protected function buildGifSubdef(SimpleXMLElement $sd)
    {
        $gif = new Gif($this->translator);
        if ($sd->size) {
            $gif->setOptionValue(Gif::OPTION_SIZE, (int) $sd->size);
        }
        if ($sd->delay) {
            $gif->setOptionValue(Gif::OPTION_DELAY, (int) $sd->delay);
        }
        return $gif;
    }