IOCTL_BTHHFP_SPEAKER_GET_VOLUME_STATUS_UPDATE IOCTL

The IOCTL_BTHHFP_SPEAKER_GET_VOLUME_STATUS_UPDATE IOCTL Gets the volume level setting of the Bluetooth device's speaker.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

A BOOL that is set to TRUE to request an immediate update. Otherwise, set this to FALSE.

Input buffer length

The size of a BOOL.

Output buffer

A LONG that represents the speaker's volume level in 1/65536 decibels.

Output buffer length

The size of a LONG.

Status block

If a request is already pending the new request fails and a STATUS_INVALID_DEVICE_REQUEST message is returned.

Remarks

This request will complete immediately if the input parameter is TRUE, or if the volume status has changed since the last request. Otherwise this request will remain pending until the volume status changes or the request is cancelled.

The audio driver sends this request to get the initial speaker and microphone volume levels, and sends subsequent requests "asking" to be updated when the levels change. The driver stores the volume levels in appropriate context data. When the volume level changes, the audio driver generates the KSEVENT_CONTROL_CHANGE event for the KSNODETYPE_VOLUME node in the KS topology of the speaker or microphone path.

The request’s output parameter is the same as the KSPROPERTY_AUDIO_VOLUMELEVEL property value.

Requirements

   
Minimum supported client Windows 8
Minimum supported server Windows Server 2012
Header bthhfpddi.h

See also

Bluetooth HFP DDI IOCTLs

KSEVENT_CONTROL_CHANGE

KSNODETYPE_VOLUME

KSPROPERTY_AUDIO_VOLUMELEVEL