是否可以在 AKAudioPlayer 上使用 AKAmplitudeTracker 并测量振幅变化？

Question

嘿，我正在做一个项目（在 swift 中），它比较两个音频信号并测量正确性。 AUDIOKIT pod 用于将来自麦克风（AKAmplitudeTracker）的音频转换为浮点数。我试图通过在 AKAudioPlayer 上应用跟踪器来实现相同的方法。我想做的是对源信号和参考信号进行采样，仅将其作为幅度数据获取，然后执行DTW(Dynamic time warping)算法。

有什么方法可以将AKAudioPlayer的音乐转换为振幅数据吗？是否可以为当前正在播放音乐的 AKAudioPlayer 添加跟踪器？代码如下。我需要一些专家建议，在此先感谢您，祝您编码愉快。

//
//  Conductor.swift
//  AmplitudeTracker
//
//  Created by Mark Jeschke on 10/3/17.
//  Copyright © 2017 Mark Jeschke. All rights reserved.
//

import AudioKit
import AudioKitUI

// Treat the conductor like a manager for the audio engine.
class Conductor {

// Singleton of the Conductor class to avoid multiple instances of the audio engine

var url:URL?
var fileName:String?
var type:String?

static let sharedInstance = Conductor()
var isPlayingKit:Bool?

var micTracker: AKAmplitudeTracker!
var mp3Tracker: AKAmplitudeTracker!

var player:AKAudioPlayer!
var mic: AKMicrophone!

var delay: AKDelay!
var reverb: AKCostelloReverb!

// Balance between the delay and reverb mix.
var reverbAmountMixer = AKDryWetMixer()

func play(file: String, type: String) -> AKAudioPlayer? {

    let url = Bundle.main.url(forResource: file, withExtension: type)
    let file = try! AKAudioFile(forReading: url!)
    player = try! AKAudioPlayer(file: file)

    if self.isPlayingKit! {
        player.play()
        mp3Tracker = AKAmplitudeTracker(player)
        delay = AKDelay(mp3Tracker)
        delay.time = 0.0
        delay.feedback = 0.0
        delay.dryWetMix = 0.5
        reverb = AKCostelloReverb(delay)
        reverb.presetShortTailCostelloReverb()
        reverbAmountMixer = AKDryWetMixer(delay, reverb, balance: 0.8)
        AudioKit.output = reverbAmountMixer
    }
    else {
        self.isPlayingKit = true
        AudioKit.output = nil
        player.stop()
    }
    return player
}

init() {
    AKSettings.playbackWhileMuted = true
    mic = AKMicrophone()
    print("INIT CONDUCTOR")

    micTracker = AKAmplitudeTracker(mic)
    delay = AKDelay(micTracker)
    delay.time = 0.5
    delay.feedback = 0.1
    delay.dryWetMix = 0.5
    reverb = AKCostelloReverb(delay)
    reverb.presetShortTailCostelloReverb()
    reverbAmountMixer = AKDryWetMixer(delay, reverb, balance: 0.8)
    AudioKit.output = reverbAmountMixer

    isPlayingKit = true
    startAudioEngine()
}

func startAudioEngine() {
    AudioKit.start()
    isPlayingKit = true
    print("Audio engine started")
}

func stopAudioEngine() {
    AudioKit.stop()
    isPlayingKit = false
    print("Audio engine stopped")
}
}

上述方法捕获麦克风的振幅。

下面给出的是我尝试在 AKAudioPlayer 上使用 AKAmplitudeTracker 的位置。

//
//  ViewController.swift
//  AudioBoom
//
//  Created by Alex Babu on 20/06/18.
//  Copyright © 2018 Naico. All rights reserved.
//

 import AudioKit

 class ViewController: UIViewController {

var instantanousAmplitudeData = [Double]()
var timer:Timer?
var timerCount:Int?
let conductor = Conductor.sharedInstance
var player:AKAudioPlayer?

@IBOutlet weak var holderView: UIView!
@IBOutlet weak var equalizer: UILabel!
@IBOutlet weak var percentageLabel: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()
    timerCount = 0
    playMusicOutlet.layer.cornerRadius = playMusicOutlet.frame.size.height/2
    playMusicOutlet.layer.borderColor = UIColor.cyan.cgColor
    playMusicOutlet.layer.borderWidth = 2.0
    playMusicOutlet.clipsToBounds = true

    musicDTW.layer.cornerRadius = musicDTW.frame.size.height/2
    musicDTW.layer.borderColor = UIColor.cyan.cgColor
    musicDTW.layer.borderWidth = 2.0
    musicDTW.clipsToBounds = true

    holderView.layer.cornerRadius = holderView.frame.size.width/2
    holderView.clipsToBounds = true
}

override var preferredStatusBarStyle: UIStatusBarStyle {
    return .lightContent
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

@IBOutlet weak var playMusicOutlet: UIButton!
@IBAction func playMusic(_ sender: Any) {
    playMusicOutlet.setTitle("Talk now", for: .normal)
    self.equalizer.isHidden = false
    timerCount = 0
    AVAudioSession.sharedInstance().requestRecordPermission({(_ granted: Bool) -> Void in
        if granted {
            print("Permission granted")
            self.timer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { [unowned self] (timer) in
                if let count = self.timerCount {
                    DispatchQueue.main.async {
                        self.timerCount = count + 1
                        print("Amplitude of mic detected:\(self.conductor.micTracker.amplitude)")
                        print("Amplitude of mic counter:\(String(describing: count))")

                        print("Amplitude of mp3 detected:\(self.conductor.micTracker.amplitude)")
                        print("Amplitude of mp3 Counter:\(String(describing: count))")

                        self.instantanousAmplitudeData.append(self.conductor.micTracker.amplitude)
                        self.equalizer.frame.size.height = CGFloat(self.conductor.micTracker.amplitude * 500)
                        self.percentageLabel.text = String(Int(((self.conductor.micTracker.amplitude * 500)/500) * 100)) + "%"

                        if count == 10000 {
                            timer.invalidate()
                            self.equalizer.isHidden = true
                        }
                    }
                }
            }
        }
        else {
            print("Permission denied")
        }
    })
}

@IBOutlet weak var musicDTW: UIButton!
@IBAction func musicDTWAction(_ sender: Any) {

    let anotherConductor = Conductor.sharedInstance
    if let ccc = anotherConductor.play(file: "Timebomb", type: "mp3") {
        musicDTW.setTitle("Music DTW on", for: .normal)
        if let mp3Tracker = conductor.mp3Tracker {
            self.equalizer.frame.size.height = CGFloat(mp3Tracker.amplitude * 500)
        }
    }
    else {
        musicDTW.setTitle("Music DTW off", for: .normal)
    }
    }
}

Answer 1

所有这些代码都发生了很多事情，因此很难对其进行调试，但你所描述的绝对是可能的，你可能只是出了一些小问题。或许您可以私下与我分享 repo，我可以为您修复它。

Answer 2

试试这些！
导体Class

import AudioKit
import AudioKitUI

// Treat the conductor like a manager for the audio engine.
class Conductor {

// Singleton of the Conductor class to avoid multiple instances of the audio engine

var url:URL?
var fileName:String?
var type:String?

static let sharedInstance = Conductor()
var isPlayingKit:Bool?

var micTracker: AKAmplitudeTracker!
var mp3Tracker: AKAmplitudeTracker!

var player:AKAudioPlayer!
var mic: AKMicrophone!

var delay: AKDelay!
var reverb: AKCostelloReverb!

// Balance between the delay and reverb mix.
var reverbAmountMixer = AKDryWetMixer()

func play(file: String, type: String) -> AKAudioPlayer? {

    let url = Bundle.main.url(forResource: file, withExtension: type)
    let file = try! AKAudioFile(forReading: url!)
    player = try! AKAudioPlayer(file: file)

    if self.isPlayingKit! {
        mp3Tracker = AKAmplitudeTracker(player)
        delay = AKDelay(mp3Tracker)
        delay.time = 0.0
        delay.feedback = 0.0
        delay.dryWetMix = 0.5
        reverb = AKCostelloReverb(delay)
        reverb.presetShortTailCostelloReverb()
        reverbAmountMixer = AKDryWetMixer(delay, reverb, balance: 0.8)
        AudioKit.output = reverbAmountMixer      //#1
        player.play()                            //#2
    }
    else {
        self.isPlayingKit = true
        AudioKit.output = nil
//            player.stop()
        stopAudioEngine()
    }
    return player
}

func isPlayingAudioKit() -> Bool {
    return isPlayingKit!
}

init() {
    self.isPlayingKit = false
}

func initMicrophone() {
    AKSettings.playbackWhileMuted = true
    mic = AKMicrophone()
    print("INIT CONDUCTOR")

    micTracker = AKAmplitudeTracker(mic)
    delay = AKDelay(micTracker)
    delay.time = 1.5
    delay.feedback = 0.1
    delay.dryWetMix = 1.0
    reverb = AKCostelloReverb(delay)
    reverb.presetShortTailCostelloReverb()
    reverbAmountMixer = AKDryWetMixer(delay, reverb, balance: 0.5)
    AudioKit.output = reverbAmountMixer

    isPlayingKit = true
    startAudioEngine()
}

func startAudioEngine() {
    AudioKit.start()
    isPlayingKit = true
    print("Audio engine started")
}

func stopAudioEngine() {
    AudioKit.stop()
    isPlayingKit = false
    print("Audio engine stopped")
}
}

ViewController

import AudioKit
class ViewController: UIViewController {
var instantanousUserAudioData = [Float]()
var referenceAudioData = [Float]()
var timer:Timer?
var timerCount:Int?
let conductor = Conductor.sharedInstance

@IBOutlet weak var holderView: UIView!
@IBOutlet weak var equalizer: UILabel!
@IBOutlet weak var percentageLabel: UILabel!

@IBOutlet weak var timerOutlet: UIButton!
@IBOutlet weak var micOutlet: UIButton!
@IBOutlet weak var DTWOutlet: UIButton!
@IBOutlet weak var musicOutlet: UIButton!
@IBOutlet weak var resultLabel: UILabel!

@IBAction func timerAction(_ sender: Any) {
    self.timer?.invalidate()
}

override func viewDidLoad() {
    super.viewDidLoad()
    timerCount = 0

    micOutlet.layer.cornerRadius = micOutlet.frame.size.height/2
    micOutlet.layer.borderColor = UIColor.cyan.cgColor
    micOutlet.layer.borderWidth = 2.0
    micOutlet.clipsToBounds = true

    musicOutlet.layer.cornerRadius = musicOutlet.frame.size.height/2
    musicOutlet.layer.borderColor = UIColor.cyan.cgColor
    musicOutlet.layer.borderWidth = 2.0
    musicOutlet.clipsToBounds = true

    DTWOutlet.layer.cornerRadius = DTWOutlet.frame.size.height/2
    DTWOutlet.layer.borderColor = UIColor.cyan.cgColor
    DTWOutlet.layer.borderWidth = 2.0
    DTWOutlet.clipsToBounds = true

    timerOutlet.layer.cornerRadius = timerOutlet.frame.size.height/2
    timerOutlet.layer.borderColor = UIColor.cyan.cgColor
    timerOutlet.layer.borderWidth = 2.0
    timerOutlet.clipsToBounds = true

    holderView.layer.cornerRadius = holderView.frame.size.width/2
    holderView.clipsToBounds = true

    self.micOutlet.isEnabled = false
    self.musicOutlet.isEnabled = false

    AVAudioSession.sharedInstance().requestRecordPermission({(_ granted: Bool) -> Void in
        self.micOutlet.isEnabled = granted
        self.musicOutlet.isEnabled = granted
    })
}

override var preferredStatusBarStyle: UIStatusBarStyle {
    return .lightContent
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

@IBAction func micAction(_ sender: Any) {

    conductor.initMicrophone()
    self.timerCount = 0
    self.equalizer.isHidden = false
    self.timer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { [unowned self] (timer) in
        if let count = self.timerCount {
            DispatchQueue.main.async {

                self.timerCount = count + 1
                print("Amplitude of mic detected:\(self.conductor.micTracker.amplitude)")
                print("Amplitude of mp3 Counter:\(String(describing: count))")

                self.instantanousUserAudioData.append(Float(self.conductor.micTracker.amplitude))
                self.equalizer.frame.size.height = CGFloat(self.conductor.micTracker.amplitude * 500)
                self.percentageLabel.text = String(Int(((self.conductor.micTracker.amplitude * 500)/500) * 100)) + "%"

                if count > 10 && self.conductor.micTracker.amplitude == 0.0 && self.instantanousUserAudioData.last == 0.0 {

                    self.micOutlet.backgroundColor = .green
                    self.micOutlet.setTitleColor(.black, for: .normal)
                    self.micOutlet.layer.borderColor = UIColor.red.cgColor
                    timer.invalidate()
                }
                if count == 0 {
                    self.micOutlet.backgroundColor = .clear
                    self.micOutlet.setTitleColor(.cyan, for: .normal)
                    self.micOutlet.layer.borderColor = UIColor.cyan.cgColor
                }
            }
        }
    }
}
@IBAction func musicAction(_ sender: Any) {
    self.timerCount = 0
        if self.conductor.play(file: voiceReference, type: type_mp3) != nil {
            self.timer?.invalidate()

            self.timer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { [unowned self] (timer) in
                if let count = self.timerCount {
                    DispatchQueue.main.async {

                        self.timerCount = count + 1
                        print("Amplitude of mp3 detected:\(self.conductor.mp3Tracker.amplitude)")
                        print("Amplitude of mp3 Counter:\(String(describing: count))")
                        self.referenceAudioData.append(Float(self.conductor.mp3Tracker.amplitude))
                        self.equalizer.frame.size.height = CGFloat(self.conductor.mp3Tracker.amplitude * 500)
                        self.equalizer.isHidden = false
                        self.percentageLabel.text = String(Int(((self.conductor.mp3Tracker.amplitude * 500)/500) * 100)) + "%"

                        if count > 10 && self.conductor.mp3Tracker.amplitude == 0.0 && self.referenceAudioData.last == 0.0 {

                            self.musicOutlet.backgroundColor = .green
                            self.musicOutlet.setTitleColor(.black, for: .normal)
                            self.musicOutlet.layer.borderColor = UIColor.red.cgColor

                            timer.invalidate()
                        }
                        if count == 0 {
                            self.musicOutlet.backgroundColor = .clear
                            self.musicOutlet.setTitleColor(.cyan, for: .normal)
                            self.musicOutlet.layer.borderColor = UIColor.cyan.cgColor
                        }
                    }
                }
            }
        }
        else {
        }
}

@IBAction func resultAction(_ sender: Any) {
    print("mic array:\(instantanousUserAudioData)")
    print("song array:\(referenceAudioData)")
    self.timer?.invalidate()

    if referenceAudioData.count > 0, instantanousUserAudioData.count > 0 {
        let refData = knn_curve_label_pair(curve: referenceAudioData,label: "reference")
        let userData = knn_curve_label_pair(curve: instantanousUserAudioData,label: "userData")
        let attempt:KNNDTW = KNNDTW()
        attempt.train(data_sets: [refData,userData])

        let prediction: knn_certainty_label_pair = attempt.predict(curve_to_test: referenceAudioData)
        print("predicted :" + prediction.label, "with ", prediction.probability * 100,"% certainty")

        resultLabel.text = "DTW cost is " + String(attempt.dtw_cost(y: referenceAudioData, x: instantanousUserAudioData))
        print("COST OF THE DTW ALGORITHM IS : \(String(attempt.dtw_cost(y: referenceAudioData, x: instantanousUserAudioData)))")
    }
}
}

是否可以在 AKAudioPlayer 上使用 AKAmplitudeTracker 并测量振幅变化？

Is it possible to use AKAmplitudeTracker on AKAudioPlayer and measure the amplitude changes?

ios

swift

audiokit