Data types

RegionConstants

typedef [v1_enum] enum RegionConstants
{
   REGION_NONE = 0,
   REGION_RECT = 1,
   REGION_ROUNDRECT = 2,
   REGION_ELLIPSE = 3,
} RegionConstants;

Describes a region in a layer.

Member	Description
REGION_NONE	The layer has no region.
REGION_RECT	The layer has a rectangular region.
REGION_ROUNDRECT	The layer has a round rectangular region.
REGION_ELLIPSE	The layer has an elliptical region.

LayerTypeConstants

typedef [v1_enum] enum LayerTypeConstants
{
   LAYERTYPE_BACKGROUND = 0,
   LAYERTYPE_VIDEO = 1,
   LAYERTYPE_OVERLAYIMAGE = 2
} LayerTypeConstants;

Constants that define the supported layer types. These will be used to identify the layer to be acted upon in the ILMVIovly interface properties and methods.

Member	Description
LAYERTYPE_BACKGROUND	The background layer is a solid color.
LAYERTYPE_VIDEO	The video stream connected to pin 0. This layer must exist (the first pin of the filter must be connected), in order for the filter to work.
LAYERTYPE_OVERLAYIMAGE	The overlay image layer: An ordinary bitmap, icon, or cursor.

Interface Properties

Type	Property name	Parameter Description	Description
Long	ActiveLayersCount	None	Gets the number of active layers. An active layer is an available layer.
VARIANT_BOOL	IsLayerActive (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer to test.	Determines whether the specified layer is active.
Long	LayerOrder (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get the order.	Gets or sets a value that indicates the specified layer's order. The order range is from 0 to 3, where 0 indicates most distant position.
BSTR	OverlayImageFileName	None	Gets or sets the name of the image file used as the overlay image layer. The image should be a 24-bpp Windows BMP file or an Icon file. Pass NULL to free the loaded image.
Long	OverlayImageDIBPointer	None	Sets a pointer to a device independent bitmap to be used as the overlay image layer. This overlay image handle pointer can be obtained using the LoadImage API; it is actually a bitmap handle, HBITMAP.
VARIANT_BOOL	IsOverlayImageLoaded	None	Gets or sets a value that indicates whether the image used as the overlay image layer is loaded.
Long	BkLayerColor	None	Gets or sets the color of the background layer.
VARIANT_BOOL	EnableMaskBitmap (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to enable or disable the mask bitmap.	Enablesor disables the mask bitmap feature for the specified layer. When the mask bitmap is used for a layer, this layers opacity and transparency properties will be ignored.
BSTR	MaskImageFileName (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the file name of the mask bitmap.	Gets or sets the file name of the mask image to be used for the specified layer. The mask image must be an 8-bpp gray scale Windows BMP file. Pass NULL to free the loaded image.
Long	MaskImageDIBPointer (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to set the DIB pointer.	Sets a pointer to a device independent bitmap to be used as the mask image for the specified layer. This pointer can be obtained using the LoadImage API; it is actually a bitmap handle, HBITMAP.
VARIANT_BOOL	IsMaskImageLoaded (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to determine whether the mask image is loaded.	Gets or sets a value that indicates whether the mask image for the specified layer is loaded.
VARIANT_BOOL	EnableOpacity (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to enable or disable opacity.	Enables or disables the opacity feature of the specified layer. When the opacity feature is enabled for a layer, the transparency feature for this layer is ignored.
Long	Opacity (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the opacity.	Gets or sets the opacity, as a percentage, for the specified layer.
VARIANT_BOOL	EnableTransparency (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to enable or disable transparency.	Enables or disables the transparency feature for the specified layer. When transparency is enabled for a layer, the Opacity property for this layer is ignored.
Long	TransparentColor (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the transparent color.	Gets or sets the transparent color for the specified layer.
Long	XPos (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the X coordinate of the position.	Gets or sets the X coordinate of the position of the specified layer. Values range from 0 to the output stream width. The output stream width is the maximum width of the 2 input videos.
Long	YPos (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the Y coordinate of the position.	Gets or sets the Y coordinate of the position of the specified layer. Values range from 0 to the output stream height. The output stream height is the maximum height of the 2 input videos.
RegionConstants	Region (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the region.	Gets or sets a region for the specified layer. After setting a region for a layer, pixels inside the region will be considered part of this layer. See RegionConstants, above, for more information on region types.
Long	RgnLeft (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the region's left boundary.	Gets or sets the coordinate of the left boundary of the region in the specified layer. This coordinate represents either the coordinate of the left boundary of a rectangular region itself, or the coordinate of the left boundary of the bounding box of the region.
Long	RgnTop (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the coordinate of the region's top boundary.	Gets or sets the coordinate of the top boundary of the region in the specified layer. This coordinate represents either the coordinate of the top boundary of a rectangular region itself, or the coordinate of the top boundary of the bounding box of the region.
Long	RgnRight (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the region's right boundary.	Gets or sets the coordinate of the right boundary of the region in the specified layer. This coordinate represents either the coordinate of the right boundary of a rectangular region itself, or the coordinate of the right boundary of the bounding box of the region.
Long	RgnBottom (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the coordinate of the region's bottom boundary.	Gets or sets the coordinate of the bottom boundary of the region in the specified layer. This coordinate represents either the coordinate of the bottom boundary of a rectangular region itself, or the coordinate of the bottom boundary of the bounding box of the region.
Long	RgnRoundRectEllipseWidth (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the width of the ellipse.	Gets or sets the width of the ellipse used to draw the rounded corners of a rounded rectangle region in the specified layer.
Long	RgnRoundRectEllipseHeight (LayerTypeConstants LayerType)	LayerTypeConstants value that indicates the layer for which to get or set the height of the ellipse.	Gets or sets the height of the ellipse used to draw the rounded corners of a rounded rectangle region in the specified layer.

Interface Methods

HRESULT GetLayerInfo(LayerTypeConstants LayerType, long pWidth, long pHeight, long *pBitsPerPixel)

Parameters

LayerType	LayerTypeConstants value that indicates the layer for which to get the information
pWidth	pointer to a variable to be updated with the width of the specified layer.
pHeight	pointer to a variable to be updated with the height of the specified layer.
pBitsPerPixel	pointer to a variable to be updated with the bits per pixel of the specified layer.

Description

Gets information for the specified layer. If the specified layer is not available, all parameters are updated with zeros.

Returns

S_OK if successful, S_FALSE otherwise.