MIDI Controller Mapping File Format

Support for extra MIDI devices can be added to Mixxx by created a new “MIDI mapping” file. This mapping file tells Mixxx how to translate MIDI commands from a controller into commands that Mixxx will understand.

The MIDI mapping files are located in the following paths:

• Windows: C:Program FilesMixxxmidi
• Linux: /usr/share/mixxx/midi (or /usr/local/share/mixxx/midi)
• OS X: /Applications/Mixxx.app/Contents/midi

The easiest way to create a new MIDI mapping is by modifying an existing one. When you've finished creating your MIDI mapping, please send it to us and we'll include it in Mixxx.

The midi mapping format is xml based. It looks something like this:

<!DOCTYPE controller> <controller>

 <controls>
   <control>
     <group>[[Master]]</group>
     <key>crossfader</key>
     <miditype>Ctrl</miditype>
     <midino>0x31</midino>
     <options>
       <hercjog/>
     </options>
   </control>
   ...
 </controls>
 <lights>
   <light>
     <group>[[Channel1]]</group>
     <key>VuMeter</key>
     <status>0xB0</status>
     <midino>0x16</midino>
     <threshold>0.5</threshold>
   </light>
   ...
 </lights>

</controller>

Definitions of the elements:

• group - The controlobject group
• key - The controlobject key, a list of which can be found on the UI/MIDI Controls and Names page.
• miditype - Midi object type: Ctrl, Key or Pitch
• midino - The MIDI control or note number
• midichan - The MIDI channel
• options - Can only handle one element currently but expandable, these aren't well described here:
  • invert
  • rot64inv
  • rot64fast
  • rot64
  • diff - Add the value to the control's current value
  • button - a button has a Down (non-zero) and an Up (zero) state, these occur together when pressed/released, this switch only triggers on the Down, Up is ignored. (Herc)
  • switch - a switch has a On (non-zero) and an Off (zero) state, these occur separately. (Herc)
  • hercjog - Handle hercules jog wheels
  • spread64 - Exponential spread either side of 64, aka “relative” controller (NEW)
• status - Status code to send to control lights
• threshold - Turn on light when control exceeds this value

Expanding the options tag should be done by changing the configobjectmidi structure to hold the QDomNode related to the options element. This can then be parsed when a value is received and used to modify the incoming value. If this is too slow it can be compiled in some way but i'd be surprised.