Want to watch a consummately talented filmmaker fall on his head by, somehow, making graphic sex as dull and monotonous as possible? Welcome to Albert Serra’s “Liberté.” Set shortly before the French Revolution in a forest somewhere between Potsdam and Berlin, the story, if you want to call it that, involves aristocratic liberties, driven out of Louis XVI’s puritanical court, gathering together to act on their wildest sexual fantasies. The expelled-from-the-palace Madame de Dumeval, the Duke de Tesis, and the Duke de Wand try to start a revolution by seeking the support of the Duc de Walchen, a German sexual freethinker. The rules are simple, anything goes, it’s a quest for lawless pleasures that these hyper-sexualized libertines are looking for. Set during the course of one long night, filled with S&M fantasies and highbrow decadence, Serra, shooting on beautifully grainy digital, tries to blur the lines between art and pornography, but what results is a film filled with alienating dread; There’s an abundance of monotonous images, half-assed metaphors, and perverse acts. It all amounts to pictorial dullness. [D]