AudioKit v5：如何选择麦克风？

Question

我正在尝试使用 SPM 将我的项目更新到 AudioKit v5。据我在当前文档中看到的，您通过将麦克风附加到音频引擎输入来实例化麦克风。

但是，我错过了以前的 AudioKit.inputDevices（然后是 AKManager.inputDevices）。我以前可以选择我喜欢的麦克风。

如何在 iOS 上使用 AudioKit v5 选择特定的麦克风？

Answer 1

截至 2020 年 11 月 6 日，您需要确保您使用的是 v5-develop 分支，因为 v5-main 仍然不支持 48K 采样率的硬件。

这是允许您根据调试描述选择麦克风的代码：

// AudioKit engine and node definitions
let engine = AudioEngine()
var mic : AudioEngine.InputNode!
var boost : Fader!
var mixer : Mixer!

// Choose device for microphone
if let inputs = AudioEngine.inputDevices {
    // print (inputs) // Uncomment to see the possible inputs
    let micSelection : String = "Front" // On a 2020 iPad pro you can also choose "Back" or "Top"
    var chosenMic : Int = 0
    var micTypeCounter : Int = 0
    for microphones in inputs {
        let micType : String = "\(microphones)"
        if micType.range(of: micSelection) != nil {
            chosenMic = micTypeCounter
        }
        // If we find a wired mic, prefer it
        if micType.range(of: "Wired") != nil {
            chosenMic = micTypeCounter
            break
        }
        // If we find a USB mic (newer devices), prefer it
        if micType.range(of: "USB") != nil {
            chosenMic = micTypeCounter
            break
        }
        micTypeCounter += 1
    }
        
    do {
        try AudioEngine.setInputDevice(inputs[chosenMic])
    } catch {
        print ("Could not set audio inputs: \(error)")
    }
    mic = engine.input
}

Settings.sampleRate = mic.avAudioNode.inputFormat(forBus: 0).sampleRate // This is essential for 48Kbps

// Start AudioKit
if !engine.avEngine.isRunning {
    do {
        boost = Fader(mic)
        // Set boost values here, or leave it for silence
        // Connect mic or boost to any other audio nodes you need
      
        // Set AudioKit's output
        mixer = Mixer(boost) // You can add any other nodes to the mixer
        engine.output = mixer

        // Additional settings
        Settings.audioInputEnabled = true

        // Start engine
        try engine.avEngine.start()
        try Settings.setSession(category: .playAndRecord)
    } catch {
        print ("Could not start AudioKit: \(error)")
    }
}

建议在 viewDidLoad 中添加音频路由更改通知：

// Notification for monitoring audio route changes
NotificationCenter.default.addObserver(
    self,
    selector: #selector(audioRouteChanged(notification:)),
    name: AVAudioSession.routeChangeNotification,
    object: nil)

这会调用

@objc func audioRouteChanged(notification:Notification) {
    // Replicate the code for choosing the microphone here (the first `if let` block)
}

Answer 2

音频套件 4 也是如此。

API 已更改。

看来你应该写：

guard let inputs = AKManager.inputDevices else{
    print("NO AK INPUT devices")
    return false
}