ffmpeg -r 12 -g 120 -s 1280x800 -f x11grab -i :0.0 -s 1280x1024 -vcodec qtrle screencast.mov

ffmpeg -f alsa -ac 2 -i hw:0,0 -acodec pcm_s16le -f x11grab -s 1280x1024 -r 25 -i :0.0 -vcodec qtrle screencast.mov

ffmpeg -f x11grab -s `xdpyinfo | grep 'dimensions:'|awk '{print $2}'` -r 25 -i :0.0 -sameq ./mydesktop.mkv