c# – 使用AudioQueue和Monotouch静音录制

我在MonoTouch中编写了一个小程序,使用InputAudioQueue从iPhone 4s的麦克风录制声音.

我将记录的数据保存在一个数组中,并将此缓冲区提供给我的音频播放器进行播放(使用OutputAudioQueue).

播放时,它只是一些口吃的垃圾/静音.我在播放前尝试用sin波填充缓冲区然后听起来不错,所以我猜问题出在录音中,而不是播放.谁能帮我看看有什么不对？ (以下代码)

public class AQRecorder
{
    private const int CountAudioBuffers = 3;
    private const int AudioBufferLength = 22050;
    private const int SampleRate = 44100;
    private const int BitsPerChannel = 16;
    private const int Channels = 1;
    private const int MaxRecordingTime = 5;
    private AudioStreamBasicDescription audioStreamDescription;
    private InputAudioQueue inputQueue;
    private short[] rawData;
    private int indexNextRawData;

    public AQRecorder ()
    {
        this.audioStreamDescription.Format = AudioFormatType.LinearPCM;
        this.audioStreamDescription.FormatFlags = AudioFormatFlags.LinearPCMIsSignedInteger | 
                                                  AudioFormatFlags.LinearPCMIsPacked;
        this.audioStreamDescription.SampleRate = AQRecorder.SampleRate;
        this.audioStreamDescription.BitsPerChannel = AQRecorder.BitsPerChannel;
        this.audioStreamDescription.ChannelsPerFrame = AQRecorder.Channels;
        this.audioStreamDescription.BytesPerFrame = (AQRecorder.BitsPerChannel / 8) * AQRecorder.Channels;
        this.audioStreamDescription.FramesPerPacket = 1;
        this.audioStreamDescription.BytesPerPacket = audioStreamDescription.BytesPerFrame * audioStreamDescription.FramesPerPacket;
        this.audioStreamDescription.Reserved = 0;
    }

    public void Start ()
    {
        int totalBytesToRecord = this.audioStreamDescription.BytesPerFrame * AQRecorder.SampleRate * AQRecorder.MaxRecordingTime;
        this.rawData = new short[totalBytesToRecord / sizeof(short)];
        this.indexNextRawData = 0;
        this.inputQueue = SetupInputQueue (this.audioStreamDescription);
        this.inputQueue.Start ();
    }

    public void Stop ()
    {
        if (this.inputQueue.IsRunning)
        {
            this.inputQueue.Stop (true);
        }
    }

    public short[] GetData ()
    {
        return this.rawData;;
    }

    private InputAudioQueue SetupInputQueue (AudioStreamBasicDescription audioStreamDescription)
    {
        InputAudioQueue inputQueue = new InputAudioQueue (audioStreamDescription);

        for (int count = 0; count < AQRecorder.CountAudioBuffers; count++)
        {
            IntPtr bufferPointer;
            inputQueue.AllocateBuffer(AQRecorder.AudioBufferLength, out bufferPointer);
            inputQueue.EnqueueBuffer(bufferPointer, AQRecorder.AudioBufferLength, null);
        }
        inputQueue.InputCompleted += HandleInputCompleted;
        return inputQueue;
    }

    private void HandleInputCompleted (object sender, InputCompletedEventArgs e)
    {
        unsafe
        {
            short* shortPtr = (short*)e.IntPtrBuffer;

            for (int count = 0; count < AQRecorder.AudioBufferLength; count += sizeof(short))
            {
                if (indexNextRawData >= this.rawData.Length)
                {
                    this.inputQueue.Stop (true);
                    return;
                }
                this.rawData [indexNextRawData] = *shortPtr;
                indexNextRawData++;
                shortPtr++;
            }
        }
        this.inputQueue.EnqueueBuffer(e.IntPtrBuffer, AQRecorder.AudioBufferLength, null);
    }
}

解决方法:

好吧,这可能为时已晚,但我只听到垃圾声并遇到了同样的问题并找到了解决办法.

您无法直接从e.IntPtrBuffer读取音频数据.此指针是指向AudioQueueBuffer对象的指针,而不是指向音频数据本身的指针.因此,要读取音频数据,您可以使用e.UnsafeBuffer,它允许您访问此对象并使用其AudioData指针.这是一个IntPtr,您可以(在不安全的上下文中)转换为字节*或短*,并且您拥有音频数据.

最好的祝福

亚历克斯

标签：c,iphone,xamarin-ios,audioqueue,recording
来源： https://codeday.me/bug/20190629/1331064.html