FYI, if you download the course materials, there are transcripts of the video lectures included, so you can get a good feel for what the lectures are like and, maybe, not have to spend over an hour per lecture. You can download the course materials here:
Note: you may still want/need to watch them since there's notation that is likely easier to read off a blackboard vs reading a transcript of someone describing it, e.g.
"The conclusion is the same thing, but summing over
all k. So, k equals one to n, alpha_k x_k. Take f of that versus taking the sum of
the alphas times the f's. k equals one to n. So, the definition of convexity is exactly
that statement, but where n equals two."
http://ocw.mit.edu/ans15436/ZipForEndUsers/6/6-046j-fall-200...
Note: you may still want/need to watch them since there's notation that is likely easier to read off a blackboard vs reading a transcript of someone describing it, e.g.
"The conclusion is the same thing, but summing over all k. So, k equals one to n, alpha_k x_k. Take f of that versus taking the sum of the alphas times the f's. k equals one to n. So, the definition of convexity is exactly that statement, but where n equals two."