[Genesis Plus GX] Scaling artifacts

I’m using ‘core provided’ aspect ratio + integer scale but there are uneven pixels. I tried other aspect ratios (NTSC, PAL, 4:3, 8:7) but all of them result in scaling artifacts.

The game I’m testing is Castlevania Bloodlines (USA) and my desktop is 1080p.

I don’t have scaling artifacts in other cores like Mesen.

You want the 1:1 PAR aspect ratio option. Otherwise, check out the shaders in the ‘retro’ directory, which will antialias the sharp pixels to avoid “shimmering” while scrolling and other artifacts caused by uneven pixel sizes.

Thanks! Why isn’t this the default setting?

Still, even though there are no scaling artifacts, the background scrolling isn’t perfect. It should be super smooth but it’s, I don’t know how to describe it, it’s kind of jaggy. My first guess is that it’s something related to framerate. I have a 60hz monitor and I set it to the same value in RetroArch (thought the estimated framerate is something like 59.988).

Not everybody likes 1:1 PAR, and some cores/systems (such as Capcom’s CPS2 arcade platform) look really bad with 1:1 PAR. We default to ‘core-provided’, which usually means 4:3 just because that’s what most people expect.

That’s probably caused by frame dupes/drops. Try going to settings > audio and disable audio sync.

Looks like it, but disabling audio synchronization doesn’t fix it. I also tried the hard gpu sync but the effect is the same.

you can try the steps from this thread/guide:

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No effect, also there’s no Audio Maximum Timing Skew or Dynamic Audio Rate Control in the audio settings, just audio synchronization. Also, NES games scroll perfectly smooth on the Mesen core without touching any of those settings and they’re also NTSC.

Ok, if your scrolling is smooth in other cores, try loading the 240p test suite for Genesis/MD (you can get it from the online updater) and see if its scroll test is smooth.

Vertical scrolling is smooth, but horizontal scrolling is smooth only on the foreground layer, the background layer scrolls the same way as in Bloodlines.

aha, the background scrolls at 30 fps, so that means bloodlines’ scrolling is doing the same.

So is there a way to make it 60 or is that a normal behavior?

If the game is programmed that way, that’s just how it is.

But it’s the same as in the test suite. Is the test also programmed that way?

the test suite’s scrolling test has the foreground scrolling at 60 fps and the background scrolling at 30 fps. As long as the foreground is scrolling smoothly and consistently, it’s functioning as intended. The background will appear jerkier, but it should also be consistent.

Ok, thanks for your time :slight_smile:

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