/work/vvdec/source/Lib/DecoderLib/DecLibParser.cpp

Source
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#include "DecLib.h"
#include "DecLibParser.h"
#include "NALread.h"

#include "CommonLib/dtrace_next.h"

#include "UnitTools.h"
#include "Utilities/ThreadPool.h"

#include <unordered_map>
#include <utility>

namespace vvdec
{
template<class TArr, class TElem = decltype( std::declval<TArr>()[0] )>
void fill_array( TArr& array, const TElem& val )
{
  std::fill( std::begin( array ), std::end( array ), val );
}

#ifdef TRACE_ENABLE_ITT
extern __itt_domain* itt_domain_prs;
extern __itt_domain* itt_domain_oth;

extern __itt_string_handle* itt_handle_parse;
extern __itt_string_handle* itt_handle_start;

#define ITT_TASKSTART( d, t ) __itt_task_begin( ( d ), __itt_null, __itt_null, ( t ) )
#define ITT_TASKEND( d, t )   __itt_task_end  ( ( d ) )
#else
#define ITT_TASKSTART( d, t )
#define ITT_TASKEND( d, t )
#endif

static const int INIT_POC = -MAX_INT;

DecLibParser::~DecLibParser()
{
  m_prefixSEINALUs.clear();

  destroy();
}

void DecLibParser::create( ThreadPool* tp, int parserFrameDelay, int numReconInst, int numDecThreads, ErrHandlingFlags errHandlingFlags )
{
  m_threadPool        = tp;
  m_parseFrameDelay   = parserFrameDelay;
  m_numDecThreads     = numDecThreads;
  m_maxPicReconSkip   = numReconInst - 1;
  m_errHandlingFlags  = errHandlingFlags;

  m_apcSlicePilot     = new Slice;
  m_uiSliceSegmentIdx = 0;

  fill_array( m_associatedIRAPType,     NAL_UNIT_INVALID );
  fill_array( m_pocCRA,                 INIT_POC );
  fill_array( m_gdrRecoveryPointPocVal, INIT_POC );
  fill_array( m_gdrRecovered,           false );

  m_cSliceDecoder.setContextStateVec( numDecThreads );
}

void DecLibParser::destroy()
{
  SEI_internal::deleteSEIs( m_seiMessageList );

  m_threadPool    = nullptr;

  delete m_apcSlicePilot;
  m_apcSlicePilot = nullptr;
  
  m_picHeader.reset();
  
  m_cSliceDecoder.destroy();
  
  if( m_dci )
  {
    delete m_dci;
    m_dci = NULL;
  }
}

bool DecLibParser::parse( InputNALUnit& nalu )
{
  if( !nalu.isVcl() )
  {
    if( nalu.m_nalUnitType == NAL_UNIT_SUFFIX_APS || nalu.m_nalUnitType == NAL_UNIT_SUFFIX_SEI )
    {
      if( m_pcParsePic )
      {
        m_pcParsePic->bits += nalu.m_bits;
      }
    }
    else
    {
      m_nonVCLbits += nalu.m_bits;
    }
  }

  GCC_EXTRA_WARNING_switch_enum;
  switch( nalu.m_nalUnitType )
  {
  case NAL_UNIT_CODED_SLICE_TRAIL:
  case NAL_UNIT_CODED_SLICE_STSA:
  case NAL_UNIT_CODED_SLICE_RADL:
  case NAL_UNIT_CODED_SLICE_RASL:
  case NAL_UNIT_CODED_SLICE_IDR_W_RADL:
  case NAL_UNIT_CODED_SLICE_IDR_N_LP:
  case NAL_UNIT_CODED_SLICE_CRA:
  case NAL_UNIT_CODED_SLICE_GDR:
    try
    {
      if( !xDecodeSliceHead( nalu ) )
      {
        return false;
      }
      if( !xDecodeSliceMain( nalu ) || m_parseFrameList.size() <= m_parseFrameDelay )
      {
        return false;
      }
      return true;
    }
    catch( ... )
    {
      if( m_pcParsePic )
      {
        m_pcParsePic->error              = true;
        m_pcParsePic->exceptionThrownOut = true;
        if( m_pcParsePic->parseDone.hasException() )   // this happens only in the single-threaded case.
        {                                              // multithreaded mode should see exceptions from the parse tasks later
          m_pcParsePic->parseDone.clearException();
        }
      }

      std::rethrow_exception( std::current_exception() );
    }

  case NAL_UNIT_OPI:
    // NOT IMPLEMENTED
    return false;

  case NAL_UNIT_DCI:
    xDecodeDCI( nalu );
    return false;

  case NAL_UNIT_VPS:
    xDecodeVPS( nalu );
    // m_vps->m_iTargetLayer = iTargetOlsIdx;
    return false;

  case NAL_UNIT_SPS:
    xDecodeSPS( nalu );
    return false;

  case NAL_UNIT_PPS:
    xDecodePPS( nalu );
    return false;

  case NAL_UNIT_PREFIX_APS:
  case NAL_UNIT_SUFFIX_APS:
    xDecodeAPS( nalu );
    return false;

  case NAL_UNIT_PH:
    xDecodePicHeader( nalu );
    return false;

  case NAL_UNIT_ACCESS_UNIT_DELIMITER:
  {
    AUDReader audReader;
    uint32_t  picType;
    audReader.parseAccessUnitDelimiter( &( nalu.getBitstream() ), picType );
    msg( VERBOSE, "Found NAL_UNIT_ACCESS_UNIT_DELIMITER\n" );
    return false;
  }

  case NAL_UNIT_EOS:
    m_associatedIRAPType[nalu.m_nuhLayerId]     = NAL_UNIT_INVALID;
    m_pocCRA[nalu.m_nuhLayerId]                 = INIT_POC;
    m_gdrRecoveryPointPocVal[nalu.m_nuhLayerId] = INIT_POC;
    m_gdrRecovered[nalu.m_nuhLayerId]           = false;
    m_pocRandomAccess                           = MAX_INT;
    m_prevPOC                                   = MAX_INT;
    m_prevSliceSkipped                          = false;
    m_skippedPOC                                = 0;
    m_bFirstSliceInSequence[nalu.m_nuhLayerId]  = true;
    m_bFirstSliceInPicture                      = true;
    m_picListManager.restart();
    return false;

  case NAL_UNIT_EOB:
    return false;

  case NAL_UNIT_PREFIX_SEI:
    // Buffer up prefix SEI messages until SPS of associated VCL is known.
    m_prefixSEINALUs.emplace_back( nalu );
    m_pictureSeiNalus.emplace_back( std::move( nalu ) );
    return false;

  case NAL_UNIT_SUFFIX_SEI:
    if( m_pcParsePic /*&& !m_pcParsePic->wasLost*/ )
    {
      m_pictureSeiNalus.emplace_back( nalu );
      const SPS* sps = m_parameterSetManager.getActiveSPS();
      const VPS* vps = m_parameterSetManager.getVPS( sps->getVPSId() );
      m_seiReader.parseSEImessage( &( nalu.getBitstream() ), m_pcParsePic->seiMessageList, nalu.m_nalUnitType, nalu.m_nuhLayerId, nalu.m_temporalId, vps, sps, m_HRD, m_pDecodedSEIOutputStream );

      if( m_parseFrameDelay == 0 && !m_pcParsePic->error )   // if m_parseFrameDelay > 0, it has to be done in finishPicture()
      {
        // if parallel parsing is disabled, wait for the picture to finish
        if( m_threadPool->numThreads() == 0 )
        {
          m_threadPool->processTasksOnMainThread();
        }
        else
        {
          m_pcParsePic->reconDone.wait();
        }
        m_decLib.checkPictureHashSEI( m_pcParsePic );
      }
    }
    else
    {
      msg( NOTICE, "Received suffix SEI but no picture currently active.\n" );
    }
    return false;

  case NAL_UNIT_FD:
    return false;

  case NAL_UNIT_RESERVED_VCL_4:
  case NAL_UNIT_RESERVED_VCL_5:
  case NAL_UNIT_RESERVED_VCL_6:
  case NAL_UNIT_RESERVED_IRAP_VCL_11:
    msg( NOTICE, "Found reserved VCL NAL unit.\n" );
    xParsePrefixSEIsForUnknownVCLNal();
    return false;
  case NAL_UNIT_RESERVED_NVCL_26:
  case NAL_UNIT_RESERVED_NVCL_27:
    msg( NOTICE, "Found reserved NAL unit.\n" );
    return false;
  case NAL_UNIT_UNSPECIFIED_28:
  case NAL_UNIT_UNSPECIFIED_29:
  case NAL_UNIT_UNSPECIFIED_30:
  case NAL_UNIT_UNSPECIFIED_31:
    msg( NOTICE, "Found unspecified NAL unit.\n" );
    return false;
  case NAL_UNIT_INVALID:
  default:
    THROW_RECOVERABLE( "Invalid NAL unit type" );
    break;
  }
  GCC_WARNING_RESET;

  return false;
}

void DecLibParser::failIncompleteParsePic()
{
  if( !m_pcParsePic || m_pcParsePic->lastSliceOfPicPresent() )
  {
    return;
  }

  // reconstruction can already be waiting for CTUs, that will never be parsed, so the picture needs to be failed explicitly
  m_pcParsePic->setParseError( std::make_exception_ptr( RecoverableException( "the slices of the picture don't cover all CTUs" ) ) );
  m_pcParsePic = nullptr;
}

Picture* DecLibParser::getNextDecodablePicture()
{
  if( m_parseFrameList.empty() )
  {
    return nullptr;
  }

  if( m_threadPool->numThreads() == 0 || m_parseFrameDelay == 0 )
  {
    // adhere to strict decoding order if running singlethreaded
    Picture * pic = m_parseFrameList.front();
    m_parseFrameList.pop_front();
    return pic;
  }

  if( m_parseFrameList.front()->skippedDecCount >= MAX_OUT_OF_ORDER_PICS || m_parseFrameList.front()->error )
  {
    Picture* pic = m_parseFrameList.front();
    m_parseFrameList.pop_front();
    return pic;
  }

  // try to find next picture, that is parsed and has all reference pictures decoded
  for( auto picIt = m_parseFrameList.begin(); picIt != m_parseFrameList.end(); ++picIt )
  {
    Picture* pic = *picIt;

    if( pic->parseDone.getState() != Barrier::unlocked )   // this doesn't throw if the barrier has an exception set
      continue;

    if( pic->wasLost || pic->error )
      continue;

    bool allRefPicsDone = true;
    for( const Slice* slice: pic->slices )
    {
      if( slice->isIntra() )
      {
        continue;
      }
      for( int iDir = REF_PIC_LIST_0; iDir < NUM_REF_PIC_LIST_01 && allRefPicsDone; ++iDir )
      {
        for( int iRefIdx = 0; iRefIdx < slice->getNumRefIdx( (RefPicList) iDir ) && allRefPicsDone; iRefIdx++ )
        {
          const Picture* refPic = slice->getRefPic( (RefPicList) iDir, iRefIdx );
          if( refPic->progress < Picture::reconstructed )
          {
            allRefPicsDone = false;
            break;
          }
        }
      }
    }

    if( allRefPicsDone )
    {
      // increase skip count for all previous pictures
      for( auto& skipped: PicListRange{ m_parseFrameList.begin(), picIt } )
      {
        skipped->skippedDecCount++;
      }

      m_parseFrameList.erase( picIt );
      return pic;
    }

//    if( pic->getTLayer() < m_parseFrameList.front()->getTLayer() )
//    {
//      break;
//    }
  }

  // if no picture has all reference-pictures decoded, use next pic in (regular) decoding order.
  Picture * pic = m_parseFrameList.front();
  m_parseFrameList.pop_front();
  return pic;
}

void DecLibParser::checkAPSInPictureUnit()
{
  bool firstVCLFound  = false;
  bool suffixAPSFound = false;

  for( auto &nalu : m_pictureUnitNals )
  {
    if( NALUnit::isVclNalUnitType(nalu) )
    {
      firstVCLFound = true;
      CHECK( suffixAPSFound, "When any suffix APS NAL units are present in a PU, they shall follow the last VCL unit of the PU" );
    }
    else if( nalu == NAL_UNIT_PREFIX_APS )
    {
      CHECK( firstVCLFound, "When any prefix APS NAL units are present in a PU, they shall precede the first VCL unit of the PU");
    }
    else if( nalu == NAL_UNIT_SUFFIX_APS )
    {
      suffixAPSFound = true;
    }
  }
}

bool DecLibParser::xDecodeSliceHead( InputNALUnit& nalu )
{
  // all slices for the previous picture have been parsed
  if( m_pcParsePic && m_pcParsePic->lastSliceOfPicPresent() )
  {
    m_pcParsePic = nullptr;
  }

  m_apcSlicePilot->initSlice(); // the slice pilot is an object to prepare for a new slice
                                // it is not associated with picture, sps or pps structures.

  m_apcSlicePilot->setNalUnitType   ( nalu.m_nalUnitType );
  m_apcSlicePilot->setNalUnitLayerId( nalu.m_nuhLayerId  );
  m_apcSlicePilot->setTLayer        ( nalu.m_temporalId  );

  m_HLSReader.setBitstream( &nalu.getBitstream() );

  m_bFirstSliceInPicture = true;  // set for now, will be set correctly in parseSliceHeader
  m_HLSReader.parseSliceHeader( m_apcSlicePilot, m_picHeader, &m_parameterSetManager, m_prevTid0POC, m_bFirstSliceInPicture );

  CHECK( m_bFirstSliceInPicture != ( m_apcSlicePilot->getCtuAddrInSlice( 0 ) == 0 ), "first slice in picture should start at CTU-addr 0" );

  if( m_bFirstSliceInPicture )
  {
    failIncompleteParsePic();   // a new picture starts, but the previous one was never completed

    m_uiSliceSegmentIdx = 0;
    m_apcSlicePilot->setPicHeader   ( m_picHeader.get() );
  }
  else // if it turns out, this was not the first slice in the picture, we need to parse the header again
  {
    m_uiSliceSegmentIdx++;
    CHECK( !m_pcParsePic, "m_pcParsePic should be initialized, when this is not the first slice in the picture" );
    CHECK( m_pcParsePic->slices.size() <= m_uiSliceSegmentIdx - 1 || m_pcParsePic->slices[m_uiSliceSegmentIdx - 1] == nullptr, "can't access previous slice" );
    CHECK( !m_pcParsePic->getMixedNaluTypesInPicFlag() && nalu.m_nalUnitType != m_pcParsePic->slices[m_uiSliceSegmentIdx - 1]->getNalUnitType(),
           "The value of NAL unit type shall be the same for all coded slice NAL units of a picture if pps_mixed_nalu_types_in_pic_flag is not set" );

    m_apcSlicePilot->copySliceInfo( m_pcParsePic->slices[m_uiSliceSegmentIdx - 1] );

    m_apcSlicePilot->setNalUnitType   ( nalu.m_nalUnitType );
    m_apcSlicePilot->setNalUnitLayerId( nalu.m_nuhLayerId );
    m_apcSlicePilot->setTLayer        ( nalu.m_temporalId );

    nalu.getBitstream().resetToStart();
    nalu.readNalUnitHeader();
    m_HLSReader.setBitstream        ( &nalu.getBitstream() );

    m_HLSReader.parseSliceHeader( m_apcSlicePilot, m_picHeader, &m_parameterSetManager, m_prevTid0POC, m_bFirstSliceInPicture );
  }

  const PPS* pps = static_cast<const ParameterSetManager&>( m_parameterSetManager ).getPPS( m_apcSlicePilot->getPicHeader()->getPPSId() );
  CHECK( pps == 0, "No PPS present" );
  const SPS* sps = static_cast<const ParameterSetManager&>( m_parameterSetManager ).getSPS( pps->getSPSId() );
  CHECK( sps == 0, "No SPS present" );
  const VPS* vps = static_cast<const ParameterSetManager&>( m_parameterSetManager ).getVPS( sps->getVPSId() );
  CHECK( sps->getVPSId() > 0 && vps == 0, "Invalid VPS" );
  if( sps->getVPSId() == 0 && m_prevLayerID != MAX_INT )
  {
    CHECK( m_prevLayerID != nalu.m_nuhLayerId, "All VCL NAL unit in the CVS shall have the same value of nuh_layer_id "
                                                           "when sps_video_parameter_set_id is equal to 0" );
  }

  CHECK( vps && !vps->getIndependentLayerFlag( nalu.m_nuhLayerId ), "Decoding of dependent layers not implemented. Dependent layer POC derivation was here." );

  if( !m_bFirstSliceInPicture )
  {
    // the slices of a picture shall be in increasing order of their addresses and shall not overlap
    const Slice* prevSlice = m_pcParsePic->slices[m_uiSliceSegmentIdx - 1];
    if( pps->getRectSliceFlag() )
    {
      // the rect slice map is a partition of the picture (verified in PPS::checkSliceMap()), so distinct indices suffice
      CHECK( m_apcSlicePilot->getSliceID() <= prevSlice->getSliceID(), "slices shall be in increasing order of their slice indices" );
    }
    else
    {
      // a raster-scan slice covers the tiles [sh_slice_address, sh_slice_address + numTilesInSlice)
      const uint32_t prevSliceLastTileIdx = pps->getTileIdx( prevSlice->getCtuAddrInSlice( prevSlice->getNumCtuInSlice() - 1 ) );
      CHECK( m_apcSlicePilot->getSliceID() <= prevSliceLastTileIdx, "slices shall be in increasing order of sh_slice_address and shall not overlap" );
    }
  }

  // update independent slice index
  m_apcSlicePilot->setIndependentSliceIdx( m_uiSliceSegmentIdx );

  DTRACE_UPDATE( g_trace_ctx, std::make_pair( "poc", m_apcSlicePilot->getPOC() ) );


  if( m_bFirstSliceInPicture )
  {
    const auto pictureType = m_apcSlicePilot->getNalUnitType();

    if( !pps->getMixedNaluTypesInPicFlag()
        && ( pictureType == NAL_UNIT_CODED_SLICE_IDR_W_RADL
             || pictureType == NAL_UNIT_CODED_SLICE_IDR_N_LP
             || pictureType == NAL_UNIT_CODED_SLICE_CRA
             || pictureType == NAL_UNIT_CODED_SLICE_GDR ) )
    {
      m_pocCRA            [nalu.m_nuhLayerId] = m_apcSlicePilot->getPOC();
      m_associatedIRAPType[nalu.m_nuhLayerId] = pictureType;
    }
  }

  xUpdatePreviousTid0POC( m_apcSlicePilot );

  m_apcSlicePilot->setAssociatedIRAPPOC ( m_pocCRA            [nalu.m_nuhLayerId] );
  m_apcSlicePilot->setAssociatedIRAPType( m_associatedIRAPType[nalu.m_nuhLayerId] );

  if( m_apcSlicePilot->getRapPicFlag() || m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR )
  {
    // Derive NoOutputBeforeRecoveryFlag
    if( !pps->getMixedNaluTypesInPicFlag() )
    {
      if( m_bFirstSliceInSequence[nalu.m_nuhLayerId] )
      {
        m_picHeader->setNoOutputBeforeRecoveryFlag( true );
      }
      else if( m_apcSlicePilot->getIdrPicFlag() )
      {
        m_picHeader->setNoOutputBeforeRecoveryFlag( true );
      }
      else if( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_CRA )
      {
        m_picHeader->setNoOutputBeforeRecoveryFlag( m_picHeader->getHandleCraAsCvsStartFlag() );
      }
      else if( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR )
      {
        m_picHeader->setNoOutputBeforeRecoveryFlag( m_picHeader->getHandleGdrAsCvsStartFlag() );
      }
    }
    else
    {
      m_picHeader->setNoOutputBeforeRecoveryFlag( false );
    }

    if( m_apcSlicePilot->isCRAorGDR() )
    {
      m_lastNoOutputBeforeRecoveryFlag[nalu.m_nuhLayerId] = m_picHeader->getNoOutputBeforeRecoveryFlag();
    }

    // the inference for NoOutputOfPriorPicsFlag
    if( m_apcSlicePilot->getNoOutputOfPriorPicsFlag() )
    {
      m_lastPOCNoOutputPriorPics = m_apcSlicePilot->getPOC();
      m_isNoOutputPriorPics      = true;
    }
    else
    {
      m_isNoOutputPriorPics = false;
    }
  }

#if !DISABLE_CHECK_NO_OUTPUT_PRIOR_PICS_FLAG
  if( m_bFirstSliceInPicture && m_apcSlicePilot->getPOC() != m_prevPOC
      && ( m_apcSlicePilot->getRapPicFlag() || m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR )
      && m_picHeader->getNoOutputBeforeRecoveryFlag()
      && getNoOutputPriorPicsFlag() )
  {
    checkNoOutputPriorPics();
    setNoOutputPriorPicsFlag( false );
  }
#endif


  //For inference of PicOutputFlag
  if( !pps->getMixedNaluTypesInPicFlag() && ( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_RASL ) )
  {
    if( m_lastNoOutputBeforeRecoveryFlag[nalu.m_nuhLayerId] )
    {
      m_picHeader->setPicOutputFlag( false );
    }
  }

  if( sps->getVPSId() > 0 )
  {
    const VPS *vps = m_parameterSetManager.getVPS( sps->getVPSId() );
    CHECK( vps == 0, "No VPS present" );
    if( ( vps->getOlsModeIdc() == 0
          && vps->getGeneralLayerIdx( nalu.m_nuhLayerId ) < ( vps->getMaxLayers() - 1 )
          && vps->getOlsOutputLayerFlag( vps->m_iTargetLayer, vps->getMaxLayers() - 1 ) == 1 )
        || ( vps->getOlsModeIdc() == 2
             && vps->getOlsOutputLayerFlag( vps->m_iTargetLayer, vps->getGeneralLayerIdx( nalu.m_nuhLayerId ) ) == 0 ) )
    {
      m_picHeader->setPicOutputFlag( false );
    }
  }

  //Reset POC MSB when CRA or GDR has NoOutputBeforeRecoveryFlag equal to 1
  if( !pps->getMixedNaluTypesInPicFlag() && m_apcSlicePilot->isCRAorGDR() && m_lastNoOutputBeforeRecoveryFlag[nalu.m_nuhLayerId] )
  {
    int iMaxPOClsb = 1 << sps->getBitsForPOC();
    m_apcSlicePilot->setPOC( m_apcSlicePilot->getPOC() & ( iMaxPOClsb - 1 ) );
    xUpdatePreviousTid0POC ( m_apcSlicePilot );
    m_lastPOCNoOutputPriorPics = m_apcSlicePilot->getPOC();
  }

  // Skip pictures due to random access
  if( isRandomAccessSkipPicture() )
  {
    m_prevSliceSkipped = true;
    m_skippedPOC       = m_apcSlicePilot->getPOC();
    msg( VERBOSE, "POC %i: RASL not decodable\n", m_skippedPOC );
    return false;
  }

  // clear previous slice skipped flag
  m_prevSliceSkipped = false;

  //we should only get a different poc for a new picture (with CTU address==0)
  if(  m_apcSlicePilot->getPOC() != m_prevPOC
   && !m_bFirstSliceInSequence[nalu.m_nuhLayerId]
   &&  m_apcSlicePilot->getFirstCtuRsAddrInSlice() != 0 )
  {
    msg( WARNING, "Warning, the first slice of a picture might have been lost!\n");
  }

  m_prevLayerID = nalu.m_nuhLayerId;

  //detect lost reference picture and insert copy of earlier frame.
  if( m_apcSlicePilot->getSliceType() != I_SLICE )
  {
    for( const auto rplIdx: { REF_PIC_LIST_0, REF_PIC_LIST_1 } )
    {
      const auto* rpl = m_apcSlicePilot->getRPL( rplIdx );

      int missingPoc         = MAX_INT;
      int missingRefPicIndex = 0;
      while( !m_apcSlicePilot->checkThatAllRefPicsAreAvailable( m_dpbReferencePics,
                                                                rpl,
                                                                m_apcSlicePilot->getNumRefIdx( rplIdx ),
                                                                &missingPoc,
                                                                &missingRefPicIndex ) )
      {
        if( !pps->getMixedNaluTypesInPicFlag()
            && ( ( m_apcSlicePilot->isIDR() && ( sps->getIDRRefParamListPresent() || pps->getRplInfoInPhFlag() ) )
                 || ( m_apcSlicePilot->isCRAorGDR() && m_picHeader->getNoOutputBeforeRecoveryFlag() ) ) )
        {
          if( !rpl->isInterLayerRefPic( missingRefPicIndex ) )
          {
            prepareUnavailablePicture( false,
                                       pps,
                                       missingPoc,
                                       m_apcSlicePilot->getNalUnitLayerId(),
                                       rpl->isRefPicLongterm( missingRefPicIndex ),
                                       m_apcSlicePilot->getTLayer() );
          }
        }
        else
        {
          prepareUnavailablePicture( true,
                                     pps,
                                     missingPoc,
                                     m_apcSlicePilot->getNalUnitLayerId(),
                                     rpl->isRefPicLongterm( missingRefPicIndex ),
                                     m_apcSlicePilot->getTLayer() );
        }
      }
    }
  }
  xActivateParameterSets( nalu.m_nuhLayerId );

  // WARNING: don't use m_apcSlicePilot after this point, because it has been reallocated

  Slice* slice = m_pcParsePic->slices[m_uiSliceSegmentIdx];

  m_pcParsePic->neededForOutput = m_picHeader->getPicOutputFlag();
  if( m_pcParsePic->lastSliceOfPicPresent() )
  {
#if 0
    // TODO for VPS support:
    if( sps->getVPSId() > 0 && NOT IN OUTPUT LAYER SET )
    {
      m_pcParsePic->neededForOutput = false;
    }
    else
#endif
    {
      if( !m_gdrRecovered[nalu.m_nuhLayerId] && slice->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR && m_gdrRecoveryPointPocVal[nalu.m_nuhLayerId] == INIT_POC )
      {
        m_gdrRecoveryPointPocVal[nalu.m_nuhLayerId] = m_pcParsePic->poc + m_picHeader->getRecoveryPocCnt();
      }

      if( !m_gdrRecovered[nalu.m_nuhLayerId]
          && ( m_gdrRecoveryPointPocVal[nalu.m_nuhLayerId] == m_pcParsePic->poc || m_picHeader->getRecoveryPocCnt() == 0 ) )
      {
        m_gdrRecovered          [nalu.m_nuhLayerId] = true;
        m_gdrRecoveryPointPocVal[nalu.m_nuhLayerId] = INIT_POC;
      }

      const bool is_recovering_picture = slice->getAssociatedIRAPType() == NAL_UNIT_CODED_SLICE_GDR && m_pcParsePic->poc < m_gdrRecoveryPointPocVal[nalu.m_nuhLayerId];
      if( slice->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR && m_gdrRecovered[nalu.m_nuhLayerId] )
      {
        m_pcParsePic->neededForOutput = true;
      }
      else if( slice->getNalUnitType() == NAL_UNIT_CODED_SLICE_RASL && m_lastNoOutputBeforeRecoveryFlag[nalu.m_nuhLayerId] )
      {
        m_pcParsePic->neededForOutput = false;
      }
      else if( ( slice->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR && m_picHeader->getNoOutputBeforeRecoveryFlag() )
               || ( is_recovering_picture && ( !m_gdrRecovered[nalu.m_nuhLayerId] || m_lastNoOutputBeforeRecoveryFlag[nalu.m_nuhLayerId] ) ) )
      {
        m_pcParsePic->neededForOutput = false;
      }
    }
  }

  return true;
}

bool DecLibParser::xDecodeSliceMain( InputNALUnit& nalu )
{
  ITT_TASKSTART( itt_domain_oth, itt_handle_start );
  // actual decoding starts here
  Slice* pcSlice = m_pcParsePic->slices[m_uiSliceSegmentIdx];
  m_pcParsePic->poc              = pcSlice->getPOC();
  m_pcParsePic->tempLayer        = pcSlice->getTLayer();
  m_pcParsePic->dpbReferenceMark = pcSlice->getPicHeader()->getNonReferencePictureFlag() ? Picture::unreferenced : Picture::ShortTerm;
  m_pcParsePic->stillReferenced  = !!m_pcParsePic->dpbReferenceMark;
  m_pcParsePic->isReferencePic   = !!m_pcParsePic->dpbReferenceMark;
  m_pcParsePic->eNalUnitType     = nalu.m_nalUnitType;
  m_pcParsePic->cts              = nalu.m_cts;
  m_pcParsePic->dts              = nalu.m_dts;
  m_pcParsePic->rap              = nalu.m_rap;
  m_pcParsePic->userData         = nalu.m_userData;
  m_pcParsePic->bits            += nalu.m_bits + m_nonVCLbits;
  m_pcParsePic->layerId          = nalu.m_nuhLayerId;
  m_pcParsePic->subLayerNonReferencePictureDueToSTSA = false;

  m_nonVCLbits = 0;

  CHECK( m_pcParsePic->tempLayer != nalu.m_temporalId,
         "Currently parsed pic should have the same temporal layer as the NAL unit" );

  if( pcSlice->getSPS()->getProfileTierLevel()->getConstraintInfo()->getNoApsConstraintFlag() )
  {
    bool flag = pcSlice->getSPS()->getUseCCALF() || pcSlice->getPicHeader()->getNumAlfAps() || pcSlice->getPicHeader()->getAlfEnabledFlag( COMPONENT_Cb ) || pcSlice->getPicHeader()->getAlfEnabledFlag( COMPONENT_Cr );
    CHECK( flag, "When no_aps_constraint_flag is equal to 1, the values of "
                             "ph_num_alf_aps_ids_luma, sh_num_alf_aps_ids_luma, ph_alf_cb_flag, "
                             "ph_alf_cr_flag, sh_alf_cb_flag, sh_alf_cr_flag, "
                             "and sps_ccalf_enabled_flag shall all be equal to 0" )
  }

  if( pcSlice->getNalUnitLayerId() != pcSlice->getSPS()->getLayerId() )
  {
    CHECK( pcSlice->getSPS()->getLayerId() > pcSlice->getNalUnitLayerId(), "Layer Id of SPS cannot be greater than layer Id of VCL NAL unit the refer to it" );
    CHECK( pcSlice->getSPS()->getVPSId() == 0, "VPSId of the referred SPS cannot be 0 when layer Id of SPS and layer Id of current slice are different" );
    for (int i = 0; i < pcSlice->getVPS()->getNumOutputLayerSets(); i++ )
    {
      bool isCurrLayerInOls = false;
      bool isRefLayerInOls = false;
      int j = pcSlice->getVPS()->getNumLayersInOls(i) - 1;
      for (; j >= 0; j--)
      {
        if( pcSlice->getVPS()->getLayerIdInOls(i, j) == pcSlice->getNalUnitLayerId() )
        {
          isCurrLayerInOls = true;
        }
        if( pcSlice->getVPS()->getLayerIdInOls(i, j) == pcSlice->getSPS()->getLayerId() )
        {
          isRefLayerInOls = true;
        }
      }
      CHECK( isCurrLayerInOls && !isRefLayerInOls, "When VCL NAl unit in layer A refers to SPS in layer B, all OLS that contains layer A shall also contains layer B" );
    }
  }
  if( pcSlice->getNalUnitLayerId() != pcSlice->getPPS()->getLayerId() )
  {
    CHECK( pcSlice->getPPS()->getLayerId() > pcSlice->getNalUnitLayerId(), "Layer Id of PPS cannot be greater than layer Id of VCL NAL unit the refer to it" );
    CHECK( pcSlice->getSPS()->getVPSId() == 0, "VPSId of the referred SPS cannot be 0 when layer Id of PPS and layer Id of current slice are different" );
    for (int i = 0; i < pcSlice->getVPS()->getNumOutputLayerSets(); i++ )
    {
      bool isCurrLayerInOls = false;
      bool isRefLayerInOls = false;
      int j = pcSlice->getVPS()->getNumLayersInOls(i) - 1;
      for (; j >= 0; j--)
      {
        if( pcSlice->getVPS()->getLayerIdInOls(i, j) == pcSlice->getNalUnitLayerId() )
        {
          isCurrLayerInOls = true;
        }
        if( pcSlice->getVPS()->getLayerIdInOls(i, j) == pcSlice->getPPS()->getLayerId() )
        {
          isRefLayerInOls = true;
        }
      }
      CHECK( isCurrLayerInOls && !isRefLayerInOls, "When VCL NAl unit in layer A refers to PPS in layer B, all OLS that contains layer A shall also contains layer B" );
    }
  }

  if( m_bFirstSliceInPicture )
  {
    m_pcParsePic->setDecodingOrderNumber( m_decodingOrderCounter );
    m_decodingOrderCounter++;

    pcSlice->getPic()->subPictures.clear();
    pcSlice->getPic()->sliceSubpicIdx.clear();

    for( int subPicIdx = 0; subPicIdx < pcSlice->getSPS()->getNumSubPics(); subPicIdx++ )
    {
      pcSlice->getPic()->subPictures.push_back( pcSlice->getPPS()->getSubPic( subPicIdx ) );
    }
  }

  pcSlice->getPic()->sliceSubpicIdx.push_back(pcSlice->getPPS()->getSubPicIdxFromSubPicId(pcSlice->getSliceSubPicId()));

  // When decoding the slice header, the stored start and end addresses were actually RS addresses, not TS addresses.
  // Now, having set up the maps, convert them to the correct form.

  // Sanity check: verify that there are no duplicate POCs in the DPB before constructing the ref picture lists
  m_tmpSeenPocs.clear();
  m_tmpSeenPocs.reserve( m_dpbReferencePics.size() );
  for( auto& p: m_dpbReferencePics )
  {
    CHECK( m_tmpSeenPocs.count( p->poc ) != 0, "duplicate POC in DPB" );
    if( p->dpbReferenceMark )   // we only care about reference pictures in the DPB
    {
      m_tmpSeenPocs.insert( p->poc );
    }
  }

#if !DISABLE_CONFROMANCE_CHECK
  pcSlice->checkCRA( m_pocCRA[nalu.m_nuhLayerId], m_associatedIRAPType[nalu.m_nuhLayerId], m_picListManager.getPicListRange( m_pcParsePic ) );
#endif
  pcSlice->constructRefPicLists( m_dpbReferencePics );
#if !DISABLE_CONFROMANCE_CHECK
  pcSlice->checkRPL(pcSlice->getRPL0(), pcSlice->getRPL1(), m_associatedIRAPDecodingOrderNumber, m_picListManager.getPicListRange( m_pcParsePic ) );
  pcSlice->checkSTSA( m_picListManager.getPicListRange( pcParsePic ) );
#endif

#if TBC
  pcSlice->setPrevGDRSubpicPOC(m_prevGDRSubpicPOC[nalu.m_nuhLayerId][currSubPicIdx]);
  pcSlice->setPrevIRAPSubpicPOC(m_prevIRAPSubpicPOC[nalu.m_nuhLayerId][currSubPicIdx]);
  pcSlice->setPrevIRAPSubpicType(m_prevIRAPSubpicType[nalu.m_nuhLayerId][currSubPicIdx]);
  pcSlice->checkSubpicTypeConstraints(m_cListPic, pcSlice->getRPL0(), pcSlice->getRPL1(), m_prevIRAPSubpicDecOrderNo[nalu.m_nuhLayerId][currSubPicIdx]);
#endif

  if( m_pcParsePic->cs->vps && !m_pcParsePic->cs->vps->getIndependentLayerFlag( m_pcParsePic->cs->vps->getGeneralLayerIdx( nalu.m_nuhLayerId ) ) && m_pcParsePic->cs->pps->getNumSubPics() > 1 )
  {
    CU::checkConformanceILRP(pcSlice);
  }

  pcSlice->scaleRefPicList();


  if (!pcSlice->isIntra())
  {
    const int iCurrPOC  = pcSlice->getPOC();

    bool bLowDelay = true;
    for( int iRefIdx = 0; iRefIdx < pcSlice->getNumRefIdx( REF_PIC_LIST_0 ) && bLowDelay; iRefIdx++ )
    {
      if( pcSlice->getRefPOC( REF_PIC_LIST_0, iRefIdx ) > iCurrPOC )
      {
        bLowDelay = false;
      }
    }
    if( pcSlice->isInterB() )
    {
      for( int iRefIdx = 0; iRefIdx < pcSlice->getNumRefIdx( REF_PIC_LIST_1 ) && bLowDelay; iRefIdx++ )
      {
        if( pcSlice->getRefPOC( REF_PIC_LIST_1, iRefIdx ) > iCurrPOC )
        {
          bLowDelay = false;
        }
      }
    }

    pcSlice->setCheckLDC( bLowDelay );
  }

  if( pcSlice->getSPS()->getUseSMVD() && !pcSlice->getCheckLDC() && !pcSlice->getPicHeader()->getMvdL1ZeroFlag() )
  {
    int currPOC = pcSlice->getPOC();

    int forwardPOC = currPOC;
    int backwardPOC = currPOC;
    int ref = 0;
    int refIdx0 = -1;
    int refIdx1 = -1;

    // search nearest forward POC in List 0
    for ( ref = 0; ref < pcSlice->getNumRefIdx( REF_PIC_LIST_0 ); ref++ )
    {
      int poc = pcSlice->getRefPOC( REF_PIC_LIST_0, ref );
      const bool isRefLongTerm = pcSlice->getIsUsedAsLongTerm( REF_PIC_LIST_0, ref );
      if( poc < currPOC && ( poc > forwardPOC || refIdx0 == -1 ) && !isRefLongTerm )
      {
        forwardPOC = poc;
        refIdx0 = ref;
      }
    }

    // search nearest backward POC in List 1
    for ( ref = 0; ref < pcSlice->getNumRefIdx( REF_PIC_LIST_1 ); ref++ )
    {
      int poc = pcSlice->getRefPOC( REF_PIC_LIST_1, ref );
      const bool isRefLongTerm = pcSlice->getIsUsedAsLongTerm( REF_PIC_LIST_1, ref );
      if( poc > currPOC && ( poc < backwardPOC || refIdx1 == -1 ) && !isRefLongTerm )
      {
        backwardPOC = poc;
        refIdx1 = ref;
      }
    }

    if ( !(forwardPOC < currPOC && backwardPOC > currPOC) )
    {
      forwardPOC = currPOC;
      backwardPOC = currPOC;
      refIdx0 = -1;
      refIdx1 = -1;

      // search nearest backward POC in List 0
      for ( ref = 0; ref < pcSlice->getNumRefIdx( REF_PIC_LIST_0 ); ref++ )
      {
        int poc = pcSlice->getRefPOC( REF_PIC_LIST_0, ref );
        const bool isRefLongTerm = pcSlice->getIsUsedAsLongTerm( REF_PIC_LIST_0, ref );
        if( poc > currPOC && ( poc < backwardPOC || refIdx0 == -1 ) && !isRefLongTerm )
        {
          backwardPOC = poc;
          refIdx0 = ref;
        }
      }

      // search nearest forward POC in List 1
      for ( ref = 0; ref < pcSlice->getNumRefIdx( REF_PIC_LIST_1 ); ref++ )
      {
        int poc = pcSlice->getRefPOC( REF_PIC_LIST_1, ref );
        const bool isRefLongTerm = pcSlice->getIsUsedAsLongTerm( REF_PIC_LIST_1, ref );
        if( poc < currPOC && ( poc > forwardPOC || refIdx1 == -1 ) && !isRefLongTerm )
        {
          forwardPOC = poc;
          refIdx1 = ref;
        }
      }
    }

    if ( forwardPOC < currPOC && backwardPOC > currPOC )
    {
      pcSlice->setBiDirPred( true, refIdx0, refIdx1 );
    }
    else
    {
      pcSlice->setBiDirPred( false, -1, -1 );
    }
  }
  else
  {
    pcSlice->setBiDirPred( false, -1, -1 );
  }

  //---------------
  xCheckMixedNalUnit( pcSlice, nalu );

  if( m_bFirstSliceInPicture )
  {
#if RECO_WHILE_PARSE
    for( int ctu = 0; ctu < pcSlice->getPPS()->pcv->sizeInCtus; ctu++ )
    {
      m_pcParsePic->ctuParsedBarrier[ctu].lock();
    }

#endif
    m_parseFrameList.push_back( m_pcParsePic );
  }

  ITT_TASKEND( itt_domain_oth, itt_handle_start );

  static const auto parseTask = []( int threadId, void* param )
  {
    Slice* slice     = static_cast<Slice*>( param );
    auto&  decLib    = slice->parseTaskParams.decLibParser;
    auto&  bitstream = slice->parseTaskParams.bitstream;
    auto*  pic       = slice->getPic();

    try
    {
      pic->startProcessingTimer();

      //  Decode a picture
      ITT_TASKSTART( itt_domain_prs, itt_handle_parse );
      decLib->m_cSliceDecoder.parseSlice( slice, &bitstream, threadId );
      ITT_TASKEND( itt_domain_prs, itt_handle_parse );

      pic->stopProcessingTimer();

      bitstream.clearFifo();
      bitstream.clearEmulationPreventionByteLocation();
    }
    catch( ... )
    {
      pic->setParseError( std::current_exception() );
      std::rethrow_exception( std::current_exception() );
    }
    return true;
  };

  pcSlice->parseTaskParams.init( this, std::move( nalu.getBitstream() ) );
  pcSlice->parseDone.lock();

  auto expected = Picture::init;
  m_pcParsePic->progress.compare_exchange_strong( expected, Picture::parsing );   // if RECO_WHILE_PARSE reconstruction can already have started, so we make sure to not overwrite that state

  if( m_threadPool && m_threadPool->numThreads() > 0 )
  {
    if( m_uiSliceSegmentIdx > 0 )
    {
      m_threadPool->addBarrierTask( TP_TASK_NAME_ARG( "POC:" + std::to_string( m_pcParsePic->poc ) + " parseTask" )
                                    parseTask, pcSlice, &m_pcParsePic->m_divTasksCounter, &pcSlice->parseDone,
                                    CBarrierVec{ &m_pcParsePic->slices[m_uiSliceSegmentIdx - 1]->parseDone } );
    }
    else
    {
      m_threadPool->addBarrierTask( TP_TASK_NAME_ARG( "POC:" + std::to_string( m_pcParsePic->poc ) + " parseTask" )
                                    parseTask, pcSlice,  &m_pcParsePic->m_divTasksCounter, &pcSlice->parseDone );
    }
  }
  else
  {
    parseTask( 0, pcSlice );
    pcSlice->parseDone.unlock();
  }

  if( pcSlice->getFirstCtuRsAddrInSlice() == 0 && !m_bFirstSliceInPicture )
  {
    if( m_prevPOC >= m_pocRandomAccess )
    {
      DTRACE_UPDATE( g_trace_ctx, std::make_pair( "final", 0 ) );
    }
  }
  else
  {
    DTRACE_UPDATE( g_trace_ctx, std::make_pair( "final", 1 ) );
  }
  m_prevPOC = pcSlice->getPOC();

  m_bFirstSliceInSequence[nalu.m_nuhLayerId] = false;
  m_bFirstSliceInBitstream                   = false;


  const unsigned lastCtuInSlice = pcSlice->getCtuAddrInSlice( pcSlice->getNumCtuInSlice() - 1 );
  if( lastCtuInSlice == pcSlice->getPPS()->pcv->sizeInCtus - 1 )
  {
    return true;
  }

  return false;
}

void DecLibParser::xActivateParameterSets( const int layerId )
{
  ParameterSetManager::ActivePSs paramSets;

  if( m_bFirstSliceInPicture )
  {
              paramSets = m_parameterSetManager.xActivateParameterSets( m_bFirstSliceInPicture, m_apcSlicePilot, m_picHeader.get() );
    const SPS*  sps     = paramSets.sps;
    const PPS*  pps     = paramSets.pps;
    const APS** alfApss = paramSets.alfAPSs->data();
    const APS*  lmcsAPS = paramSets.lmcsAps;
    const APS*  scalingListAPS = paramSets.scalingListAps;

    xParsePrefixSEImessages();

    applyReferencePictureListBasedMarking( m_apcSlicePilot, layerId, *pps );

    //  Get a new picture buffer
    m_pcParsePic = m_picListManager.getNewPicBuffer( *sps, *pps, m_apcSlicePilot->getTLayer(), layerId, m_parameterSetManager.getVPS( sps->getVPSId() ) );
    CHECK( std::find( m_dpbReferencePics.cbegin(), m_dpbReferencePics.cend(), m_pcParsePic ) != m_dpbReferencePics.cend(), "reused picture shouldn't be in decoded picture buffer" );
    m_dpbReferencePics.push_back( m_pcParsePic );
    // assign these fields already, because they are needed by PicListManager::getPicListRange() and Slice::applyReferencePictureSet()
    m_pcParsePic->poc          = m_apcSlicePilot->getPOC();
    m_pcParsePic->eNalUnitType = m_apcSlicePilot->getNalUnitType();
    m_pcParsePic->finalInit( &m_cuChunkCache, &m_tuChunkCache, &m_cuMapCache, &m_chromaCuMapCache, sps, pps, m_picHeader, alfApss, lmcsAPS, scalingListAPS );

#if !DISABLE_CONFROMANCE_CHECK
    m_apcSlicePilot->checkLeadingPictureRestrictions( m_dpbReferencePics );
#endif

    m_pcParsePic->dpbReferenceMark = m_apcSlicePilot->getPicHeader()->getNonReferencePictureFlag() ? Picture::unreferenced : Picture::ShortTerm;
    m_pcParsePic->stillReferenced  = !!m_pcParsePic->dpbReferenceMark;
    m_pcParsePic->isReferencePic   = !!m_pcParsePic->dpbReferenceMark;

    // Set Field/Frame coding mode
    bool isField    = false;
    bool isTopField = false;
    if(!m_seiMessageList.empty())
    {
      // Check if any new Frame Field Info SEI has arrived
      seiMessages frameFieldSEIs = SEI_internal::getSeisByType( m_seiMessageList, VVDEC_FRAME_FIELD_INFO );
      if(!frameFieldSEIs.empty())
      {
        const vvdecSEIFrameFieldInfo* ff = (vvdecSEIFrameFieldInfo*) frameFieldSEIs.front()->payload;
        isField    = ff->fieldPicFlag;
        isTopField = isField && (!ff->bottomFieldFlag);
      }
    }
    m_pcParsePic->fieldPic = isField;
    m_pcParsePic->topField = isTopField;

    // transfer any SEI messages that have been received to the picture
    m_pcParsePic->seiMessageList = m_seiMessageList;
    m_seiMessageList.clear();

    m_apcSlicePilot->setPicHeader( m_picHeader.get() );
  }
  else
  {
    paramSets = m_parameterSetManager.xActivateParameterSets( m_bFirstSliceInPicture, m_apcSlicePilot, m_picHeader.get() );
    m_apcSlicePilot->setAlfApss( paramSets.alfAPSs->data() );

    for( int i = 0; i < ALF_CTB_MAX_NUM_APS; ++i )
    {
      m_pcParsePic->cs->alfApss[i] = paramSets.alfAPSs->data()[i] ? paramSets.alfAPSs->data()[i]->getSharedPtr() : nullptr;
    }
  }

  // make the slice-pilot a real slice, and set up the slice-pilot for the next slice
  Slice* pSlice = m_pcParsePic->allocateNewSlice( &m_apcSlicePilot );
  CHECK_FATAL( m_pcParsePic->slices.size() != ( m_uiSliceSegmentIdx + 1 ), "Invalid number of slices" );

  const VPS* vps = pSlice->getVPS_nothrow();
  const SPS* sps = pSlice->getSPS();
  const PPS* pps = pSlice->getPPS();

  if( !m_bFirstSliceInPicture )
  {
    const APS*  lmcsAPS = pSlice->getPicHeader()->getLmcsAPS().get();

    // check that the current active PPS has not changed...
    CHECK( sps->getChangedFlag(), "Error - a new SPS has been decoded while processing a picture" );
    CHECK( pps->getChangedFlag(), "Error - a new PPS has been decoded while processing a picture" );
    for( int i = 0; i < ALF_CTB_MAX_NUM_APS; i++ )
    {
      const APS* aps = m_parameterSetManager.getAPS_nothrow( i, ALF_APS );
      CHECK( aps && aps->getChangedFlag(), "Error - a new APS has been decoded while processing a picture" );
    }
    CHECK( lmcsAPS && lmcsAPS->getChangedFlag(), "Error - a new LMCS APS has been decoded while processing a picture" );

    xParsePrefixSEImessages();

    // Check if any new SEI has arrived
    if( !m_seiMessageList.empty() )
    {
      // Currently only decoding Unit SEI message occurring between VCL NALUs copied
      seiMessages& picSEI = m_pcParsePic->seiMessageList;
      seiMessages decodingUnitInfos = SEI_internal::extractSeisByType( m_seiMessageList, VVDEC_DECODING_UNIT_INFO );
      picSEI.insert( picSEI.end(), decodingUnitInfos.begin(), decodingUnitInfos.end() );
      SEI_internal::deleteSEIs   ( m_seiMessageList );
    }
  }

  CHECK( !sps->getGDREnabledFlag() && m_picHeader->getGdrPicFlag(), "When gdr_enabled_flag is equal to 0, the value of gdr_pic_flag shall be equal to 0 " );
  CHECK( !sps->getUseWP() && pps->getUseWP(), "When sps_weighted_pred_flag is equal to 0, the value of pps_weighted_pred_flag shall be equal to 0." );
  CHECK( !sps->getUseWPBiPred() && pps->getWPBiPred(),
         "When sps_weighted_bipred_flag is equal to 0, the value of pps_weighted_bipred_flag shall be equal to 0." );

  CHECK( !sps->getResChangeInClvsEnabledFlag() && pps->getPicWidthInLumaSamples() != sps->getMaxPicWidthInLumaSamples(),
         "When res_change_in_clvs_allowed_flag equal to 0, the value of pic_width_in_luma_samples shall be equal to pic_width_max_in_luma_samples." );
  CHECK( !sps->getResChangeInClvsEnabledFlag() && pps->getPicHeightInLumaSamples() != sps->getMaxPicHeightInLumaSamples(),
         "When res_change_in_clvs_allowed_flag equal to 0, the value of pic_height_in_luma_samples shall be equal to pic_height_max_in_luma_samples." );
  CHECK( sps->getResChangeInClvsEnabledFlag() && sps->getSubPicInfoPresentFlag() != 0,
         "When res_change_in_clvs_allowed_flag is equal to 1, the value of subpic_info_present_flag shall be equal to 0." );
  CHECK( sps->getResChangeInClvsEnabledFlag() && sps->getVirtualBoundariesEnabledFlag(),
         "when the value of res_change_in_clvs_allowed_flag is equal to 1, the value of sps_virtual_boundaries_present_flag shall be equal to 0" );
  if( vps && vps->m_numOutputLayersInOls[vps->m_iTargetLayer] > 1 )
  {
    CHECK( sps->getMaxPicWidthInLumaSamples() > vps->getOlsDpbPicSize( vps->m_iTargetLayer ).width,
           "pic_width_max_in_luma_samples shall be less than or equal to the value of ols_dpb_pic_width[ i ]" );
    CHECK( sps->getMaxPicHeightInLumaSamples() > vps->getOlsDpbPicSize( vps->m_iTargetLayer ).height,
           "pic_height_max_in_luma_samples shall be less than or equal to the value of ols_dpb_pic_height[ i ]" );
  }

  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getOneTilePerPicConstraintFlag() && pps->getNumTiles() != 1,
         "When one_tile_per_pic_constraint_flag is equal to 1, each picture shall contain only one tile" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getOneSlicePerPicConstraintFlag() && pps->getRectSliceFlag() && pps->getNumSlicesInPic() != 1,
         "When one_slice_per_pic_constraint_flag is equal to 1 and if pps_rect_slice_flag is equal to 1, the value of num_slices_in_pic_minus1 shall be equal to 0" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoRprConstraintFlag() && sps->getRprEnabledFlag(),
         "When gci_no_ref_pic_resampling_constraint_flag is equal to 1, the value of sps_ref_pic_resampling_enabled_flag shall be equal to 0" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoResChangeInClvsConstraintFlag() && sps->getResChangeInClvsEnabledFlag(),
         "When gci_no_res_change_in_clvs_constraint_flag is equal to 1, the value of sps_res_change_in_clvs_allowed_flag shall be equal to 0" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoIdrRplConstraintFlag() && sps->getIDRRefParamListPresent(),
         "When gci_no_idr_rpl_constraint_flag equal to 1 , the value of sps_idr_rpl_present_flag shall be equal to 0" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoMixedNaluTypesInPicConstraintFlag() && pps->getMixedNaluTypesInPicFlag(),
         "When gci_no_mixed_nalu_types_in_pic_constraint_flag equal to 1, the value of pps_mixed_nalu_types_in_pic_flag shall be equal to 0" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoRectSliceConstraintFlag() && pps->getRectSliceFlag(),
         "When gci_no_rectangular_slice_constraint_flag equal to 1, the value of pps_rect_slice_flag shall be equal to 0" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getOneSlicePerSubpicConstraintFlag() && !pps->getSingleSlicePerSubPicFlag(),
         "When gci_one_slice_per_subpic_constraint_flag equal to 1, the value of pps_single_slice_per_subpic_flag shall be equal to 1" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoSubpicInfoConstraintFlag() && sps->getSubPicInfoPresentFlag(),
         "When gci_no_subpic_info_constraint_flag is equal to 1, the value of sps_subpic_info_present_flag shall be equal to 0" );

  if( sps->getProfileTierLevel()->getConstraintInfo()->getNoMttConstraintFlag() )
  {
    CHECK( sps->getMaxMTTHierarchyDepth() || sps->getMaxMTTHierarchyDepthI() || sps->getMaxMTTHierarchyDepthIChroma(),
           "When gci_no_mtt_constraint_flag is equal to 1, the values of sps_max_mtt_hierarchy_depth_intra_slice_luma, sps_max_mtt_hierarchy_depth_inter_slice"
           " and sps_max_mtt_hierarchy_depth_intra_slice_chroma shall be equal to 0" );
  }
  if( sps->getProfileTierLevel()->getConstraintInfo()->getNoWeightedPredictionConstraintFlag() )
  {
    CHECK( sps->getUseWP() || sps->getUseWPBiPred(),
           "When gci_no_weighted_prediction_constraint_flag is equal to 1, the values of sps_weighted_pred_flag and sps_weighted_bipred_flag shall be equal to 0" );
  }

  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoChromaQpOffsetConstraintFlag() && pps->getCuChromaQpOffsetEnabledFlag(),
         "When gci_no_ChromaQpOffset_constraint_flag is equal to 1, the values of pps_cu_chroma_qp_offset_list_enabled_flag shall be equal to 0" );

  CHECK( sps->getCTUSize() > ( 1 << sps->getProfileTierLevel()->getConstraintInfo()->getMaxLog2CtuSizeConstraintIdc() ),
         "The CTU size specified by sps_log2_ctu_size_minus5 shall not exceed the constraint specified by gci_three_minus_max_log2_ctu_size_constraint_idc" );
  CHECK( sps->getProfileTierLevel()->getConstraintInfo()->getNoLumaTransformSize64ConstraintFlag() && sps->getLog2MaxTbSize() != 5,
         "When gci_no_luma_transform_size_64_constraint_flag is equal to 1, the value of sps_max_luma_transform_size_64_flag shall be equal to 0" );

#if 0
  if( vps && vps->getMaxLayers() > 1 )
  {
    // TODO: fix MT static maps
    static std::unordered_map<int, int> m_layerChromaFormat;
    static std::unordered_map<int, int> m_layerBitDepth;

    int curLayerIdx          = vps->getGeneralLayerIdx(layerId);
    int curLayerChromaFormat = sps->getChromaFormatIdc();
    int curLayerBitDepth     = sps->getBitDepth();

    if( pSlice->isClvssPu() && m_bFirstSliceInPicture )
    {
      m_layerChromaFormat[curLayerIdx] = curLayerChromaFormat;
      m_layerBitDepth    [curLayerIdx] = curLayerBitDepth;
    }
    else
    {
      CHECK( m_layerChromaFormat[curLayerIdx] != curLayerChromaFormat, "Different chroma format in the same layer." );
      CHECK( m_layerBitDepth    [curLayerIdx] != curLayerBitDepth, "Different bit-depth in the same layer." );
    }

    for( int i = 0; i < curLayerIdx; i++ )
    {
      if( vps->getDirectRefLayerFlag( curLayerIdx, i ) )
      {
        int refLayerChromaFormat = m_layerChromaFormat[i];
        CHECK( curLayerChromaFormat != refLayerChromaFormat, "The chroma formats of the current layer and the reference layer are different" );
        int refLayerBitDepth = m_layerBitDepth[i];
        CHECK( curLayerBitDepth != refLayerBitDepth, "The bit-depth of the current layer and the reference layer are different" );
      }
    }
  }
#endif

  const int minCuSize = 1 << sps->getLog2MinCodingBlockSize();
  CHECK( ( pps->getPicWidthInLumaSamples()  % ( std::max( 8, minCuSize) ) ) != 0, "Coded frame width must be a multiple of Max(8, the minimum unit size)" );
  CHECK( ( pps->getPicHeightInLumaSamples() % ( std::max( 8, minCuSize) ) ) != 0, "Coded frame height must be a multiple of Max(8, the minimum unit size)" );

  if( sps->getCTUSize() + 2 * ( 1 << sps->getLog2MinCodingBlockSize() ) > pps->getPicWidthInLumaSamples() )
  {
    CHECK( pps->getUseWrapAround(),
           "Wraparound shall be disabled when the value of ( CtbSizeY / MinCbSizeY + 1) is greater than or equal to"
           " ( pic_width_in_luma_samples / MinCbSizeY - 1 )" );
  }

  if( pSlice->getPicHeader()->getGdrOrIrapPicFlag() && !pSlice->getPicHeader()->getGdrPicFlag()
      && ( !vps || vps->getIndependentLayerFlag( vps->getGeneralLayerIdx( layerId ) ) ) )
  {
    CHECK( pSlice->getPicHeader()->getPicInterSliceAllowedFlag(),
           "When gdr_or_irap_pic_flag is equal to 1 and gdr_pic_flag is equal to 0 and vps_independent_layer_flag[ GeneralLayerIdx[ nuh_layer_id ] ] "
           "is equal to 1, ph_inter_slice_allowed_flag shall be equal to 0" );
  }

  if( sps->getVPSId() && vps && vps->m_numLayersInOls[vps->m_iTargetLayer] == 1 )
  {
    CHECK( !sps->getPtlDpbHrdParamsPresentFlag(),
           "When sps_video_parameter_set_id is greater than 0 and there is an OLS that contains only one layer"
           " with nuh_layer_id equal to the nuh_layer_id of the SPS, the value of sps_ptl_dpb_hrd_params_present_flag shall be equal to 1" );
  }

  ProfileLevelTierFeatures ptlFeature;
  ptlFeature.extractPTLInformation(*sps);

  const LevelTierFeatures* ltFeature = ptlFeature.getLevelTierFeatures();
  const ProfileFeatures*   pFeature  = ptlFeature.getProfileFeatures();

  CHECK( ltFeature && pps->getNumTileColumns() > ltFeature->maxTileCols, "Num tile columns signaled in PPS exceed level limits" );
  CHECK( ltFeature && pps->getNumTiles() > ltFeature->maxTilesPerAu, "Num tiles signaled in PPS exceed level limits" );
  CHECK( pFeature && sps->getBitDepth() > pFeature->maxBitDepth, "Bit depth exceed profile limit" );
  CHECK( pFeature && sps->getChromaFormatIdc() > pFeature->maxChromaFormat, "Chroma format exceed profile limit" );
}

void DecLibParser::prepareUnavailablePicture( bool isLost, const PPS* pps, int iUnavailablePoc, const int layerId, const bool longTermFlag, const int temporalId )
{
  if( isLost )
  {
    CHECK( !( m_errHandlingFlags & ERR_HANDLING_TRY_CONTINUE ), "missing reference picture poc: " << iUnavailablePoc );

    if( !m_picListManager.getBackPic() )
    {
      THROW_RECOVERABLE( "no pictures yet." );
      return;
    }
    msg( WARNING, "inserting lost poc : %d\n", iUnavailablePoc );
  }
  else
  {
    msg( INFO, "inserting unavailable poc : %d\n", iUnavailablePoc );
  }
  // use the parameter sets of the referencing picture, so the generated reference has a compatible buffer layout
  const SPS* sps = static_cast<const ParameterSetManager&>( m_parameterSetManager ).getSPS( pps->getSPSId() );
  CHECK( !sps, "no SPS for unavailable reference picture" );
  Picture* cFillPic = m_picListManager.getNewPicBuffer( *sps, *pps, 0, layerId, m_parameterSetManager.getVPS( sps->getVPSId() ) );
  CHECK( std::find( m_dpbReferencePics.cbegin(), m_dpbReferencePics.cend(), cFillPic ) != m_dpbReferencePics.cend(), "reused picture shouldn't be in decoded picture buffer" );
  m_dpbReferencePics.push_back( cFillPic );
  const APS* nullAlfApss[ALF_CTB_MAX_NUM_APS] = { nullptr, };
  cFillPic->finalInit( &m_cuChunkCache, &m_tuChunkCache, &m_cuMapCache, &m_chromaCuMapCache, sps, pps, m_picHeader, nullAlfApss, nullptr, nullptr, false );

  CHECK_FATAL( !cFillPic->slices.empty(), "fill pic should not contain slices, already." );
  cFillPic->allocateNewSlice();
  cFillPic->slices[0]->initSlice();
  cFillPic->slices[0]->setPOC( iUnavailablePoc );
  cFillPic->slices[0]->setTLayer( temporalId );
  cFillPic->slices[0]->setNalUnitLayerId( layerId );

  // picture header is not derived for generated reference picture
  cFillPic->slices[0]->setPicHeader( nullptr );
  cFillPic->slices[0]->setPPS( pps->getSharedPtr() );

  cFillPic->dpbReferenceMark        = longTermFlag ? Picture::LongTerm : Picture::ShortTerm;
  cFillPic->stillReferenced         = true;
  cFillPic->isReferencePic          = true;
  cFillPic->poc                     = iUnavailablePoc;
  cFillPic->neededForOutput         = false;
  cFillPic->tempLayer               = temporalId;
  cFillPic->nonReferencePictureFlag = false;
  cFillPic->wasLost                 = isLost;

  if( cFillPic->slices[0]->getTLayer() == 0 &&
      cFillPic->slices[0]->getNalUnitType() != NAL_UNIT_CODED_SLICE_RASL &&
      cFillPic->slices[0]->getNalUnitType() != NAL_UNIT_CODED_SLICE_RADL )
  {
    m_prevTid0POC = cFillPic->slices[0]->getPOC();
  }

  cFillPic->subPictures.clear();
  cFillPic->sliceSubpicIdx.clear();

  for( int subPicIdx = 0; subPicIdx < pps->getNumSubPics(); subPicIdx++ )
  {
    cFillPic->subPictures.push_back( pps->getSubPic( subPicIdx ) );
  }

  cFillPic->parseDone.unlock();

#if 0
// NOT YET IMPLEMENTED
  if( isLost && ( m_errHandlingFlags & ERR_HANDLING_COPY_CLOSEST ) )
  {
    // this will be filled in later, when closer pictures might have been reconstructed.

    cFillPic->progress = Picture::parsed;
    m_parseFrameList.push_back( cFillPic );
    return;
  }
#endif

  cFillPic->fillGrey( sps );

  if( m_pocRandomAccess == MAX_INT )
  {
    m_pocRandomAccess = iUnavailablePoc;
  }
}

#if 0
// NOT YET IMPLEMENTED
void DecLibParser::fillMissingPicBuf( Picture* pcPic, bool copyClosest )
{
  if( copyClosest )
  {
    CHECK_FATAL( pcPic->progress != Picture::parsed, "filled in picture should have been marked as parsed" );
    CHECK_FATAL( pcPic->parseDone.isBlocked(), "parsed barrier should be unlocked" );

    auto closestPic = m_picListManager.findClosestPic( pcPic->poc );
    if( closestPic )
    {
      CHECK_FATAL( closestPic->progress < Picture::reconstructed, "closest Picture is not yet reconstructed" )
      // the next not-lost picture in the parseFrameList should be the one, that referenced this picture
      auto referencedBy = std::find_if( m_parseFrameList.begin(), m_parseFrameList.end(), []( Picture* p ) { return !p->wasLost && !p->error; } );
      msg( INFO, "copying picture %d to %d (%d)\n", closestPic->getPOC(), pcPic->poc, ( referencedBy != m_parseFrameList.end() ) ? ( *referencedBy )->poc : -1 );

      pcPic->getRecoBuf().copyFrom( closestPic->getRecoBuf() );

      pcPic->slices[0]->copySliceInfo( closestPic->slices[0] );
      pcPic->slices[0]->setPOC( pcPic->poc );
    }

    // currently we don't output filled-in reference pictures
    // pcPic->neededForOutput = true;
  }
  else
  {
    pcPic->fillGrey( pcPic->cs->sps.get() );
  }

  pcPic->progress = Picture::reconstructed;
  pcPic->reconDone.unlock();
}
#endif


// Function for applying picture marking based on the Reference Picture List
void DecLibParser::applyReferencePictureListBasedMarking( Slice* currSlice, const int layerId, const PPS& pps )
{
  //  checkLeadingPictureRestrictions(rcListPic, pps);

  // mark long-term reference pictures in List0
  for( const auto l: { REF_PIC_LIST_0, REF_PIC_LIST_1 } )
  {
    const ReferencePictureList* rpl = currSlice->getRPL( l );

    for( int i = 0; i < rpl->getNumRefEntries(); i++ )
    {
      if( !rpl->isRefPicLongterm( i ) || rpl->isInterLayerRefPic( i ) )
      {
        continue;
      }

      Picture* availableST = nullptr;
      for( Picture* pic: m_dpbReferencePics )
      {
        if( !pic->dpbReferenceMark )
        {
          continue;
        }

        const int bitsForPoc = pic->cs->sps->getBitsForPOC();
        const int curPoc     = pic->getPOC();
        const int ltRefPoc   = rpl->calcLTRefPOC( currSlice->getPOC(), bitsForPoc, i );
        if( pic->dpbReferenceMark == Picture::LongTerm && isLTPocEqual( curPoc, ltRefPoc, bitsForPoc, rpl->getDeltaPocMSBPresentFlag( i ) ) )
        {
          break;
        }

        // if there was no such long-term check the short terms
        if( pic->dpbReferenceMark == Picture::ShortTerm && isLTPocEqual( curPoc, ltRefPoc, bitsForPoc, rpl->getDeltaPocMSBPresentFlag( i ) ) )
        {
          availableST = pic;
          // but don't break here, because we might still find a LT
        }
      }

      // the found picture was not yet marked as long term, so we mark it here
      if ( availableST )
      {
        availableST->dpbReferenceMark = Picture::LongTerm;
      }
    }
  }

  if( currSlice->isIDR() && !pps.getMixedNaluTypesInPicFlag() )
  {
    for( Picture* pic: m_dpbReferencePics )
    {
      pic->dpbReferenceMark = Picture::unreferenced;
    }

    // ignore neededForOutput flag here, because we only care about reference pictures in the DPB
    m_dpbReferencePics.remove_if( []( Picture* pic ) { return !pic->dpbReferenceMark; } );
    return;
  }

  // loop through all pictures in the reference picture buffer
  for( Picture* pic: m_dpbReferencePics )
  {
    if( !pic->dpbReferenceMark )
    {
      continue;
    }

    bool isReference = false;

    for( const auto l: { REF_PIC_LIST_0, REF_PIC_LIST_1 } )
    {
      if( currSlice->getRPL( l )->findInRefPicList( pic, currSlice->getPOC(), layerId ) )
      {
        isReference = true;
        break;
      }
    }

    // mark the picture as "unused for reference" if it is not in
    // the Reference Picture List
    if( !isReference && pic->poc != currSlice->getPOC() && pic->layerId == layerId )
    {
      pic->dpbReferenceMark = Picture::unreferenced;
    }

    // // sanity checks
    // if( pic->referenced )
    // {
    //   // check that pictures of higher temporal layers are not used
    //   CHECK_FATAL( pic->usedByCurr && pic->temporalId > this->getTLayer(), "Invalid state" );
    // }
  }

  // ignore neededForOutput flag here, because we only care about reference pictures in the DPB
  m_dpbReferencePics.remove_if( []( Picture* pic ) { return !pic->dpbReferenceMark; } );
}

void DecLibParser::xParsePrefixSEImessages()
{
  while( !m_prefixSEINALUs.empty() )
  {
    InputNALUnit& nalu = m_prefixSEINALUs.front();
    const SPS *sps = m_parameterSetManager.getActiveSPS();
    const VPS *vps = m_parameterSetManager.getVPS(sps->getVPSId());
    m_seiReader.parseSEImessage( &(nalu.getBitstream()), m_seiMessageList, nalu.m_nalUnitType, nalu.m_nuhLayerId, nalu.m_temporalId, vps, sps, m_HRD, m_pDecodedSEIOutputStream );
    m_prefixSEINALUs.pop_front();
  }
}

void DecLibParser::xParsePrefixSEIsForUnknownVCLNal()
{
  while (!m_prefixSEINALUs.empty())
  {
    // do nothing?
    msg( VERBOSE, "Discarding Prefix SEI associated with unknown VCL NAL unit.\n");
    m_prefixSEINALUs.pop_front();
  }
  // TODO: discard following suffix SEIs as well?
}

void DecLibParser::xDecodePicHeader( InputNALUnit& nalu )
{
  m_HLSReader.setBitstream( &nalu.getBitstream() );
  m_picHeader = std::make_shared<PicHeader>();
  m_HLSReader.parsePictureHeader( m_picHeader.get(), &m_parameterSetManager, true );
}

void DecLibParser::xDecodeVPS( InputNALUnit& nalu )
{
  // We don't parse the VPS, because the needed bounds checks in parseVPS() are not yet implemented, and we don't process it anyways
#if 0
  std::unique_ptr<VPS> vps( new VPS() );
  m_HLSReader.setBitstream( &nalu.getBitstream() );
  m_HLSReader.parseVPS( vps.get() );
  m_parameterSetManager.storeVPS( vps.release(), nalu.getBitstream().getFifo() );
#endif
}

void DecLibParser::xDecodeDCI( InputNALUnit& nalu )
{
  m_HLSReader.setBitstream(&nalu.getBitstream());

  CHECK(nalu.m_temporalId, "The value of TemporalId of DCI NAL units shall be equal to 0");
  if( !m_dci )
  {
    m_dci = new DCI;
    m_HLSReader.parseDCI( m_dci );
  }
  else
  {
    DCI dupDCI;
    m_HLSReader.parseDCI( &dupDCI );
    CHECK( !m_dci->IsIndenticalDCI( dupDCI ), "Two signaled DCIs are different");
  }
}

void DecLibParser::xDecodeSPS( InputNALUnit& nalu )
{
  std::unique_ptr<SPS> sps( new SPS() );
  m_HLSReader.setBitstream( &nalu.getBitstream() );
  m_HLSReader.parseSPS( sps.get(), &m_parameterSetManager );
  sps->setLayerId( nalu.m_nuhLayerId );
  DTRACE( g_trace_ctx, D_QP_PER_CTU, "CTU Size: %dx%d", sps->getMaxCUWidth(), sps->getMaxCUHeight() );  // don't move after storeSPS, because SPS could have been deleted
  m_parameterSetManager.storeSPS( sps.release(), nalu.getBitstream().getFifo() );
}

void DecLibParser::xDecodePPS( InputNALUnit& nalu )
{
  std::unique_ptr<PPS> pps( new PPS() );
  m_HLSReader.setBitstream( &nalu.getBitstream() );
  m_HLSReader.parsePPS( pps.get(), &m_parameterSetManager );
  pps->setLayerId( nalu.m_nuhLayerId );
  m_parameterSetManager.storePPS( pps.release(), nalu.getBitstream().getFifo() );
}

void DecLibParser::xDecodeAPS( InputNALUnit& nalu )
{
  std::unique_ptr<APS> aps( new APS() );
  m_HLSReader.setBitstream( &nalu.getBitstream() );
  if( !m_HLSReader.parseAPS( aps.get() ) )
  {   // ignore unsupported APS types
    return;
  }
  aps->setTemporalId( nalu.m_temporalId );
  aps->setLayerId( nalu.m_nuhLayerId );
  aps->setHasPrefixNalUnitType( nalu.m_nalUnitType == NAL_UNIT_PREFIX_APS );
  m_parameterSetManager.storeAPS( aps.release(), nalu.getBitstream().getFifo() );
}

void DecLibParser::xUpdatePreviousTid0POC(Slice * pSlice)
{
  if( pSlice->getTLayer() == 0 && pSlice->getNalUnitType() != NAL_UNIT_CODED_SLICE_RASL && pSlice->getNalUnitType() != NAL_UNIT_CODED_SLICE_RADL
      && !pSlice->getPicHeader()->getNonReferencePictureFlag() )
  {
    m_prevTid0POC = pSlice->getPOC();
  }
}


void DecLibParser::checkNoOutputPriorPics()
{
  if( !m_isNoOutputPriorPics )
  {
    return;
  }

  for( auto& pcPicTmp: m_dpbReferencePics )
  {
    if( pcPicTmp->progress >= Picture::reconstructed && pcPicTmp->getPOC() < m_lastPOCNoOutputPriorPics )
    {
      pcPicTmp->neededForOutput = false;
    }
  }
}

/** Function for checking if picture should be skipped because of random access. This function checks the skipping of pictures in the case of -s option random access.
 *  All pictures prior to the random access point indicated by the counter iSkipFrame are skipped.
 *  It also checks the type of Nal unit type at the random access point.
 *  If the random access point is CRA/CRANT/BLA/BLANT, TFD pictures with POC less than the POC of the random access point are skipped.
 *  If the random access point is IDR all pictures after the random access point are decoded.
 *  If the random access point is none of the above, a warning is issues, and decoding of pictures with POC
 *  equal to or greater than the random access point POC is attempted. For non IDR/CRA/BLA random
 *  access point there is no guarantee that the decoder will not crash.
 */
bool DecLibParser::isRandomAccessSkipPicture()
{
  if( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_IDR_W_RADL || m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_IDR_N_LP )
  {
    m_pocRandomAccess = -MAX_INT;   // no need to skip the reordered pictures in IDR, they are decodable.
  }
  else if( m_pocRandomAccess == MAX_INT )   // start of random access point, m_pocRandomAccess has not been set yet.
  {
#if GDR_ADJ
    if( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_CRA || m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR )
#else
    if( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_CRA )
#endif
    {
      // set the POC random access since we need to skip the reordered pictures in the case of CRA/CRANT/BLA/BLANT.
      m_pocRandomAccess = m_apcSlicePilot->getPOC();
    }
    else
    {
      if( !m_warningMessageSkipPicture )
      {
        msg( WARNING, "Warning: this is not a valid random access point and the data is discarded until the first CRA picture\n" );
        m_warningMessageSkipPicture = true;
      }
      return true;
    }
  }
  // skip the reordered pictures, if necessary
  else if( m_apcSlicePilot->getPOC() < m_pocRandomAccess && ( m_apcSlicePilot->getNalUnitType() == NAL_UNIT_CODED_SLICE_RASL ) )
  {
    return true;
  }
  // if we reach here, then the picture is not skipped.
  return false;
}

void DecLibParser::xCheckMixedNalUnit( Slice* pcSlice, const InputNALUnit& nalu )
{
  if( pcSlice->getPPS()->getMixedNaluTypesInPicFlag() )
  {
    CHECK(pcSlice->getPPS()->getNumSlicesInPic() < 2, "mixed nal unit type picture, but with less than 2 slices");

    CHECK( pcSlice->getNalUnitType() == NAL_UNIT_CODED_SLICE_GDR, "picture with mixed NAL unit type cannot have GDR slice");

    //Check that if current slice is IRAP type, the other type of NAL can only be TRAIL_NUT
    if( pcSlice->getNalUnitType() == NAL_UNIT_CODED_SLICE_IDR_W_RADL
        || pcSlice->getNalUnitType() == NAL_UNIT_CODED_SLICE_IDR_N_LP
        || pcSlice->getNalUnitType() == NAL_UNIT_CODED_SLICE_CRA )
    {
      for( int i = 0; i < m_uiSliceSegmentIdx; i++ )
      {
        Slice* preSlice = m_pcParsePic->slices[i];
        CHECK( pcSlice->getNalUnitType() != preSlice->getNalUnitType()
                 && preSlice->getNalUnitType() != NAL_UNIT_CODED_SLICE_TRAIL,
               "In a mixed NAL unt type picture, an IRAP slice can be mixed with Trail slice(s) only" );
      }
    }

    // if this is the last slice of the picture, check whether that there are at least two different NAL unit types in the picture
    if( pcSlice->getPPS()->getNumSlicesInPic() == (m_uiSliceSegmentIdx + 1) )
    {
      bool hasDiffTypes = false;
      for( int i = 1; !hasDiffTypes && i <= m_uiSliceSegmentIdx; i++ )
      {
        Slice* slice1 = m_pcParsePic->slices[i-1];
        Slice* slice2 = m_pcParsePic->slices[i];
        if( slice1->getNalUnitType() != slice2->getNalUnitType())
        {
          hasDiffTypes = true;
        }
      }
      CHECK( !hasDiffTypes, "VCL NAL units of the picture shall have two or more different nal_unit_type values");
    }
  }
  else   // all slices shall have the same nal unit type
  {
    bool sameNalUnitType = true;
    for( int i = 0; i < m_uiSliceSegmentIdx; i++ )
    {
      Slice* PreSlice = m_pcParsePic->slices[i];
      if( PreSlice->getNalUnitType() != pcSlice->getNalUnitType() )
      {
        sameNalUnitType = false;
      }
    }
    CHECK( !sameNalUnitType, "mixed_nalu_types_in_pic_flag is zero, but have different nal unit types" );
  }
}

}   // namespace vvdec

Coverage Report

Created: 2026-10-17 06:56