IVMRMixerBitmap interface (strmif.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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 IVMRMixerBitmap interface enables an application to blend a static image from a bitmap or DirectDraw surface onto the video stream, when using the Video Mixing Renderer Filter 7 (VMR-7).
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. Therefore the VMR must be configured correctly prior to commencing video playback. Even if only a single video stream is present, applications should call IVMRFilterConfig::SetNumberOfStreams with a value of "1" to cause the VMR to load the mixer and compositor. 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.
Inheritance
The IVMRMixerBitmap interface inherits from the IUnknown interface. IVMRMixerBitmap also has these types of members:
Methods
The IVMRMixerBitmap interface has these methods.
| IVMRMixerBitmap::GetAlphaBitmapParameters The GetAlphaBitmapParameters method retrieves a copy of the current image and related blending parameters. |
| IVMRMixerBitmap::SetAlphaBitmap The SetAlphaBitmap method specifies a new bitmap image and the source location of the bitmap and how and where it should be rendered on the destination rectangle. |
| IVMRMixerBitmap::UpdateAlphaBitmapParameters The UpdateAlphaBitmapParameters method changes the bitmap location, size and blending value. |
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows XP [desktop apps only] |
| Minimum supported server | Windows Server 2003 [desktop apps only] |
| Target Platform | Windows |
| Header | strmif.h (include Dshow.h) |
See also
Displaying an Application-Supplied Bitmap on the Composited Image