To create a sound buffer, your application fills a DSBUFFERDESC structure and then passes its address to the IDirectSound::CreateSoundBuffer method. This method creates a DirectSoundBuffer object and returns a pointer to an IDirectSoundBuffer interface. Your application uses this interface to manipulate and play the buffer.

The following example illustrates how to create a basic secondary sound buffer:

BOOL AppCreateBasicBuffer( 
        LPDIRECTSOUND lpDirectSound, 
        LPDIRECTSOUNDBUFFER *lplpDsb) 
{ 
    PCMWAVEFORMAT pcmwf; 
    DSBUFFERDESC dsbdesc; 
    HRESULT hr; 
    // Set up wave format structure. 
    memset(&pcmwf, 0, sizeof(PCMWAVEFORMAT)); 
    pcmwf.wf.wFormatTag = WAVE_FORMAT_PCM; 
    pcmwf.wf.nChannels = 2; 
    pcmwf.wf.nSamplesPerSec = 22050; 
    pcmwf.wf.nBlockAlign = 4; 
    pcmwf.wf.nAvgBytesPerSec = 
        pcmwf.wf.nSamplesPerSec * pcmwf.wf.nBlockAlign; 
    pcmwf.wBitsPerSample = 16; 
    // Set up DSBUFFERDESC structure. 
    memset(&dsbdesc, 0, sizeof(DSBUFFERDESC)); // Zero it out. 
    dsbdesc.dwSize = sizeof(DSBUFFERDESC); 
    // Need default controls (pan, volume, frequency). 
    dsbdesc.dwFlags = DSBCAPS_CTRLPAN | DSBCAPS_CTRLVOLUME | DSBCAPS_CTRLFREQUENCY; 
    // 3-second buffer. 
    dsbdesc.dwBufferBytes = 3 * pcmwf.wf.nAvgBytesPerSec; 
    dsbdesc.lpwfxFormat = (LPWAVEFORMATEX)&pcmwf; 
    // Create buffer. 
    hr = lpDirectSound->lpVtbl->CreateSoundBuffer(lpDirectSound, 
        &dsbdesc, lplpDsb, NULL); 
    if SUCCEEDED(hr) 
    { 
        // Valid interface is in *lplpDsb. 
        return TRUE; 
    } 
    else 
    { 
        // Failed. 
        *lplpDsb = NULL; 
        return FALSE; 
    } 
} 
 

Your application should create buffers for the most important sounds first, and then create buffers for other sounds in descending order of importance. DirectSound allocates hardware resources to the first buffer that can take advantage of them.

If your application must explicitly locate buffers in hardware or software, you can specify either the DSBCAPS_LOCHARDWARE or DSBCAPS_LOCSOFTWARE flag in the DSBUFFERDESC structure. If the DSBCAPS_LOCHARDWARE flag is specified and there is insufficient hardware memory or mixing capacity, the buffer creation request fails.

You can ascertain the location of an existing buffer by using the IDirectSoundBuffer::GetCaps method and checking the dwFlags member of the DSBCAPS structure for either the DSBCAPS_LOCHARDWARE or DSBCAPS_LOCSOFTWARE flags. One or the other is always specified.

To create a sound buffer, your application fills a DSBUFFERDESC type and then passes it to the DirectSound.CreateSoundBuffer method. This method creates and returns a DirectSoundBuffer object. Your application uses this object to manipulate and play the buffer.

The following example illustrates how to create a basic secondary sound buffer:

Dim m_dx As New DirectX7
Dim m_ds As DirectSound

Private Sub Form_Load()
  Set m_ds = m_dx.DirectSoundCreate("")
  CreateSoundBuffer
End Sub 

Public Sub CreateSoundBuffer()
  Dim m_dsb As DirectSoundBuffer
  Dim buffdesc As DSBUFFERDESC
  Dim format As WAVEFORMATEX

  ' First you must specify the wave format
  format.nFormatTag = WAVE_FORMAT_PCM
  format.nChannels = 2
  format.lSamplesPerSec = 22050
  format.nBitsPerSample = 16
  format.nBlockAlign = (format.nChannels * format.nBitsPerSample) / 8
  format.lAvgBytesPerSec = format.lSamplesPerSec * format.nBlockAlign
  format.nSize = 0

  ' Next describe the sound buffer to be created
  buffdesc.lBufferBytes = format.lAvgBytesPerSec
  buffdesc.lFlags = DSBCAPS_CTRLPAN Or DSBCAPS_CTRLVOLUME Or DSBCAPS_CTRLFREQUENCY Or DSBCAPS_STATIC

  ' Create the buffer
  Set m_dsb = m_ds.CreateSoundBuffer(buffdesc, format)
End Sub

Your application should create buffers for the most important sounds first, and then create buffers for other sounds in descending order of importance. DirectSound allocates hardware resources to the first buffer that can take advantage of them.

If your application must explicitly locate buffers in hardware or software, you can specify either the DSBCAPS_LOCHARDWARE or DSBCAPS_LOCSOFTWARE flag in the DSBUFFERDESC type. If the DSBCAPS_LOCHARDWARE flag is specified and there is insufficient hardware memory or mixing capacity, the buffer creation request fails.

You can ascertain the location of an existing buffer by using the DirectSoundBuffer.GetCaps method and checking the lFlags member of the DSBCAPS type for either the DSBCAPS_LOCHARDWARE or DSBCAPS_LOCSOFTWARE flags. One or the other is always specified.