As you may know, mpv is an open-source, command-line, media player based on mplayer2. It does not have any interface at all, the video being opened in a simple, borderless windows.
The latest version available is MPV 0.29.1, which comes with a bunch of fixes.
Installation instructions:
In order to install the latest version of MPV on Ubuntu 18.10 Cosmic Cuttlefish, you only need to refresh the repo list and install the mpv package:
$ sudo apt-get update
$ sudo apt-get install mpv
For Ubuntu 18.04 Bionic Beaver, Ubuntu 16.04 Xenial Xerus, Linux Mint, Elementary OS and other derivative systems, you need to add the required PPA, update the local repo index and install the mpv package:
$ sudo add-apt-repository ppa:mc3man/mpv-tests
$ sudo apt-get update
$ sudo apt-get install mpv
To remove the software, do:
$ sudo apt-get remove mpv