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The Screen Capture Filter is a DirectShow® source filter that delivers a video stream captured from the screen. This filter can capture from the full screen (one or multiple monitors), a window, or a region. Many options are provided for flexibility and convenience. These are summarized as follows:
Capturing source:
The following options are available for the capturing source:
Option |
Description |
CAPTURE_FULLSCREEN |
The capturing source is the full screen. This can be the entire screen (one or multiple monitors) or a region defined by screen coordinates. |
CAPTURE_ACTIVEWINDOW |
The capturing source is the active window. This can be the entire active window or a region defined by window coordinates. |
CAPTURE_ACTIVECLIENT |
The capturing source is the client area of the active window. This can be the entire client window or a region defined by window coordinates. |
CAPTURE_SELECTEDWINDOW |
The capturing source is some chosen window, not necessarily the active window. This can be the entire window area (client and non-client), or a region defined by window coordinates. |
In case the capturing source is not CAPTURE_FULLSCREEN (neither the entire screen nor a region), the filter provides an option to track the capturing source so that no matter where the source is moved, the captured contents are the same. For more information, refer to the TrackWindow property of the ILMScrCap Interface. When the capture source goes off screen or gets covered partially by another window, the filter can fill the hidden area with a specified color or capture whatever contents are in the capture area.
Notification:
The filter provides notification of many events to enable the user to have control over the capturing process and make the correct decision. In addition, the filter provides informational notifications. Notifications are provided through a callback mechanism where the user should have an object that implements the ILMScrCapUserCallback and ILMScrCapUserEventsCallback Interfaces. For more information, refer to ILMScrCapUserCallback Interface, ILMScrCapUserEventsCallback.
On event action:
The filter can be configured to take specific actions on specific events. For more information, refer to the OnSourceMinimize, OnSourceClose, and OnSourceAreaChange properties of the ILMScrCap Interface.
Tools:
The filter provides tools for region selection and window selection. The user can use these tools programmatically, integrating them with a custom user interface. Many options are provided with these tools for convenience. For more information, refer to SelectRegionTool and SelectWindowTool methods, and the ShowXXXX properties of the ILMScrCap Interface.
Other:
Other options and helper properties are provided for flexibility and convenience. For more information, refer to the properties and methods of the ILMScrCap Interface, the ILMScrCapUserCallback Interface, and the ILMMCommon Interface. All the mentioned functionalities are exposed through both user and programming interfaces.
Filter Interface(s) |
ILMScrCap, ILMScrCapUserCallback, ILMScrCapUserEventsCallback, ILMMCommon |
Interface ID |
IID_ILMScrCap, IID_ILMScrCapUserCallback, IID_ILMMCommon |
Output Media Types |
MEDIATYPE_Video |
Filter CLSID |
CLSID_LMScrCap |
Property Page(s) CLSID |
CLSID_LMScrCapPropertyPage |
Filter category |
CLSID_VideoInputDeviceCategory |
Executable |
LMScrCap2.dll, DSKernel2.dll |
Header |
ILMScrCap2.h |
Win32, x64
LEAD Screen Capture Filter User Interface
You need to unlock the LEAD Screen Capture Filter (2.0) to use the filter in RELEASE mode.
For more information, refer to:
Evaluation Mechanism Overview.