The buttons are currently mapped to different controls.

Right now, they're set up for Adobe Premiere. From top left to bottom right, they're mapped like this:

1. Undo
2. Redo
3. Unmapped
4. Save
5. Ripple Trim to Previous Edit
6. Add Edit to all tracks
7. Ripple Trim to Next Edit
8. Play
9. Zoom in
10. Ripple Delete
11. Zoom out
12. Unmapped
13. Go to In
14. Go to Previous Edit
15. Go to Next Edit
16. Go to Out

The knob is a rotary encoder, and is used for scrubbing back and forth in the timeline. If you press it down, it'll select all clips under the current play head. If you double press it, it'll switch to a faster scrubbing mode that doesn't play back audio as you scrub (useful to move quickly through the clips).

Again, this is VERY Premiere specific at this point, but I programmed it so that you can have multiple arrays that store the button maps. In some future release, as I actually start to understand what I'm doing with video editing, or if I decide to work with audio more, I will make it so you can hold down one of the unmapped buttons, and then press one of the other 15 buttons to load up a different button map. The lights will change accordingly under the buttons to show that you're looking at a different function.