msycamore: Sorry, I'm not sure if I get what you really mean or what you're referring to, erri_wan could easily get an editable SRT-file from the DVD by simply demux it.

Are you sure about that? I'm quite sure that in order to work, subs on a DVD have to be rendered as bitmaps, so he could hardly just demux a SRT file from the DVD.

Wikipedia:

Subtitles are stored as bitmap images and therefore can contain messages in any language. Subtitles are restricted to four colors, including transparent "color", and thus tend to look cruder than permanent subtitles on film.^[27] Transparency allows laying subtitles over the video during playback.^[28] The subtitle tracks are contained within the VOB file of the DVD.

DVD Video may also contain closed captioning material which can only be viewed on a television set with a decoder.