MiSTer FPGA Forum

This may not be feasible, but I’ll go ahead and ask anyways:

Would it be possible to force a 4:3 aspect ratio for displays that don’t have a 4:3 option?

Ex: My 4K TV supports 1440p video mode, but stretches the aspect ratio. It has no option for 4:3 when I go into the display settings.

I’m guessing that maybe the MiSTer is already trying to force 4:3 (it does in 1080p and 720p) and that it’s just not going to work on my TV, but I’d love to hear someone say it may be possible

Does your TV have letter box detection and tries to stretch the image maybe?

Not as far as I can tell. I’ll probably dig through the settings again tomorrow and see if I missed anything.

Looked at my settings again. No settings that appear to be stretching the image or anything like that (no overscan happening either in 1440p or higher mode). I even accessed the hidden service menu and there’s nothing there either. Interesting thing is, I usually have picture setting options like “Zoom, Wide, Cinema” etc, but in 1440p or higher I lose those options.

Oh well, chances are I need a better TV...

My Acer monitor (1080p 27") doesn't have a 4:3 option but it displays MiSTer cores in 4:3 and the main menu in 16:9

There's no additional metadata in the HDMI signal that indicates whether it should be interpreted as 4:3 or 16:9. 1920x1440 is already a 4:3 aspect ratio assuming square pixels. The rest is up to the display.

Mister's 1080p is 1920x1080, which is already a 16:9 aspect ratio. It just puts black bars in the signal on either side for most cores and scaling modes (Try going into the core's menu and change aspect ratio and watch it fill the screen.)

I think the only way to force it to 4:3 if your TV doesn’t have an option for it is to have the mister output at the full resolution of your TV (presumably 2560x1440?) and set the core’s aspect ratio to 4:3. Then the image sent to the TV will be 16:9, but the active area in it will be 4:3. But, according to this post, you can’t set it above a horizontal of 2048, so that’s not gonna work for you. I’d try 1280x720 (MiSTer’s default setting) and see how well the TV upscales it. It’s a straight doubling, so if you’re lucky you can get your TV to scale with minimal processing for a clean picture.

Actually I just saw that the TV in question is 4K, so 720 is probably a better option anyway since there’ll be upscaling regardless. 720 gets tripled to 4K. 1440 gets multiplied by 1.5, which is a recipe for bad scaling by the TV. Edit: or use 1080, then it gets doubled. Depends on the resolution put out by the core you want to use and your preference for how it gets scaled.

What make and model is your tv? Pretty much every TV has an option to switch the way it's scaling the image to some degree, and there usually is one that is called "Standard" or "Aspect" or something like that, not necessarily "4:3"

I could probably take a look at the manual to yours and figure it out.

aberu wrote: ↑Wed Jan 27, 2021 4:06 pm What make and model is your tv? Pretty much every TV has an option to switch the way it's scaling the image to some degree, and there usually is one that is called "Standard" or "Aspect" or something like that, not necessarily "4:3"

I could probably take a look at the manual to yours and figure it out.

My 1440p ASUS monitor, which is also G-SYNC capable, just refuses to display 1920x1440, let alone non-standard refresh rates, unless it's driven by Windowsthe OS According to the manual, these capabilities can only be activated with a display port connection.

Same with my old PAL CRT TV; it won't accept anything over or under the exact B/G standard, except if it's fed with with a fake vscaler signal.