I assembled a video player c2play, created by crashoverride, with the possibility of hardware decoding and rendering for a boxes on the S912 SOC. To achieve this, was used EGL and GLES libraries from Android, libhybris, libamcodec and ffmpeg with the support of the above library, as well kernel package with Mali driver for T820 GPU. All this was integrated into the firmware of Ubuntu Armbian 16.04 Mate Desktop, building by balbes150. You can download this firmware from here.
c2play perfectly playing, both local and network video H.264 and H.265 10-bit, checked up to 4K. Declared support of MP4, MKV and AVI containers.
A small help to managing the c2play from the keyboard:
ESC - to finish playing, LEFT - 30 sec. back, RIGHT - 30 sec. forward, DOWN - 10 min ahead, UP - 10 min. back. SPACE - pause.
To play video, open the terminal window or go to the virtual console (Ctrl-Alt-F1). enter the command: c2play <path to your video>. Or, assign c2play as the default application for the desired file type. More details here or here.
In the folder /opt are deb-packages with libhybris and kernel 3.14.29 with the driver Mali.
For those who want to build c2play itself, I bring links to resources on the github.