Sure, "just" pick patches from LE build system. Note, Kodi on LE does HW video decoding with patched ffmpeg and proper use of it. This probably won't work with random video player. I think that mpv needs only one small patch but I didn't try it in a long time. There is also an effort to make proper VAAPI layer which would be useful for most players but it currently doesn't work with latest kernel and wouldn't work with HW decoding improvements from LE without modifications. That's because kernel API for this kind of VPU HW is not yet stable and changes from kernel to kernel.
Thanks for your answer.
I would like to try that.
So in theory I need to apply the patches from 'http://LibreELEC.tv/packages/multimedia/ffmpeg/patches' ?
The player i would like to use is indeed mpv. Do you know where i can find the patch ?
Would I also need patches from libreelec for the kernel ? It seems so because when looking at linux/patches/amlogic/ there is some patches linked to lima.
Should I also use the patches from projects/Allwinner/devices/A64/patches ?
The build i would to try first is OLIMEX/build.