Add example on how to synchronize bluez volume with pulseaudio

Author: paxal

examples/bluez-music-notify.php

@@ -21,14 +21,12 @@
 
 $lastItem = null;
 while (true) {
-    $start = microtime(true);
     $ffi->dbus_connection_read_write($conn, 0);
     $msg = $ffi->dbus_connection_pop_message($conn);
     $end = microtime(true);
 
     // loop again if we haven't read a message
     if (NULL === $msg) {
-	//echo "\r".microtime(true)." ".sprintf('%d us   ', (int) (($end-$start)*1000000));
         usleep(100000);
         continue;
     }

examples/bluez-volume-sync.php

@@ -0,0 +1,76 @@
+<?php
+
+const BLUEZ_TO_PA_FACTOR = 512;
+
+require_once __DIR__.'/../vendor/autoload.php';
+$ffi = require_once __DIR__.'/../load.php';
+
+$err = $ffi->new('struct DBusError');
+$ffi->dbus_error_init(FFI::addr($err));
+$args = $ffi->new('struct DBusMessageIter');
+$conn = $ffi->dbus_bus_get(DBus::BUS_SYSTEM, FFI::addr($err));
+
+$ffi->dbus_bus_add_match($conn,
+    "arg0=org.bluez.MediaTransport1",
+    FFI::addr($err));
+$ffi->dbus_connection_flush($conn);
+if ($ffi->dbus_error_is_set(FFI::addr($err))) {
+    fprintf(stderr, "Match Error (%s)\n", $err->message);
+    exit(1);
+}
+
+$decoder = new DBusMessageIterDecoder($ffi);
+
+$lastItem = null;
+while (true) {
+    $ffi->dbus_connection_read_write($conn, 0);
+    $msg = $ffi->dbus_connection_pop_message($conn);
+    $end = microtime(true);
+
+    // loop again if we haven't read a message
+    if (NULL === $msg) {
+        usleep(100000);
+        continue;
+    }
+
+    if (!$ffi->dbus_message_iter_init($msg, FFI::addr($args))) {
+        error_log("Message has no arguments!\n");
+        continue;
+    }
+
+    $message = new Message();
+    $message->interface = $ffi->dbus_message_get_interface($msg);
+    $message->path = $ffi->dbus_message_get_path($msg);
+    $message->member = $ffi->dbus_message_get_member($msg);
+    $message->arguments = $decoder->decode($args);
+
+    $ffi->dbus_message_unref($msg);
+
+    if (strpos($message->path, '/org/bluez') !== 0) {
+        continue;
+    }
+
+    if ($message->interface !== 'org.freedesktop.DBus.Properties' || $message->member !== 'PropertiesChanged') {
+        continue;
+    }
+
+    $arguments = $message->arguments;
+    if (!is_array($arguments)) {
+        continue;
+    }
+
+    $objectType = $arguments[0];
+    if ($objectType !== 'org.bluez.MediaTransport1') {
+        continue;
+    }
+
+    $volume = $arguments[1]['Volume'] ?? null;
+    if (null === $volume) {
+        continue;
+    }
+
+    $addr = preg_replace('@^.*/dev_(.*?)(/.*)$@', '$1', $message->path);
+    $paVolume = BLUEZ_TO_PA_FACTOR * (int) $volume;
+    echo "Set volume to ".round($paVolume / 65535 * 100).'%'.PHP_EOL;
+    exec("pactl set-source-volume bluez_source.{$addr}.a2dp_source {$paVolume}");
+}