Hi,
I tried Orange Pi One Plus H6 version of LibreElec from here: https://test.libreelec.tv, sound is working through HDMI, also detects resolution with HDMI-VGA converter and in both cases i have sound and hardware accelerated graphics, youtube at full fps with audio sync.
I disabled 2 cores with
echo 0 | sudo tee /sys/devices/system/cpu/cpu2/online
echo 0 | sudo tee /sys/devices/system/cpu/cpu3/online
and works perfect without heatsink.
But sadly this is not what I want, I need X11 with hardware acceleration and chrome browser, I tested in Armbian and works ok, but without sound.
Also I tested recent Xunlong orange pi mainline kernel and I have audio but no graphics acceleration and no thermal sensors, I tried to recompile kernel myself several times with different settings without good results.
I'm struggling with this for several days, perhaps with mainline version in Xunlong OrangePi repositories plus LibreElec dtb/dts, and https://github.com/warpme/minimyth2/tree/master/script/kernel/linux-5.4/files patches someone like Igor can enable sound, I'm years away of knowledge needed, I dedicated about 12 days (almost full-time) trying to have a distro working with sound and video, I purchased 3 different sd cards, I downloaded and built All Oficial repositories images of OrangePi with kernel 4.9 and mainline and I failed every time to get all working together, I tried several versions of Ubuntu, Debian, I debootstraped rootfs of debian and also of course I tried Armbian, for me this last one is perfect, stable and great, so if anyone can make sound via HDMI working will be great for all newbies like me.
Thanks!