This should be everything you need to install on a bare Ubuntu Trusty system
$ sudo apt-get install toonloop xserver-xephyr vlc wmctrl gstreamer1.0-tools gstreamer1.0-plugins-base gstreamer1.0-plugins-good graphicsmagick metacity
You can change the RGB value that it is chromakeying by changing the KEY_R,G and B values.
Then run it with:
$ bash chromakey.bash
pix