public function getFrameRate()
    {
        if ($this->frameRate === null) {
            $match = [];
            preg_match(self::$REGEX_FRAME_RATE, $this->output, $match);
            $this->frameRate = (float)(array_key_exists(1, $match) ? $match[1] : 0.0);
        }

        return $this->frameRate;
    }