[1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Discussion about displays and related hardware including MiSTer filters and video settings.
User avatar
ItalianGrandma
Posts: 211
Joined: Sun May 24, 2020 7:09 pm
Has thanked: 45 times
Been thanked: 52 times
Contact:

[1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by ItalianGrandma »

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 :D
User avatar
Phaedrus
Posts: 70
Joined: Mon May 25, 2020 12:57 am
Has thanked: 41 times
Been thanked: 13 times

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by Phaedrus »

Does your TV have letter box detection and tries to stretch the image maybe?
User avatar
ItalianGrandma
Posts: 211
Joined: Sun May 24, 2020 7:09 pm
Has thanked: 45 times
Been thanked: 52 times
Contact:

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by ItalianGrandma »

Not as far as I can tell. I’ll probably dig through the settings again tomorrow and see if I missed anything.
User avatar
ItalianGrandma
Posts: 211
Joined: Sun May 24, 2020 7:09 pm
Has thanked: 45 times
Been thanked: 52 times
Contact:

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by ItalianGrandma »

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...
mcmister
Posts: 3
Joined: Tue Jun 16, 2020 9:37 pm
Been thanked: 1 time

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by mcmister »

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
FoxbatStargazer
Top Contributor
Posts: 1019
Joined: Thu Dec 10, 2020 5:44 pm
Has thanked: 315 times
Been thanked: 238 times

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by FoxbatStargazer »

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.)
Yim
Posts: 126
Joined: Mon Jan 18, 2021 11:51 pm
Has thanked: 3 times
Been thanked: 87 times

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by Yim »

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.
User avatar
aberu
Core Developer
Posts: 1192
Joined: Tue Jun 09, 2020 8:34 pm
Location: Longmont, CO
Has thanked: 247 times
Been thanked: 411 times
Contact:

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by aberu »

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.
birdybro~
User avatar
lamarax
Top Contributor
Posts: 472
Joined: Wed Nov 11, 2020 6:28 pm
Has thanked: 33 times
Been thanked: 202 times

Re: [1440p] Possible to add option for “force 4:3” on displays that don’t have 4:3 option?

Unread post by lamarax »

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.
Post Reply