IltmmTargetFormat::put_UseFilterCache Example for C++

#include "ltmm.h"
#include "Filters/ILMMpg2MxT.h"
#include <time.h>



HRESULT UseFilterCache_Example (IltmmCapture* pCapture)
{
   HRESULT hr;
   IltmmDevices* devices   = NULL;
   IltmmCompressors* compressors = NULL;
   IltmmTargetFormats* pformats = NULL;
   IltmmTargetFormat*  pformat  = NULL;
   IUnknown*           pUnknown = NULL;
   ILMMpg2MxT*         pMpgMux = NULL;
   long lIndex = 0;



   // mpeg2 compressor
   static TCHAR SZ_MPEG2_Compressor[] = "@device:sw:{33D9A760-90C8-11D0-BD43-00A0C911CE86}\\LEAD MPEG2 Encoder (3.0)";



   // get the video devices collection
   hr = m_capture->get_VideoDevices(&devices);
   if(FAILED(hr))
      return hr;



   // select the capture device
   hr = devices->put_Selection(0); // Use a different video device if you want



   // release the video devices collection object
   devices->Release();
   if(FAILED(hr))
      return hr;



   // get the video compressors collection
   hr = m_capture->get_VideoCompressors(&compressors);
   if(FAILED(hr))
      return hr;



   USES_CONVERSION;
   // find mpeg2 compressor
   hr = compressors->Find(T2OLE(SZ_MPEG2_Compressor), &lIndex);
   if(FAILED(hr) || lIndex == -1)
   {
      // release the compressors collection object


      compressors->Release();
      return S_FALSE;
   }



   // set the video compressor (only if the capture device is not already capturing compressed video)
   compressors->put_Selection(lIndex);



   // release the compressors collection object
   compressors->Release();



   // set the target output file
   BSTR bstr = SysAllocString(L"c:\\CaptureKLV.avi");
   m_capture->put_TargetFile(bstr);
   SysFreeString(bstr);



   // just 10 seconds of capture time
   m_capture->put_UseTimeLimit (VARIANT_TRUE);
   m_capture->put_TimeLimit(10);



   // get the target formats collection
   hr = m_capture->get_TargetFormats(&pformats);
   if(FAILED(hr))
      return hr;



   // get the MPEG2Transport target format object
   hr = pformats->Item(ltmmCapture_TargetFormat_MPEG2_TRANSPORT, &pformat);
   if(FAILED(hr))
   {
      // release the formats collection object
      pformats->Release();
      return hr;
   }



   // IN a capture situation
   // in order to get the mux in a capture situation, set the UseFilterCache property for the target format to TRUE
   // This tells the toolkit to create a Mux object and keep it around when building or rebuilding graphs
   // enable filter cache
   hr = pformat->put_UseFilterCache(VARIANT_TRUE);
   if(FAILED(hr))
   {
      // release the format and collection objects
      pformat->Release();
      pformats->Release();
      return hr;
   }



   // select MPEG2Transport target format
   hr = m_capture->put_TargetFormat (ltmmCapture_TargetFormat_MPEG2_TRANSPORT);
   if(FAILED(hr))
      return hr;



   // get the multiplexer object for this format
   hr = pformat->GetCacheObject(ltmmTargetFormat_Object_Mux, &pUnknown);
   if(FAILED(hr))
   {
      // release the format and collection objects
      pformat->Release();
      pformats->Release();
      return hr;
   }



   // release the format and collection objects
   pformat->Release();
   pformats->Release();
   hr = pUnknown->QueryInterface(IID_ILMMpg2MxT, (void **)&pMpgMux);
   pUnknown->Release();
   if(FAILED(hr))
      return hr;



   if(pMpgMux)
   {
      pMpgMux->put_PrivateDataPID(0x70);
      pMpgMux->put_PrivateDataFormatID(0x41564c4b);
      pMpgMux->put_EnablePrivateData(VARIANT_TRUE);
   }



   // release the multiplexer object
   pMpgMux->Release();



   // start capture
   hr = m_capture->StartCapture(ltmmCapture_Mode_Video);
   if(FAILED(hr))
      return hr;



   hr = WriteKLVData(pMpgMux);
   return hr;
}


 


HRESULT WriteKLVData (ILMMpg2MxT*   pMpgMux )


{


   HRESULT hr = S_OK;


   time_t basetime;


   time(&basetime);


   unsigned __int64 timestamp = ((unsigned __int64) basetime * 1000000);


 


   // get the mux builder


   ILMKlvBuilder* builder;


   hr = pMpgMux->get_KlvBuilder(&builder);


   if(FAILED(hr))


      goto abort;


 


   // clear out any existing data


   builder->Clear();


 


   // write the UDS timestamp


   hr = builder->InsertUInt64(-1L, CComBSTR(L"06 0E 2B 34 01 01 01 03 07 02 01 01 01 05 00 00"), timestamp);


   if(FAILED(hr))


   {


      builder->Release();


      goto abort;


   }


 


   // get KLV data


   VARIANT v;


   VariantInit(&v);


   hr = builder->GetData(&v);


   if(FAILED(hr))


   {


      builder->Release();


      goto abort;


   }


 


   // write one KLV data at the beginning


   hr = pMpgMux->WritePrivateData(Mpg2MxT_WriteFlag_PTSValid | Mpg2MxT_WriteFlag_PTSInSeconds, 1.0, v, -1);


   VariantClear(&v);


   if(FAILED(hr))


   {


      builder->Release();


      goto abort;


   }


 


   builder->Release();


 


abort:


   // close the stream


   pMpgMux->ClosePrivateData();


   return hr;


}