There’s a thread for this already but I don’t know what it’s called.
I’m assuming this is about anime. If you are looking for subs for 8 1/2 or something I don’t know how to help.
I’ve only ever done this totally analog. I use an old PC running Substation Alpha going through an external genlock. In this scenario the box pretty much just mixes two signals together. The PC is just playing a chroma key background and subs and the LD player is just playing. It’s pretty much impossible to screw up.
Once you get into the realm of digitally capturing the source there are innumerable ways of mixing the streams, seriously, uncountable, and that’s all left to people who have time to keep up with constantly changing tech. I tend to leave things alone once they are working (obviously).
All the digital means involve storing huge files, waiting for stuff to render, and dealing with the overall unpleasantness of PC on a much more time consuming level.
For anime LDs you’re going to want to find vintage subtitles files, probably in the SSA or maybe Jacosub format. This...is surprisingly hard to do. A member here sent me some. I feel like a dink for losing the hundreds of files I had back in the day.
Using DVD subs would be hard. They aren’t stored as text so it would require OCR, wouldn’t it? And the timing will be all messed up.
If it’s realistic I strongly recommend the old fashion real time way of doing it. It won’t look as good but it’s almost as easy as dubbing a movie to VHS.
You aren’t going to usually find SSA scripts for something if it was licensed for North America in the VHS era. There is a lot of Gundam and Ghibli because those took forever to make it to the US but you aren’t going to find a lot of Ranma 1/2 or Bubblegum Crisis because those were licensed early in their lives and fansubbers usually would concentrate on stuff that hadn’t been translated.
If you find a script for Run Melos please let me know. I know it existed at one point because I still have a fan sub of it.