#!/bin/sh -eu
program=$(basename "$0")
option=${1:-}
real=${option%%@*}
virtual=${option#*@}
[ "$#" = 0 ] && printf '%s 0@9\n# /dev/video0 -> /dev/video9\n' "$program" && exit;
ffmpeg -i "/dev/video$real" -f v4l2 -vcodec rawvideo -pix_fmt rgb24 "/dev/video$virtual"