initially from http://www.oz9aec.net/index.php/gstreamer/473-using-the-logitech-c920-webcam-with-gstreamer with modifications from https://github.com/derekmolloy/boneCV
initially from http://www.oz9aec.net/index.php/gstreamer/473-using-the-logitech-c920-webcam-with-gstreamer with modifications from https://github.com/derekmolloy/boneCV