There are many websites around that allow you to download videos from YouTube. But it’s not possible to do it directly from YouTube. And you end up with a proprietary Flash video file. Although you can install the Flash plug-in on your computer, there are cases when you don’t want to do so or you are even not able to do so.

So, for whatever reason, you want a video from YouTube on your computer in a file format suitable for any kind of multimedia viewer? Here is a small (15 lines) bash script to download and convert a YouTube video you like in standard MPEG format. For that purpose, you’ll need wget (usually, you already have it on your GNU/Linux box) and ffmpeg.

Now, suppose you want to watch a video about Morris water maze, just look at the URL (http://youtube.com/watch?v=y2kJ2Zw9ZgI) and you’ll see the video ID (y2kJ2Zw9ZgI). Now, copy this ID and choose a proper filename for your file. Simply type “./youtubedownload.sh y2kJ2Zw9ZgI MorrisWaterMazeVideo” and after a few seconds, you’ll get a file called MorrisWaterMazeVideo.mpeg you can watch with the player you want. 🙂

Note 1: it doesn’t work with all the files on YouTube but almost all of them
Note2: Google Video gives the opportunity to directly download videos in mp4 format (which is standaradized)