Hi very simple:
I propose 3 options
If you have Gnome 3
You can start/stop recording your GNOME 3 Desktop by pressing the Ctrl+Shift+Alt+R key combination.
The first time when you press this key combination, GNOME 3 will start recording your Desktop and any movements that happen on it. A red circle is displayed in the bottom right corner of the screen when the recording is in progress. Pressing the same key combination a second time will stop the recording.
The process can be simplified using the EasyScreenCast GNOME Shell extension.
Now on any desktop
Use VLC Player
How to install vlc?
from a terminal (Available via 3rd party RPM fusion repository)
su -c 'yum -y install vlc'
How to make a screencast using Vlc?
Select OPEN MEDIA
Select CAPTURE DEVICE tab
Change capture mode to DESKTOP
Change Options to 25 f/s
Choose CONVERT option instead of play
option
In the Convert window add the
destination file via the BROWSE button
then name the file TEST.MPG (VLC does
require the extension so the file
becomes TEST.MPG rather than just
TEST)
Change the PROFILE to VIDEO - H.264 +
AAC (TS)
Click the setting button and change
the VIDEO CODEC options to:
BITRATE 1200kb/s
FRAME RATE 25.00 fps
Click SAVE
Choose the DEINTERLACE option
Click START
OR
use the programs proposed by Fedora wiki
http://fedoraproject.org/wiki/ScreenCasting