title: Writing a .wmv file using WMA sf filter
body: <p>I am trying to create an output .wmv file using WM Asf writer filter.Here is my code .</p>
  
  <blockquote>
    <p>IBaseFilter* pASFWriter;
       CoCreateInstance(CLSID_WMAsfWriter,NULL,CLSCTX_INPROC_SERVER,IID_IBaseFilter,(void**)  (&amp;pASFWriter));<br>
                                                             pGraphBuilder->AddFilter(pASFWriter,L"FileWriter");<br>
       IFileSinkFilter *pSink2=NULL;<br>
      pASFWriter->QueryInterface(IID_IFileSinkFilter,(void**)&amp;pSink2);
      pSink2->SetFileName(OUTFILENAME,NULL); </p>
  </blockquote>
  
  <p>All of the above return S_OK  however there is no file created .I am not able to understand why this is so?</p>