如何获取音频录制缓冲区数据？

Question

我正在从iPhone麦克风获取音频数据并将其发送到套接字，我已经尝试使用AVAudioEngine来获取音频缓冲区，但是一些如何不使用它。所以你可以给我建议什么是更好的方式来实时获取记录缓冲数据。

override func viewDidLoad() { 
     super.viewDidLoad() 



     // initialize engine 
     engine = AVAudioEngine() 
     guard nil != engine?.inputNode else { 
      // @TODO: error out 
      return 
     } 



     SocketIOManager.sharedInstance.socket.on("listen") {data, ack in 

      let BuffurData:Data = data[0] as! Data 

      // let playData = self?.audioBufferToNSData(PCMBuffer: BuffurData as! AVAudioPCMBuffer) 
      do { 
       // let data = NSData(bytes: &BuffurData, length: BuffurData.count) 

       let player = try AVAudioPlayer(data:BuffurData) 
       player.play() 
      } catch let error as NSError { 
       print(error.description) 
      } 



      print("socket connected \(data)") 
     } 
    } 

func installTap() { 

     engine = AVAudioEngine() 
     guard let engine = engine, let input = engine.inputNode else { 
      // @TODO: error out 
      return 
     } 

     let format = input.inputFormat(forBus: 0) 
     input.installTap(onBus: 0, bufferSize:4096, format:format, block: { [weak self] buffer, when in 

      guard let this = self else { 
       return 
      } 

      // writing to file: for testing purposes only 
      do { 
       try this.file!.write(from: buffer) 
      } catch { 

      } 

      if let channel1Buffer = buffer.floatChannelData?[0] { 
       let test = self?.copyAudioBufferBytes(buffer) 
       let stram = self?.toNSData(PCMBuffer: buffer) 
       SocketIOManager.sharedInstance.socket.emit("talk",stram!); 

       // socket.on("listen", function (data) 



       /*! @property floatChannelData 
       @abstract Access the buffer's float audio samples. 
       @discussion 
       floatChannelData returns pointers to the buffer's audio samples if the buffer's format is 
       32-bit float, or nil if it is another format. 

       The returned pointer is to format.channelCount pointers to float. Each of these pointers 
       is to "frameLength" valid samples, which are spaced by "stride" samples. 

       If format.interleaved is false (as with the standard deinterleaved float format), then 
       the pointers will be to separate chunks of memory. "stride" is 1. 

       If format.interleaved is true, then the pointers will refer into the same chunk of interleaved 
       samples, each offset by 1 frame. "stride" is the number of interleaved channels. 
       */ 

       // @TODO: send data, better to pass into separate queue for processing 
      }    
     }) 

     engine.prepare() 

     do { 
      try engine.start() 
     } catch { 
      // @TODO: error out 
     } 
    } 

Answer 1

试试这个代码：

var audioPlayerQueue = DispatchQueue(label: "audioPlayerQueue", qos: DispatchQoS.userInteractive) 

    var peerAudioPlayer: AVAudioPlayerNode = AVAudioPlayerNode() 
     var peerInputFormat: AVAudioFormat? 

    override func viewDidLoad() { 
      super.viewDidLoad() 
      // initialize engine 
      engine = AVAudioEngine() 
      guard nil != engine?.inputNode else { 
       // @TODO: error out 
       return 
      } 
      engine.attach(self.peerAudioPlayer) 
      self.peerInputFormat = AVAudioFormat.init(commonFormat: .pcmFormatFloat32, sampleRate: 44100, channels: 1, interleaved: false) 
    self.peerAudioEngine.connect(peerAudioPlayer, to: self.peerAudioEngine.mainMixerNode, format: peerInput?.outputFormat(forBus: 0)) 
      do { 
       peerAudioEngine.prepare() 
       try peerAudioEngine.start() 

      }catch let error { 
       print(error.localizedDescription) 
      } 

      SocketIOManager.sharedInstance.socket.on("listen") {data, ack in 


          let pcmBuffer = toPCMBuffer(data: data) 
    self.audioPlayerQueue.async { 
         self.peerAudioPlayer.scheduleBuffer(pcmBuffer, completionHandler: nil) 
         if self.peerAudioEngine.isRunning { 
          self.peerAudioPlayer.play() 
         }else { 
          do { 
           try self.peerAudioEngine.start() 
          }catch { 
           print(error.localizedDescription) 
          } 
         } 
        } 
    } 

       print("socket connected \(data)") 
      } 
     } 


    func toPCMBuffer(data: NSData) -> AVAudioPCMBuffer { 
      let audioFormat = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatFloat32, sampleRate: 44100, channels: 1, interleaved: false) // given NSData audio format 
      let PCMBuffer = AVAudioPCMBuffer(pcmFormat: audioFormat, frameCapacity: UInt32(data.length)/audioFormat.streamDescription.pointee.mBytesPerFrame) 
      PCMBuffer.frameLength = PCMBuffer.frameCapacity 
      let channels = UnsafeBufferPointer(start: PCMBuffer.floatChannelData, count: Int(PCMBuffer.format.channelCount)) 
      data.getBytes(UnsafeMutableRawPointer(channels[0]) , length: data.length) 
      return PCMBuffer 
     } 




func installTap() { 

     engine = AVAudioEngine() 
     guard let engine = engine, let input = engine.inputNode else { 
      // @TODO: error out 
      return 
     } 

     let format = input.inputFormat(forBus: 0) 
     input.iinstallTap(onBus: 0, bufferSize: 4410, format: format, block: { (buffer:AVAudioPCMBuffer, AVAudioTime) in 
      guard let this = self else { 
       return 
      } 
       let stram = self?.toNSData(PCMBuffer: buffer) 
       SocketIOManager.sharedInstance.socket.emit("talk",stram!); 
      }    
     }) 

     do {  
      engine.prepare() 
      try engine.start() 
     } catch { 
      // @TODO: error out 
     } 
    } 

编辑：对于启用大功率音箱

func speakerEnabled(_ enabled:Bool)->Bool{ 
     let session = AVAudioSession.sharedInstance(); 
     var options = session.categoryOptions; 

     if (enabled) { 
      options.insert(AVAudioSessionCategoryOptions.defaultToSpeaker); 
     } else { 
      options.remove(AVAudioSessionCategoryOptions.defaultToSpeaker); 
     } 


     try! session.setCategory(AVAudioSessionCategoryPlayAndRecord, 
           with:options) 
     return true; 
    }