def is_valid(self):
        """Check if a :attr:`text` is a valid SubRip format.

        :return: whether or not the subtitle is valid.
        :rtype: bool

        """
        if not self.text:
            return False

        try:
            pysrt.from_string(self.text, error_handling=pysrt.ERROR_RAISE)
        except pysrt.Error as e:
            if e.args[0] < 80:
                return False

        return True