A catalytic converter assembly, for use in the exhaust systems of vehicles or machinery using internal combustion engines, consisting of a square tube, with perforated rectangular baffles made from common sheet metal of stainlees-steel, folded at angles, affixed within it. An example composer to author a variable video includes a labeler to tag each of a plurality of scenes with at least one vector based on the content of the respective scenes. A housing includes a catalyst in fluid communication with the conduit to receive exhaust produced by the engine.