--
-- <signals> is basically an exposed InputState, which you can use to
-- query for information about the signals at the point of the current
--- frame. In particular, you can call get_width() and get_height()
+-- frame. In particular, you can call get_frame_width() and get_frame_height()
-- for any signal number, and use that to e.g. assist in scene selection.
+-- (You can also use get_width() and get_height(), which return the
+-- _field_ size. This has half the height for interlaced signals.)
--
-- You should return the scene to use, after having set any parameters you
-- want to set (through set_int() etc.). The parameters will be snapshot