Programmatically Inserting a Processor Filter

Assume you want to insert the mosaic as the first filter to the play object.

1. Create an instance of the ltmmPlay class. This is accomplished using the Win32 CoCreateInstance function as follows:

   C API

   IltmmPlay* pPlay;   
   CoCreateInstance(&CLSID_ltmmPlay, NULL, CLSCTX_INPROC_SERVER, &IID_IltmmPlay, (void**) &pPlay); 

   C++

   IltmmPlay* pPlay;   
   CoCreateInstance(CLSID_ltmmPlay, NULL, CLSCTX_INPROC_SERVER, IID_IltmmPlay, (void**) &pPlay); 

2. Get the registered processors collection as follows:

   C API

   IltmmProcessors* pProcessors;   
   IltmmPlay_get_VideoProcessors (pPlay, &pProcessors); 

   C++

   IltmmProcessors* pProcessors;   
   pPlay->get_VideoProcessors(&pProcessors); 

3. Find the processor index by name as follows:

   C API

   long index; 
   BSTR bstr; 
   // The string below is retrieved from the Filters List utility 
   bstr = SysAllocString(L"@device:sw:{E526D606-22E7-494C-B81E-AC0A94BFE603}\\{E2B7DB28-38C5-11D5-91F6-00104BDB8FF9}"); 
   IltmmProcessors_Find (pProcessors, bstr, &index); 
   SysFreeString(bstr); 

   C++

   long index; 
   BSTR bstr; 
   // The string below is retrieved from the Filters List utility 
   bstr = SysAllocString(L"@device:sw:{E526D606-22E7-494C-B81E-AC0A94BFE603}\\{E2B7DB28-38C5-11D5-91F6-00104BDB8FF9}"); 
   pProcessors->Find (bstr, &index); 
   SysFreeString(bstr); 

4. Get the processor interface and the selected processors collection as follows:

   C API

   IltmmProcessors* pSelProcessors;    
   IltmmProcessor* pProcessor;   
   // get the processor interface   
   IltmmProcessors_Item(pProcessors, index, &pProcessor);    
   // get the selected processors collection   
   IltmmPlay_get_SelectedVideoProcessors (pPlay, &pSelProcessors); 

   C++

   IltmmProcessors* pSelProcessors;    
   IltmmProcessor* pProcessor;   
   // get the processor interface   
   pProcessors->Item (index, &pProcessor);    
   // get the selected processors collection   
   pPlay->get_SelectedVideoProcessors (&pSelProcessors); 

5. Finally, add the processor to the selected processors collection as the first filter as follows:

   C API

   IltmmProcessors_Add (pSelProcessors, pProcessor, 0);    
   // release interfaces   
   IUnknown_Release(pProcessor);    
   IUnknown_Release(pProcessors);    
   IUnknown_Release(pSelProcessors); 

   C++

   pSelProcessors->Add (pProcessor, 0);    
   // release interfaces   
   pProcessor->Release();   
   pProcessors->Release();   
   pSelProcessors->Release(); 

Note: If you want to know how to use the interface of the filter, refer to Access the Interface of Filters.