IOCTL_BTHHFP_DEVICE_GET_VOLUMEPROPERTYVALUES IOCTL (bthhfpddi.h)
The IOCTL_BTHHFP_DEVICE_GET_VOLUMEPROPERTYVALUES IOCTL returns KSPROPERTY_VALUES data for the KSPROPERTY_AUDIO_VOLUMELEVEL property.
Major code
Input buffer
None.
Input buffer length
None.
Output buffer
A buffer containing a KSPROPERTY_VALUES structure followed by any other data referenced by this structure.
Output buffer length
The size of a KSPROPERTY_VALUES structure and referenced data.
Status block
N/A
Remarks
The audio driver’s KS filter topology includes a KS node of type KSNODETYPE_VOLUME for both input and output if the BTHHFP_DESCRIPTOR descriptor indicates volume support. The audio driver’s KSNODE_DESCRIPTOR structure for this node includes a PKSPROPERTY_ITEM for the KSPROPERTY_AUDIO_VOLUMELEVEL property. The audio driver sets the PKSPROPERTY_ITEM.Values member to the KSPROPERTY_VALUES structured returned by this request.
This allows the Handsfree profile (HFP) driver to almost entirely handle the problem of mapping KSPROPERTY_AUDIO_VOLUMELEVEL property values to the Bluetooth Handsfree profile. The audio driver’s property Get and Set handlers for this property simply call the HFP driver.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 8 |
| Minimum supported server | Windows Server 2012 |
| Header | bthhfpddi.h |