DecApp.cpp

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/** \file     DecApp.cpp
    \brief    Decoder application class
*/

#include <list>
#include <vector>
#include <stdio.h>
#include <fcntl.h>

#include "DecApp.h"
#include "DecoderLib/AnnexBread.h"
#include "DecoderLib/NALread.h"
#if RExt__DECODER_DEBUG_STATISTICS
#include "CommonLib/CodingStatistics.h"
#endif
#include "CommonLib/dtrace_codingstruct.h"


//! \ingroup DecoderApp
//! \{

// ====================================================================================================================
// Constructor / destructor / initialization / destroy
// ====================================================================================================================

DecApp::DecApp()
: m_iPOCLastDisplay(-MAX_INT)
{
}

// ====================================================================================================================
// Public member functions
// ====================================================================================================================

/**
 - create internal class
 - initialize internal class
 - until the end of the bitstream, call decoding function in DecApp class
 - delete allocated buffers
 - destroy internal class
 - returns the number of mismatching pictures
 */
uint32_t DecApp::decode()
{
  int                 poc;
  PicList* pcListPic = NULL;

  ifstream bitstreamFile(m_bitstreamFileName.c_str(), ifstream::in | ifstream::binary);
  if (!bitstreamFile)
  {
    EXIT( "Failed to open bitstream file " << m_bitstreamFileName.c_str() << " for reading" ) ;
  }

  InputByteStream bytestream(bitstreamFile);

  if (!m_outputDecodedSEIMessagesFilename.empty() && m_outputDecodedSEIMessagesFilename!="-")
  {
    m_seiMessageFileStream.open(m_outputDecodedSEIMessagesFilename.c_str(), std::ios::out);
    if (!m_seiMessageFileStream.is_open() || !m_seiMessageFileStream.good())
    {
      EXIT( "Unable to open file "<< m_outputDecodedSEIMessagesFilename.c_str() << " for writing decoded SEI messages");
    }
  }

  // create & initialize internal classes
  xCreateDecLib();

  m_iPOCLastDisplay += m_iSkipFrame;      // set the last displayed POC correctly for skip forward.

  // clear contents of colour-remap-information-SEI output file
  if (!m_colourRemapSEIFileName.empty())
  {
    std::ofstream ofile(m_colourRemapSEIFileName.c_str());
    if (!ofile.good() || !ofile.is_open())
    {
      EXIT( "Unable to open file " << m_colourRemapSEIFileName.c_str() << " for writing colour-remap-information-SEI video");
    }
  }

  // main decoder loop
  bool loopFiltered = false;

  bool bPicSkipped = false;

  while (!!bitstreamFile)
  {
    InputNALUnit nalu;
    nalu.m_nalUnitType = NAL_UNIT_INVALID;

    // determine if next NAL unit will be the first one from a new picture
    bool bNewPicture = isNewPicture(&bitstreamFile, &bytestream);
    bool bNewAccessUnit = bNewPicture && isNewAccessUnit( bNewPicture, &bitstreamFile, &bytestream );
    if(!bNewPicture) 
    { 
      AnnexBStats stats = AnnexBStats();

      // find next NAL unit in stream
      byteStreamNALUnit(bytestream, nalu.getBitstream().getFifo(), stats);
      if (nalu.getBitstream().getFifo().empty())
      {
        /* this can happen if the following occur:
         *  - empty input file
         *  - two back-to-back start_code_prefixes
         *  - start_code_prefix immediately followed by EOF
         */
        msg( ERROR, "Warning: Attempt to decode an empty NAL unit\n");
      }
      else
      {
        // read NAL unit header
        read(nalu);

        // flush output for first slice of an IDR picture
        if(m_cDecLib.getFirstSliceInPicture() &&
            (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_IDR_W_RADL ||
             nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_IDR_N_LP))
        {
          xFlushOutput(pcListPic, nalu.m_nuhLayerId);
        }

        // parse NAL unit syntax if within target decoding layer
        if ((m_iMaxTemporalLayer < 0 || nalu.m_temporalId <= m_iMaxTemporalLayer) && isNaluWithinTargetDecLayerIdSet(&nalu))
        {
          if (bPicSkipped)
          {
            if ((nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_TRAIL) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_STSA) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_RASL) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_RADL) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_IDR_W_RADL) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_IDR_N_LP) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_CRA) || (nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_GDR))
            {
              if (m_cDecLib.isSliceNaluFirstInAU(true, nalu))
              {
                m_cDecLib.resetAccessUnitNals();
                m_cDecLib.resetAccessUnitApsNals();
              }
              bPicSkipped = false;
            }
          }
          m_cDecLib.decode(nalu, m_iSkipFrame, m_iPOCLastDisplay);
          if (nalu.m_nalUnitType == NAL_UNIT_VPS)
          {
            deriveOutputLayerSet();
          }
        }
        else
        {
          bPicSkipped = true;
        }
      }
    }


    if ((bNewPicture || !bitstreamFile || nalu.m_nalUnitType == NAL_UNIT_EOS) && !m_cDecLib.getFirstSliceInSequence() && !bPicSkipped)
    {
      if (!loopFiltered || bitstreamFile)
      {
        m_cDecLib.executeLoopFilters();
        m_cDecLib.finishPicture( poc, pcListPic );
      }
      loopFiltered = (nalu.m_nalUnitType == NAL_UNIT_EOS);
      if (nalu.m_nalUnitType == NAL_UNIT_EOS)
      {
        m_cDecLib.setFirstSliceInSequence(true);
      }

    }
    else if ( (bNewPicture || !bitstreamFile || nalu.m_nalUnitType == NAL_UNIT_EOS ) &&
              m_cDecLib.getFirstSliceInSequence () )
    {
      m_cDecLib.setFirstSliceInPicture (true);