It’s easy man.. first of all, you have to use a object called btrack, which you can find in here -> http://www.eecs.qmul.ac.uk/~adams/software.html .. then, you have to pick up your sound.. use a biquad+filtergraph to track each band you wanna analyse.. then you route the resulting audio, through a peekamp~, then you scale the resulting data into the DMX protocol values, and use a library or a object that allows you to output values to DMX.. easy..

ah, you can also have a general peekamp tracking for tracking the general amplitude eheh good luck.. and earn a lot of money ;)