A process would drop a video file and a text file in a directory, and then a script would execute the MacCaption binary for each file with a list of parameters to get the result we wanted. A captioned video file, as well as a WebVTT caption file, would be the results of the process. Those were then put into another workflow for dissemination.

Straightforward, although MacCaption was a terrible product to work with. They're owned by Telestream now (www.telestream.net/captioning/compare.htm).