Duvernay, 42, delivered a wide-ranging, funny and at times emotional keynote speech at SXSW, reported Variety.
Asked in a Q&A session following the speech why it had taken so long for Hollywood to tell Martin Luther King's story, she said: "The studios aren't lining up to make films about black protagonists. Black people being autonomous and independent."
In her speech, Duvernay reflected on her career, her struggle to get films screened at Sundance and her motivations for making "Selma".
She talked about screening "Selma" at the White House 100 years after DW Griffith's "The Birth of a Nation" played there, and staying for dinner with the Obamas.