Flycast Dreamcast Emulator vs Overlays

Norstein

I cannot get lr-flycast to display my overlays as intended.
At first, I simply chose an overlay (Orionsangel's Samsung Day), set Integer Scaling to true, Aspect Ratio to custom, chose a viewport height and width that's the same as in my other consoles, set viewport x and y to 0.
Result: The overlay is there, but the actual emulation video still takes up the entire screen (I can see that because I still have my overlay opacity at 70).
It is working perfectly in SNES mode (overlay in 1920x1080 resolution, emulator video scaled to the viewport), so then I did the following:

renamed dreamcast retroarch.cfg to retroarch.cfg.old
copied my snes retroarch.cfg into the dreamcast folder
restarted emulationstation
Result: the overlay is clearly not in 1920x1080. Although it is stretched to the whole screen, it looks like it is rendered in 640x480 instead. The emulation video itself is so fucking big, that only the upper left quarter or less fits on the screen, the rest is outside of it.

Can anyone hit me up with a working overlay config? All I want is my Dreamcast output trapped in a CRT overlay, because that looks a little less shitty than stretching it to 1920x1080 and more nostalgic because of the fake CRT.

Norstein

Still not working properly.
Also, that might be an issue of my 4k screen (which runs at 1080p60 though), but the retroarch menu is for the most part outside of the screen, so I can't make any adjustments on the fly.

quicksilver

I recently started trying to get vectrex overlays set up on my pi 4 and I'm having a similar issue. No matter what I set the size in the config it doesn't seem to change at all. Can you post a sample of your configs and maybe we can compare notes?

Norstein

I'm not home right now, so I can't make a picture, but it turns out that my problem is not reproducable on normal 1080 displays, it seems to be a 2160p issue.
Will post my config if it helps you, though.

Anyway, even if it is just a problem with flycast vs 4k displays, that's still an issue.
Is there a proper place to post that? Like a bugtracker or git or whatever?

roslof

@Norstein - If you wouldn't mind locking your Pi to HD 1080P, you could modify /boot/config.txt

You might want to make a backup of config.txt first with:

sudo cp /boot/config.txt /boot/config.txt.original

Then add these two lines to the config.txt file:

hdmi_max_pixel_freq:0=200000000
hdmi_max_pixel_freq:1=200000000

Then save and reboot.

This change solved all my problems similar to what you described. Should work for you too. Remember that this puts your Pi into a 1080P state. If you need 4K, just comment out the lines and reboot.

EDIT: I'm personally, also using (uncommented out) these next two lines, but they may not be required to solve your trouble:

hdmi_group=1
hdmi_mode=16

Norstein

@roslof
Hm, nope. All that does is give my DOSBox a nasty single horizontal black bar (under the video output), on the 4k display flycast is still only showing the upper left corner of the video output.
And on a normal 1080p display, everything was working as intended to begin with, I just didn't know because I only tested that yesterday.

roslof

In addition to the change I suggested above, check your RetroArch settings. Not your core settings.

Make note of the RetroArch Video Settings

Set them up like this:

Start in Fullscreen Mode (Enable)
Windowed Fullscreen Mode (Enable)
Fullscreen Width 1920
Fullscreen Height 1080

We're basically forcing an HD environment. Again, you may need to lock HD as specified in my previous post.

Norstein

@roslof
Did that, but nothing changed.
I have no idea where else to look.
Talk about frustrating.