Usage of dbus for bt audio information and control

bt-audioparser/bt-audioparser.py

@@ -1,58 +1,92 @@
 import config
+import dbus
+import dbus.mainloop.glib
+from gi.repository import GLib
 import logging
 import mqtt
 import report
-import select
-from systemd import journal
+import sys
 import time
 
-
 try:
     from config import APP_NAME as ROOT_LOGGER_NAME
 except ImportError:
     ROOT_LOGGER_NAME = 'root'
 logger = logging.getLogger(ROOT_LOGGER_NAME).getChild('main')
 
+player_state = False
+current_title = ''
 
-PLAY = "New A2DP transport"
-STOP = "Closing A2DP transport"
-
-def send_state_msg_mqtt(mc, state):
+def send_state_mqtt(state):
     topic = config.MQTT_TOPIC + "/state"
     logger.info("Sending BT-Audio status information to mqtt %s = %s", topic, str(state))
     mc.send(topic, "true" if state else "false")
 
-def send_title_msg_mqtt(mc, title):
+
+def send_title_mqtt(title):
     topic = config.MQTT_TOPIC + "/title"
     logger.info("Sending BT-Audio status information to mqtt %s = %s", topic, title)
     mc.send(topic, title)
 
 
-if __name__ == "__main__":
-    report.stdoutLoggingConfigure(((config.APP_NAME, config.LOGLVL), ), fmt=config.formatter)
+def on_property_changed(interface, changed, invalidated):
+    global player_state
+    global current_title
+    #
+    if interface != 'org.bluez.MediaPlayer1':
+        return
+    for prop, value in changed.items():
+        if prop == 'Status':
+            logger.debug("BT-PLAYER status changed to %s", repr(value))
+            player_state = value == "playing"
+            send_state_mqtt(player_state)
+            send_title_mqtt(current_title if player_state else '')
+        elif prop == 'Track':
+            logger.debug("BT-PLAYER track information changed to %s", repr(value))
+            if 'Title' in value:
+                current_title = value.get('Title', '')
+                if player_state:
+                    send_title_mqtt(current_title)
 
-    mc = mqtt.mqtt_client(config.APP_NAME, config.MQTT_SERVER, 1883, config.MQTT_USER, config.MQTT_PASS)
 
-    j = journal.Reader()
-    j.log_level(journal.LOG_INFO)
-    j.add_match(_SYSTEMD_UNIT="bluealsa.service")
+def on_mqtt_ctrl(client, userdata, message):
+    if message.topic == config.MQTT_TOPIC + "/PLAY":
+        player_iface.Play()
+    elif message.topic == config.MQTT_TOPIC + "/PAUSE":
+        player_iface.Pause()
+    elif message.topic == config.MQTT_TOPIC + "/TRACK_PREV":
+        player_iface.Previous()
+    elif message.topic == config.MQTT_TOPIC + "/TRACK_NEXT":
+        player_iface.Next()
+    else:
+        logger.info(message.topic)
 
-    j.seek_tail()
-    j.get_next()
 
-    playing = False
-    send_state_msg_mqtt(mc, playing)
+if __name__ == "__main__":
+    report.stdoutLoggingConfigure(((config.APP_NAME, config.LOGLVL), ), fmt=config.formatter)
+    #
+    mc = mqtt.mqtt_client(config.APP_NAME, config.MQTT_SERVER, 1883, config.MQTT_USER, config.MQTT_PASS)
+    mc.add_callback(config.MQTT_TOPIC + '/#', on_mqtt_ctrl)
+    #
+    send_state_mqtt(player_state)
+    send_title_mqtt(current_title)
+    #
     while True:
-        while j.get_next():
-            for entry in j:
-                if entry['MESSAGE'] != "":
-                    if playing:
-                        if STOP in entry['MESSAGE']:
-                            playing = False
-                            send_state_msg_mqtt(mc, playing)
-                    else:
-                        if PLAY in entry['MESSAGE']:
-                            playing = True
-                            send_state_msg_mqtt(mc, playing)
-                    logger.debug(str(entry['__REALTIME_TIMESTAMP'] )+ ' ' + entry['MESSAGE'])
+        dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
+        bus = dbus.SystemBus()
+        obj = bus.get_object('org.bluez', "/")
+        mgr = dbus.Interface(obj, 'org.freedesktop.DBus.ObjectManager')
+        player_iface = None
+        transport_prop_iface = None
+        for path, ifaces in mgr.GetManagedObjects().items():
+            if 'org.bluez.MediaPlayer1' in ifaces:
+                player_iface = dbus.Interface(bus.get_object('org.bluez', path), 'org.bluez.MediaPlayer1')
+            elif 'org.bluez.MediaTransport1' in ifaces:
+                transport_prop_iface = dbus.Interface(bus.get_object('org.bluez', path), 'org.freedesktop.DBus.Properties')
+        if player_iface and transport_prop_iface:
+            break
         time.sleep(0.1)
+
+    bus.add_signal_receiver(on_property_changed, bus_name='org.bluez', signal_name='PropertiesChanged', dbus_interface='org.freedesktop.DBus.Properties')
+    GLib.MainLoop().run()
+

bt-audioparser/requirements.txt

@@ -1 +1,4 @@
-systemd-python
+dbus-python
+pycairo
+PyGObject
+