ThioJoe / Auto-Synced-Translated-Dubs
The video linked below will explain far better than I can type here. However, it looks like ThioJoe has written a python application with some great logic for handling SRT and also using google services to output SRT's in alternative languages. Github url below.
https://www.youtube.com/watch?v=uaHmtJrZRdM
https://github.com/ThioJoe/Auto-Synced-Translated-Dubs