Although Gnome Shell comes with screencasting abilities by default, it really isn’t there yet in terms of CPU load and codec functionality and the options are limited and not easily accessible. SSR can act as a straight replacement for every screencasting task under Gnome.
Graphical user interface (Qt-based).
Faster than VLC and ffmpeg/avconv.
Records the entire screen or part of it, or records OpenGL applications directly (similar to Fraps on Windows).
Synchronizes audio and video properly (a common issue with VLC and ffmpeg/avconv).
Reduces the video frame rate if your computer is too slow (rather than using up all your RAM like VLC does).
Fully multithreaded: small delays in any of the components will never block the other components, resulting is smoother video and better performance on computers with multiple processors.
Pause and resume recording at any time (either by clicking a button or by pressing a hotkey).
Shows statistics during recording (file size, bit rate, total recording time, actual frame rate, ...).
Can show a preview during recording, so you don't waste time recording something only to figure out afterwards that some setting was wrong.
Uses libav/ffmpeg libraries for encoding, so it supports many different codecs and file formats (adding more is trivial).
Can also do live streaming (experimental).
Sensible default settings: no need to change anything if you don't want to.
Tooltips for almost everything: no need to read the documentation to find out what something does.
Install SimpleScreenRecorder in ubuntu
Open the terminal and run the following commands
sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
sudo apt-get update
sudo apt-get install simplescreenrecorder
# if you want to record 32-bit OpenGL applications on a 64-bit system:
sudo apt-get install simplescreenrecorder-lib:i386