WODM_SETVOLUME

This message is used in an MMDRV_MESSAGE_PARAMS structure passed to the WAV_IOControl function to request a waveform output driver to set the playback rate multiplier value for the specified device.

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
Specifies a DWORD containing the volume setting.
dwParam2
Not used.

Return Values

MMSYSERR_NOERROR indicates success. Otherwise, the driver returns one of the MMSYSERR or WAVEERR 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. Support for this message by drivers is optional. However, if the driver supports this message, it must support WODM_GETVOLUME. The following table shows which bytes in dwParam1 indicate the volume settings for both stereo and monaural audio channels.

Channel
Portion of dwParam1 Used
Left Channel Low word
Right Channel High word
Single Channel Low word

A value of 0 is silence, 0xFFFF is full volume.