Dumb Questions About Automatics

[Chiboy]

Do Rolexes self-wind due to arm movement in both directions or just one way?

Also, how does the winding mechanism compare to winding the crown? In other words, if I manipulate my watch near my ear, I can hear the self-winding mechanism turning. But as I visualize it swinging around and around, I am curious as to how many times (roughly) around would equate to a single wind of the crown?

Thanks for any insight. I'd kinda like to know a little more about these little instruments we all like so much.