WIDM_START

This message is used in an MMDRV_MESSAGE_PARAMS structure passed to the WAV_IOControl function to request a waveform input driver to begin recording.

Parameters

uDeviceId

Device identifier—0, 1, 2, and so on—for the target device.

uMsg

Specifies this message.

dwUser

Specifies a device instance identifier.

dwParam1

Not used.

dwParam2

Not used.

Return Values

MMSYSERR_NOERROR indicates success. Otherwise, the driver returns one of the MMSYSERR or WAVERR error values declared in the Mmsystem.h header file.

Remarks

The ACM sends this message by calling the audio driver’s WAV_IOControl entry point through the DeviceIoControl function.