For reason I can't explain here , I had to run a video player at Non-X window OS  ( Armbian_5.96_Aml-g12_Ubuntu_bionic_default_5.3.0_server ) at a S905X tv-box.

I tried to play a mp4 video ( H.264 + AAC ) at the video player ( mpv ) with drm driver. The quality is just so so. Is there any other driver recommended ?  Did Amlogic provide a linux video driver which can hard-decode h.264 ？ Regards !

If i'm not wrong, there is an ongoing development on a mainline kernel module called "meson_vdec" that should allow to take advantage (at least partially) of the VPU inside the soc to get hardware decoding. I also tried to get this module working with modprobe, but with no success. Probably a very cutting edge kernel is needed to get this working. Once this module starts to working, i think libraries like  ffmpeg and gstreamer (and consequently the programs that use them) should take advantage of it.and consequently the programs that use them) should take advantage of it.

There is also a guide on the Amlogic forum section to get hardware acceleration using some scrips, but, like the author says, it is for testers, not for daily use. I have not tried it personally.