Function ParseEXRVersionWithReader

Source/ThirdParty/tinyexr.h:10385–10439

Parse EXR version header using Reader class

// Parse EXR version header using Reader class
static int ParseEXRVersionWithReader(EXRVersion *version, tinyexr::Reader& reader) {
  if (version == NULL) {
    return TINYEXR_ERROR_INVALID_ARGUMENT;
  }

  if (reader.length() < tinyexr::kEXRVersionSize) {
    reader.add_error("Insufficient data size for EXR version header");
    return TINYEXR_ERROR_INVALID_DATA;
  }

  // Check magic number: 0x76, 0x2f, 0x31, 0x01
  uint8_t header[4];
  if (!reader.read(4, header)) {
    return TINYEXR_ERROR_INVALID_DATA;
  }

  const uint8_t expected_header[] = {0x76, 0x2f, 0x31, 0x01};
  if (header[0] != expected_header[0] || header[1] != expected_header[1] ||
      header[2] != expected_header[2] || header[3] != expected_header[3]) {
    reader.add_error("Invalid EXR magic number");
    return TINYEXR_ERROR_INVALID_MAGIC_NUMBER;
  }

  // Parse version byte (must be 2)
  uint8_t version_byte;
  if (!reader.read1(&version_byte)) {
    return TINYEXR_ERROR_INVALID_DATA;
  }

  if (version_byte != 2) {
    reader.add_error("Invalid EXR version");
    return TINYEXR_ERROR_INVALID_EXR_VERSION;
  }

  version->version = 2;

  // Parse flags byte
  uint8_t flags;
  if (!reader.read1(&flags)) {
    return TINYEXR_ERROR_INVALID_DATA;
  }

  version->tiled = (flags & 0x2) ? true : false;       // 9th bit
  version->long_name = (flags & 0x4) ? true : false;   // 10th bit
  version->non_image = (flags & 0x8) ? true : false;   // 11th bit (deep image)
  version->multipart = (flags & 0x10) ? true : false;  // 12th bit

  // Skip remaining 2 bytes to complete the 8-byte version header
  uint8_t dummy[2];
  if (!reader.read(2, dummy)) {
    return TINYEXR_ERROR_INVALID_DATA;
  }

  return TINYEXR_SUCCESS;
}

}  // anonymous namespace