Unity编程笔录--Unity中Microphone类进行录音保存

前言：

使用Unity中自带的Microphone类进行录音保存，由于录音是比较简单，但是保存就有问题了，需要保存就要注意音频格式了，Unity录音默认是wav格式。

正文：

开始录音

private AudioClip clip;
    //录音的采样率
    const int samplingRate = 44100;
    private TimerInfo timerInfo;
    /// 

    /// 开始录音
    /// 
    public void Recording()
    {
        string[] micDevices = Microphone.devices;
        if (micDevices.Length == 0)
        {
            Util.Log("没有找到录音组件");
            UpdateMessage("没有找到录音组件");
            return;
        }

        Util.Log("录音时长为30秒");
        UpdateMessage("录音时长为30秒");
        Microphone.End(null);//录音前先停掉录音，录音参数为null时采用的是默认的录音驱动
        clip = Microphone.Start(null, false, 30, samplingRate);
        timerInfo = new TimerInfo(this);//时间管理
        TimerManager.AddTimerEvent(timerInfo);//添加到时间管理器中
    }

  /// 

    /// 停止录音
    /// 
    public void StopRecord()
    {
        TimerManager.StopTimerEvent(timerInfo);
        TimerManager.RemoveTimerEvent(timerInfo);
        index = 0;
        int audioLength;
        int lastPos = Microphone.GetPosition(null);
        if (Microphone.IsRecording(null))
        {
            audioLength = lastPos / samplingRate;
        }
        else
        {
            audioLength = 30;
        }

        Microphone.End(null);

        if (audioLength < 1.0f)
        {
            Util.Log("录音时长短");
            UpdateMessage("录音时长短");
        }
    }

  /// 

    /// 播放录音
    /// 
    public void PlayRecord()
    {
        StopRecord();
        AudioSource.PlayClipAtPoint(clip, Vector3.zero);
    }

    /// 

    /// 保存录音
    /// 
    public void SaveRecord()
    {
        try
        {
            Util.Save(clip, Util.DataPath + "testmodel/testproject/other/record.wav");
            Util.Log("保存完毕");
            UpdateMessage("保存完毕");
        }
        catch (Exception ex)
        {
            Util.Log(ex.Message + ex.StackTrace);
            UpdateMessage(ex.Message + ex.StackTrace);
        }
    }

        public static void Save(AudioClip clip, string path)
        {
            string filePath = Path.GetDirectoryName(path);
            if (!Directory.Exists(filePath))
            {
                Directory.CreateDirectory(filePath);
            }
            using (FileStream fileStream = CreateEmpty(path))
            {
                ConvertAndWrite(fileStream, clip);
                WriteHeader(fileStream, clip);
            }

        }

private static void ConvertAndWrite(FileStream fileStream, AudioClip clip)
        {

            float[] samples = new float[clip.samples];

            clip.GetData(samples, 0);

            Int16[] intData = new Int16[samples.Length]; 

            Byte[] bytesData = new Byte[samples.Length * 2];

            int rescaleFactor = 32767; //to convert float to Int16 

            for (int i = 0; i < samples.Length; i++)
            {
                intData[i] = (short)(samples[i] * rescaleFactor);
                Byte[] byteArr = new Byte[2];
                byteArr = BitConverter.GetBytes(intData[i]);
                byteArr.CopyTo(bytesData, i * 2);
            } 
            fileStream.Write(bytesData, 0, bytesData.Length);
        }

 private static FileStream CreateEmpty(string filepath)
        {
            FileStream fileStream = new FileStream(filepath, FileMode.Create);
            byte emptyByte = new byte();

            for (int i = 0; i < 44; i++) //preparing the header 
            {
                fileStream.WriteByte(emptyByte);
            }

            return fileStream;
        }
 private static void WriteHeader(FileStream stream, AudioClip clip)
        { 
            int hz = clip.frequency;
            int channels = clip.channels;
            int samples = clip.samples;

            stream.Seek(0, SeekOrigin.Begin);

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

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

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

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

            Byte[] subChunk1 = BitConverter.GetBytes(16);
            stream.Write(subChunk1, 0, 4);

            UInt16 two = 2;
            UInt16 one = 1;

            Byte[] audioFormat = BitConverter.GetBytes(one);
            stream.Write(audioFormat, 0, 2);

            Byte[] numChannels = BitConverter.GetBytes(channels);
            stream.Write(numChannels, 0, 2);

            Byte[] sampleRate = BitConverter.GetBytes(hz);
            stream.Write(sampleRate, 0, 4);

            Byte[] byteRate = BitConverter.GetBytes(hz * channels * 2); // sampleRate * bytesPerSample*number of channels, here 44100*2*2 
            stream.Write(byteRate, 0, 4);

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

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

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

            Byte[] subChunk2 = BitConverter.GetBytes(samples * channels * 2);
            stream.Write(subChunk2, 0, 4);

        }