MiSTer FPGA Forum

The new 24-bit rendering is very interesting. Really helps you clean up dithering and banding, best of both worlds.

However I noticed a bug? specifically with the "Dither 24 bit for VGA". In Final Fantasy VII, right after the intro movie, there's like flickering lines of light emminating from all the moving polygon characters. This applies to both the field and battle, and looks the same on both analog and HDMI. Turning off "Dither 24 bit for VGA" is the only thing that seems to fix it.

A different bug I noticed was the distant fog in Silent Hill gets all "glassy" looking as soon as you turn off dithering and turn on 24 bit rendering

"Dither 24 bit for VGA" will add some noise that is usually hidden on a CRT TV. Never use it for HDMI.

Also 24 Bit rendering can always have some problems, because it uses bits in the rendering path the developers have never seen.
So if there is e.g. flickering or weird effects in the additional 3 bits, it's just like this and i cannot do anything about it, sorry.

So far i have not seen many games with problems there, but in some it was visible, e.g. with dynamic light sources.
You must decide yourself if it distracts you.

I don't think you exactly described what I'm seeing. Its more bright bands of flickering light, not random static noise, and its in an area that should be completely static. Note that this only shows up with "24-bit dithering for VGA". It does not apply to just 24-bit rendering by itself, that looks fine. Hopefully this animated GIF shows it.

FoxbatStargazer wrote: ↑Mon Oct 24, 2022 8:20 pm I don't think you exactly described what I'm seeing. Its more bright bands of flickering light, not random static noise, and its in an area that should be completely static. Note that this only shows up with "24-bit dithering for VGA". It does not apply to just 24-bit rendering by itself, that looks fine. Hopefully this animated GIF shows it.

I have also noticed the same lighting effect with 24 bit rendering on.

blacklistedcard wrote: ↑Tue Oct 25, 2022 12:39 am

FoxbatStargazer wrote: ↑Mon Oct 24, 2022 8:20 pm I don't think you exactly described what I'm seeing. Its more bright bands of flickering light, not random static noise, and its in an area that should be completely static. Note that this only shows up with "24-bit dithering for VGA". It does not apply to just 24-bit rendering by itself, that looks fine. Hopefully this animated GIF shows it.

I have also noticed the same lighting effect with 24 bit rendering on.

Did you also use "Dither 24 bit for VGA"? I only see the effect with that switch flipped on together with 24-bit rendering. Just one of them on doesn't do anything weird. And can you see this in an early scene you can name?

FoxbatStargazer wrote: ↑Tue Oct 25, 2022 3:22 am

blacklistedcard wrote: ↑Tue Oct 25, 2022 12:39 am

FoxbatStargazer wrote: ↑Mon Oct 24, 2022 8:20 pm I don't think you exactly described what I'm seeing. Its more bright bands of flickering light, not random static noise, and its in an area that should be completely static. Note that this only shows up with "24-bit dithering for VGA". It does not apply to just 24-bit rendering by itself, that looks fine. Hopefully this animated GIF shows it.

I have also noticed the same lighting effect with 24 bit rendering on.

Did you also use "Dither 24 bit for VGA"? I only see the effect with that switch flipped on together with 24-bit rendering. Just one of them on doesn't do anything weird. And can you see this in an early scene you can name?

My options, I have the 24 bit for VGA turned off.

VGA 24bits should never be used with hdmi output.
Like it was said earlier, 24bits could interfere in some rare cases, when it's the case just turn it off ^^
also always have the 2d detect (it shound't be off ever really) if you use texture filtering

Neocaron wrote: ↑Tue Oct 25, 2022 5:19 am VGA 24bits should never be used with hdmi output.
Like it was said earlier, 24bits could interfere in some rare cases, when it's the case just turn it off ^^
also always have the 2d detect (it shound't be off ever really) if you use texture filtering

I'm seeing the exact same effect on the VGA port, no scaler (15khz).
If it were a 24-bit rendering error or a texture filtering error I'd expect to see the same issue with 24-bit dither off. Personally I don't.
It makes me suspect something up with the dither algorithm or some unintended interaction.