Hey @amazingfate, the above-mentioned av1 decoder issue was fixed, turned out that the Rock 5A and a few other boards did not have the av1d node enabled in the device tree. I did update ffmpeg and added some patches to mpv last night, after testing everything it looks good to go.
The packages ffmpeg, librga, libv4l-rkmpp, mpp, and mpv are ready to be copied to your PPA.
https://launchpad.net/~jjriek/+archive/ubuntu/rockchip-multimedia/+packages?field.name_filter=&field.status_filter=published&field.series_filter=jammy