Remote Control

Audio speakers can send commands to the AirPlay client to change the current track, pause and resume playback, shuffle the playlist, and more. This uses a subset of [DACP]. An AirPlay client advertises this capability by including a DACP-ID header in its RTSP requests, with a 64-bit ID for the DACP server. An Active-Remote header is included as well, serving as an authentication token.

The AirPlay server needs to browse the mDNS _dacp._tcp services for a matching DACP server. Server names look like iTunes_Ctrl_$ID.

DACP service from iTunes

name: iTunes_Ctrl_56B29BB6CB904862
type: _dacp._tcp
port: 3689

Once the DACP server has been identified, HTTP requests can be sent to the corresponding service port. The Active-Remote header must be included in these requests, so no additional pairing is required. The location for remote control commands is /ctrl-int/1/$CMD. The following commands are available:

beginffbegin fast forward
beginrewbegin rewind
mutetoggletoggle mute status
nextitemplay next item in playlist
previtemplay previous item in playlist
pausepause playback
playpausetoggle between play and pause
playstart playback
stopstop playback
playresumeplay after fast forward or rewind
shuffle_songsshuffle playlist
volumedownturn audio volume down
volumeupturn audio volume up

Example: send a pause command

server → client

GET /ctrl-int/1/pause HTTP/1.1
Host: starlight.local.
Active-Remote: 1986535575

client → server

HTTP/1.1 204 No Content
Date: Tue, 06 Mar 2012 16:38:51 GMT
DAAP-Server: iTunes/10.6 (Mac OS X)
Content-Type: application/x-dmap-tagged
Content-Length: 0