Hi guy, I want to play a 4k HDR .mkv movie on my galaxy S9 Plus. Anyone recommend me a video player can do the best. Btw, my .mkv movie has multiple audio track and multi-language subtitle embedded. Thank you!!!

Vlc

Xplayer

The inbuilt Video Player should be fine. However, you shouldn't require to install any player to play HDR, its done by the device and the video player itself once it finds the HDR metadata in the Video.