Aswin F. van Woudenberg

The ‘Oldehove’ is an unfinished church tower in the centre of my hometown Leeuwarden. It leans even more than the tower of Pisa and is a must see for anyone visiting Leeuwarden. It’s open to the public from May to September.

Tresoar, the Frisian Historical and Literary Centre has a webcam on its roof that allows one to see the Oldehove in real time via this link. By grabbing and saving an image of the tower every 10 seconds for 24 hours, I was able to create the following video.

I first made a simple shell script to download the latest webcam image every ten seconds. The script looks like this.

#!/bin/bash
let c=1000000;
while [ 1 ];
do
        let c = $c + 1;
        wget http://83.136.192.185/record/current.jpg?rand=$c;
        sleep 10;
done

I got the URL by looking at the image source on the tresoar page. I let this script run for 24 hours starting at midnight. After the script finished I renamed all files using the following command:

rename 's/current\.jpg\?rand=(\d{7})$/current$1.jpg/' \
current.jpg\?rand\=*

The image files are then combined into the final movie by issuing the following command:

mencoder "mf://*.jpg" -mf fps=10 -o oldehove.avi -ovc \
lavc -lavcopts vcodec=msmpeg4v2:vbitrate=800

Of course you should have the required binaries installed.