Here is a small tutorial about how to use VLC player to record the desktop on Linux.
1.Open VLC.
Media->Convert/Save
2.Capture Device
change the capture mode to "Desktop"
change the frame rate to 15
after that, click Convert/Save button.
3.outputs
save your file to your local directory
4.Encapsulation
choose MP4
5.Video code
choose H-264
adjust the Birate to 8192kb/s
setting Scale to 1
That's all.
Advantage: It's free and already in our image. The video size is small and the quality is good.
Disadvantage: We can not see the mouse cursor in the video.