Swift :查询以确定 Mac OS 上的默认输入设备

Question

我正在尝试在 Swift 中做一些相当基本的事情，即确定当前用于录制我声音的设备。

(即我使用以下代码通过我的命令行应用程序录制声音(

let settings = [
AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
AVSampleRateKey: 12000,
AVNumberOfChannelsKey: 1,
AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
]
let recorder = try AVAudioRecorder(url: fileUrl, settings: settings);
audioRecorder.start();

如何从AVAudioRecorder获取详细信息，告诉我"这是系统用于录制的默认输入设备"？ 即默认设备是"内部麦克风"或"Airpods"等。

Answer 1

我设法通过使用核心音频库解决了我的问题。以下是将从当前选定的默认设备获取设备名称的代码：

func showDeviceName() {
// load the current default device
var deviceId = AudioDeviceID(0);
var deviceSize = UInt32(MemoryLayout.size(ofValue: deviceId));
var address = AudioObjectPropertyAddress(mSelector: kAudioHardwarePropertyDefaultInputDevice, mScope: kAudioObjectPropertyScopeGlobal, mElement: kAudioObjectPropertyElementMaster);
var err = AudioObjectGetPropertyData(AudioObjectID(kAudioObjectSystemObject), &address, 0, nil, &deviceSize, &deviceId);
if ( err == 0) {
// change the query property and use previously fetched details
address.mSelector = kAudioDevicePropertyDeviceNameCFString;
var deviceName = "" as CFString;
deviceSize = UInt32(MemoryLayout.size(ofValue: deviceName));
err = AudioObjectGetPropertyData( deviceId, &address, 0, nil, &deviceSize, &deviceName);
if (err == 0) {
print("### current default mic:: (deviceName) ");
} else {
// TODO:: unable to fetch device name 
}
} else {
// TODO:: unable to fetch the default input device
}
}