So just to update this thread and I mentioned this elsewhere I did try this out with windows 10 and using windows built in media player whatever they are calling it these days.
Windows 10 media player does play hdr files in hdr mode and hdr files in sdr mode both fine without any issue.
PMP i cant get hdr to display quite right these artifacts/macroblocking? Not sure what to call it is the main issue. Not sure why I am seeing this on an AMD rx 460 in PMP but not in windows player.
Basically any bright or dark scenes show massive macroblocking or digital noise whatever it should be called such as my picture in the first post. I have played around with the settings recommended in another thread to get hdr files working but no luck.
PMP playing an hdr file in Standard definition color and without windows 10 hdr mode enabled actually does a really good job even compared to windows media player in standard color, but i still get the macroblocking artifacts, if i could get rid of those i would still at least get the resolution increase from 4k and again in general pmp does a good job playing hdr files back outside of windows 10 hdr mode. The macroblocking does get worse in hdr mode though and we have a few additional issues such as the picture looking washed out.
I wonder if its a target brightness issue i should set in mpv.conf maybe its to bright? Or if vlang has any ideas. I do have it outputting ycbcr 4:4:4 at 10 bits @ 24hz. This occurs in angle or non angle and with hardware decoding off or on last i checked.The artifacts do not appear in windows media player though.