IVMRMixerBitmap9 Interface

Microsoft DirectShow 9.0

IVMRMixerBitmap9 Interface

The IVMRMixerBitmap9 interface enables an application to blend a static image from a bitmap or Direct3D surface onto the video stream, when using the Video Mixing Renderer Filter 9 (VMR-9).

You can pass images to the VMR as frequently as you like, but changing the image several times per second may impact the performance and smoothness of the video being rendered. The new image will be blended with the next and all subsequent video frames rendered by the VMR.

Internally, the VMR uses its mixer component to perform the blending operation. In the VMR-9, the mixer is always present by default except in "renderless" mode in which the application is performing its own rendering. The image can contain embedded per pixel alpha information; this allows the image to contain regions that are transparent. Transparent areas can also be identified by a color key value. Changes in the image are only shown on the screen while the filter graph is running.

In addition to the methods inherited from IUnknown, the IVMRMixerBitmap9 interface exposes the following methods.

Method	Description
GetAlphaBitmapParameters	Retrieves a copy of the current image and related blending parameters.
SetAlphaBitmap	Specifies a new bitmap image and the source location of the bitmap and how and where it should be rendered on the destination rectangle.
UpdateAlphaBitmapParameters	Changes the bitmap location, size and blending value.

Requirements

Header: Include D3d9.h, Vmr9.h.

Library: Use Strmiids.lib.