ios 内置麦克风录音只有一个声道声音

Posted 2023-02-25

【中文标题】ios 内置麦克风录音只有一个声道声音

【英文标题】：ios recording with built-in mic only have one channel sound

【发布时间】：2016-04-22 12:38:15

【问题描述】：

我正在使用 AVAudioEngine 来捕捉用户的声音并对其应用一些效果。使用耳机麦克风录制时，一切正常。但是用手机内置mic录音，再通过耳机播放声音时，只有左侧耳塞有声音，看来内置mic只有单声道输入。那么我该如何解决这个问题呢？这是我的一些代码：

func connectNode()
  engine.connect(engine.inputNode!, to: reverbNode, format:reverbNode.outputFormatForBus(0))
  engine.connect(reverbNode, to: delayNode, format: delayNode.outputFormatForBus(0))
  engine.connect(delayNode, to: distortion, format: distortion.outputFormatForBus(0))
  engine.connect(distortion, to: engine.mainMixerNode, format: engine.mainMixerNode.outputFormatForBus(0))
  engine.connect(player, to: engine.mainMixerNode, format: engine.mainMixerNode.outputFormatForBus(0))


func recordToFile()
  setSessionRecord()
  recordSetting[AVFormatIDKey] = NSNumber(unsignedInt: UInt32(kAudioFormatMPEG4AAC))
  recordSetting[AVNumberOfChannelsKey] = NSNumber(int: 2)
  var file: AVAudioFile!
  do
    try file = AVAudioFile(forWriting: URLFor(fileName)!, settings: recordSetting)
  catch let error as NSError
  print("error:\(error)")
  
  engine.mainMixerNode.installTapOnBus(0, bufferSize: 1024, format: file.processingFormat)  (buffer, time) -> Void in
  try! file.writeFromBuffer(buffer)
  


func playbackRecord()
  setSessionPlayback()
  var file:AVAudioFile!
  file = try! AVAudioFile(forReading:URLFor(fileName)!)
  let audioFormat = file.processingFormat
  let audioFrameCount = UInt32(file.length)
  let audioFileBuffer = AVAudioPCMBuffer(PCMFormat: audioFormat, frameCapacity: audioFrameCount)
  try! file.readIntoBuffer(audioFileBuffer, frameCount: audioFrameCount)
  player.scheduleBuffer(audioFileBuffer, atTime: nil, options: .Interrupts, completionHandler: print(self.player.stop()))
  if(!player.playing)
    player.play()
  else
    print("stop")
    player.stop()
   

【参考方案1】：

我找到了解决此问题的方法。只需修改此方法，为引擎提供单通道格式，然后一切都会好起来的。

func connectNode()
  let format = AVAudioFormat(commonFormat: AVAudioCommonFormat.PCMFormatFloat32, sampleRate: 44100.0, channels:AVAudioChannelCount(1), interleaved: false)
  engine.connect(engine.inputNode!, to: reverbNode, format:format)
  engine.connect(reverbNode, to: delayNode, format: format)
  engine.connect(delayNode, to: distortion, format: format)
  engine.connect(distortion, to: engine.mainMixerNode, format: format)
  engine.connect(player, to: engine.mainMixerNode, format: engine.mainMixerNode.outputFormatForBus(0))