KSPROPERTY_CAMERACONTROL_FOCUS_RELATIVE
The KSPROPERTY_CAMERACONTROL_FOCUS_RELATIVE property specifies the focus setting of the camera.
Usage Summary Table
| Get | Set | Target | Property Descriptor Type | Property Value Type |
|---|---|---|---|---|
| Yes | Yes | Filter or node | KSPROPERTY_CAMERACONTROL_S or KSPROPERTY_CAMERACONTROL_NODE_S | LONG |
The property value (operation data) is a LONG that specifies a camera's relative focus setting. The size of the value represents the speed at which the focal point changes; a higher value represents a higher speed.
| Value | Description |
|---|---|
| 0 | Stop focus motion. |
| Positive value | Start moving the focus closer to the object. |
| Negative value | Start moving the focus farther away from the object. |
Remarks
When making a set request, provide one of the values in the preceding table in the Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure.
When making a get request, the client receives one of the values in the preceding table in the Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure. The value indicates the current focus setting for the camera.
Note that a particular device might support only a certain speed range. To determine the range of speeds supported by the device, an application can issue a KSPROPERTY_TYPE_BASICSUPPORT request. You can specify KSPROPERTY_TYPE_BASICSUPPORT in the Flags member of the KSPROPERTY_ITEM structure.
Some devices support only a single focus speed. In this case, the sign of the Value member simply indicates whether the lens should shorten its focus or lengthen it.
Requirements
Header: ksmedia.h (include Ksmedia.h)