I don't think that video capture for animations is trivial, even the way that you plan to go could be full of efforts without result and more time consuming than you expect. It depends very much on the sort of movements that you need, too.
The following is a result of tweaking two of the free .bvh-files in the internet. First, I made a cycle in bvhacker (free program), then connected it with a model in fragmotion, reduced the frames per cycle (don't know if in bvhacker or fragmotion), and after exporting it to mdl7, I changed the model in MED and re-rigged it with a very lowpoly model from one of Rincewind's contributions.
Could be worth a look or two.
knight_walking.zip