Software is FFmpeg (mainly/exclusively C for the subtitles part). If I need to use the API, I'll probably go for Python or shell scripting with curl & friends.

Hi, I'm working on a large (open-source) software trying to support all kind of subtitles formats. So far, I think it supports every format allowed on opensubtitles.org. But from time to time, we get bug reports with subtitles files broken in various ways, or simply with unsupported features. Opensu...