It's confusing as this is not my project, I have taken the mpv.net name 2 years before this project was created and because of that the project was renamed to Mpv.NET-lib-.
Mpv.NET-lib- has a sample application included:
https://github.com/hudec117/Mpv.NET-...ive/master.zip
I had started with a C# sample provided by the mpv project:
https://github.com/mpv-player/mpv-ex...ive/master.zip
My project is here:
https://github.com/stax76/mpv.net
I hope this will get you started.