How to make screencasts with FFmpeg

FFmpeg is able to use audio and video streams from many different sources. In order to record a screencast, you can use the x11grab input module for recording an X screen and the alsa input module for audio recording.

How to compile Truecrypt from source

A few days ago my new USB hard drive arrived. My idea was to connect the hard drive to my Raspberry Pi so that everyone in the network can read the data on that drive. But all the data stored on that drive should be encrypted. The problem was that I also wanted to use the hard drive to copy files from a computer of a friend. Not everyone uses Linux, so I could not encrypt the hard drive with LUKS.
But I had an idea to encrypt the hard drive with Truecrypt, which is available for Windows, Mac OS X and Linux. I created a little partition (about 100MB) which is not encrypted and download the Truecrypt installer for each OS to that partition. The advantage is that you don’t need an internet connection to download the installer. The rest of the hard drive is encrypted with Truecrypt.

The main problem was the installation of Truecrypt on my Pi because there is no ARM binary. I’ve no X-Server on my Pi so I had to install Truecrypt as console-only version. Here are the steps I’ve done to install Truecrypt on my Pi.

How to enable SWAP without restart

I use Conky to monitor my computer status, e.g. current cpu, memory and swap usage network connections etc. A few weeks ago I noticed that my SWAP-partition was not enabled. Maybe Conky was wrong, but I took a deeper look at it:

$ cat /proc/meminfo
[...]
SwapTotal:             0 kB
SwapFree:              0 kB
[...]