Medusa Midi Transformer
An app for all your esoteric MIDI message transformation needs.
You can remap the faders on your favorite control surface, convert pitch bend data to CC and much more. You can halve the range of a fader or transpose a keyboard. Just about any conversion that can be described by adding, multiplying and diving can be set up quickly and easily.
The app is available for free from the Mac App Store here. The free version enables 2 connection and 4 transformations for testing purposes, and an unlock of unlimited connections and transformations is available for $10 (or your local currency equivalent.)
The genesis of this project was my personal need to connect a Behringer xtouch mini to the RME Totalmix interface. This required remapping the knobs from CC to the right pitchbend values the RME software was expecting. I made a quick mockup and decided it was something worth making available to other musicians. I still use this app every single day to control the RME software.
It can also be used to define your control surface in software and not having to worry about booting up a PC to run proprietary application (or go down the endless rabbit hole of assigning knobs via a hardware interface, if that is an option at all!) Plus, if you ever need to replace a control surface, you can just drop in a replacement with the default assignments and be back up and running.