Bug Fixes in Multimedia
Ask to v4l2src for images of 640x480 and only in raw yuv || rgb
Just to be sure that v4l2src is not sending giants images(some
modern webcams send HD frames by default) ask for the size we're
going to use.
In the future we have to make this configurable (maybe for 2.0?)
but atm is ok by just hardcoding it.