WAVEOPENDESC

typedef struct waveopendesc_tag {
   HWAVE hWave;
   LPWAVEFORMAT lpFormat;
   DWORD dwCallback;
   DWORD dwInstance;
   UINT uMappedDeviceID;
} WAVEOPENDESC;


The WAVEOPENDESC structure contains information needed by user-mode waveform input and output drivers. The structure is created by winmm.dll and passed to the driver with a WODM_OPEN or WIDM_OPEN message.

Members

hWave

Specifies the client’s handle to the device, as assigned by winmm.dll. User-mode drivers specify this handle as the hDriver parameter to DriverCallback, when sending a callback message.

lpFormat

Points to a WAVEFORMATEX structure, indicating the waveform data format requested by the client. (The WAVEFORMATEX structure is described in the Win32 SDK.)

dwCallback

Specifies either the address of a callback function, a window handle, an event handle, or a task handle, depending on the flag contained in the dwParam2 parameter of the WODM_OPEN or WIDM_OPEN message.

dwInstance

Contains the dwCallbackInstance argument that the client specified when calling the waveInOpen or waveOutOpen function. This value is returned to the client as the dwInstance parameter to DriverCallback.

uMappedDeviceID

For wave mapper, contains device identifier of mapped device.