sound_detector.sh

#!/bin/bash

# ========================
# || sound_detector.sh || 
# by elektr0nisch © 2023
# ========================
#
# This script constantly checks whether there are any active audio streams. (= sound is playing on the machine)
# Originally being used with an Raspberry Pi in an BT/DLNA/AirPlay/Spotify receiver setup.

playing=0

while true
do
  if (cat /proc/asound/card*/pcm*/sub*/status | grep -q 'RUNNING')
  then
    if [[ $playing -eq 0 ]]; then
      echo "start"
      # Do something when audio is detected
      playing=1
    fi
  else
   if [[ $playing -eq 1 ]]; then
     echo "stop"
     # Do something when audio has stopped
     playing=0
   fi
  fi
done