I am trying to get HDR video playback from my PC using an RX 480. I do not like Windows 10 CU's 'Film ^& TV' application and instead prefer using MPC-HC + MadVR. Unfortunately it does not work well with AMD's drivers. Unlike the Nvidia drivers the AMD drivers do not contain a private API that allows 'on-the-fly' switching between SDR and HDR modes. The AMD solution relies entirely on Windows and is clunky as heck. For more details see this post by Madshi, the creator of MadVR.
Please can AMD consider implementing a similar method of pass through HDR metadata as Nvidia does as it would be of great benefit to all who enjoy HDR Video and HDR gaming.