访问麦克风后整个应用程序的音量变得更安静

Posted 2023-02-23

【中文标题】访问麦克风后整个应用程序的音量变得更安静

【英文标题】：Volume of entire app gets quieter after accessing mic

【发布时间】：2016-04-14 16:45:02

【问题描述】：

我的 ios 应用程序出现音量问题。当我拨打setupMic() 时，整个应用程序的音量显着降低。 这是我正在使用的代码：

func setupMic() 
    //make an AudioSession, set it to PlayAndRecord and make it active
    let audioSession: AVAudioSession = AVAudioSession.sharedInstance()
    do 
        try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord)
     catch 
       print("There was an error setting the category")
    
    do 
       try audioSession.setActive(true)
     catch 
       print("There was an error setting the audio session to active")
    


    //set up the URL for the audio file
    let documents: AnyObject = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0]
    let str = documents.stringByAppendingPathComponent("recordTest.caf")
    let url = NSURL.fileURLWithPath(str as String)

    //make a dictionary to hold the recording setting so we can instantiate our AVAudioRecorder
    let number = NSNumber(unsignedInt: kAudioFormatAppleIMA4)
    let recordSettings: [String: AnyObject] = [AVFormatIDKey: number,
                                                 AVSampleRateKey: 44100.0,
                                                 AVNumberOfChannelsKey: 2,
                                                 AVEncoderBitRateKey: 12800,
                                                 AVLinearPCMBitDepthKey: 16,
                                                 AVEncoderAudioQualityKey: AVAudioQuality.Min.rawValue]

    //Instantiate an AVAudioRecorder
    do 
        recorder = try AVAudioRecorder(URL: url, settings: recordSettings)
     catch 
      print("There was an error")
    


//This function is called everytime our timer levelTimer fires
func levelTimerCallback() 
    recorder.updateMeters()
    let averagePower = self.recorder.peakPowerForChannel(0)
    if averagePower > -7 
        stopMonitoring()

        print(recorder.peakPowerForChannel(0))
        didCompleteChallenge(true)
    


func startMonitoring() 
    if self.recorder != nil 
        recorder.prepareToRecord()
        recorder.meteringEnabled = true
        //start recording
        recorder.record()
        //instantiate a timer to be called with whatever frequency we want to grab metering values
        self.levelTimer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: #selector(levelTimerCallback), userInfo: nil, repeats: true)
    


func stopMonitoring() 
    self.recorder.stop()
    self.recorder.deleteRecording()
    self.levelTimer.invalidate()

我在updateWith() 方法中调用setupMic() 和startMonitoring()。当视图再次使用updateWith() 更新时，我也会调用stopMonitoring() 访问麦克风后，音量会降低。有什么建议么？有什么修复吗？

【参考方案1】：

解决了这个问题。音量实际上并没有变小，音频实际上是通过听筒传输的。我只需要将音频会话类别选项设置为 .DefaultToSpeaker。 AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayAndRecord, withOptions: [.DefaultToSpeaker])。无论如何感谢互联网。

【讨论】：

我设置了这个类别，但是当我插入耳机时，我知道只有一侧有声音，另一侧不工作，有什么线索吗？