This is about making subtitles for lecture videos.

Something’s a bit odd about the subtitles autogenerated by YouTube. When I downloaded (go to YouTube Studio, videos, find the video, select “details”, More Options, then it’s on that screen) the subtitles for one of mine, they came out as a sbv file like this:

0:00:00.880,0:00:03.919
in this video we're going to recap the

0:00:02.560,0:00:07.279
absolute basics of

0:00:03.919,0:00:09.280
informal set theory. We will

You can see that the times don’t make sense. It’s very odd. The same thing happened with another of mine I tried.

It causes problems when you convert them. I did it using ffmpeg (see below) and they were wrongly ordered, and with this website when they were a bit better but overlapped (on MS Stream) in a bad way.

Conclusion: don’t get the subtitles from YouTube.

Downloading from MS Stream (find the video in my videos, select details) gives a vtt file which doesn’t seem to have this problem. It’s more cluttered though - you get some weird hex stuff and NOTE Confidence: 0.xyz after every caption.

In Lecturecast: library (top left), find video, “…”, more actions, edit transcript, export, choose vtt or txt. Again the vtt has a bunch of annoying clutter (confidence, speaker tags).

Converting

ffmpeg -i captions.sbv captions.vtt

This site probably doesn’t use ffmpeg as its back end (since it produced different results), so could be useful.