I always referred to a music player as an API to avoid confusion with the video player, but this is not suitable for end-users without previous knowledge of what an API is. The initial screen should have the following texts, or something similar:

Select an API: -> Select your music player:

Select a Player: -> Where to play the videos?

Mpv should remove its reference to VLC in its description, as it might not even show up if it's not installed.

These concepts should also be applied to the docs, specially on the website.

• Website's Getting Started
• Website's wiki
• GitHub docs (README)
• Inside Vidify
• Inside Vidify TV