I've been adding subtitles to the talks from EmacsConf 2020, taking advantage of the text that was helpfully autogenerated when I uploaded the videos to the EmacsConf channel on YouTube. Today I spent some time figuring out how to add WebVTT support to subed, an Emacs major mode for editing subtitles. It turns out that it's pretty cool to be able to bring up the relevant segment in the video whenever the text wasn't clear. Here's a quick video of it in action. It shows how I can mostly focus on adding punctuation and changing capitalization, checking every so often with mpv via mpv.el. All in all, it took me 24 minutes to edit the subtitles for a 17-minute talk. Whee!

I submitted a pull request to get the .vtt support into subed-mode in case anyone else finds it helpful. I've only tested the mpv synchronization so far, and I'm looking forward to exploring its other features.

You can see these particular subtitles on the talk page for Beyond Vim and Emacs: A Scalable UI Paradigm. Enjoy!

Update 2020-12-13: subed-vtt.el has been merged into master, so you'll get it when you check out subed. Yay!

Update 2021-07-19: Check out Lindsey Kuper's step-by-step instructions for getting YouTube to autogenerate captions that you can edit.