private function parseSubtitles()
{
$matches = array();
$res = preg_match_all(self::pattern, $this->file_content, $matches);
if (!$res || $res == 0) {
throw new \Exception($this->filename . ' is not a proper .srt file.');
}
if (strpos('.', $matches[1][0])) {
$this->is_WebVTT = true;
}
$entries_count = sizeof($matches[1]);
for ($i = 0; $i < $entries_count; $i++) {
$sub = new srtFileEntry($matches[1][$i], $matches[2][$i], $matches[3][$i]);
$this->subs[] = $sub;
}
}