the horizontal resolution on chrominance for both, PAL + NTSC. And half the vertical resolution also only affects the chrominance.

[José Pereira]

That is just a bad image on google images.

Ðon't even know if there's any other computer doing pal artifacting.

That bad image just give me some ideas and remind me ours scanlines based like, for example, project m.

[Rybags]

It's not the computer that does the artifacting, it's the TV (Pal colour blending).

In the case of artifacting due to placement of pixels to get the extra colours it's due to the way the signals are encoded for RF or composite.

 

Practically any device that outputs RF or composite can generate them, in most cases though they're undesirable effects.

[Heaven/TQA]

so in theory Master System & NES & 7800 could do PAL artifacting & interlacing stuff?

[Rybags]

Pal colour blending, you really need a decent range of greys and availability of dark normal colours for it to be useful.

[Lazarus]

so in theory Master System & NES & 7800 could do PAL artifacting & interlacing stuff?

Depends on what you mean by artefacting. Only some computers can generate new solid colors by using hires pixel patterns, for example Atari 8 bit NTSC or Apple II. Others (Atari 8 bit PAL, C64...) will not be able to produce a solid color by that. But you can still use the chrominance effects, like vertical chroma mixing on PAL. On A8 this is not that useful since the A8 already has quite some freedom on chrominance selection, but on C64 this is a real benefit since you can create real new colors and are not bound to the 16 hardwired ones.

 

Oh, and the A8 mode doing 256 colors relies on that ofcourse.

Edited August 29, 2012 by Lazarus

[Rybags]

The NTSC type artifacting relies on the pixel clock having a direct ratio relative to the colour carrier, ie 3.59 MHz NTSC to work properly.

 

That's the case for A8, 7800, Amiga, Commodore Plus/4, Apple 2 - and quite a few others.

[Lazarus]

It should be mentioned that the hires pixel pattern artefacting will not happen when using an S-Video cable. Other PAL/NTSC effects will still be there.

[Bryan]

It should be mentioned that the hires pixel pattern artefacting will not happen when using an S-Video cable. Other PAL/NTSC effects will still be there.

Right. Artifacting is when the TV cannot distinguish between chroma and luma components of the video because the luminance is changing at a rate that gets through the chroma filter. S-video solves the problem completely.