[noggin]

Thought I'd try a Milhouse nightly build on my UP Squared N3350 Celeron board (until recently serving pfSense firewall/VPN duties).  

I'm running it via a Displayport 1.2->HDMI 2.0 3D Club converter which handles proper 2160p50 and p59.94 output.  

Watching the BBC iPlayer 36Mbs 2160p50 HEVC Wimbledon stream which is wide colour gamut Rec 2020 with HLG EOTF it's interesting to see what happens with my Apollo Lake.

I'm getting 2160p50 RGB 8 bit output (594MHz) - with what looks like a Rec 2020 to Rec 709 conversion.  It doesn't seem to be Rec 2020 incorrectly output as Rec 709 (as some platforms deliver) - it does look as if Kodi or the Intel drivers are doing some gamut conversion.  No idea how accurate it is - but if I force Rec 2020 colour gamut, it looks very, very wrong.  The SDR backwards compatibility of HLG HDR seems to be pretty effective too.

I'm getting very occasional dropped frames - and initially it takes a while to work - but I'm pretty impressed that a low-end Apollo Lake can do this at all.

(It's a passively cooled Celeron with a chunky heatsink the size of the board area. But goodness does it get hot...)

Also interesting that the 2160p50/59.94p output is 8-bit, but 1080p, 720p and 576p is 12 bit.

Wenn render to 8 bit visuals srgb. Whatever you change behind that will make everything worse.   

But what colour gamut RGB? Rec 2020 or Rec 709 primaries?  

When fed YCbCr Rec 2020 does the content get converted to RGB (Rec 2020 primaries) following the Rec 2020 YCbCr->RGB matrix?  And is there an assumption that RGB output will be Rec2020?  Or do the drivers get Rec 2020 flagged and do a tone map to Rec 709 RGB primaries?