Access a Filter Interface

The example shows how to access the mosaic filter that was inserted as the first filter to the play object in the Programmatically Inserting a Processor Filter tutorial.

  1. Call the play object to retrieve the first selected video processor as follows:

C Source 

IUnknown *pUnk;   
IltmmPlay_GetSubObject(pPlay, ltmmPlay_Object_SelVideoProcessor, &pUnk);

C++ Source 

IUnknown *pUnk;   
pPlay->GetSubObject(ltmmPlay_Object_SelVideoProcessor, &pUnk);

  1. Retrieve the mosaic interface as follows:

C Source 

ILMVMosaic *pVMF;   
IUnknown_QueryInterface(pUnk, &IID_ILMVMosaic, (void**) &pVMF);   
IUnknown_Release(pUnk);

C++ Source 

ILMVMosaic *pVMF;   
pUnk->QueryInterface(&IID_ILMVMosaic, (void**) &pVMF);   
pUnk->Release();

  1. Access the mosaic filter. For example, set the mosaic filter effect area rectangle.

C Source 

CROP_ATTRIBUTES CropAttrib;   
CropAttrib.lLeft = 0;   
CropAttrib.lTop = 0;   
CropAttrib.lRight = 0;   
CropAttrib.lBottom = 0;   
CropAttrib.bEnabled = TRUE;   
ILMVMosaic_SetCropAttributes(pVMF, CropAttrib);   
IUnknown_Release(pVMF);

C++ Source 

CROP_ATTRIBUTES CropAttrib;   
CropAttrib.lLeft = 0;   
CropAttrib.lTop = 0;   
CropAttrib.lRight = 0;   
CropAttrib.lBottom = 0;   
CropAttrib.bEnabled = TRUE;   
pVMF->SetCropAttributes(CropAttrib);   
pVMF->Release();

  1. Clean up the play object.

C Source 

IUnknown_Release(pPlay);

C++ Source 

pPlay->Release();

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LEADTOOLS Multimedia C API Help
Introduction
Version History
Getting Started
Copyright Notice
Directories
Multimedia Files You Must Include With Your Application (Redistributables)
Frequently Asked Questions
LEADTOOLS Multimedia Features
Add-on Modules
Programming with LEADTOOLS Multimedia
Appendix
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