HDR on Win 10 is still a mess, right now I just wouldn't bother building a media machine on a Ryzen APU (or anything else) for use with HDR.
I've been through several AM4 ITX motherboards, ASRock, Gigabyte and MSI, none of them handle HDR with a Ryzen APU on a 4K HDR TV
The ASRock didn't even work properly at 4k 60hz (RMA'd one board thinking it was a fault and the the replacement did exactly the same thing)
I've tried several APU's to eliminate that, multiple ram kits.
I'm currently using the Gigabyte B450-I-AORUS-PRO.
It works fine running an LG OLED TV at 4k 60hz (HDR is a mess)
If you want HDR that just works, get an Nvidia Shield tv or just use the apps on the TV you buy for Netflix etc.
Or just build the Ryzen system for light gaming and 4k 60hz playback and forget about HDR (for now)
You could also investigate an Intel system using Kaby Lake (or newer) CPU and a low end Nvidia card (such as a GTX 1050)
I just got so fed up with HDR on Win 10, I've completely given up on it until it works properly !!!!
Oh, you sound like just the right person for me to brain-pick on
I too have a 4k LG HDR TV, the OLED55B6V from 2016. I've been using the internal player with DLNA to play back 4k UHD HDR rips, and it's been so-so. The quality, when it works, is fantastic. But she's a mean mistress, my LG. That player dislikes so many little details that my jumping through hoops to create an MKV that it'll play back is starting to drive me insane.
This has prompted me to look for HDMI-connected alternatives pretty much since I got the TV. It's amazing how difficult it is to find something that'll properly produce HDR 4k without some deal-breaker thrown in there. My previous plan was to get an Android box based on the S922x SoC, but while it actually seems to be able to do proper HDR, in Android I'll be stuck with a 1080p UI (and I will *not* settle for Google Photos and similar apps in 1080p) as well as an inability to switch to native refresh rates for videos, and unknowns WRT older content of mine in funky codecs, and questions as to how well it can handle software decoding when needed.
LibreELEC presents its own issues, and seems more miss than hit so far with the S922x SoC, and I just don't want to buy another Android device because "it looks to be supported fully soon." I already have two of those in my drawers somewhere.
So now I'm thinking, if I'm gonna throw more than €100 at it anyway, why not go €150 and get a system that's truly powerful, expandable, and capable of running any OS and software with a little tinkering? So, now I ended up here, again baffled at how confusing something so seemingly simple is
So... This thread is helpful, but it's also confusing, because HDR, subsampling, and 8, 10, or 12 bits per channel, as well as refresh rates and technologies make for so many combinations that may or may not satisfy each person's idea about "HDR" and "4k" compatibility.
For me, I care about one thing, and one thing only: Can I get Kodi to put out 4k over HDMI at refresh rates matching source content frame rates ranging from 23.976-60 FPS (25 and 50 fps included), interlaced and progressive alike, and can it put out such content with that illusive "HDR stuff" that makes my LG TV show the little "HDR" or "Dolby Vision" badge at the top right and display beautiful HDR colours? And judging from what you wrote in this thread, you seem like the person to ask, because you seem to me to have the same goal?
So, if that's the case, could you please elaborate on your successes and failures in trying to achieve this?
Personally, I don't mind if I have to run some hacked-up version of Windows 10, with "MadVR" and "MPC-HC" and what have you stitched together, so long as it can do what I want, and it can do it from Kodi. I'd prefer to run Linux (or MacOS, but that seems like a no-go with Vega graphics, and I don't believe HDR over HDMI works in macOS land yet anyway, so...), but Windows or LibreELEC will do, too
Sorry for the long rant, and thanks a lot if you can enlighten me further.