How to use ltmmProcessors object to register a 3rd-party DirectShow filter as a video processor (C++)

The following method for C++ shows how to use the ltmmProcessors object from the ltmmPlayControl object to register a 3rd-party video processor.

void PlayerEnableCustomVideoProcessor(IltmmPlay *pPlay) 
{ 
   IltmmProcessors *pVideoProcessors = NULL;
   
   // try to get the video processors collection object
   HRESULT hr = pPlay->get_VideoProcessors(&pVideoProcessors);
   if (SUCCEEDED(hr) && NULL != pVideoProcessors) 
   { 
       // Register the external filter by class id 
      pVideoProcessors->RegisterExternalProcessor(L"{AFF289A6-ABF1-4d68-9A51-634BF7077CFC}", VARIANT_TRUE);
      pVideoProcessors->Release(); 
   }
}