MiSTer FPGA Forum

Hello all,

I was hoping to get some clarity on the easiest way to understand how the MiSTer displays aspect ratios. I stream on Twitch and I want to create different overlays for each console I play. I'm pretty OCD about this stuff and I want to have the binding box for the system on the overlay match the game, no black borders or anything once you sort out all the overscan settings.

For now, I've been trying to use https://mister-devel.github.io/MkDocs_M ... esolutions as the guide to create the game footage binding box in Photoshop for the overlays. For example, the page claims NES's default native resolution is 256x224, which is an aspect ratio of 8:7, which is consistent with what other articles about the original NES claim. So far, so good. However, I create a 256x224 binding box in Photoshop, and then retain-scale it up to 1023x1014, keeping the 8:7 aspect ratio. Nice.


Then I try to overlay the game footage after cropping out the black borders, and boom, it's more like an aspect ratio of 4:3 or something. I have tried to set the MiSTer.ini file to scale to integer scaling only, I've played around with the crop/overscan/aspect ratio in the NES core, and the only thing that even came close to actual 8:7 was to turn off all the overscan, automask the edges and use the Narrower HV-Integer. Even then, there's still a vertical remainder compared to 8:7. This is a problem for pretty much every other core that isn't flat out 4:3 (sometimes) or 16:9 stretched.

Essentially, I'm just looking for some clarity on what the best way to create these binding boxes to the correct size each time. It's pretty slow and tedious just doing minor crop tweaks in Photoshop over and over trying to get it to match to what the MiSTer is outputting. Is there some sort of consideration or reference I can use? I really appreciate any help on this, thank you.

The mister ini only addresses vertical integer scaling, mainly so that scanlines line up. It doesn't affect horizontal integer scaling. For that, you need to boot up the core and go into the video options on the HuD. Many cores let you toggle past normal to HV integer scaling (horizontal-vertical). HV- is probably what you want here.

Just for clarity though, the 4:3 image is much closer to what you would see from a real NES hooked up to a CRT TV of the time. Pixels on CRTs were often represented as non-square (fat rectangles in this case), so you can't derive the true aspect ratio from just the resolution numbers. I will leave aside the interminable arguments about artistic intent but just be aware that 4:3 or something close to it is how the majority of systems that Mister emulates were experienced by consumers back in the day, and that is what the default scaling settings on Mister aim for.

That's a good mindbending layering of info, but good info regardless, thanks. I suppose it'll be easier if I just keep most of the cores on a 4:3 ideal based on what a CRT would display instead of thinking via internal resolutions. Maybe a couple 16:9 opportunities in PSX/Saturn or something, but majority just 4:3.