Miskatonic University Press

Technical Aide-Mémoire

Here I am building up a list of things I sometimes need to do on a computer but not often enough that I remember how to do them. Now all I have to remember is to check here first when I want to, for example, extract audio from a video. And, if the solution isn’t here, to add it after I find it.

Extract audio from a video

ffmpeg -i video.mp4 -q:a 0 -map a audio.mp3

(Source: Stack Overflow.)

Slice an image vertically

With Imagemagick’s crop, to cut an image into a stack of five slices:

convert -crop 100%x20% input.jpg cropped_%d.jpg

Make a favicon

Makes a favicon that contains different sizes.

convert -background transparent "favicon.png" -define icon:auto-resize=32,64,128,256 "favicon.ico"

OpenStreetMap documentation I might look at