Ok so here is the definitive solution :
You need panfrost so use the correct armbian version with vendor kernel, then you are going to need to compile ffmpeg for rockchip, just follow those instructions :
Once it is done, you might have some performance issues when capturing the screen with either x11 or Wayland, BUT ffmpeg allows you to capture directly from the device through kmsgrab
sudo setcap cap_sys_admin+ep /usr/bin/ffmpeg
sudo ffmpeg -device /dev/dri/card0 -f kmsgrab -i - -r 60 -vcodec h264_rkmpp -f rtp rtp://localhost:8004
There I am streaming to a rtp server but you can write into a file. Do not forget to use the -vcodec h264_rkmpp which will use hardware encoding through VPU.
