Method parseAndAddNALUnit

YUViewLib/src/parser/Mpeg2/ParserAnnexBMpeg2.cpp:59–243

using namespace mpeg2;

ParserAnnexB::ParseResult
ParserAnnexBMpeg2::parseAndAddNALUnit(int                                           nalID,
                                      const ByteVector &                            data,
                                      std::optional<BitratePlotModel::BitrateEntry> bitrateEntry,
                                      std::optional<pairUint64> nalStartEndPosFile,
                                      std::shared_ptr<TreeItem> parent)
{
  ParserAnnexB::ParseResult parseResult;

  // Skip the NAL unit header
  unsigned readOffset = 0;
  if (data.at(0) == (char)0 && data.at(1) == (char)0 && data.at(2) == (char)1)
    readOffset = 3;
  else if (data.at(0) == (char)0 && data.at(1) == (char)0 && data.at(2) == (char)0 &&
           data.at(3) == (char)1)
    readOffset = 4;
  else
  {
    ByteVector startCode({char(0), char(0), char(1)});
    auto itStartCode = std::search(data.begin(), data.end(), startCode.begin(), startCode.end());
    if (itStartCode == data.end())
      // No start code found in the whole data. Try to start reading with a header.
      readOffset = 0;
    else
      readOffset = unsigned(itStartCode - data.begin()) + 3;
  }

  // Use the given tree item. If it is not set, use the nalUnitMode (if active).
  // We don't set data (a name) for this item yet.
  // We want to parse the item and then set a good description.
  std::string               specificDescription;
  std::shared_ptr<TreeItem> nalRoot;
  if (parent)
    nalRoot = parent->createChildItem();
  else if (packetModel->rootItem)
    nalRoot = packetModel->rootItem->createChildItem();

  reader::SubByteReaderLogging reader(data, nalRoot, "", readOffset);

  if (nalRoot)
    ParserAnnexB::logNALSize(data, nalRoot, nalStartEndPosFile);

  // Create a nal_unit and read the header
  NalUnitMpeg2 nal_mpeg2(nalID, nalStartEndPosFile);
  nal_mpeg2.header.parse(reader);

  bool        currentSliceIntra = false;
  std::string currentSliceType;
  if (nal_mpeg2.header.nal_unit_type == NalType::SEQUENCE_HEADER)
  {
    DEBUG_MPEG2("ParserAnnexBMpeg2::parseAndAddNALUnit Sequence header");

    auto newSequenceHeader = std::make_shared<sequence_header>();
    newSequenceHeader->parse(reader);

    if (!this->firstSequenceHeader)
      this->firstSequenceHeader = newSequenceHeader;