objective-c - 如何将 UnsafeMutablePointer> 变量转换为 AudioBufferList？

Question

我的 Swift 项目中有这个 EZAudio 方法，用于从麦克风捕获音频:

func microphone(microphone: EZMicrophone!, hasAudioReceived bufferList: UnsafeMutablePointer<UnsafeMutablePointer<Float>>, withBufferSize bufferSize: UInt32, withNumberOfChannels numberOfChannels: UInt32) {

}

但我真正需要的是将“bufferList”参数作为 AudioBufferList 类型传入，以便通过套接字发送这些音频数据包，就像我在 Objective C 中所做的那样:

//Objective C pseudocode:
for(int i = 0; i < bufferList.mNumberBuffers; ++i){
   AudioBuffer buffer = bufferList.mBuffers[i];
   audio = ["audio": NSData(bytes: buffer.mData, length: Int(buffer.mDataByteSize))];
   socket.emit("message", audio);
}

如何将 UnsafeMutablePointer> 变量转换为 AudioBufferList？

Answer 1

我能够将麦克风中的音频流式传输到套接字中，如下所示:

func microphone(microphone: EZMicrophone!, hasBufferList bufferList: UnsafeMutablePointer<AudioBufferList>, withBufferSize bufferSize: UInt32, withNumberOfChannels numberOfChannels: UInt32) {
        let blist:AudioBufferList=bufferList[0]
        let buffer:AudioBuffer = blist.mBuffers
        let audio = ["audio": NSData(bytes: buffer.mData, length: Int(buffer.mDataByteSize))];
        socket.emit("message", audio);//this socket comes from Foundation framework
    }

这个通用的 AudioStreamDescriptor 设置对我有用，您可能需要根据自己的需要对其进行调整或省略某些部分，例如波形动画:

func initializeStreaming() {
        var streamDescription:AudioStreamBasicDescription=AudioStreamBasicDescription()
        streamDescription.mSampleRate       = 16000.0
        streamDescription.mFormatID         = kAudioFormatLinearPCM
        streamDescription.mFramesPerPacket  = 1
        streamDescription.mChannelsPerFrame = 1
        streamDescription.mBytesPerFrame    = streamDescription.mChannelsPerFrame * 2
        streamDescription.mBytesPerPacket   = streamDescription.mFramesPerPacket * streamDescription.mBytesPerFram
        streamDescription.mBitsPerChannel   = 16
        streamDescription.mFormatFlags      = kAudioFormatFlagIsSignedInteger
        microphone = EZMicrophone(microphoneDelegate: self, withAudioStreamBasicDescription: sstreamDescription, startsImmediately: false)
        waveview?.plotType=EZPlotType.Buffer
        waveview?.shouldFill = false
        waveview?.shouldMirror = false
    }

让这个东西运行起来很复杂，祝你好运!