更改“发声器”的音频音高
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【中文标题】更改“发声器”的音频音高【英文标题】：Changing Audio Pitch of "sounder" 【发布时间】：2018-06-03 18:09:18 【问题描述】：编辑：在底部添加了新代码。
我对编码很陌生，所以我从创建一个音板应用开始。我已经能够使用“rate”命令来减慢或加快音频的速度，但现在我也想改变音高。理想情况下，我想要两个开关。一种可以加快音频速度并提高音调，一种可以减慢和降低，如果它们都关闭，则播放正常。下面是我的代码，它适用于除了改变音高之外的所有东西。非常感谢任何输入。作为参考，sass 慢，chip 快。
import UIKit
import AVFoundation
var Sounder1 = AVAudioPlayer()
var Sounder2 = AVAudioPlayer()
let sassFloat: Float = 0.5
let myInt = Int(sassFloat)
let chipFloat: Float = 3.0
let myInt2 = Int(chipFloat)
class ViewController: UIViewController
@IBOutlet weak var sassSwitch: UISwitch!
@IBOutlet weak var chipSwitch: UISwitch!
override func viewDidLoad()
super.viewDidLoad()
do
Sounder1 = try AVAudioPlayer(contentsOf: URL.init(fileURLWithPath: Bundle.main.path(forResource: "Sound1", ofType: "mp3")!))
Sounder1.prepareToPlay()
Sounder1.enableRate = true
catch
do
Sounder2 = try AVAudioPlayer(contentsOf: URL.init(fileURLWithPath: Bundle.main.path(forResource: "Sound2", ofType: "wav")!))
Sounder2.prepareToPlay()
Sounder2.enableRate = true
catch
// Do any additional setup after loading the view, typically from a nib.
@IBAction func sassAction(_ sender: UISwitch)
chipSwitch.setOn(false, animated: true)
@IBAction func chipAction(_ sender: UISwitch)
sassSwitch.setOn(false, animated: true)
@IBAction func play(_ sender: Any)
if sassSwitch.isOn
Sounder1.rate = sassFloat
Sounder1.play()
else if chipSwitch.isOn
Sounder1.rate = chipFloat
Sounder1.play()
else
Sounder1.rate = 1.0
Sounder1.play()
@IBAction func play2(_ sender: Any)
if sassSwitch.isOn
Sounder2.rate = sassFloat
Sounder2.play()
else if chipSwitch.isOn
Sounder2.rate = chipFloat
Sounder2.play()
else
Sounder2.rate = 1.0
Sounder2.play()
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
这是我根据@ericl 的建议提出的新代码。我仍然需要reset() audioEngine 但我也有一些问题。
1) if else if else 语句在这种情况下真的有效吗？
2) 我在哪里添加reset() 语句。
3）播放完每个声音后我需要分离节点吗？还是只是重置？
class ViewController: UIViewController
@IBOutlet weak var sassSwitch: UISwitch!
@IBOutlet weak var chipSwitch: UISwitch!
@IBAction func sassAction(_ sender: UISwitch)
chipSwitch.setOn(false, animated: true)
@IBAction func chipSwitch(_ sender: UISwitch)
sassSwitch.setOn(false, animated: true)
///Playback Engine
private let audioEngine = AVAudioEngine()
///Player's Nodes
private let pitchPlayer = AVAudioPlayerNode()
private let timePitch = AVAudioUnitTimePitch()
///Audio Files to be played
private var audioFile1 = AVAudioFile()
private var audioFile2 = AVAudioFile()
override func viewDidLoad()
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
if let filePath = Bundle.main.path(forResource: "PeteNope", ofType:
"mp3")
let filePathURL = URL(fileURLWithPath: filePath)
setPlayerFile(filePathURL)
if let filePath2 = Bundle.main.path(forResource: "Law_WOW", ofType:
"mp3")
let filePath2URL = URL(fileURLWithPath: filePath2)
setPlayerFile2(filePath2URL)
private func setPlayerFile(_ fileURL: URL)
do
let file = try AVAudioFile(forReading: fileURL)
self.audioFile1 = file
catch
fatalError("Could not create AVAudioFile instance. error: \(error).")
private func setPlayerFile2(_ fileURL: URL)
do
let file = try AVAudioFile(forReading: fileURL)
self.audioFile2 = file
catch
fatalError("Could not create AVAudioFile instance. error: \(error).")
@IBAction func sound1Play(_ sender: UIButton)
if sassSwitch.isOn
timePitch.pitch = -300
timePitch.rate = 0.5
audioEngine.attach(pitchPlayer)
audioEngine.attach(timePitch)
audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile1.processingFormat)
audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile1.processingFormat)
pitchPlayer.scheduleFile(audioFile1, at: nil, completionHandler: nil)
// Start the engine.
do
try audioEngine.start()
catch
fatalError("Could not start engine. error: \(error).")
pitchPlayer.play()
else if chipSwitch.isOn
timePitch.pitch = +500
timePitch.rate = 2.0
audioEngine.attach(pitchPlayer)
audioEngine.attach(timePitch)
audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile1.processingFormat)
audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile1.processingFormat)
pitchPlayer.scheduleFile(audioFile1, at: nil, completionHandler: nil)
// Start the engine.
do
try audioEngine.start()
catch
fatalError("Could not start engine. error: \(error).")
pitchPlayer.play()
else
timePitch.pitch = +0
timePitch.rate = 1.0
audioEngine.attach(pitchPlayer)
audioEngine.attach(timePitch)
audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile1.processingFormat)
audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile1.processingFormat)
pitchPlayer.scheduleFile(audioFile1, at: nil, completionHandler: nil)
// Start the engine.
do
try audioEngine.start()
catch
fatalError("Could not start engine. error: \(error).")
pitchPlayer.play()
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
【问题讨论】：
你不尝试在任何地方改变音高吗？当你做你使用什么价值观？在我的项目中，我将音高设置为 1000（花栗鼠模式）或 -1000（darth vadar 模式）。 正确，这就是我要设置的。基本上，这两个开关我都有减慢或加快速度。我想将音高变化与这些开关联系起来。一旦音高进入，我什至可能不需要改变速率，但我想我会尝试将两者都绑在开关上，然后在需要时将其中一个去掉。 【参考方案1】：您将使用AVAudioEngine 将AVAudioPlayerNode 附加到AVAudioUnitTimePitch 效果。我检查了 Apple 的 AudioUnitV3Example 示例代码并从中拼凑出一个工作示例。您将希望实现更多可以在其中找到的状态和错误处理。无论如何，这里是：
在类的顶部定义一些私有变量：
/// Playback engine.
private let audioEngine = AVAudioEngine()
/// Engine's player node.
private let pitchPlayer = AVAudioPlayerNode()
private let timePitch = AVAudioUnitTimePitch()
/// File to play.
private var audioFile: AVAudioFile?
检查有效的音频文件：
override func viewDidLoad()
super.viewDidLoad()
if let filePath = Bundle.main.path(forResource: "Sound1", ofType:
"mp3")
let filePathURL = URL(fileURLWithPath: filePath)
setPlayerFile(filePathURL)
private func setPlayerFile(_ fileURL: URL)
do
let file = try AVAudioFile(forReading: fileURL)
self.audioFile = file
catch
fatalError("Could not create AVAudioFile instance. error: \(error).")
@IBAction func verySlowPlayback(sender: UIButton)
timePitch.pitch = -300
timePitch.rate = 0.5
audioEngine.attach(pitchPlayer)
audioEngine.attach(timePitch)
audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile?.processingFormat)
audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile?.processingFormat)
pitchPlayer.scheduleFile(audioFile!, at: nil, completionHandler: nil)
// Start the engine.
do
try audioEngine.start()
catch
fatalError("Could not start engine. error: \(error).")
pitchPlayer.play()
【讨论】：
谢谢。当我可以在电脑前时，它将帮助我稍后开始。你对我如何将它们绑定到开关而不是按钮有什么建议吗？基本上我想要两个开关，一个用于快速和高音，一个用于慢速和低音。我想要多个按钮正常播放声音，但如果启用开关，它会加快或减慢它。 顺便说一句：我编辑了帖子以将rate 属性添加到AVAudioUnitTimePitch 类：timePitch.rate = 0.5。
您可以让play1() 和play2() 开关更改AVAudioUnitTimePitch 属性。您将看到是否需要 reset() 音频引擎。
感谢@ericl 的所有帮助。我用一些新代码编辑了这篇文章，这些代码是我和你的编辑一起扔的。如果你有机会，就看看它，让我知道它是否有意义或者我是否偏离了基地。
我认为您应该使用一个文件和一个开关创建一个更简单的测试项目，然后让它工作。看一下 Apple 示例代码，了解一下兔子洞之旅，并考虑使用类似 `isPlaying' 的布尔值来检查状态。找出另一个问题的下一个最小完整和可验证示例，您可能会在此过程中找到答案！ （我也是初学者；看到我的低分了吗？）无论如何，我确实回答了您最初的问题“如何改变音高”，所以请接受我的回答！以上是关于更改“发声器”的音频音高的主要内容，如果未能解决你的问题，请参考以下文章