IMVGDIOverlay

The IMVGDIOverlay Interface provides methods to configure the MV GDI Overlay filter.

Header file: IMVGDIOverlay.h
Interface definition language file: IMVGDIOverlay.idl
Typelib: MVGDIOverlay
Interface ID: IID_IMVGDIOverlay

Method IMVGDIOverlay::EraseDC

Declaration: Sub EraseDC

Immediately erases the filters DC surface.

Prototype:

HRESULT EraseDC();

Method IMVGDIOverlay::GetDC

Declaration: Function GetDC As Long

Returns the filters DC. Call this method to get the overlay DC. Draw into this DC. After calling ReleaseDC the filter draws the content of the DC bitmap over the video stream.

Prototype:

HRESULT GetDC(LONG* value);

Property IMVGDIOverlay::InputAlpha

Declaration: Property Get/Put InputAlpha As Byte

Alpha value for alpha blending in MV_GDI_OVERLAY_CONSTANTALPHA mode.

Prototype:

HRESULT put_InputAlpha(BYTE Value);
HRESULT get_InputAlpha(BYTE* Value);

Property IMVGDIOverlay::Mode

Declaration: Property Get/Put Mode As Long

The filters working mode as MV_GDI_OVERLAY_MODE..

typedef enum _MV_GDI_OVERLAY_MODE
{
    MV_GDI_OVERLAY_TRANSPARENT,
    MV_GDI_OVERLAY_CONSTANTALPHA
} MV_GDI_OVERLAY_MODE;

Prototype:

HRESULT put_Mode(LONG Mode);
HRESULT get_Mode(LONG* Mode);

Property IMVGDIOverlay::Persistence

Declaration: Property Get/Put Persistence As Long

Specifies whether the DC surface is erased on GetDC().

Prototype:

HRESULT put_Persistence(LONG Enable);
HRESULT get_Persistence(LONG* Enable);

Method IMVGDIOverlay::ReleaseDC

Declaration: Sub ReleaseDC(phDC As Long)

Releases the overlay DC. Call this method after drawing to the DC. At that time the filter draws the DC bitmap over the video stream. Call the GetDC method to get the overlay DC.

Parameter:

phDC

Releases the DC

Prototype:

HRESULT ReleaseDC(LONG phDC);

Property IMVGDIOverlay::TransparentColour

Declaration: Property Get/Put TransparentColour As Long

Transparent colour used for background transparency in MV_GDI_OVERLAY_TRANSPARENT mode.

Prototype:

HRESULT put_TransparentColour(LONG Colour);
HRESULT get_TransparentColour(LONG* Colour);