How to enable "MMAL x11 splitter for Raspberry Pi" on vlc (or mpv) for rpi(4)?

[gc-user]

I'm in the process of testing if I can switch from PiOS to void linux on my rpi4.

Video playback is an essential feature that has to work on the rpi.

On PiOS, the only player that works for hd playback in full screen mode is vlc when set to "mmal x11 splitter for Raspberry Pi" for video output. Otherwise the playback is "juttery" or video / audio are even out of sync.

On void linux, I haven't yet found a setup that works in that regard. Neither vlc (with any of the available output settings) nor mpv nor mpcqt.

Transferring over the vlc mmal libraries from debian to void didn't work.

That's why I wanted to compile vlc (or mpv) with mmal x11 splitter included. But so far I haven't been able to succeed - I just added entries for mmal analogue to the omxli entries in the configure_args+= section of the template for vlc (line 83). But that's apparently not correct or not sufficient.

I wonder if therein lies the clue?

	aarch64*)
		# XXX only for rpi
		build_options_default+=" rpi"
		;;

I'm cross-building on x86_64 and now I'm wondering if ./xbps-src -a aarch64 pkg vlc isn't enough, and I somehow have to also state that I want to build for rpi? Or does aarch64 automatically mean "for rpi"?

Maybe someone else knows how to do that and can point me in the right direction or maybe make the rpi build for all include mmal x11 splitter.

Thank you!