The Full Form of VMR is Video Mixing Renderer.

In DirectX 9, the Video Mixing Renderer 9 (VMR-9) filter offers advanced video rendering capabilities on all platforms supported by DirectX. It is fully integrated with DirectX 9 3D capabilities. For example, that you can easily add video to games and other 3D environments or transform video images using the Direct3D pixel shaders and other effects.

This filter does not support video ports.

To maintain backward compatibility, the VMR-9 is not the default renderer on any system. To use this filter, add it to the filter graph explicitly and configure it before connecting any of its input pins. The VMR-9 uses its own set of interfaces, structures, and enumerations, which are not always identical to the corresponding data types used with the VMR-7.