用NAudio解码mu律音频

因为您只有原始的mu定律数据,所以不能在上面使用waveilereader。相反,创建一个继承自WaveStream的新类。

在its中 Read 方法,从tmpMemStream返回数据。作为一个 WaveFormat 返回一个mu定律波形。

下面是一个可以使用的通用帮助类:

public class RawSourceWaveStream : WaveStream
{
    private Stream sourceStream;
    private WaveFormat waveFormat;

    public RawSourceWaveStream(Stream sourceStream, WaveFormat waveFormat)
    {
        this.sourceStream = sourceStream;
        this.waveFormat = waveFormat;
    }

    public override WaveFormat WaveFormat
    {
        get { return this.waveFormat; }
    }

    public override long Length
    {
        get { return this.sourceStream.Length; }
    }

    public override long Position
    {
        get
        {
            return this.sourceStream.Position;
        }
        set
        {
            this.sourceStream.Position = value;
        }
    }

    public override int Read(byte[] buffer, int offset, int count)
    {
        return sourceStream.Read(buffer, offset, count);
    }
}

现在,您可以像以前一样继续创建转换后的文件,并将RawSourceWaveStream作为输入传入:

var waveFormat = WaveFormat.CreateMuLawFormat(8000, 1);
var reader = new RawSourceWaveStream(tmpMemStream, waveFormat);
using (WaveStream convertedStream = WaveFormatConversionStream.CreatePcmStream(reader))
{
    WaveFileWriter.CreateWaveFile(recordingsPath + "/" + outputFileName, convertedStream);
}