[[!meta title="Captioning tips"]] [[!meta copyright="Copyright © 2021 Sacha Chua"]] Captions are great for making videos (especially technical ones!) easier to understand and search. If you see a talk at https://media.emacsconf.org/2021/protected/ that you'd like to caption, feel free to download it and start working on it with your favourite subtitle editor. Let me know what you pick by e-mailing me at so that I can update the index and try to avoid duplication of work. We've been using to caption things as VTT or SRT in Emacs, often starting with autogenerated captions from YouTube (the .vtt or .srt file), but you're welcome to make captions using your favourite tool. I generally find it easier to start with the autogenerated captions and then refer to any resources provided by the speaker in order to figure out spelling. Sometimes speakers provide pretty complete scripts, which is great, but they also tend to add extra words. I tried uploading the scripts to YouTube in order to get YouTube to automatically align the text, but then the timing information wasn't granular enough for easy splitting, so correcting the autogenerated captions myself seemed to be easier. I use some code in my [subed configuration](https://sachachua.com/dotemacs/#subed) (see `my-subed-fix-common-error` and `my-subed-common-edits`) to help with capitalization and commonly misrecognized words. Please keep captions to one line each so that they can be displayed without wrapping, as we plan to broadcast by resizing the video and displaying open captions below. Maybe 50 characters max? Since the captions are also displayed as text on the talk pages, you can omit filler words. We've also been trying to break captions at reasonable points (ex: phrases). For example, instead of: - so i'm going to talk today about a - fun rewrite i did of uh of the bindat - package I would probably edit it to be more like: - So I'm going to talk today - about a fun rewrite I did - of the bindat package. If you use subed.el, you can use: - `C-c C-v` to load the video - `M-SPC` to toggle pause/play - `M-j` to jump to the current subtitle - `M-.` to split the subtitle at the current playing position (or a reasonable guess) - `M-m` to merge with previous - `M-M` to merge with next - `C-c [` to set the start time to the playing position - `C-c ]` to set the stop time to the playing position. If you want to take advantage of the autogenerated captions and the word-level timing data from YouTube, you can start with the VTT file for the video you want, then use `my-caption-load-word-data` from to load the srv2 file (also attached), and then use `my-caption-split` to split using the word timing data if possible. You can bind this to a keystroke with something like `M-x local-set-key M-' my-caption-split`. We'll be posting VTT files so that they can be included by the HTML5 video player (demo: https://emacsconf.org/2021/talks/news/), so if you use a different tool that produces another format, any format that can be converted into that one (like SRT or ASS) is fine. You can e-mail me the subtitles when you're done, and then I can merge it into the video. Please let me know if you need any help! Sacha