Question

我正在尝试演奏音符，然后检测麦克风的频率。当我使用振荡器弹奏音符时，如果我将耳机连接到设备，但不能使用内置扬声器，则可以使用。当我尝试根据麦克风的输入来检测声音频率时，情况正好相反。它仅适用于内置麦克风，如果我连接了耳机，则无效。

这是我用来跟踪麦克风声音频率的方法：

    private var micTrackerTimer: Timer? = nil
    private var micTracker: AKMicrophoneTracker? = nil

    @IBAction func listen(_ sender: UIButton) {
        micTrackerTimer?.invalidate()
        micTracker?.stop()

        micTracker = AKMicrophoneTracker()
        micTracker!.start()
        DispatchQueue.main.async {
            self.micTrackerTimer = Timer.scheduledTimer(
                timeInterval: 0.02,
                target: self,
                selector: #selector(self.renderPitch),
                userInfo: nil,
                repeats: true
            )
        }
    }

renderPitch暂时仅将音高输出到UITextField。如果我没有连接耳机，它会使用内置麦克风成功检测到频率。如果连接了耳机，则无法使用，并且以下内容会打印到Xcode控制台上：

2019-03-30 15:14:50.449326+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headphones (type: Headphones)
2019-03-30 15:14:50.450672+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headphones (type: Headphones)
2019-03-30 15:14:50.611809+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headphones (type: Headphones)
2019-03-30 15:14:50.614450+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headset Microphone (type: MicrophoneWired)
2019-03-30 15:14:50.614522+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headphones (type: Headphones)
2019-03-30 15:14:50.619233+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headset Microphone (type: MicrophoneWired)
2019-03-30 15:14:50.619377+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headphones (type: Headphones)
2019-03-30 15:14:50.625743+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headset Microphone (type: MicrophoneWired)
2019-03-30 15:14:50.625829+0100 Interval Training[994:165902] [avas] AVAudioSessionPortImpl.mm:56:ValidateRequiredFields: Unknown selected data source for Port Headphones (type: Headphones)

我使用其他动作播放声音

    var player: Player!

    @IBAction func play(_ sender: UIButton) {
        player = Player()
        player.playNote()
    }

我最基本的玩家职业是这样的：

import Foundation
import AudioKit

let triangle = AKTable(.triangle, count: 256)

class Player {
    var oscillator: AKOscillator!

    func playNote() {
        oscillator = AKOscillator(waveform: triangle)
        AudioKit.output = oscillator
        do {
            try AudioKit.start()
        } catch {
            print("Unable to start AudioKit. \(error)")
        }
        oscillator.start()
        let note: MIDINoteNumber = 57
        oscillator.frequency = note.midiNoteToFrequency()
        print("\(note.midiNoteToFrequency())")
        oscillator.rampDuration = 0.0
        oscillator.amplitude = 0.5

    }

    func stop() {
        oscillator.stop()
        do {
            try AudioKit.stop()
        } catch {
            print("Failed to stop AudioKit...\(error)")
        }
    }
}

如果连接了耳机，声音将按预期开始，但是如果尝试使用内置扬声器播放声音，则不会发出声音（但仍会在控制台上打印频率）。

关于如何使它既能播放又能听的任何想法，无论我是否连接了耳机？

如何使用AudioKit在iOS上控制输入和输出

0 个答案: