使用AudioToolbox - Swift从音频信号中获取原始样本流

let audioSession = AVAudioSession.sharedInstance()
do {
    try audioSession.setCategory(.playAndRecord, mode: .default)
    try audioSession.setActive(true)
} catch {
    print("Failed to set audio session category.")
}

if let input = audioSession.availableInputs?.first {
    do {
        try audioSession.setPreferredInput(input)
    } catch {
        print("Failed to set preferred audio input.")
    }
}

var audioQueue: AudioQueueRef?
var audioFormat = AudioStreamBasicDescription()
audioFormat.mSampleRate = 44100.0
audioFormat.mFormatID = kAudioFormatLinearPCM
audioFormat.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked
audioFormat.mFramesPerPacket = 1
audioFormat.mChannelsPerFrame = 1
audioFormat.mBitsPerChannel = 16
audioFormat.mBytesPerFrame = audioFormat.mChannelsPerFrame * audioFormat.mBitsPerChannel / 8
audioFormat.mBytesPerPacket = audioFormat.mBytesPerFrame * audioFormat.mFramesPerPacket

AudioQueueNewInput(&audioFormat, audioQueueInputCallback, nil, nil, nil, 0, &audioQueue)

let audioQueueInputCallback: AudioQueueInputCallback = { (inUserData, inAQ, inBuffer, inStartTime, inNumPackets, inPacketDesc) in
    // 处理音频数据
}

AudioQueueStart(audioQueue, nil)