Keyboard mapping for PLEX client on Nvidia Shield TV



Is there a mapping of keyboard presses to functions: pause, play, ff, etc? I am using a remote that is sending keyboard commands to the Shield via USB input and would like to map all the remote keys. Some I've found:
right arrow: skip fwd
left arrow: skip back
space bar: pause
In order to FF or Rewind it looks like I have to use the down arrow and the on screen there a direct FF/RW button?


Following. Have flirc which works well but more direct features like sleep, play pause etc would be awesome in plex and Amazon