Method parseMakerNote

src/librawspeed/tiff/TiffIFD.cpp:130–202

This will attempt to parse makernotes and return it as an IFD */

/* This will attempt to parse makernotes and return it as an IFD */
TiffRootIFDOwner TiffIFD::parseMakerNote(NORangesSet<Buffer>* ifds,
                                         TiffEntry* t) {
  assert(ifds);

  // go up the IFD tree and try to find the MAKE entry on each level.
  // we can not go all the way to the top first because this partial tree
  // is not yet added to the TiffRootIFD.
  TiffIFD* p = this;
  TiffEntry* makeEntry;
  do {
    makeEntry = p->getEntryRecursive(MAKE);
    p = p->parent;
  } while (!makeEntry && p);
  string make = makeEntry != nullptr ? trimSpaces(makeEntry->getString()) : "";

  ByteStream bs = t->getData();

  // helper function for easy setup of ByteStream buffer for the different maker note types
  // 'rebase' means position 0 of new stream equals current position
  // 'newPosition' is the position where the IFD starts
  // 'byteOrderOffset' is the position where the 2 magic bytes (II/MM) may be found
  // 'context' is a string providing error information in case the byte order parsing should fail
  auto setup = [&bs](bool rebase, uint32_t newPosition,
                     uint32_t byteOrderOffset = 0,
                     const char* context = nullptr) {
    if (rebase)
      bs = bs.getSubStream(bs.getPosition(), bs.getRemainSize());
    if (context)
      bs.setByteOrder(getTiffByteOrder(bs, byteOrderOffset, context));
    bs.skipBytes(newPosition);
  };

  if (bs.hasPrefix("AOC\0", 4)) {
    setup(false, 6, 4, "Pentax makernote");
  } else if (bs.hasPrefix("PENTAX", 6)) {
    setup(true, 10, 8, "Pentax makernote");
  } else if (bs.hasPrefix("FUJIFILM\x0c\x00\x00\x00", 12)) {
    bs.setByteOrder(Endianness::little);
    setup(true, 12);
  } else if (bs.hasPrefix("Nikon\x00\x02", 7)) {
    // this is Nikon type 3 maker note format
    // TODO: implement Nikon type 1 maker note format
    // see http://www.ozhiker.com/electronics/pjmt/jpeg_info/nikon_mn.html
    bs.skipBytes(10);
    setup(true, 8, 0, "Nikon makernote");
  } else if (bs.hasPrefix("OLYMPUS", 7)) { // new Olympus
    setup(true, 12);
  } else if (bs.hasPrefix("OLYMP", 5)) {   // old Olympus
    setup(true, 8);
  } else if (bs.hasPrefix("EPSON", 5)) {
    setup(false, 8);
  } else if (bs.hasPatternAt("Exif", 4, 6)) {
    // TODO: for none of the rawsamples.ch files from Panasonic is this true, instead their MakerNote start with "Panasonic"
    // Panasonic has the word Exif at byte 6, a complete Tiff header starts at byte 12
    // This TIFF is 0 offset based
    setup(false, 20, 12, "Panosonic makernote");
  } else if (make == "SAMSUNG") {
    // Samsung has no identification in its MakerNote but starts with the IFD right away