AudioClipExtension//clipToWav

using UnityEngine;
using System;
using System.IO;

public static class AudioClipExtension
{
public static byte[] GetData(this AudioClip clip)
{
var data = new float[clip.samples * clip.channels];

    clip.GetData(data, 0);

    byte[] bytes = new byte[data.Length * 4];
    Buffer.BlockCopy(data, 0, bytes, 0, bytes.Length);

    return bytes;
}

public static void SetData(this AudioClip clip, byte[] bytes)
{
    float[] data = new float[bytes.Length / 4];
    Buffer.BlockCopy(bytes, 0, data, 0, bytes.Length);

    clip.SetData(data, 0);
}

public static byte[] GetData16(this AudioClip clip)
{
    var data = new float[clip.samples * clip.channels];

    clip.GetData(data, 0);

    byte[] bytes = new byte[data.Length * 2];

    int rescaleFactor = 32767;

    for (int i = 0; i < data.Length; i++)
    {
        short value = (short)(data[i] * rescaleFactor);
        BitConverter.GetBytes(value).CopyTo(bytes, i * 2);
    }

    return bytes;
}

public static byte[] EncodeToWAV(this AudioClip clip)
{
    byte[] bytes = null;

    using (var memoryStream = new MemoryStream())
    {
        memoryStream.Write(new byte[44], 0, 44);//预留44字节头部信息

        byte[] bytesData = clip.GetData16();

        memoryStream.Write(bytesData, 0, bytesData.Length);

        memoryStream.Seek(0, SeekOrigin.Begin);

        byte[] riff = System.Text.Encoding.UTF8.GetBytes("RIFF");
        memoryStream.Write(riff, 0, 4);

        byte[] chunkSize = BitConverter.GetBytes(memoryStream.Length - 8);
        memoryStream.Write(chunkSize, 0, 4);

        byte[] wave = System.Text.Encoding.UTF8.GetBytes("WAVE");
        memoryStream.Write(wave, 0, 4);

        byte[] fmt = System.Text.Encoding.UTF8.GetBytes("fmt ");
        memoryStream.Write(fmt, 0, 4);

        byte[] subChunk1 = BitConverter.GetBytes(16);
        memoryStream.Write(subChunk1, 0, 4);

        UInt16 two = 2;
        UInt16 one = 1;

        byte[] audioFormat = BitConverter.GetBytes(one);
        memoryStream.Write(audioFormat, 0, 2);

        byte[] numChannels = BitConverter.GetBytes(clip.channels);
        memoryStream.Write(numChannels, 0, 2);

        byte[] sampleRate = BitConverter.GetBytes(clip.frequency);
        memoryStream.Write(sampleRate, 0, 4);

        byte[] byteRate = BitConverter.GetBytes(clip.frequency * clip.channels * 2); // sampleRate * bytesPerSample*number of channels
        memoryStream.Write(byteRate, 0, 4);

        UInt16 blockAlign = (ushort)(clip.channels * 2);
        memoryStream.Write(BitConverter.GetBytes(blockAlign), 0, 2);

        UInt16 bps = 16;
        byte[] bitsPerSample = BitConverter.GetBytes(bps);
        memoryStream.Write(bitsPerSample, 0, 2);

        byte[] datastring = System.Text.Encoding.UTF8.GetBytes("data");
        memoryStream.Write(datastring, 0, 4);

        byte[] subChunk2 = BitConverter.GetBytes(clip.samples * clip.channels * 2);
        memoryStream.Write(subChunk2, 0, 4);

        bytes = memoryStream.ToArray();
    }

    return bytes;
}

}