HEVC代码追踪（十五）:解码之decompressSlice

Void TDecGop::decompressSlice(TComInputBitstream* pcBitstream, TComPic*& rpcPic)
{
  TComSlice*  pcSlice = rpcPic->getSlice(rpcPic->getCurrSliceIdx());
  // Table of extracted substreams.
  // These must be deallocated AND their internal fifos, too.
  TComInputBitstream **ppcSubstreams = NULL;

  //-- For time output for each slice
  long iBeforeTime = clock();
  m_pcSbacDecoder->init( (TDecBinIf*)m_pcBinCABAC );
  m_pcEntropyDecoder->setEntropyDecoder (m_pcSbacDecoder);

  UInt uiNumSubstreams = pcSlice->getPPS()->getEntropyCodingSyncEnabledFlag() ? pcSlice->getNumEntryPointOffsets()+1 : pcSlice->getPPS()->getNumSubstreams();

  // init each couple {EntropyDecoder, Substream}
  UInt *puiSubstreamSizes = pcSlice->getSubstreamSizes();
  ppcSubstreams    = new TComInputBitstream*[uiNumSubstreams];
  m_pcSbacDecoders = new TDecSbac[uiNumSubstreams];
  m_pcBinCABACs    = new TDecBinCABAC[uiNumSubstreams];
  for ( UInt ui = 0 ; ui < uiNumSubstreams ; ui++ )
  {
    m_pcSbacDecoders[ui].init(&m_pcBinCABACs[ui]);
    ppcSubstreams[ui] = pcBitstream->extractSubstream(ui+1 < uiNumSubstreams ? puiSubstreamSizes[ui] : pcBitstream->getNumBitsLeft());
  }

  for ( UInt ui = 0 ; ui+1 < uiNumSubstreams; ui++ )
  {
    m_pcEntropyDecoder->setEntropyDecoder ( &m_pcSbacDecoders[uiNumSubstreams - 1 - ui] );
    m_pcEntropyDecoder->setBitstream      (  ppcSubstreams   [uiNumSubstreams - 1 - ui] );
    m_pcEntropyDecoder->resetEntropy      (pcSlice);
  }

  m_pcEntropyDecoder->setEntropyDecoder ( m_pcSbacDecoder  );
  m_pcEntropyDecoder->setBitstream      ( ppcSubstreams[0] );
  m_pcEntropyDecoder->resetEntropy      (pcSlice);
  m_pcSbacDecoders[0].load(m_pcSbacDecoder);
  m_pcSliceDecoder->decompressSlice( ppcSubstreams, rpcPic, m_pcSbacDecoder, m_pcSbacDecoders);
  m_pcEntropyDecoder->setBitstream(  ppcSubstreams[uiNumSubstreams-1] );
  // deallocate all created substreams, including internal buffers.
  for (UInt ui = 0; ui < uiNumSubstreams; ui++)
  {
    ppcSubstreams[ui]->deleteFifo();
    delete ppcSubstreams[ui];
  }
  delete[] ppcSubstreams;
  delete[] m_pcSbacDecoders; m_pcSbacDecoders = NULL;
  delete[] m_pcBinCABACs; m_pcBinCABACs = NULL;

  m_dDecTime += (Double)(clock()-iBeforeTime) / CLOCKS_PER_SEC;
}