The WIM_DATA callback message notifies a client that a user-mode driver has filled a buffer with waveform data.
Parameters
dwMsg
WIM_DATA
dwParam1
Address of a WAVEHDR structure identifying a buffer containing the message. (WAVEHDR is defined in the Win32 SDK.)
dwParam2
NULL
Comments
A user-mode waveform input driver sends a WIM_DATA message to its client, by means of a callback, when the driver has filled a buffer with waveform data. The driver sends the message to the client by calling DriverCallback, passing the specified parameters.
The WAVEHDR structure is one that was received along with a WIDM_ADDBUFFER message.
The driver sends the WIM_DATA message only if the client has previously specified a notification target with a WIDM_OPEN message.
Win32 SDK documentation states that clients receive an MM_WIM_DATA message if the notification target is a window handle. WIM_DATA and MM_WIM_DATA are equivalent.
For additional information, see Notifying Clients from Audio Drivers and Transferring Waveform Input Data.