Got the last bug fixed to make #gtk4 play video *with overlay* in full zero-copy / hardware plane only mode \o/
This allows highly efficient playback with e.g. subtitles and other overlays, only using the GPU when GTK needs to repaint parts of the main window / the overlay.
I'll talk more about this at my presentation at #fosdem2024, see https://fosdem.org/2024/schedule/event/fosdem-2024-3557-the-state-of-video-offloading-on-the-linux-desktop/
