IVMRMixerBitmap9接口应该对您有所帮助，该接口由VMR实现。这是MSDN的链接：

IVMRMixerBitmap9 interface should help you, which is implemented by the VMR. This is the link to MSDN:

[http://msdn.microsoft.com/zh-cn/library/windows/desktop/dd390451（v = vs.85 ）.aspx] [1]

[http://msdn.microsoft.com/en-us/library/windows/desktop/dd390451(v=vs.85).aspx][1]

位图需要具有alpha值，以便可以与渲染的视频混合。

The bitmap needs to have alpha values so that it can be blended with the rendered video.