audio-sketch on SAM processor

I'm a new user of Arduino, and wants to play with audio on the SAM processor. Due-board.
I have installed the board-type and now I want to try the example software which plays 3 files from an SD-card. That file begins with include audio.h and include DAC.h, but arduino can't find these libraries, and so can't I.
Not in the installed software and not on the arduino-site.
Please someone give me some advice.