I doubt it will matter if you're breaking up mid sentence if you pass in the previous as a prompt and split words. This is how Whisper does it internally.

It's not absolutely perfect, but splitting on the word boundary is one line of code with the same package in their docs: https://github.com/jiaaro/pydub/blob/master/API.markdown#sil...

25MB is also a lot. That's 30 minutes to an hour on MP3 at reasonable compression. A 2 hour movie would have three splits.