XVidCap is a free software used for recording a screencast or digital recording of an X Window System screen output with an audio narration. With it you can make a movie of anything running on under X.
Quoted from the xvidcap sourceforge page:
- "Xvidcap is a small tool to capture things going on on an X-Windows display to either individual frames or an MPEG video. On Windows machines there are commercial tools like Lotus ScreenCam or Camtasia which do a very good job esp. for the purpose I was needing such a tool for: Software documentation, esp. installation procedures and such.
- On UNIX machines I have searched for a comparable tool for a long time with little luck. Some day, I came across a program written by Rasca Gmelch which went a good way, just not quite there. It was able to capture to individual frames and save them in indivdual screenshots (which can be converted into a video with tools like transcode.)
- This approach for me required more storage than I had available, so I added an on-line encoding facility using FFMPEG's libavcodec/libavformat. And since Rasca no longer has the time to maintain his code, I took over and the code to sourceforge.
- Today, I suppose xvidcap does its basic job, though I find bugs and possible improvements every day. If you are a developer, appreciate a tool like xvidcap, and want to help improve it, contact me at the sourceforge site."
xvidcap support has been droppend in official arch repos (ie. community), try installing it from AUR. 
Using the software is pretty self-explanatory. Be sure to select the desired framerate prior to starting a capture. As well, setup the quality level and video codec of your choice. Do not forget to save your preferences.