Selecting a Decoder

Define the Decoder on the Server

First you need to define the codec or audio format that snapcast is using in /etc/snapserver.conf

codec = pcm

is selecting pcm the data will be provided as pcm. Supported values are flac, ogg, opus and pcm. The default sample rate is a bit high for pcm, so I suggest to adjust it as well e.g. with

sampleformat = 44100:16:2

Define the Decoder for the Arduino Client

You need to install the necessary decoder library first! (See the urls below). Then you can use them in your Arduino sketch as follows:

#include "AudioCodecs/CodecOpus.h"   // https://github.com/pschatzmann/arduino-libopus.git
#include "AudioCodecs/CodecFLAC.h"   // https://github.com/pschatzmann/arduino-libflac.git
#include "AudioCodecs/CodecVorbis.h" //https://github.com/pschatzmann/arduino-libvorbis-idec

// codecs
OpusAudioDecoder opus;
FLACDecoder flac;
VorbisDecoder ogg;
WAVDecoder pcm;
// setup client
WiFiClient wifi;
I2SStream out;
SnapClient client(wifi, out, opus);

In the example above we defined all possible decoders, but we only use opus in the snap client.