pareceive 
S/PDIF receiver with support of compressed formats
This tool is a PulseAudio application that captures the audio from S/PDIF (aka IEC 958) input and plays it back on an output device. When it encounteres a compressed (IEC61937) signal, it decodes it using libav.
Latest stable version of PulseAudio is recommended. Older PulseAudio versions may have issues with latency.
Tested on Raspberry Pi with HiFiBerry Digi+ I/O board as SPDIF input device and ST Lab M-330 USB soundard as 7.1 DAC output device
If you have an issue with input device over pulseaudio, you can also try piping audio from arecord via stdin:
arecord -D hw:CARD=sndrpihifiberry,DEV=0 -q -C -f s16_le -c 2 -t raw --disable-channels --disable-format --disable-resample --disable-softvol | pareceive -
If this is the case, you may also want to tell pulseaudio to ignore the card via udev rules.