I prefer tools like https://asciinema.org/ when I want to show terminal tricks and cli tools I build, but sometimes you need to show something that breaks out of the terminal. In this case I record a .mov screen cast using quicktime then do several transformations using ffmpeg to get a small uploaded web friendly .webm file.
- cut down the video if need be
$ ffmpeg -i movie.mp4 -ss 00:00:03 -t 00:00:08 -async 1 cut.mp4
- scale down the .mov file to something more web friendly
$ ffmpeg -i vim_dic.mov -filter:v scale=512:-1 -c:a copy vim_dic_small.mov
- convert the .mov to .webm
$ ffmpeg -i vim_dic_small.mov -c:v libvpx -crf 10 -b:v 1M -c:a libvorbis vim_dic.webm
If you don’t have ffmpeg is available via brew