[noggin]

Got it, but I'm talking about 4:2:2, not the usual 4:2:0. Can you guys try this sample? Thanks.

Both MrMC and Infuse Apps on the ATV 4K have no problems playing that 4:2:2 10bit HEVC clip smoothly

MrMC on my ATV4K playing that clip is massively out of AV sync.

InFuse plays it much more in sync.

Both are playing in full 50fps - and at first glance it's perfectly watchable - though I can't swear there aren't any dups or skips as I've not watched for long enough.

I'm blown away that my ATV4K can play HEVC 10-bit 4:2:2 - either the hardware decode is more capable than we think, or the CPU really is amazing. (We know Apple are very proud of their silicon...). That said - if Apple have added YouTube 4K support - could they have had to add software decode of Google's VP9 codec?

Is there a way of bringing up the 'O' and CTRL+SHIFT+'O' displays in MrMC to confirm (I don't have a bluetooth keyboard to hand I can pair with the ATV at the moment)

Let's see if it can play AVCi100 100Mbs 4:2:2 1080i AVC Intra (which is 4:2:2 h.264 10-bit I-frame only) - the UK standard HD broadcast file delivery format, and 4:2:2 IMX50 (the SD equivalent which is I-frame only MPEG2 at 50Mbs 4:2:2 576i - albeit with the oddball 720x608 format as it records an additional 32 lines of vertical blanking interval to preserve vertical interval timecode etc.)