The word "Introduction" is key... while not an exhaustive history of African cinema, it's a decent start/introduction for the uninitiated. I just realized that I don't think I've watched a documentary that I'd say does a really thorough, comprehensive job of documenting the history of African cinema. However, if you know something I don't know, feel free to leave a comment.
After you watch this 30-minute film, I'd recommend picking up copies of 2 books, both penned by Manthia Diawara - filmmaker, scholar, distinguished professor at New York University, and director of the Institute of Afro-American Affairs; first, African Cinema: Politics and Culture (Blacks in the Diaspora), and second, African Film: New Forms of Aesthetics and Politics
Both are available on Amazon.com.
Watch below (Black British actor David Oyelowo narrates this by the way):