snapcast/doc/player_setup.md

Setup of audio players/server

Snapcast can be used with a number of different audio players and servers, and so it can be integrated into your favorite audio-player solution and make it synced-multiroom capable. The only requirement is that the player's audio can be redirected into the Snapserver's fifo /tmp/snapfifo. In the following configuration hints for MPD and Mopidy are given, which are base of other audio player solutions, like Volumio or RuneAudio (both MPD) or Pi MusicBox (Mopidy).

The goal is to build the following chain:

audio player software -> snapfifo -> snapserver -> network -> snapclient -> alsa

###MPD setup To connect MPD to the Snapserver, edit /etc/mpd.conf, so that mpd will feed the audio into the snapserver's named pipe

Disable alsa audio output by commenting out this section:

#audio_output {
#       type            "alsa"
#       name            "My ALSA Device"
#       device          "hw:0,0"        # optional
#       format          "48000:16:2"    # optional
#       mixer_device    "default"       # optional
#       mixer_control   "PCM"           # optional
#       mixer_index     "0"             # optional
#}

Add a new audio output of the type "fifo", which will let mpd play audio into the named pipe /tmp/snapfifo. Make sure that the "format" setting is the same as the format setting of the Snapserver (default is "48000:16:2", which should make resampling unnecessary in most cases)

audio_output {
    type            "fifo"
    name            "my pipe"
    path            "/tmp/snapfifo"
    format          "48000:16:2"
    mixer_type      "software"
}

To test your mpd installation, you can add a radio station by

$ sudo su
$ echo "http://1live.akacast.akamaistream.net/7/706/119434/v1/gnl.akacast.akamaistream.net/1live" > /var/lib/mpd/playlists/einslive.m3u

###Mopidy setup Mopidy can stream the audio output into the Snapserver's fifo with a filesink as audio output in mopidy.conf:

[audio]
#output = autoaudiosink
output = audioresample ! audioconvert ! audio/x-raw,rate=48000,channels=2,format=S16LE ! wavenc ! filesink location=/tmp/snapfifo

###MPlayer setup Use -novideo and -ao to pipe MPlayer's audio output to the snapfifo:

mplayer http://wms-15.streamsrus.com:11630 -novideo -channels 2 -srate 48000 -af format=s16le -ao pcm:file=/tmp/snapfifo

###Alsa setup If the player cannot be configured to route the audio stream into the snapfifo, Alsa or PulseAudio can be redirected, resulting in this chain:

audio player software -> Alsa -> Alsa file plugin -> snapfifo -> snapserver -> network -> snapclient -> Alsa

Edit or create your Alsa config /etc/asound.conf like this:

pcm.!default {
	type plug
	slave.pcm rate48000Hz
}

pcm.rate48000Hz {
	type rate
	slave {
		pcm writeFile # Direct to the plugin which will write to a file
		format S16_LE
		rate 48000
	}
}

pcm.writeFile {
	type file
	slave.pcm null
	file "/tmp/snapfifo"
	format "raw"
}

###PulseAudio setup Redirect the PulseAudio stream into the snapfifo:

audio player software -> PulseAudio -> PulsaAudio pipe sink -> snapfifo -> snapserver -> network -> snapclient -> Alsa

Load the module pipe-sink like this:

pacmd load-module module-pipe-sink file=/tmp/snapfifo sink_name=Snapcast
pacmd update-sink-proplist Snapcast device.description=Snapcast

It might me neccessary to set the pulse audio latency environment variable to 60 msec: PULSE_LATENCY_MSEC=60