Function ParseEXRVersionFromMemory

third-party/tinyexr/tinyexr.h:8763–8818

}

int ParseEXRVersionFromMemory(EXRVersion *version, const unsigned char *memory,
                              size_t size) {
  if (version == NULL || memory == NULL) {
    return TINYEXR_ERROR_INVALID_ARGUMENT;
  }

  if (size < tinyexr::kEXRVersionSize) {
    return TINYEXR_ERROR_INVALID_DATA;
  }

  const unsigned char *marker = memory;

  // Header check.
  {
    const char header[] = {0x76, 0x2f, 0x31, 0x01};

    if (memcmp(marker, header, 4) != 0) {
      return TINYEXR_ERROR_INVALID_MAGIC_NUMBER;
    }
    marker += 4;
  }

  version->tiled = false;
  version->long_name = false;
  version->non_image = false;
  version->multipart = false;

  // Parse version header.
  {
    // must be 2
    if (marker[0] != 2) {
      return TINYEXR_ERROR_INVALID_EXR_VERSION;
    }

    if (version == NULL) {
      return TINYEXR_SUCCESS;  // May OK
    }

    version->version = 2;

    if (marker[1] & 0x2) {  // 9th bit
      version->tiled = true;
    }
    if (marker[1] & 0x4) {  // 10th bit
      version->long_name = true;
    }
    if (marker[1] & 0x8) {        // 11th bit
      version->non_image = true;  // (deep image)
    }
    if (marker[1] & 0x10) {  // 12th bit
      version->multipart = true;
    }
  }

  return TINYEXR_SUCCESS;
}

int ParseEXRVersionFromFile(EXRVersion *version, const char *filename) {