ICameraControl::get_ZoomRelative method (vidcap.h)
[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The get_ZoomRelative method returns the camera's relative zoom. The relative zoom indicates the direction in which the lens is moving.
Syntax
HRESULT get_ZoomRelative(
[out] long *pValue,
[out] long *pFlags
);
Parameters
[out] pValue
Receives the relative zoom. The size of the value represents the desired zoom speed; a higher value represents a higher speed. To get the range of possible values, call ICameraControl::getRange_ZoomRelative.
| Value | Description |
|---|---|
| 0 | Stopped. |
| Positive value | Zoom lens moving in the telephoto direction. |
| Negative value | Zoom lens moving in the wide angle direction. |
[out] pFlags
Receives one or more flags. See CameraControlFlags.
Return value
Returns an HRESULT value.
Requirements
| Minimum supported client | Windows XP with SP2 [desktop apps only] |
| Minimum supported server | Windows Server 2003 [desktop apps only] |
| Target Platform | Windows |
| Header | vidcap.h |
| Library | Strmiids.lib |