Linux BlueZ dbus 通信 a2dp

Question

作为一个简短的总结，我目前正在构建一个 Raspberry Pi，它能够充当蓝牙 A2DP 接收器并将该音频路由到 3.5 毫米连接。我运行的 Python 脚本之一使用 BlueZ 和 Dbus 与蓝牙设备通信，目前我正在使用的脚本找到一个之前与系统配对的 BT 设备并自动连接到它(脚本在 cron 上运行)，然后我可以在我的 iPhone 上按播放开始音频流。但是我想要做的是一旦它找到一个设备并连接发送一个 dBus 命令来开始播放音频而不是必须手动按手机上的播放本身。

这是代码的摘录，以及我为使其正常工作而添加的内容，但没有成功。

            bus = dbus.SystemBus()

            #Get bluez dbus objects
            man = bus.get_object('org.bluez', '/')
            iface = dbus.Interface(man, 'org.bluez.Manager')
            adapterPath = iface.DefaultAdapter()
            adapter = dbus.Interface(bus.get_object('org.bluez', adapterPath),dbus_interface='org.bluez.Adapter')
            devices = adapter.GetProperties()['Devices']

            #for each device on this bluetooth adapter look for ones with A2DP sink service UUID and 
            # register for the propertychanged dbus signal
            for d in devices:
                dev = dbus.Interface(bus.get_object('org.bluez', d),dbus_interface='org.bluez.Device')
                props = dev.GetProperties()
                if any(AudioSourceServiceClass_UUID in UUID.upper() for UUID in props["UUIDs"]):
                    #This device is an A2DP Audio source
                    devobj = bus.get_object('org.bluez', d)
                            devobj.Trusted = True
                            if props["Connected"] == True:
                        print  props["Name"] + " is connected!"
                        exit()

            for d in devices:
                    dev = dbus.Interface(bus.get_object('org.bluez', d),dbus_interface='org.bluez.Device')
                    props = dev.GetProperties()
                if any(AudioSourceServiceClass_UUID in UUID.upper() for UUID in props["UUIDs"]):
                    #This device is an A2DP Audio source
                    print  props["Name"] + " has A2DP audio source"
                    #dev.connect_to_signal("PropertyChanged", handler_for_device(dev))
                    #dev.connect_to_signal("PropertyChanged", cb)
                    devobj = bus.get_object('org.bluez', d)
                    try:
                        devobj.Connect(dbus_interface='org.bluez.AudioSource')
                        devobj.Play()
                        exit()
                    except dbus.DBusException, e:
                        print str(e)

如果不容易看到，我在“devobj.Play()”行中添加了从底部算起大约 4 行。

但是我得到了错误:

iPhone 有 A2DP 音源org.freedesktop.DBus.Error.UnknownMethod:接口(interface)“(空)”上带有签名“”的方法“Play”不存在

Answer 1

如果您知道设备已经这样做了:

player = dbus.Interface(bus.get_object('org.bluez', '/org/bluez/hci0/dev_' + device.replace(":","_") + '/player0'), 'org.bluez.MediaPlayer1')

然后:

player.Play()

设备应该是xx_xx_xx_xx_xx_xx