If you don't want to watch the video -for whatever reason- almost all of the courses provide the text of the close captioning. Download and read that along with any other lecture notes that are available. Better yet, just troll Amazon for the "best" book on the subject as that is all you really want anyway.
The rest of us, who actually do want the video because, have among many reasons, a) we find the pace to be more conducive to long term learing, b) we like to take notes while we listen, c) (course dependent) we like to see problems worked out with verbal explanation, d) we like to hear the occasional question from those in physical attendance or as result of those posted to message boards.