Need help with a class structure

I am building an application that will have most of its functionality the same, but some parts will be different.

The main application is a straight video player, with a timeline, play/pause and volume.

I need that as one application and then in another instance I need to add timeline constraints to the player.

So I want to be able to have this standalone player with no bells and whistles that I can use over and over. I then want to build this other class that can extend my video player that will add timeline constraints.

What is the best way to do this?