Print fourCC characters instead of the hex value in toString() as they are more informative. Also, write the tests for this in formats.cpp Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>