Controlling Photoshop with Midi-Controller

What I want is a Plugin that lets me change the RGB color channels of the brush with a physical Midi-Controller. I DON't want the Midi-Controller to simulate Keystrokes like someone did in this video: [login to view URL] It should work as it works in gimp ([login to view URL]), that you can draw a stroke and for example change the brightness WHILE your are making the stroke. That's not possible when simulating keystrokes. Anybody has an idea how to do that?