Method parse

include/libremidi/reader.cpp:536–703

}

LIBREMIDI_INLINE
auto reader::parse(const uint8_t* dataPtr, std::size_t size) noexcept -> parse_result
try
{
  using namespace util;

  tracks.clear();

  if (size == 0)
  {
#if defined(__LIBREMIDI_DEBUG__)
    std::cerr << "empty buffer passed to parse." << std::endl;
#endif
    return parse_result::invalid;
  }

  const uint8_t* const data_end = dataPtr + size;

  uint32_t header_id = read_checked::read_uint32_be(dataPtr, data_end);
  uint32_t header_length = read_checked::read_uint32_be(dataPtr, data_end);

  if (static_cast<int>(header_id) != str_to_headerid("MThd") || header_length != 6)
  {
#if defined(__LIBREMIDI_DEBUG__)
    std::cerr << "couldn't parse header" << std::endl;
#endif
    return parse_result::invalid;
  }

  format = read_checked::read_uint16_be(
      dataPtr, data_end); //@tofix format type -> save for later eventually
  if (format > 2)
  {
#if defined(__LIBREMIDI_DEBUG__)
    std::cerr << "unknown format" << std::endl;
#endif
    return parse_result::invalid;
  }
  int track_count = read_checked::read_uint16_be(dataPtr, data_end);
  uint16_t time_division = read_checked::read_uint16_be(dataPtr, data_end);

  // CBB: deal with the SMPTE style time coding
  // timeDivision is described here http://www.sonicspot.com/guide/midifiles.html
  if (time_division & 0x8000)
  {
#if defined(__LIBREMIDI_DEBUG__)
    std::cerr << "found SMPTE time frames (unsupported)" << std::endl;
    int fps = (timeDivision >> 16) & 0x7f;
    if (fps != -30 && fps != -29 && fps != -25 && fps != -24)
      return parse_result::invalid;
    int ticksPerFrame = timeDivision & 0xff;
#endif
    // given beats per second, timeDivision should be derivable.
    return parse_result::invalid;
  }

  startingTempo = 120.0f;              // midi default
  ticksPerBeat = float(time_division); // ticks per beat (a beat is defined as a quarter note)