Can I add horizontal padding without a custom aspect ratio?


After a few weeks of headaches I finally managed to get RetroArch working on a Linux machine outputting a nice VGA signal to a 15khz CRT TV with switchres. Things are glorious and I’m very pleased with the results, every core I’ve tested so far is working wonderfully and resolutions are crisp and nice all around.

I have a problem with my TV, however, that I’d like to see if I can fix with RetroArch. Basically, the service menu gives me several options to adjust vertical geometry but it provides absolutely no options to handle horizontal geometry. Because of this, I have no way of adjusting the image to not be cut off on the left and right of the screen (overscan).

Some games handle this well, others not so much, so I’d like to fix it.

If I try to use a custom aspect ratio it works, but then for each core (and possible game) I have to set up the correct number of vertical lines, otherwise I lose crispiness and even get some artifacts since I don’t use bilinear filtering. Core-provided aspect ratio is working perfectly.

Since I’m using one of those super resolutions - 1920x240, 2560x224, that kind of stuff - I have plenty of pixels to go horizontally for any kind of processing, so I was thinking that maybe I could use some kind of shader to add black bars to the left and right of the image, effectively squishing it horizontally.

Is this possible? If so, which shader do I use? If not, is there another solution (other than acquiring a new TV)?


If you’re already using a super-res, I think you should be able to just change your custom width to be a higher scale, right? like 6-ish?

The options for super-res on switchres are 1920, 2560 and 3840. All options - including not using super-res at all - fill the screen horizontally. Just changing the super-res does not change the actual width of the image on the screen.

Unless you’re talking about the custom aspect ratio. In which case, that one won’t do because my resolution is not fixed - switchres changes the width to the selected super-res and the height/refreshrate to the exact ones used by the content so I get perfect lines/pixels. Changing the aspect ratio to a custom one, while fixing the problem, messes up the height of the custom resolution, making lines uneven.

To anyone who might come across this, I solved my problem by using the misc/image-adjustment shader and changing the value for the Horizontal Overscan %. Since I have plenty of horizontal pixels it works just fine as long as I don’t touch the vertical sizing.

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