recently bought 4K LG TV to my parents. I noticed, that default CE behauviour is
4:4:4 when 30fps or lower
4:2:0 when higher fps
which could be overwritten by 4:2:2 CE option. My trouble is, that older receiver (Pioneer VSX 323) supports only 4:2:0 and only fps =<30. At least that my assumption from digging 4k specs from later pioneer models; for this mode from 2014 there is no reference according chroma at all, just mention about max 30fps. I know that default CE setting doesnt work for my 30fps test video.
Could I ask to add 4:2:0 option to the menu aswell, for the older receiver compatibility? Next time I visit parents Ill try 4:2:2 option, but I think 4:2:0 will be needed, and kinda makes sense as an option, when >30 fps have those by default and many videos using just 4:2:0.
I ordered also some expensive HDMI cables, but considering existing 50cm length, and especially after digging into Pioneer 2015 specs, 4:2:0 would be much appretiated.
I guess I could use some
/sys/class/amhdmitx/amhdmitx0/attr attribute to trigger YUV420 for testing purposes? Maybe
echo '420,10bit' > /sys/class/amhdmitx/amhdmitx0/attr
or is it overriden by CE when starting video? I know its valid for all videos and it breaks autoswitch functionality, but for testing purposes, I think correct solution would be add 4:2:0 to switch for legacy devices (that AVR is brand new condition