function youtube() {
  if [ -z "$1" ]||[ -z "$2" ]
  then
    echo usage: $0 link out.flv
    return
  fi
      wget "$1" -qO- | sed -n "/fmt_url_map/{s/[\'\"\|]/\n/g;p}" | sed -n '/^fmt_url_map/,/videoplayback/p' | sed -e :a -e '$q;N;5,$D;ba' | tr -d '\n' | sed -e 's/\(.*\),\(.\)\{1,3\}/\1/' | wget -i - -O "$2"

}