https://blog.faceutil.com/2017/03/26/vobsub-2-23-%ec%9c%88%eb%8f%84%ec%9a%b0-%eb%af%b8%eb%94%94%ec%96%b4%ed%94%8c%eb%a0%88%ec%9d%b4%ec%96%b4%ec%97%90%ec%84%9c-%ec%9e%90%eb%a7%89%ec%9d%84-%eb%b4%85%ec%8b%9c%eb%8b%a4-oe/