Scanlines while scrolling

[akeley]

So I had a quick foray into the HDMI land...

For some reason my monitor (Acer Predator XB271HU) had refused to work with video_mode=12 (even with vsync_adjust=0) so I settled on 8. Then tried PVM and Trinitron presets. The "disappearing" effect seems stronger on MiSter than on my Trinitron, but not by that much. It depends on a game and scroll speed. Eg in 240p suite, in the vertical scroll test, lowest speed, I can still just about see the scanlines/pixels on my CRT, but not on MiSTer...the switch seems more immediate. But in the Addams Family Values on SNES (which is my personal "test suite") the disappearance factor is about the same on both MiSTer and the CRT. Guess on even faster scrolling games it'd be also indistinguishable.

More worrying was a rather ugly blur when moving on a horizontal plane. That's definitely not present on a CRT. I also saw odd vertical banding in some games. These artifacts might be down to something with my setup, since I don't know much about HDMI settings. However, I haven't really changed anything apart from the resolution in the ini + presets, and a quick browse through the cores' Video scaling ones.

You can have a gander at my mister.ini, but I got a fresh one from the wiki for this experiment so there shouldn't be any old residue present.

[Sigismond0]

You can have a gander at my mister.ini, but I got a fresh one from the wiki for this experiment so there shouldn't be any old residue present.

I think this is your culprit:

Code: Select all

vscale_mode=0          ; 0 - scale to fit the screen height.
                       ; 1 - use integer scale only.
                       ; 2 - use 0.5 steps of scale.
                       ; 3 - use 0.25 steps of scale.

Try setting to 1 insead of 0. If you're set to 1080p output, most cores are scaling at 4.5x which means you have uneven vertical scaling and that WILL impact how good scanlines look. This will change soon with the introduction of 256 phase filters, but that'll take a little while to get implemented into cores and the filter repository.

Alternatively, leave it set to 0, and in your SNES core set the crop mode to 5x. This will lose a few rows of pixels at the top/bottom of the screen, but will guarantee that you're integer scaled for perfect scanlines.

[akeley]

I did try the vscale "1" but it didn't seem to do much. Crop mode was better and got rid of the "banding" effect, but it does not seem to work in all cores (eg, not in the few microcomputer ones I've tried). Maybe they need dedicated shadowmasks or other filters?

The horizontal blur is there no matter what, though how pronounced it is depends on the game. I don't think it's down to my settings so perhaps it's inherent to the usage of filters or the nature of modern panels themselves.

Overall, the new shadowmasks are looking pretty good, definitely zillion times better than the "raw" unfiltered look. They could use some help from shaders, to make it all look a bit more lively (maybe OLEDs are better than computer monitors in that department) but I guess that's not possible here. I could probably get used to them, especially if it'd be possible to tweak that blur away.

One worrying thing though is that my ~400USD gaming monitor refused to work in 1920x1440@60 at all, and in mode 8 I had to use mostly vsync_adjust=0. If I was ever considering using HDMI, searching for one that could both look good and sync to everything could be quite a hassle.

[Chris23235]

I use a 32 inch gsync capable gaming monitor that works well with 1920*1440. It syncs with vsync_adjust=2. Systems that change the resolution often like PSX always take a few seconds to sync after a change but it works. Blur is definitely stronger than on a CRT, but I think this couldn't be helped without BFI or a similar technique.

[FoxbatStargazer]

This is a bit niche but I was looking at the tail end of the intro for Arcus Oddessey (Genesis), it features some white text slowly scrolling up on a background (with a sword graphic rising up even slower.) And even on the CRT monitors I have (including a 15khz one) the scanlines seemed to vanish on the scrolling text. So uh maybe don't drive yourself too crazy trying to eliminate this effect.

[akeley]

So uh maybe don't drive yourself too crazy trying to eliminate this effect.

The blur I'm talking about is horizontal and not present on CRTs (or at least to much lesser extent). It causes individual pixels to blend, not scanlines. The scanline-vertical one, the one OP was referring to, is indeed nearly the same on both, so that's fine.

[Sigismond0]

The blur I'm talking about is horizontal and not present on CRTs (or at least to much lesser extent). It causes individual pixels to blend, not scanlines. The scanline-vertical one, the one OP was referring to, is indeed nearly the same on both, so that's fine.

Blending is controlled by the horizontal filter. If you go into the recommended upscaling folder, the GS_Sharpness_000.txt filter is razor sharp, but GS_Sharpness_100.txt is super blended. For a CRT look, GS_Sharpness_040.txt is about right, but just find what looks good for you. If you really want razor sharp pixels to go with your scanlines and shadowmasks, try the SharpBilinear filters instead.

[akeley]

Blending is controlled by the horizontal filter. If you go into the recommended upscaling folder, the GS_Sharpness_000.txt filter is razor sharp, but GS_Sharpness_100.txt is super blended. For a CRT look, GS_Sharpness_040.txt is about right, but just find what looks good for you. If you really want razor sharp pixels to go with your scanlines and shadowmasks, try the SharpBilinear filters instead.

I might try it next time but I'm pretty sure we're talking about two different things. The image looks ok when static, using the settings and presets that have been recommended so far. The pixels (or phosphors, if you will) are separated and look like on a real CRT (well, to an extent allowed by resolution and lack of shaders), but when I move my character horizontally they blend/disappear/blur. When I stop moving they shift back into focus. I'm comparing versus original hardware connected to CRTs and that is not happening there, so that's definitely not a "CRT look" or, better yet, "CRT behaviour".

[FoxbatStargazer]

Yes sample-and-hold tech does in fact work very differently from CRTs! The only tools you have to combat this are overdrive, strobing, and black frame insertion, which many displays lack. Motion clarity is one of the main reasons enthusiasts still bother with this ancient out-of-production technology.

[akeley]

Yes, indeed...that is one of the reasons I bother with this "ancient" technology

Anyway, I have Overdrive enabled on Medium (this is a monitor I use for modern gaming after all) but it didn't seem to help much. And from what I recall BFI is not possible on MiSTer.

[clarkkent]

In my opinion the scanlines should be static and not influenced by any scrolling.