It's from the film "Woman with an Editing Bench", http://www.imdb.com/title/tt5870326/?ref_=fn_al_tt_1

I'd say there is truth to both. 10,000 hours refers to Tiger-Woods-like mastery, Kaufman's 20 hours is for getting pretty good at something in an efficient way. To be at the top of your craft you're probably leaning towards the higher end :)