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.

Help Version 22.0.2022.8.22
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