More than most other black filmmakers in Hollywood today, Ava DuVernay elicits a certain giddiness in black moviegoers. Her path to stardom as the director of the Oscar-nominated Martin Luther King Jr. biopic “Selma” is certainly a draw. Before stepping behind the camera, DuVernay spent 12 years as a publicist who specialized in building audiences of color for Hollywood films. As she once recounted to the Boston Globe, she used to “plan junkets and actually be on my hands and knees rolling the red carpet.” She’s a consummate underdog—a black woman in a male-dominated and stubbornly white industry who’s worked her way into the foreground by unapologetically telling nuanced black stories. But an equally indelible part of her story is the film distribution network she founded in 2011 to help connect black audiences with black films. The African-American Film Festival Releasing Movement (AFFRM) is, she told the New York Times that year, more of a “call to action” than a business. The plan is to put films by black directors and majority black casts into commercial theaters by first drumming up support for them on the festival circuit.