If you have an MKV video file that already has IDX/SUB subtitles inside it, you can extract them.
Because they are images, you cannot simply open an IDX file with Notepad to read or edit the text. This guide covers everything you need to know: how to use them, how to convert them to text, and how to edit them. idx subtitle
Contains the actual graphical images of the subtitles (ripped directly from the VOB files on a DVD). If you have an MKV video file that