Hello.
I am not familiar with this 3rd party library in details, however from what I read online you basically need (after all other things are done like code-registration and so) to run some simple code to convert upload video into a different format, as it is described e.g.
here.
Particular place where to run any such a code and the way how depends on where you want to store those files. It can be stored as one of these three kinds of
attachments, or within Media library. Can you clarify where you want to store those files? Thank you.
Best Regards,
Radek Macalik