利用DirectX处理声音文件.doc

VB下利用DirectX处理声音文件责任编辑：ncic 更新日期：2007-4-2前言微软提供的DirectX技术不仅可以实现图形图像的处理，而且DirectX提供了DirectSound和DirectMusic类以分别支持声音（WAVE）文件和音乐（MIDI）文件，笔者结合自己的学习体会，介绍如何在Visual Basic环境下利用DirectX技术实现WAVE和MIDI文件的处理，和广大编程爱好者一起交流，希望能够互相学习，共同进步。一、DirectSound声音处理技术DirectSound类对象是DirectX提供的实现播放、捕捉数字声音文件的对象，它不仅可以播放声音文件，还可以实现声音在虚拟的三维空间的定位。它包括以下的几个对象：DirectSound、DirectSoundBuffer、DirectSound3Dbuffer、Direct3DsoundListner、DirectSoundCapture、DirectSoundCaptureBuffer。其中DirectSound对象和DirectSoundCapture对象是DirectSound类对象的基本对象，利用DirectX7对象的DirectSoundCreate()方法和DirectSoundCaptureCreate()方法可以分别建立DirectSound对象和DirectSoundCapture对象。DirectSoundBuffer对象和DirectSound3Dbuffer是音频播放缓冲对象，顾名思义，前者是音频播放对象，而后者是三维音频播放对象。DirectSound对象实现声音文件的播放，而DirectSoundCapture对象是用来捕捉声音数据的基本对象。Direct3DSoundListner对象用于设置播放三维声音效果时收听者所处的位置。下面通过一个程序来介绍DirectSound的应用，这个程序可以利用DirectSound3DBuffer播放文件并可以动态的设置声音位置。首先建立一个工程文件，在其中加入DirectX7说明库，然后在Form1中加入一个PictureBox控件和两个CommandButton控件。将Picture1的Width和Height属性都设置为3000；将Picture1的Scale属性设置为3-Pixel。保存工程文件，并在工程所在的目录下放置一个名为 Demo.wav 的声音文件。在Form1的代码窗口加入以下代码： Dim m_dx As New DirectX7Dim m_ds As DirectSoundDim m_dsBuffer As DirectSoundBufferDim m_ds3dBuffer As DirectSound3DBufferDim m_dsPrimaryBuffer As DirectSoundBufferDim m_dsListener As DirectSound3DListenerDim m_pos As D3DVECTORSub DrawPositions()Dim X As IntegerDim z As IntegerPicture1.Cls以黑色圈标出收听者所在的位置Picture1.Circle (Picture1.ScaleWidth / 2, Picture1.ScaleHeight / 2), 4以红色圈标出声音所在的位置X = CInt(m_pos.X) + Picture1.ScaleWidth / 2z = CInt(m_pos.z) + Picture1.ScaleHeight / 2Picture1.Circle (X, z), 4, RGB(255, 0, 0)End SubSub Load(sFile As String)Dim bufferDesc1 As DSBUFFERDESCDim waveFormat1 As WAVEFORMATEX设置将建立的DirectSoundBuffer对象的属性bufferDesc1.lFlags = (DSBCAPS_CTRL3D Or DSBCAPS_CTRLFREQUENCY Or _DSBCAPS_CTRLPAN Or DSBCAPS_CTRLVOLUME) Or DSBCAPS_STATIC建立DirectSoundBuffer对象Set m_dsBuffer = m_ds.CreateSoundBufferFromFile(sFile, bufferDesc1, _waveFormat1)设置DirectSoundBuffer对象的声音（0为最大）m_dsBuffer.SetVolume 0设置DirectSoundBuffer对象Set m_ds3dBuffer = m_dsBuffer.GetDirectSound3DBuffer设置DirectSoundBuffer对象的播放方向属性m_ds3dBuffer.SetConeOrientation 1, 1, 1, DS3D_IMMEDIATEm_ds3dBuffer.SetConeAngles DS3D_MINCONEANGLE, 100, DS3D_IMMEDIATEm_ds3dBuffer.SetConeOutsideVolume -100, DS3D_IMMEDIATE设置DirectSoundBuffer对象的播放位置属性m_ds3dBuffer.SetPosition m_pos.X / 50, 0, m_pos.z / 50, DS3D_IMMEDIATEEnd SubSub UpdatePosition(X As Single, z As Single)m_pos.X = X - Picture1.ScaleWidth / 2m_pos.z = z - Picture1.ScaleHeight / 2DrawPositionsIf m_ds3dBuffer Is Nothing Then Exit Sub重新设置DirectSoundBuffer对象的播放位置属性m_ds3dBuffer.SetPosition m_pos.X / 50, 0, m_pos.z / 50, DS3D_IMMEDIATEEnd SubPrivate Sub Command1_Click()If m_dsBuffer Is Nothing ThenCall Load(App.Path + demo.wav)End If循环播放声音文件m_dsBuffer.Play 1End SubPrivate Sub Command2_Click()If m_dsBuffer Is Nothing Then Exit Subm_dsBuffer.Stopm_dsBuffer.SetCurrentPosition 0End SubPrivate Sub Form_Load()Dim i As IntegerCommand1.Caption = 播放Command2.Caption = 停止Me.ShowDoEventsOn Local Error Resume Next建立DirectSound对象Set m_ds = m_dx.DirectSoundCreate(vbNullString)If Err.Number 0 ThenMsgBox 无法建立DirectSound对象，请查看声卡或驱动程序是否安装正确EndEnd If设置DirectSound对象的协作模式m_ds.SetCooperativeLevel Me.hWnd, DSSCL_PRIORITYDim primDesc As DSBUFFERDESC, format As WAVEFORMATEXprimDesc.lFlags = DSBCAPS_CTRL3D Or DSBCAPS_PRIMARYBUFFER建立主声音缓冲对象Set m_dsPrimaryBuffer = m_ds.CreateSoundBuffer(primDesc, format)建立DirectSound3DListener对象Set m_dsListener = m_dsPrimaryBuffer.GetDirectSound3DListener()m_pos.X = 10: m_pos.z = 50UpdatePosition m_pos.X, m_pos.zEnd SubPrivate Sub Picture1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)If Button = 1 ThenUpdatePosition X, YEnd IfEnd SubPrivate Sub Picture1_Paint()DrawPositio