IltmfConvert::SetPreferredMediaSourceHandler Example for C++

// This function does the following: 
// 1) Sets all preferred media source handlers to LEAD Default. 
// 2) Then resets all preferred media source handlers to NULL, or does not use any preferred media source handlers. 
// 3) Then sets the LEAD ISO Media Source Handler as the ISO Preferred media source handlers using its GUID. 
// 4) Gets the preferred ISO Media Source Handler GUID. 
void TestSetPreferredMediaSourceHandler(IltmfConvert *pConvert) 
{ 
   HRESULT hr = S_OK; 
   BSTR bstr = NULL; 
   // Set all media source handlers to LEAD Default 
   bstr = SysAllocString(ltmfMediaSourceHandler_LEADDefault); 
   hr = pConvert->SetPreferredMediaSourceHandler(ltmfConvert_PreferredMediaSourceHandler_Generic, bstr); 
   // free the bstr 
   SysFreeString(bstr); 
   // Reset all the preferred media source handlers to NULL, or don't use any preferred media source handler. 
   bstr = SysAllocString(ltmfMediaSourceHandler_DontCare); 
   hr = pConvert->SetPreferredMediaSourceHandler(ltmfConvert_PreferredMediaSourceHandler_Generic, bstr); 
   // free the bstr 
   SysFreeString(bstr); 
   // Set the ISO Media Source handler to the LEAD ISO Media Source handler, using it's GUID. 
   bstr = SysAllocString(L"EFE620B5-0A2C-49FA-8A01-3768B559B6DA"); 
   hr = pConvert->SetPreferredMediaSourceHandler(ltmfConvert_PreferredMediaSourceHandler_ISO, bstr); 
   // free the bstr 
   SysFreeString(bstr); 
   // Get the preferred ISO Media Source handler 
   bstr = NULL; 
   hr = pConvert->GetPreferredMediaSourceHandler(ltmfConvert_PreferredMediaSourceHandler_ISO, &bstr); 
   // check that the preferred handler for ISO media source is the LEAD ISO Media Source handler 
   if(bstr != NULL && !_wcsicmp(bstr, ltmfMediaSourceHandler_LEAD_ISO)) 
      MessageBox(NULL, TEXT("The preferred media source handler was set properly!"), TEXT("SUCCESS"), MB_OK); 
   else 
      MessageBox(NULL, TEXT("The preferred media source handler was not set properly!"), TEXT("FAILURE"), MB_OK); 
   // free the bstr 
   SysFreeString(bstr); 
}