Turn downloaded movies to images

Introduction

You know how it is you downloaded a movie fron say Youtube and you see something whizz past that makes no sense and you think I know I will capture it to an image, show my friends right - but how.

How to convert a single short movie to a progression of images

The console is such a powerful interface and really quite fast, below is the command. It is assumed that you have previously installed "ffmpeg" and it's necessary codecs.