For those S912 users that have had 4K HDR Green Screen playback issues when setting a 422,10bit or 422,12bit Chroma and color depth I've been playing around with @kszaq's LE 8.2.x S912 code (thx mate !), and plugged the newer, improved LE linux-amlogic Kernel into it.
The one that is also used for alpha versions of AML LE Kodi Leia 8.9.x that GDPR-2 is releasing.
Note: there will be no ongoing support due to LE Kodi Krypton reaching stable status.
Be aware existing IR remotes have been reported cease functioning with this Kernel. I use a USB Wireless dongle - MINIX A2 lite remote.
There are also slight video playback juddering problems when watching Interlaced TV with this newer Kernel.
You can follow the discussion over on the Kodi forum if interested, where you will also find a S912 LE 8.2.x .img.gz update to drop into the update folder:
Auto frame rate switching & dynamic range matching - 4K (HDR10) capable Hardware
Some useful info here for 422 4K HDR testing (before very first video playback):
echo '422,10bit' > /sys/class/amhdmitx/amhdmitx0/attr
echo '422,12bit' > /sys/class/amhdmitx/amhdmitx0/attr
To permanently set on LE device bootup:
echo "echo '422,10bit' > /sys/class/amhdmitx/amhdmitx0/attr" >> /storage/.config/autostart.sh
Want to see the what your HDMI connected display is capable of:
For those feeling adventurous, you can ramp up the GPU clock to 792MHz for a bit more GUI snappiness, however chipset temps will increase quite a bit and may overheat and crash S912 devices.
In reality you need good Chipset cooling like the MINIX U1/U9 has:
echo 2 > /sys/class/mpgpu/scale_mode
Current GPU clock Frequency: