Xavier Dolan, a 21-year-old wunderkind actor-filmmaker whose first film, J'ai Tué Ma Mère, won Cannes awards in 2009, is back with another madly stylish Montreal-made delight (Hearbeats), happily under the influence of Godard, Audrey Hepburn, and Wong Kar-wai. Here boy-girl friends obsess competitively about a beautiful young man (Niels Schneider, up to the assignment). Dolan, who plays the boy with the crush, also has a cool side gig: In Quebec, he is the voice of Stan on the French-language South Park. (Also available on cable via on demand) A–