Arduino mega adk and sound over usb

Using Arduino Audio
1

Not sure if this is the right forum, hopefully the right guess.

I want to make my own diy Android dock. One of the fueteres I am looking for is audio (music) over USB.
This is possible since android 4.1 (which I have on my phone) and the Arduino mega ADK.
Question is:

  1. How should I request this with the mega adk from my phone?
  2. How should I output this PCM stream to a mini jack (and wire it to a mini jack)?
2

Do you get any progress? I have the same problem like yours.