Go into System Preferences > Keyboard and under the Keyboard tab, check of `Use all F1, F2, etc. keys as standard function keys`, as in the image below.  Then, you can use the Rewind function as Fn - F7, Play/Pause as Fn - F8, etc (you can then map the buttons on your mouse to these).

![enter image description here][1]


  [1]: https://i.sstatic.net/zNJNH.png