Detects sound playing on a Linuxsystem. Sends messages via Mqtt when sound starts and stops.

sounddetector.py

#!/usr/bin/env python
'''
Send a Mqtt message if system is playing sound, another if it's stopped
Put Mqtt server password in a separate file named "mqttpass.txt".
'''
import os, time, json, sys
import paho.mqtt.client as mqtt

MQTT_HOST = '192.168.1.79'
MQTT_PORT = 1883
MQTT_USER = 'emonpi'
MQTT_TOPIC = 'HallwaySound'

# Mqtt server password in a separate file
f = open('mqttpass.txt', 'r')
MQTT_PASS = f.readline().strip()

soundstatus=0

def on_connect(client, userdata, flags, rc):
    if rc==0:
        client.connected_flag=True #set flag
        print("connected OK Returned code=",rc)
    else:
        print("Bad connection Returned code=",rc)
        client.bad_connection_flag=True

try:
	mqtt.Client.connected_flag=False
	mqtt.Client.bad_connection_flag=False 
	client = mqtt.Client("Sounddetector")
	client.username_pw_set(MQTT_USER, MQTT_PASS)
	client.on_connect=on_connect  #bind call back function
	client.loop_start()
	print("Start Mqtt loop")	
	client.connect(MQTT_HOST, MQTT_PORT)
	while not client.connected_flag and not client.bad_connection_flag: #wait in loop
		print("In wait loop")
		time.sleep(1)
	if client.bad_connection_flag:
		client.loop_stop()    #Stop loop
		print("Mqtt connection failed, exiting.")
		sys.exit()
	client.publish(MQTT_TOPIC, "Sound detector started")

	print ("Connected to Mqtt server")
#except:
#	print "Unexpected error:", sys.exc_info()[0]

except Exception as e:
    exc_type, exc_obj, exc_tb = sys.exc_info()
    fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
    print(exc_type, fname, exc_tb.tb_lineno)

while 1:
	if not (os.system("pacmd list-sink-inputs | grep -c 'state: RUNNING' >/dev/null")):
		if (soundstatus == 0):
			print("Sound on")
			try:
				mqtt_client = mqtt.Client()
				mqtt_client.username_pw_set(MQTT_USER, MQTT_PASS)
				mqtt_client.connect(MQTT_HOST, MQTT_PORT)
				mqtt_client.publish(MQTT_TOPIC, "on")
			except:
				print ("Unexpected error:", sys.exc_info()[0])
			soundstatus = 1
	else:
		if (soundstatus == 1):
			print("Sound off")
			try:
				mqtt_client = mqtt.Client()
				mqtt_client.username_pw_set(MQTT_USER, MQTT_PASS)
				mqtt_client.connect(MQTT_HOST, MQTT_PORT)
				mqtt_client.publish(MQTT_TOPIC, "off")
			except:
				print ("Unexpected error:", sys.exc_info()[0])
			
			soundstatus = 0
	time.sleep(5)
mqtt_client.loop_stop()    #Stop loop 
mqtt_client.disconnect() # disconnect