Ok, last pipeline. This one crops the top and the bottom so it fills the whole mirror window:

gst-launch-0.10 v4l2src device=/dev/video1 ! "video/x-raw-yuv,pixel-aspect-ratio=(fraction)1/1" ! ffmpegcolorspace ! videoflip method=4 ! videocrop top=60 bottom=160 right=122 ! xvimagesink force-aspect-ratio=true

EDIT: v4l2camsrc looks identical to v4l2src