Native resolution on EU games (PAL) with Beetle PSX

RetroArch General
#1

For many years, I’ve had great success finding the native resolution on US games (NTSC) for the beetle psx libretro core.

If I take a game like the original Gex, I make a separate cfg file within the config folder of beetle psx, and add the following:

aspect_ratio_index = “20” video_aspect_ratio = “1.33”

The native resolution of Gex must be 320x240, hence the aspect ratio of 1.33 (320 divided by 240 equals 1.33). I have to pixel peep on each 2D sprite based ps1 game to make sure that the native resolution actually matches the image. If some of the square pixels are not indeed square at all, then most notably I’ve chosen the wrong aspect ratio.

On US releases we have resolutions like the following for 2D sprite based games:

256x240 320x240 364x240 (the two Oddworld games)

However; I’m having a hard time nailing the native resolution of the EU PAL release of Mickey’s Wild Adventure. It seems I’m able to get the horizontal resolution about right, but in the vertical space it seems like some of the pixels are a bit taller than the other pixels.

There is some options called beetle_psx_initial_scanline_pal and beetle_psx_last_scanline_pal (I’m just reading from my config file for RetroArch now), but I haven’t really had any kind of success as of yet when trying to get even pixels on the whole image for Mickey’s Wild Adventure. Earlier on I did manage to discover that the native resolution of that game to be something like 320x252 (I don’t remember exactly how I did that though, it was many years ago).

Any suggestions when it comes to EU PAL game and it’s native resolution?

#2

PAL games that are optimized for the region may use 256 lines instead of 240. Not all lines need to be used of course, much like with NTSC games that will only show 224 lines.

Beetle will also account for the PAL overscan, so it will put the active res into a 288 line frame. You can see the internal resolution by turning the “GPU screenshot” setting to off and then taking a screenshot in Retroarch.

1 Like
#3

Thanks for the reply.

With the help of the information you provided, I managed to figure out what I did wrong. Somehow I had managed to change the default values on psx last scanline pal; it was way lower than the default 287. Once I corrected that, the selected EU PAL games ran at a native resolution of 320x240, and turning the GPU screenshot setting on again & taking a new screenshot the image was output at 1280x960 on my 1080p screen with integer scaling enabled.