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2011-08-07 17:31:12

声卡录音的基本原理

为了实现一个录音的基本过程,至少需要以下对象的支持:

1. 录音设备,对我们的PC设备就是声卡。这个录音设备可以进行的操作应该有开始和关闭。

2. 缓冲区,也就是录制的声音放在哪里的问题。


二.DirectSound 对录音的描述模型

1. DirectSound对录音的支持类

? Capture,设备对象,可以看作是声卡的描述。

? CaptureBuffer,缓冲区对象,存放录入的音频数据。

? Notify,事件通知对象,由于录音是一个长时间的过程,因此使用一个缓冲队列(多个缓冲区)接收数据,每当一个缓冲区满的时候,系统使用这个对象通知 应用程序取走这个缓冲区,并继续录音。

以上三个对象是进行录音操作的主要对象,由于在C++中对DirectSound的操作 DirectX帮助文档中已经有很详细的说明,这里就不再赘述了。本文是针对Managed Code。除了以上三个主要的DirectSound类,还需要以下几个辅助类。

? WaveFormat,描述了进行录制的声音波形的格式,例如采样率,单声道还是立体声,每个采样点的长度等等。

? Thread,线程类,由于录音的过程是需要不断处理缓冲区满的事件,因此新建一个线程对此进行单独处理。

? AutoResetEvent,通知的事件,当缓冲区满的时候,使用该事件作为通知事件。


三.代码解析(SoundRecord 类)

1.需要引用的程序集

using System;

using System.Windows.Forms;

using System.Threading;

using System.IO;


// 对DirectSound的支持

using Microsoft.DirectX;

using Microsoft.DirectX.DirectSound;


2. SoundRecord的成员数据

public const int cNotifyNum = 16; // 缓冲队列的数目


private int mNextCaptureOffset = 0; // 该次录音缓冲区的起始点

private int mSampleCount = 0; // 录制的样本数目


private int mNotifySize = 0; // 每次通知大小

private int mBufferSize = 0; // 缓冲队列大小


private string mFileName = string.Empty; // 文件名

private FileStream mWaveFile = null; // 文件流

private BinaryWriter mWriter = null; // 写文件


private Capture mCapDev = null; // 音频捕捉设备

private CaptureBuffer mRecBuffer = null; // 缓冲区对象

private Notify mNotify = null; // 消息通知对象


private WaveFormat mWavFormat; // 录音的格式

private Thread mNotifyThread = null; // 处理缓冲区消息的线程

private AutoResetEvent mNotificationEvent = null; // 通知事件


3. 对外操作的函数

///

/// 构造函数,设定录音设备,设定录音格式.

///


public SoundRecord()

{

// 初始化音频捕捉设备

InitCaptureDevice();



// 设定录音格式

mWavFormat = CreateWaveFormat();

}



///

/// 设定录音结束后保存的文件,包括路径

///


/// 保存wav文件的路径名

public void SetFileName(string filename)

{

mFileName = filename;

}



///

/// 开始录音

///


public void RecStart()

{

// 创建录音文件

CreateSoundFile();



// 创建一个录音缓冲区,并开始录音

CreateCaptureBuffer();



// 建立通知消息,当缓冲区满的时候处理方法

InitNotifications();



mRecBuffer.Start(true);

}



///

/// 停止录音

///


public void RecStop()

{

// 关闭通知消息

if (null != mNotificationEvent)

mNotificationEvent.Set();



// 停止录音

mRecBuffer.Stop();



// 写入缓冲区最后的数据

RecordCapturedData();



// 回写长度信息

mWriter.Seek(4, SeekOrigin.Begin);

mWriter.Write((int)(mSampleCount + 36)); // 写文件长度

mWriter.Seek(40, SeekOrigin.Begin);

mWriter.Write(mSampleCount); // 写数据长度



mWriter.Close();

mWaveFile.Close();

mWriter = null;

mWaveFile = null;

}



4.内部调用函数

///

/// 初始化录音设备,此处使用主录音设备.

///


/// 调用成功返回true,否则返回false

private bool InitCaptureDevice()

{

// 获取默认音频捕捉设备

CaptureDevicesCollection devices = new CaptureDevicesCollection(); // 枚举音频捕捉设备

Guid deviceGuid = Guid.Empty; // 音频捕捉设备的ID



if (devices.Count>0)

deviceGuid = devices[0].DriverGuid;

else

{

MessageBox.Show(" 系统中没有音频捕捉设备");

return false;

}



// 用指定的捕捉设备创建Capture对象

try

{

mCapDev = new Capture(deviceGuid);

}

catch (DirectXException e)

{

MessageBox.Show(e.ToString());

return false;

}



return true;

}



///

/// 创建录音格式,此处使用16bit,16KHz,Mono的录音格式

///


/// WaveFormat结构体

private WaveFormat CreateWaveFormat()

{

WaveFormat format = new WaveFormat();



format.FormatTag = WaveFormatTag.Pcm; // PCM

format.SamplesPerSecond = 16000; // 16KHz

format.BitsPerSample = 16; // 16Bit

format.Channels = 1; // Mono

format.BlockAlign = (short)(format.Channels * (format.BitsPerSample / 8));

format.AverageBytesPerSecond = format.BlockAlign * format.SamplesPerSecond;



return format;

}



///

/// 创建录音使用的缓冲区

///


private void CreateCaptureBuffer()

{

// 缓冲区的描述对象

CaptureBufferDescription bufferdescription = new CaptureBufferDescription();



if (null != mNotify)

{

mNotify.Dispose();

mNotify = null;

}

if (null != mRecBuffer)

{

mRecBuffer.Dispose();

mRecBuffer = null;

}



// 设定通知的大小,默认为1s钟

mNotifySize = (1024 > mWavFormat.AverageBytesPerSecond / 8) ? 1024 : (mWavFormat.AverageBytesPerSecond / 8);

mNotifySize -= mNotifySize % mWavFormat.BlockAlign;



// 设定缓冲区大小

mBufferSize = mNotifySize * cNotifyNum;



// 创建缓冲区描述

bufferdescription.BufferBytes = mBufferSize;

bufferdescription.Format = mWavFormat; // 录音格式



// 创建缓冲区

mRecBuffer = new CaptureBuffer(bufferdescription, mCapDev);



mNextCaptureOffset = 0;

}



///

/// 初始化通知事件,将原缓冲区分成16个缓冲队列,在每个缓冲队列的结束点设定通知点.

///


/// 是否成功

private bool InitNotifications()

{

if (null == mRecBuffer)

{

MessageBox.Show(" 未创建录音缓冲区");

return false;

}



// 创建一个通知事件,当缓冲队列满了就激发该事件.

mNotificationEvent = new AutoResetEvent(false);



// 创建一个线程管理缓冲区事件

if (null == mNotifyThread)

{

mNotifyThread = new Thread(new ThreadStart(WaitThread));

mNotifyThread.Start();

}



// 设定通知的位置

BufferPositionNotify[] PositionNotify = new BufferPositionNotify[cNotifyNum + 1];

for (int i = 0; i < cNotifyNum; i++)

{

PositionNotify[i].Offset = (mNotifySize * i) + mNotifySize - 1;

PositionNotify[i].EventNotifyHandle = mNotificationEvent.Handle;

}



mNotify = new Notify(mRecBuffer);

mNotify.SetNotificationPositions(PositionNotify, cNotifyNum);



return true;

}



///

/// 将录制的数据写入wav文件

///


private void RecordCapturedData()

{

byte[] CaptureData = null;

int ReadPos;

int CapturePos;

int LockSize;



mRecBuffer.GetCurrentPosition(out CapturePos, out ReadPos);

LockSize = ReadPos - mNextCaptureOffset;

if (LockSize < 0)

LockSize += mBufferSize;



// 对齐缓冲区边界,实际上由于开始设定完整,这个操作是多余的.

LockSize -= (LockSize % mNotifySize);



if (0 == LockSize)

return;



// 读取缓冲区内的数据

CaptureData = (byte[])mRecBuffer.Read(mNextCaptureOffset, typeof(byte), LockFlag.None, LockSize);



// 写入Wav文件

mWriter.Write(CaptureData, 0, CaptureData.Length);



// 更新已经录制的数据长度.

mSampleCount += CaptureData.Length;



// 移动录制数据的起始点,通知消息只负责指示产生消息的位置,并不记录上次录制的位置

mNextCaptureOffset += CaptureData.Length;

mNextCaptureOffset %= mBufferSize; // Circular buffer

}



///

/// 接收缓冲区满消息的处理线程

///


private void WaitThread()

{

while(true)

{

// 等待缓冲区的通知消息

mNotificationEvent.WaitOne(Timeout.Infinite, true);

// 录制数据

RecordCapturedData();

}

}



///

/// 创建保存的波形文件,并写入必要的文件头.

///


private void CreateSoundFile()

{

/**************************************************************************

Here is where the file will be created. A

wave file is a RIFF file, which has chunks

of data that describe what the file contains.

A wave RIFF file is put together like this:



The 12 byte RIFF chunk is constructed like this:

Bytes 0 - 3 : 'R' 'I' 'F' 'F'

Bytes 4 - 7 : Length of file, minus the first 8 bytes of the RIFF description.

(4 bytes for "WAVE" + 24 bytes for format chunk length +

8 bytes for data chunk description + actual sample data size.)

Bytes 8 - 11: 'W' 'A' 'V' 'E'



The 24 byte FORMAT chunk is constructed like this:

Bytes 0 - 3 : 'f' 'm' 't' ' '

Bytes 4 - 7 : The format chunk length. This is always 16.

Bytes 8 - 9 : File padding. Always 1.

Bytes 10- 11: Number of channels. Either 1 for mono, or 2 for stereo.

Bytes 12- 15: Sample rate.

Bytes 16- 19: Number of bytes per second.

Bytes 20- 21: Bytes per sample. 1 for 8 bit mono, 2 for 8 bit stereo or

16 bit mono, 4 for 16 bit stereo.

Bytes 22- 23: Number of bits per sample.



The DATA chunk is constructed like this:

Bytes 0 - 3 : 'd' 'a' 't' 'a'

Bytes 4 - 7 : Length of data, in bytes.

Bytes 8 -...: Actual sample data.

***************************************************************************/

// Open up the wave file for writing.

mWaveFile = new FileStream(mFileName, FileMode.Create);

mWriter = new BinaryWriter(mWaveFile);



// Set up file with RIFF chunk info.

char[] ChunkRiff = {'R','I','F','F'};

char[] ChunkType = {'W','A','V','E'};

char[] ChunkFmt = {'f','m','t',' '};

char[] ChunkData = {'d','a','t','a'};



short shPad = 1; // File padding

int nFormatChunkLength = 0x10; // Format chunk length.

int nLength = 0; // File length, minus first 8 bytes of RIFF description. This will be filled in later.

short shBytesPerSample = 0; // Bytes per sample.



// 一个样本点的字节数目

if (8 == mWavFormat.BitsPerSample && 1 == mWavFormat.Channels)

shBytesPerSample = 1;

else if ((8 == mWavFormat.BitsPerSample && 2 == mWavFormat.Channels) || (16 == mWavFormat.BitsPerSample && 1 == mWavFormat.Channels))

shBytesPerSample = 2;

else if (16 == mWavFormat.BitsPerSample && 2 == mWavFormat.Channels)

shBytesPerSample = 4;



// RIFF 块

mWriter.Write(ChunkRiff);

mWriter.Write(nLength);

mWriter.Write(ChunkType);



// WAVE块

mWriter.Write(ChunkFmt);

mWriter.Write(nFormatChunkLength);

mWriter.Write(shPad);

mWriter.Write(mWavFormat.Channels);

mWriter.Write(mWavFormat.SamplesPerSecond);

mWriter.Write(mWavFormat.AverageBytesPerSecond);

mWriter.Write(shBytesPerSample);

mWriter.Write(mWavFormat.BitsPerSample);



// 数据块

mWriter.Write(ChunkData);

mWriter.Write((int)0); // The sample length will be written in later.

}



5.外部 窗体调用方式

声明部分:

private SoundRecord recorder = null; // 录音

窗 体构造函数:

recorder = new SoundRecord();

启动录音按钮:

private void btnStart_Click(object sender, System.EventArgs e)

{

//

// 录音设置

//

string wavfile = null;

wavfile = “test.wav”;

recorder.SetFileName(wavfile);

recorder.RecStart();

}

中 止录音按钮:

private void btnStop_Click(object sender, System.EventArgs e)

{

recorder.RecStop();

recorder = null;

}



6. 需要添加的外部引用文件

在系统的System32目录下添加以下两个引用文件,如果没有,在DirectX的开发包内可以找到。

Microsoft.DirectX.dll

Microsoft.DirectX.DirectSound.dll




一. 声卡录音的基本原理

为了实现一个录音的基本过程,至少需要以下对象的支持:

1.   录音设备,对我们的PC设备就是声卡。这个录音设备可以进行的操作应该有开始和关闭。

2.   缓冲区,也就是录制的声音放在哪里的问题。


二.DirectSound对录音的描述模型

1.   DirectSound对录音的支持类

?         Capture,设备对象,可以看作是声卡的描述。

?         CaptureBuffer,缓冲区对象,存放录入的音频数据。

?         Notify,事件通知对象,由于录音是一个长时间的过程,因此使用一个缓冲队列(多个缓冲区)接收数据,每当一个缓冲区满的时候,系统使用这个对象通知 应用程序取走这个缓冲区,并继续录音。

以上三个对象是进行录音操作的主要对象,由于在C++中对DirectSound的操作 DirectX帮助文档中已经有很详细的说明,这里就不再赘述了。本文是针对Managed Code。除了以上三个主要的DirectSound类,还需要以下几个辅助类。

?         WaveFormat,描述了进行录制的声音波形的格式,例如采样率,单声道还是立体声,每个采样点的长度等等。

?         Thread,线程类,由于录音的过程是需要不断处理缓冲区满的事件,因此新建一个线程对此进行单独处理。

?         AutoResetEvent,通知的事件,当缓冲区满的时候,使用该事件作为通知事件。


三.代码解析(SoundRecord 类)

1.需要引用的程序集

using System;

using System.Windows.Forms;

using System.Threading;

using System.IO;


// 对DirectSound的支持

using Microsoft.DirectX;

using Microsoft.DirectX.DirectSound;


2.   SoundRecord的成员数据

public const int cNotifyNum = 16;       // 缓冲队列的数目


private int mNextCaptureOffset = 0;      // 该次录音缓冲区的起始点

private int mSampleCount = 0;            // 录制的样本数目


private int mNotifySize = 0;             // 每次通知大小

private int mBufferSize = 0;             // 缓冲队列大小


private string mFileName = string.Empty;     // 文件名

private FileStream mWaveFile = null;         // 文件流

private BinaryWriter mWriter = null;         // 写文件


private Capture mCapDev = null;              // 音频捕捉设备

private CaptureBuffer mRecBuffer = null;     // 缓冲区对象

private Notify mNotify = null;               // 消息通知对象


private WaveFormat mWavFormat;                       // 录音的格式

private Thread mNotifyThread = null;                 // 处理缓冲区消息的线程

private AutoResetEvent mNotificationEvent = null;    // 通知事件


3.   对外操作的函数

///

/// 构造函数,设定录音设备,设定录音格式.

///


public SoundRecord()

{

    // 初始化音频捕捉设备

    InitCaptureDevice();



    // 设定录音格式

    mWavFormat = CreateWaveFormat();

}



///

/// 设定录音结束后保存的文件,包括路径

///


/// 保存wav文件的路径名

public void SetFileName(string filename)

{

    mFileName = filename;

}



///

/// 开始录音

///


public void RecStart()

{

    // 创建录音文件

    CreateSoundFile();



    // 创建一个录音缓冲区,并开始录音

    CreateCaptureBuffer();



    // 建立通知消息,当缓冲区满的时候处理方法

    InitNotifications();



    mRecBuffer.Start(true);

}



///

/// 停止录音

///


public void RecStop()

{

    // 关闭通知消息

    if (null != mNotificationEvent)

        mNotificationEvent.Set();



    // 停止录音

    mRecBuffer.Stop();



    // 写入缓冲区最后的数据

    RecordCapturedData();

    

    // 回写长度信息

    mWriter.Seek(4, SeekOrigin.Begin);

    mWriter.Write((int)(mSampleCount + 36));   // 写文件长度

    mWriter.Seek(40, SeekOrigin.Begin);

    mWriter.Write(mSampleCount);                // 写数据长度

    

    mWriter.Close();

    mWaveFile.Close();

    mWriter = null;

    mWaveFile = null;

}



4.内部调用函数

///

/// 初始化录音设备,此处使用主录音设备.

///


/// 调用成功返回true,否则返回false

private bool InitCaptureDevice()

{

    // 获取默认音频捕捉设备

    CaptureDevicesCollection devices = new CaptureDevicesCollection(); // 枚举音频捕捉设备

    Guid deviceGuid = Guid.Empty;                                       // 音频捕捉设备的ID



    if (devices.Count>0)

        deviceGuid = devices[0].DriverGuid;

    else

    {

        MessageBox.Show("系统中没有音频捕捉设备");

        return false;

    }



    // 用指定的捕捉设备创建Capture对象

    try

    {

        mCapDev = new Capture(deviceGuid);

    }

    catch (DirectXException e)

    {

        MessageBox.Show(e.ToString());

        return false;

    }



    return true;

}



///

/// 创建录音格式,此处使用16bit,16KHz,Mono的录音格式

///


/// WaveFormat结构体

private WaveFormat CreateWaveFormat()

{

    WaveFormat format = new WaveFormat();



    format.FormatTag = WaveFormatTag.Pcm;   // PCM

    format.SamplesPerSecond = 16000;        // 16KHz

    format.BitsPerSample = 16;              // 16Bit

    format.Channels = 1;                    // Mono

    format.BlockAlign = (short)(format.Channels * (format.BitsPerSample / 8));

    format.AverageBytesPerSecond = format.BlockAlign * format.SamplesPerSecond;



    return format;

}



///

/// 创建录音使用的缓冲区

///


private void CreateCaptureBuffer()

{

    // 缓冲区的描述对象

    CaptureBufferDescription bufferdescription = new CaptureBufferDescription();



    if (null != mNotify)

    {

        mNotify.Dispose();

        mNotify = null;

    }

    if (null != mRecBuffer)

    {

        mRecBuffer.Dispose();

        mRecBuffer = null;

    }



    // 设定通知的大小,默认为1s钟

    mNotifySize = (1024 > mWavFormat.AverageBytesPerSecond / 8) ? 1024 : (mWavFormat.AverageBytesPerSecond / 8);

    mNotifySize -= mNotifySize % mWavFormat.BlockAlign;  



    // 设定缓冲区大小

    mBufferSize = mNotifySize * cNotifyNum;



    // 创建缓冲区描述           

    bufferdescription.BufferBytes = mBufferSize;

    bufferdescription.Format = mWavFormat;           // 录音格式



    // 创建缓冲区

    mRecBuffer = new CaptureBuffer(bufferdescription, mCapDev);



    mNextCaptureOffset = 0;

}



///

/// 初始化通知事件,将原缓冲区分成16个缓冲队列,在每个缓冲队列的结束点设定通知点.

///


/// 是否成功

private bool InitNotifications()

{

    if (null == mRecBuffer)

    {

        MessageBox.Show("未创建录音缓冲区");

        return false;

    }       



    // 创建一个通知事件,当缓冲队列满了就激发该事件.

    mNotificationEvent = new AutoResetEvent(false);



    // 创建一个线程管理缓冲区事件

    if (null == mNotifyThread)

    {

        mNotifyThread = new Thread(new ThreadStart(WaitThread));

        mNotifyThread.Start();

    }



    // 设定通知的位置

    BufferPositionNotify[] PositionNotify = new BufferPositionNotify[cNotifyNum + 1];

    for (int i = 0; i < cNotifyNum; i++)

    {

        PositionNotify[i].Offset = (mNotifySize * i) + mNotifySize - 1;

        PositionNotify[i].EventNotifyHandle = mNotificationEvent.Handle;               

    }



    mNotify = new Notify(mRecBuffer);

    mNotify.SetNotificationPositions(PositionNotify, cNotifyNum);



    return true;

}



///

/// 将录制的数据写入wav文件

///


private void RecordCapturedData()

{

    byte[] CaptureData = null;

    int ReadPos;

    int CapturePos;

    int LockSize;



    mRecBuffer.GetCurrentPosition(out CapturePos, out ReadPos);

    LockSize = ReadPos - mNextCaptureOffset;

    if (LockSize < 0)

        LockSize += mBufferSize;



    // 对齐缓冲区边界,实际上由于开始设定完整,这个操作是多余的.

    LockSize -= (LockSize % mNotifySize);



    if (0 == LockSize)

        return;

   

    // 读取缓冲区内的数据

    CaptureData = (byte[])mRecBuffer.Read(mNextCaptureOffset, typeof(byte), LockFlag.None, LockSize);



    // 写入Wav文件

    mWriter.Write(CaptureData, 0, CaptureData.Length);



    // 更新已经录制的数据长度.

    mSampleCount += CaptureData.Length;



    // 移动录制数据的起始点,通知消息只负责指示产生消息的位置,并不记录上次录制的位置

    mNextCaptureOffset += CaptureData.Length;

    mNextCaptureOffset %= mBufferSize; // Circular buffer

}



///

/// 接收缓冲区满消息的处理线程

///


private void WaitThread()

{

    while(true)

    {

        // 等待缓冲区的通知消息

        mNotificationEvent.WaitOne(Timeout.Infinite, true);

        // 录制数据

        RecordCapturedData();

    }

}



///

/// 创建保存的波形文件,并写入必要的文件头.

///


private void CreateSoundFile()

{

    /**************************************************************************

Here is where the file will be created. A

wave file is a RIFF file, which has chunks

of data that describe what the file contains.

A wave RIFF file is put together like this:



The 12 byte RIFF chunk is constructed like this:

Bytes 0 - 3 : 'R' 'I' 'F' 'F'

Bytes 4 - 7 : Length of file, minus the first 8 bytes of the RIFF description.

                   (4 bytes for "WAVE" + 24 bytes for format chunk length +

                   8 bytes for data chunk description + actual sample data size.)

Bytes 8 - 11: 'W' 'A' 'V' 'E'



The 24 byte FORMAT chunk is constructed like this:

Bytes 0 - 3 : 'f' 'm' 't' ' '

Bytes 4 - 7 : The format chunk length. This is always 16.

Bytes 8 - 9 : File padding. Always 1.

Bytes 10- 11: Number of channels. Either 1 for mono, or 2 for stereo.

Bytes 12- 15: Sample rate.

Bytes 16- 19: Number of bytes per second.

Bytes 20- 21: Bytes per sample. 1 for 8 bit mono, 2 for 8 bit stereo or

                  16 bit mono, 4 for 16 bit stereo.

Bytes 22- 23: Number of bits per sample.



The DATA chunk is constructed like this:

Bytes 0 - 3 : 'd' 'a' 't' 'a'

Bytes 4 - 7 : Length of data, in bytes.

Bytes 8 -...: Actual sample data.

            ***************************************************************************/

    // Open up the wave file for writing.

    mWaveFile = new FileStream(mFileName, FileMode.Create);

    mWriter = new BinaryWriter(mWaveFile);



    // Set up file with RIFF chunk info.

    char[] ChunkRiff = {'R','I','F','F'};

    char[] ChunkType = {'W','A','V','E'};

    char[] ChunkFmt = {'f','m','t',' '};

    char[] ChunkData = {'d','a','t','a'};

   

    short shPad = 1;                // File padding

    int nFormatChunkLength = 0x10; // Format chunk length.

    int nLength = 0;                // File length, minus first 8 bytes of RIFF description. This will be filled in later.

    short shBytesPerSample = 0;     // Bytes per sample.



    // 一个样本点的字节数目

    if (8 == mWavFormat.BitsPerSample && 1 == mWavFormat.Channels)

        shBytesPerSample = 1;

    else if ((8 == mWavFormat.BitsPerSample && 2 == mWavFormat.Channels) || (16 == mWavFormat.BitsPerSample && 1 == mWavFormat.Channels))

        shBytesPerSample = 2;

    else if (16 == mWavFormat.BitsPerSample && 2 == mWavFormat.Channels)

        shBytesPerSample = 4;



    // RIFF 块

    mWriter.Write(ChunkRiff);

    mWriter.Write(nLength);

    mWriter.Write(ChunkType);



    // WAVE块

    mWriter.Write(ChunkFmt);

    mWriter.Write(nFormatChunkLength);

    mWriter.Write(shPad);

    mWriter.Write(mWavFormat.Channels);

    mWriter.Write(mWavFormat.SamplesPerSecond);

    mWriter.Write(mWavFormat.AverageBytesPerSecond);

    mWriter.Write(shBytesPerSample);

    mWriter.Write(mWavFormat.BitsPerSample);

   

    // 数据块

    mWriter.Write(ChunkData);

    mWriter.Write((int)0);   // The sample length will be written in later.

}



5.外部窗体调用 方式

声明部分:

private SoundRecord recorder = null;    // 录音

窗 体构造函数:

recorder = new SoundRecord();

启动录音按钮:

private void btnStart_Click(object sender, System.EventArgs e)

{

    //

    // 录音设置

    //

    string wavfile = null;

    wavfile = “test.wav”;

    recorder.SetFileName(wavfile);

    recorder.RecStart();

}

中止录音按钮:

private void btnStop_Click(object sender, System.EventArgs e)

{

    recorder.RecStop();

    recorder = null;

}



6. 需要添加的外部引用文件

在系统的System32目录下添加以下两个引用文件,如果没有,在DirectX的开发包内可以找到。

Microsoft.DirectX.dll

Microsoft.DirectX.DirectSound.dll



using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.DirectX;
using Microsoft.DirectX.DirectSound;
using System.IO;
using System.Windows.Forms;
using System.Threading;


namespace WindowsApplication1
{

    ///
    /// 声音录制
    ///

    public class SoundRecord
    {
        public const int cNotifyNum = 16;       // 缓冲队列的数目

        private int mNextCaptureOffset = 0;      // 该次录音缓冲区的起始点

        private int mSampleCount = 0;            // 录制的样本数目

        private int mNotifySize = 0;             // 每次通知大小

        private int mBufferSize = 0;             // 缓冲队列大小

        private string mFileName = string.Empty;     // 文件名

        private FileStream mWaveFile = null;         // 文件流

        private BinaryWriter mWriter = null;         // 写文件

        private Capture mCapDev = null;              // 音频捕捉设备

        private CaptureBuffer mRecBuffer = null;     // 缓冲区对象

        private Notify mNotify = null;               // 消息通知对象

        private WaveFormat mWavFormat;                       // 录音的格式

        private Thread mNotifyThread = null;                 // 处理缓冲区消息的线程

        private AutoResetEvent mNotificationEvent = null;    // 通知事件


        //3.   对外操作的函数
        ///
        /// 构造函数,设定录音设备,设定录音格式.
        ///

        public SoundRecord()
        {
            // 初始化音频捕捉设备
            InitCaptureDevice();
            // 设定录音格式
            mWavFormat = CreateWaveFormat();

        }


        ///
        /// 设定录音结束后保存的文件,包括路径
        ///

        /// 保存wav文件的路径名
        public void SetFileName(string filename)
        {
            mFileName = filename;
        }

        ///
        /// 开始录音
        ///

        public void RecStart()
        {

            // 创建录音文件
            CreateSoundFile();

            // 创建一个录音缓冲区,并开始录音
            CreateCaptureBuffer();
            // 建立通知消息,当缓冲区满的时候处理方法

            InitNotifications();

            mRecBuffer.Start(true);

        }

        ///
        /// 停止录音
        ///

        public void RecStop()
        {


            // 关闭通知消息

            if (null != mNotificationEvent)

                mNotificationEvent.Set();

            // 停止录音

            mRecBuffer.Stop();

            // 写入缓冲区最后的数据

            RecordCapturedData();

            // 回写长度信息

            mWriter.Seek(4, SeekOrigin.Begin);

            mWriter.Write((int)(mSampleCount + 36));   // 写文件长度

            mWriter.Seek(40, SeekOrigin.Begin);

            mWriter.Write(mSampleCount);                // 写数据长度

            mWriter.Close();

            mWaveFile.Close();

            mWriter = null;

            mWaveFile = null;

        }


        //4.内部调用函数
        ///
        /// 初始化录音设备,此处使用主录音设备.
        ///

        /// 调用成功返回true,否则返回false
        private bool InitCaptureDevice()
        {

            // 获取默认音频捕捉设备

            CaptureDevicesCollection devices = new CaptureDevicesCollection(); // 枚举音频捕捉设备

            Guid deviceGuid = Guid.Empty;                                       // 音频捕捉设备的ID

            if (devices.Count > 0)
                deviceGuid = devices[0].DriverGuid;
            else
            {

                MessageBox.Show("系统中没有音频捕捉设备");
                return false;
            }
            // 用指定的捕捉设备创建Capture对象
            try
            {
                mCapDev = new Capture(deviceGuid);
            }
            catch (DirectXException e)
            {
                MessageBox.Show(e.ToString());
                return false;
            }
            return true;
        }


        ///
        /// 创建录音格式,此处使用16bit,16KHz,Mono的录音格式
        ///

        /// WaveFormat结构体
        private WaveFormat CreateWaveFormat()
        {
            WaveFormat format = new WaveFormat();
            format.FormatTag = WaveFormatTag.Pcm;   // PCM
            format.SamplesPerSecond = 16000;        // 16KHz
            format.BitsPerSample = 16;              // 16Bit
            format.Channels = 1;                    // Mono
            format.BlockAlign = (short)(format.Channels * (format.BitsPerSample / 8));
            format.AverageBytesPerSecond = format.BlockAlign * format.SamplesPerSecond;
            return format;
        }


        ///
        /// 创建录音使用的缓冲区
        ///

        private void CreateCaptureBuffer()
        {
            // 缓冲区的描述对象
            CaptureBufferDescription bufferdescription = new CaptureBufferDescription();
            if (null != mNotify)
            {
                mNotify.Dispose();
                mNotify = null;
            }
            if (null != mRecBuffer)
            {
                mRecBuffer.Dispose();
                mRecBuffer = null;
            }
            // 设定通知的大小,默认为1s钟
            mNotifySize = (1024 > mWavFormat.AverageBytesPerSecond / 8) ? 1024 : (mWavFormat.AverageBytesPerSecond / 8);
            mNotifySize -= mNotifySize % mWavFormat.BlockAlign;
            // 设定缓冲区大小

            mBufferSize = mNotifySize * cNotifyNum;
            // 创建缓冲区描述           
            bufferdescription.BufferBytes = mBufferSize;
            bufferdescription.Format = mWavFormat;           // 录音格式

            // 创建缓冲区
            mRecBuffer = new CaptureBuffer(bufferdescription, mCapDev);
            mNextCaptureOffset = 0;
        }

        ///
        /// 初始化通知事件,将原缓冲区分成16个缓冲队列,在每个缓冲队列的结束点设定通知点.
        ///

        /// 是否成功
        private bool InitNotifications()
        {
            if (null == mRecBuffer)
            {
                MessageBox.Show("未创建录音缓冲区");
                return false;
            }


            // 创建一个通知事件,当缓冲队列满了就激发该事件.
            mNotificationEvent = new AutoResetEvent(false);

            // 创建一个线程管理缓冲区事件
            if (null == mNotifyThread)
            {
                mNotifyThread = new Thread(new ThreadStart(WaitThread));
                mNotifyThread.Start();
            }

            // 设定通知的位置
            BufferPositionNotify[] PositionNotify = new BufferPositionNotify[cNotifyNum + 1];

            for (int i = 0; i < cNotifyNum; i++)
            {
                PositionNotify[i].Offset = (mNotifySize * i) + mNotifySize - 1;
                PositionNotify[i].EventNotifyHandle = mNotificationEvent.Handle;
            }
            mNotify = new Notify(mRecBuffer);
            mNotify.SetNotificationPositions(PositionNotify, cNotifyNum);
            return true;

        }

        ///
        /// 将录制的数据写入wav文件
        ///

        private void RecordCapturedData()
        {

            byte[] CaptureData = null;

            int ReadPos;

            int CapturePos;

            int LockSize;

            mRecBuffer.GetCurrentPosition(out CapturePos, out ReadPos);

            LockSize = ReadPos - mNextCaptureOffset;

            if (LockSize < 0)

                LockSize += mBufferSize;

            // 对齐缓冲区边界,实际上由于开始设定完整,这个操作是多余的.

            LockSize -= (LockSize % mNotifySize);

            if (0 == LockSize)

                return;

            // 读取缓冲区内的数据

            CaptureData = (byte[])mRecBuffer.Read(mNextCaptureOffset, typeof(byte), LockFlag.None, LockSize);

            // 写入Wav文件

            mWriter.Write(CaptureData, 0, CaptureData.Length);

            // 更新已经录制的数据长度.
            mSampleCount += CaptureData.Length;
            // 移动录制数据的起始点,通知消息只负责指示产生消息的位置,并不记录上次录制的位置
            mNextCaptureOffset += CaptureData.Length;
            mNextCaptureOffset %= mBufferSize; // Circular buffer
        }

        public byte[] RecordCapturedByte()
        {

        }

        ///
        /// 接收缓冲区满消息的处理线程
        ///

        private void WaitThread()
        {
            while (true)
            {
                // 等待缓冲区的通知消息
                mNotificationEvent.WaitOne(Timeout.Infinite, true);
                // 录制数据
                RecordCapturedData();
            }
        }

        ///
        /// 创建保存的波形文件,并写入必要的文件头.
        ///

        private void CreateSoundFile()
        {

            /**************************************************************************

         Here is where the file will be created. A

         wave file is a RIFF file, which has chunks

         of data that describe what the file contains.

         A wave RIFF file is put together like this:

         The 12 byte RIFF chunk is constructed like this:

         Bytes 0 - 3 : 'R' 'I' 'F' 'F'

         Bytes 4 - 7 : Length of file, minus the first 8 bytes of the RIFF description.

          (4 bytes for "WAVE" + 24 bytes for format chunk length + 8 bytes for data chunk description + actual sample data size.)

          Bytes 8 - 11: 'W' 'A' 'V' 'E'

          The 24 byte FORMAT chunk is constructed like this:

          Bytes 0 - 3 : 'f' 'm' 't' ' '

          Bytes 4 - 7 : The format chunk length. This is always 16.

          Bytes 8 - 9 : File padding. Always 1.

          Bytes 10- 11: Number of channels. Either 1 for mono, or 2 for stereo.

          Bytes 12- 15: Sample rate.

          Bytes 16- 19: Number of bytes per second.

          Bytes 20- 21: Bytes per sample. 1 for 8 bit mono, 2 for 8 bit stereo or

                          16 bit mono, 4 for 16 bit stereo.
          Bytes 22- 23: Number of bits per sample.

          The DATA chunk is constructed like this:

          Bytes 0 - 3 : 'd' 'a' 't' 'a'

          Bytes 4 - 7 : Length of data, in bytes.

          Bytes 8 -...: Actual sample data.

                    ***************************************************************************/

            // Open up the wave file for writing.

            mWaveFile = new FileStream(mFileName, FileMode.Create);

            mWriter = new BinaryWriter(mWaveFile);

            // Set up file with RIFF chunk info.

            char[] ChunkRiff = { 'R', 'I', 'F', 'F' };

            char[] ChunkType = { 'W', 'A', 'V', 'E' };

            char[] ChunkFmt = { 'f', 'm', 't', ' ' };

            char[] ChunkData = { 'd', 'a', 't', 'a' };

            short shPad = 1;                // File padding

            int nFormatChunkLength = 0x10; // Format chunk length.

            int nLength = 0;                // File length, minus first 8 bytes of RIFF description. This will be filled in later.

            short shBytesPerSample = 0;     // Bytes per sample.

            // 一个样本点的字节数目

            if (8 == mWavFormat.BitsPerSample && 1 == mWavFormat.Channels)

                shBytesPerSample = 1;

            else if ((8 == mWavFormat.BitsPerSample && 2 == mWavFormat.Channels) || (16 == mWavFormat.BitsPerSample && 1 == mWavFormat.Channels))

                shBytesPerSample = 2;

            else if (16 == mWavFormat.BitsPerSample && 2 == mWavFormat.Channels)

                shBytesPerSample = 4;


            // RIFF 块

            mWriter.Write(ChunkRiff);

            mWriter.Write(nLength);

            mWriter.Write(ChunkType);

            // WAVE块

            mWriter.Write(ChunkFmt);

            mWriter.Write(nFormatChunkLength);

            mWriter.Write(shPad);

            mWriter.Write(mWavFormat.Channels);

            mWriter.Write(mWavFormat.SamplesPerSecond);

            mWriter.Write(mWavFormat.AverageBytesPerSecond);

            mWriter.Write(shBytesPerSample);

            mWriter.Write(mWavFormat.BitsPerSample);

            // 数据块

            mWriter.Write(ChunkData);

            mWriter.Write((int)0);   // The sample length will be written in later.

        }

    }


    ///
    /// 声音播放
    ///

    public class SoundPlay : IDisposable
    {
        private string m_soundfile ="";

        private Device m_soundDevice = null;

        private SecondaryBuffer m_soundBuffer = null;

        private bool canUseSounds = true;

        public void Dispose()
        {
            if (m_soundBuffer != null)
            {
                m_soundBuffer.Dispose();
            }
            if (m_soundDevice != null)
            {
                m_soundDevice.Dispose();
            }
        }

        public void SetSoundFile(string soundfile)
        {
            this.m_soundfile = soundfile;
        }

        public SoundPlay(IntPtr parent)
        {
            try
            {
                m_soundDevice = new Device();
                m_soundDevice.SetCooperativeLevel(parent, CooperativeLevel.Normal);
            }
            catch
            {
                canUseSounds = false;
            }
        }

        public void Play()
        {
            if (!canUseSounds)
                return;
            m_soundBuffer = new SecondaryBuffer(m_soundfile, m_soundDevice);
            if (m_soundBuffer == null)
                return;
            m_soundBuffer.Play(0, BufferPlayFlags.Default);
        }
       

    }
}

原文:http://gcm8431274.blog.163.com/blog/static/11937487200811871511533/
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