dalrun

At least in 5.20 desktop, everything but VDPAU_OSD=1 is setup/configured for desktop playback, including --profile=pseudo-gui which provides a simple OSC (on screen controller) when VDPAU_OSD=1. I don't know where VDPAU_OSD=1 is supposed to be enabled, but prepending it to the ~/.local/share/applications/mpv.desktop Exec command works. That's essentially the same as manually running $ VDPAU_OSD=1 mpv --profile=pseudo-gui [filename] - a modified version of rellla's suggestion.

I didn't think it would work, because the display still dims somewhere in the middle of the boot sequence, but video playback is noticeably brighter. Thank you. It works when installed w/ dpkg -i, but then I get notified of one upgrade and I'm back to dark video after running apt get upgrade.