Method mediaHeaderDecoder

src/quicktimevideo.cpp:1402–1460

}  // QuickTimeVideo::fileTypeDecoder

void QuickTimeVideo::mediaHeaderDecoder(size_t size) {
  DataBuf buf(5);
  std::memset(buf.data(), 0x0, buf.size());
  buf.data()[4] = '\0';
  int64_t time_scale = 1;

  for (int i = 0; size / 4 != 0; size -= 4, i++) {
    io_->readOrThrow(buf.data(), 4);

    switch (i) {
      case MediaHeaderVersion:
        if (currentStream_ == Video)
          xmpData_["Xmp.video.MediaHeaderVersion"] = static_cast<int>(buf.read_uint8(0));
        else if (currentStream_ == Audio)
          xmpData_["Xmp.audio.MediaHeaderVersion"] = static_cast<int>(buf.read_uint8(0));
        break;
      case MediaCreateDate:
        // A 32-bit integer that specifies (in seconds since midnight, January 1, 1904) when the movie atom was created.
        if (currentStream_ == Video)
          xmpData_["Xmp.video.MediaCreateDate"] = buf.read_uint32(0, bigEndian);
        else if (currentStream_ == Audio)
          xmpData_["Xmp.audio.MediaCreateDate"] = buf.read_uint32(0, bigEndian);
        break;
      case MediaModifyDate:
        // A 32-bit integer that specifies (in seconds since midnight, January 1, 1904) when the movie atom was created.
        if (currentStream_ == Video)
          xmpData_["Xmp.video.MediaModifyDate"] = buf.read_uint32(0, bigEndian);
        else if (currentStream_ == Audio)
          xmpData_["Xmp.audio.MediaModifyDate"] = buf.read_uint32(0, bigEndian);
        break;
      case MediaTimeScale:
        if (currentStream_ == Video)
          xmpData_["Xmp.video.MediaTimeScale"] = buf.read_uint32(0, bigEndian);
        else if (currentStream_ == Audio)
          xmpData_["Xmp.audio.MediaTimeScale"] = buf.read_uint32(0, bigEndian);
        time_scale = buf.read_uint32(0, bigEndian);
        if (time_scale <= 0)
          time_scale = 1;
        mdhdTimeScale_ = time_scale;
        break;
      case MediaDuration:
        if (currentStream_ == Video)
          xmpData_["Xmp.video.MediaDuration"] = time_scale ? buf.read_uint32(0, bigEndian) / time_scale : 0;
        else if (currentStream_ == Audio)
          xmpData_["Xmp.audio.MediaDuration"] = time_scale ? buf.read_uint32(0, bigEndian) / time_scale : 0;
        break;
      case MediaLanguageCode:
        if (currentStream_ == Video)
          xmpData_["Xmp.video.MediaLangCode"] = buf.read_uint16(0, bigEndian);
        else if (currentStream_ == Audio)
          xmpData_["Xmp.audio.MediaLangCode"] = buf.read_uint16(0, bigEndian);
        break;

      default:
        break;
    }
  }
  io_->readOrThrow(buf.data(), size % 4);