xcode 使用 Swift 通过 iPhone 扬声器强制播放音频文件

Force audio file playback through iPhone loud speaker using Swift

提问by Unconquered82

I have an App that records and then plays back an audio file. Currently the audio playback is playing through the earpiece speaker. Could someone tell me how Swift would handle coding this to force the audio out the loud speaker instead?

我有一个应用程序可以记录然后播放音频文件。目前正在通过听筒扬声器播放音频。有人能告诉我 Swift 将如何处理编码以强制将音频从扬声器中传出吗？

Below is a one of the instances I'm using to play the audio file:

下面是我用来播放音频文件的实例之一：

@IBAction func playAudioVader(sender: UIButton) {
    playAudioWithVariablePitch(-1000)
    }

    func playAudioWithVariablePitch(pitch: Float){
    audioPlayer.stop()
    audioEngine.stop()
    audioEngine.reset()

        var audioPlayerNode = AVAudioPlayerNode()
        audioEngine.attachNode(audioPlayerNode)

        var changePitchEffect = AVAudioUnitTimePitch()
        changePitchEffect.pitch = pitch
        audioEngine.attachNode(changePitchEffect)

        audioEngine.connect(audioPlayerNode, to: changePitchEffect, format: nil)
        audioEngine.connect(changePitchEffect, to: audioEngine.outputNode, format: nil)

        audioPlayerNode.scheduleFile(audioFile, atTime: nil, completionHandler: nil)
        audioEngine.startAndReturnError(nil)

        audioPlayerNode.play()

}

   override func viewDidLoad() {

    super.viewDidLoad()

    audioPlayer = AVAudioPlayer(contentsOfURL:receivedAudio.filePathURL, error: nil)
    audioPlayer.enableRate = true
    audioEngine = AVAudioEngine()
    audioFile = AVAudioFile(forReading:receivedAudio.filePathURL, error: nil)


}

回答by HoboFlo

EDIT July 2017:Refer to Husam's answer for the Swift 2.0 solution.

编辑 2017 年 7 月：请参阅 Husam 对 Swift 2.0 解决方案的回答。

As of Swift 1.2, you use overrideOutputAudioPort and AVAudioSessionPortOverride. It can be implemented by doing something like this:

从 Swift 1.2 开始，您使用 overrideOutputAudioPort 和 AVAudioSessionPortOverride。它可以通过执行以下操作来实现：

if !session.overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker, error:&error) {
   println("could not set output to speaker")
   if let e = error {
      println(e.localizedDescription)
   }
}

I'm working on an app that uses this now, and I have a function called setSessionPlayandRecord, which looks like:

我正在开发一个现在使用它的应用程序，我有一个名为 setSessionPlayandRecord 的函数，它看起来像：

func setSessionPlayAndRecord() {
    let session:AVAudioSession = AVAudioSession.sharedInstance()
    var error: NSError?
    if !session.setCategory(AVAudioSessionCategoryPlayAndRecord, error:&error) {
        println("could not set session category")
        if let e = error {
            println(e.localizedDescription)
        }
    }
    if !session.overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker, error:&error) {
        println("could not set output to speaker")
        if let e = error {
            println(e.localizedDescription)
        }
    }
    if !session.setActive(true, error: &error) {
        println("could not make session active")
        if let e = error {
            println(e.localizedDescription)
        }
    }
}

回答by Husam

Swift 2.0Code

Swift 2.0代码

func setSessionPlayerOn()
{
    do {
        try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayAndRecord)
    } catch _ {
    }
    do {
        try AVAudioSession.sharedInstance().setActive(true)
    } catch _ {
    }
    do {
        try AVAudioSession.sharedInstance().overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker)
    } catch _ {
    }
}
func setSessionPlayerOff()
{
    do {
        try AVAudioSession.sharedInstance().setActive(false)
    } catch _ {
    }
}