Method doWriteMetadata

src/webpimage.cpp:105–404

}  // WebPImage::writeMetadata

void WebPImage::doWriteMetadata(BasicIo& outIo) {
  if (!io_->isopen())
    throw Error(ErrorCode::kerInputDataReadFailed);
  if (!outIo.isopen())
    throw Error(ErrorCode::kerImageWriteFailed);

#ifdef EXIV2_DEBUG_MESSAGES
  std::cout << "Writing metadata" << std::endl;
#endif

  byte data[WEBP_TAG_SIZE * 3];
  DataBuf chunkId(WEBP_TAG_SIZE + 1);
  chunkId.write_uint8(WEBP_TAG_SIZE, '\0');

  io_->readOrThrow(data, WEBP_TAG_SIZE * 3, Exiv2::ErrorCode::kerCorruptedMetadata);
  uint64_t filesize = Exiv2::getULong(data + WEBP_TAG_SIZE, littleEndian);

  /* Set up header */
  if (outIo.write(data, WEBP_TAG_SIZE * 3) != WEBP_TAG_SIZE * 3)
    throw Error(ErrorCode::kerImageWriteFailed);

  /* Parse Chunks */
  bool has_size = false;
  bool has_xmp = false;
  bool has_exif = false;
  bool has_vp8x = false;
  bool has_alpha = false;
  bool has_icc = iccProfileDefined();

  uint32_t width = 0;
  uint32_t height = 0;

  byte size_buff[WEBP_TAG_SIZE];
  Blob blob;

  if (!exifData_.empty()) {
    ExifParser::encode(blob, littleEndian, exifData_);
    if (!blob.empty()) {
      has_exif = true;
    }
  }

  if (!xmpData_.empty() && !writeXmpFromPacket()) {
    XmpParser::encode(xmpPacket_, xmpData_, XmpParser::useCompactFormat | XmpParser::omitAllFormatting);
  }
  has_xmp = !xmpPacket_.empty();
  std::string xmp(xmpPacket_);

  /* Verify for a VP8X Chunk First before writing in
   case we have any exif or xmp data, also check
   for any chunks with alpha frame/layer set */
  while (!io_->eof() && io_->tell() < filesize) {
    io_->readOrThrow(chunkId.data(), WEBP_TAG_SIZE, Exiv2::ErrorCode::kerCorruptedMetadata);
    io_->readOrThrow(size_buff, WEBP_TAG_SIZE, Exiv2::ErrorCode::kerCorruptedMetadata);
    const uint32_t size_u32 = Exiv2::getULong(size_buff, littleEndian);

    // Check that `size_u32` is within bounds.
    Internal::enforce(size_u32 <= io_->size() - io_->tell(), Exiv2::ErrorCode::kerCorruptedMetadata);