WODM_GETVOLUME (Windows CE 5.0)
This message is used in an MMDRV_MESSAGE_PARAMS structure passed to the WAV_IOControl function to request a waveform output driver to return the current volume level setting for the specified device.
Parameters
- uDeviceId
Device identifier — 0, 1, 2, and so on — for the target device. - uMsg
Specifies this structure. - dwUser
Specifies a device instance identifier. - dwParam1
Pointer to a DWORD location to receive the volume setting. - 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 WAVEFORM API MANAGER 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 WODM_SETVOLUME, it must support this message. 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, and a value of 0xFFFF is full volume.
Requirements
OS Versions: Windows CE 1.0 and later.
Header: Mmddk.h.
See Also
Waveform Output Driver Messages | WAV_IOControl | Audio Device Instances | MMDRV_MESSAGE_PARAMS
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