This project is an adaptation of the QR example from http://shiffman.net/p5/qrcode-processing/
to get it to work with an Sweex webcam which only outputs 640x480 

For ubuntu 12.04 it needs the gstreamer video for processing package (http://gsvideo.sourceforge.net/)
which in turn needs the following gstreamer packages 
gir1.2-gstreamer-0.10 
gstreamer0.10-alsa
gstreamer0.10-ffmpeg
gstreamer0.10-gconf
gstreamer0.10-gnomevfs
gstreamer0.10-nice
gstreamer0.10-plugins-bad
gstreamer0.10-plugins-base
gstreamer0.10-plugins-good
gstreamer0.10-plugins-ugly
gstreamer0.10-pulseaudio
gstreamer0.10-x
libgstreamer-plugins-bad0.10-0
libgstreamer-plugins-bad0.10-dev 
libgstreamer-plugins-base0.10-0
libgstreamer-plugins-base0.10-dev
libgstreamer0.10-0
libgstreamer0.10-dev 

Just in case use v4l-ctl or v4l-dbg (v4l-utils package) for webcam debugging