As camera names can be cumbersome to type, selection of cameras by index from a list can be useful. Print the list of detected cameras with an index for each item, and interpret the camera name as an index if it is a numerical value in the range from 1 to the number of cameras. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>