The app can already play 4K video and HEVC. MX Player uses ffmpeg as a base decoder, so whatever ffmpeg can play, MX can play. Of course, 4K and HEVC support isn't optimal by anyone right now, so don't expect stellar results.
Be sure to hit Thanks when someone helps you out!
MX Player sub-forum Moderator; Primary User Support: http://forum.xda-developers.com/apps/mx-player
The Developer/Owner of MX Player is bleu8888
. Please post a thread in the MX Player sub-forum for support.
I do not answer MX Player questions in PM. Post a thread in the MX Player sub-forum if you need support.