Ardour 2.X supported MIDI learning for more or less any control. This was a nice feature that quite a few other DAWs are providing by now, but it didn't allow Ardour to work "out of the box" with sensible defaults for existing commercial MIDI controllers. In Ardour 3 and later versions, we have augmented the MIDI learn feature with the ability to load a MIDI binding map for a given controller, which can set up an arbitrary number of physical controls with anything inside Ardour that can be controlled.

Currently (August 2016), we have presets for the following devices/modes:

• AKAI MPD-32
• AKAI MPK61
• AKAI MPKmini
• Behringer BCF2000
• Behringer BCF2000 (Mackie Emulation mode; better to use Ardour's actual Mackie Control Protocol support)
• Behringer DDX3216
• Korg nanoKONTROL (2 layouts)
• Korg nanoKONTROL 2 (2 layouts)
• Korg Taktile
• M-Audio Axiom 25 (2 layouts)
• M-Audio Axiom 61
• M-Audio Oxygen 49
• M-Audio Oxygen 61v3
• M-Audio Oxygen 25
• M-Audio Oxygen 8v2
• Novation Impulse 49
• Novation Impulse 61
• Novation LaunchControl XL
• Novation LaunchKey 25
• Roland SI-24
• Roland V Studio 20
• Yamaha KX25

MIDI binding maps are accessible by double-clicking Edit > Preferences > Control Surfaces > Generic MIDI. Ardour will retain your selection after you choose one.

Creating new MIDI maps

The Basic Concept

Since the beginning of time (well, sometime early in the 2.X series), Ardour has had the concept of identifying each track and bus with a remote control ID. This ID uniquely identifies a track or bus so that when messages arrive from elsewhere via MIDI or OSC , we can determine which track or bus they are intended to control. See remote control IDs for more information. You just need to know that there is a "first track" and its remote control ID is 1, and so on.

Getting Started

MIDI bindings are stored in files with the suffix ".map" attached to their name. The minimal content looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<ArdourMIDIBindings version="1.0.0" name="The name of this set of
bindings">
</ArdourMIDIBindings>

So, to start, create a file with that as the initial contents.

On OS X, Ardour loads midi maps from its binary-bundle folder in Ardour-<version>/midi_maps/ and checks various other locations as well (defined by the ARDOUR_MIDIMAPS_PATH environment variable). On GNU/Linux the easiest is to save the file to ~/.config/ardour3/midi_maps/.

Finding out what your MIDI control surface sends

This is the most complex part of the job, but its still not very hard. You need to connect the control surface to an application that will show you the information that the device sends each time you modify a knob, slider, button etc. There are a variety of such applications (notably gmidimon and kmidimon, but you can actually use Ardour for this if you want. Start Ardour in a terminal window, connect MIDI ports up, and in the Preferences window, enable "Trace Input" on the relevant MIDI port. A full trace of the MIDI data received will show up in the terminal window. (Note: in Ardour3, you get a dedicated, custom dialog for this kind of tracing.)

Types of Bindings

There are two basic kinds of bindings you can make between a MIDI message and something inside Ardour. The first is a binding to a specific parameter of a track or bus. The second is a binding to a function that will change Ardour's state in some way.

Binding to Track/Bus controls

A track/bus binding has one of two basic structures

Message specifications

You can create a binding for either 3 types of channel messages, or for a system exclusive ("sysex") message. A channel message specification looks like this:

This defines a binding for a MIDI Continuous Controller message involving controller 13, arriving on channel 1. There are 16 MIDI channels, numbered 1 to 16. Where the example above says ctl, you can alternatively use note (to create binding for a Note On message) or pgm (to create a binding for a Program Change message).

As of Ardour 4.2, enc-r, enc-l, enc-2 and enc-b may be used for surfaces that have encoders that send offsets rather than values. These accept Continuous Controller messages but treat them as offsets. These are good for banked controls as they are always at the right spot to start adjusting. ( Learn more about working with encoders )

You can also bind sysex messages:

The string after the sysex= part is the sequence of MIDI bytes, as hexadecimal values, that make up the sysex message.

Finally, you can bind a totally arbitrary MIDI message:

The string after the msg= part is the sequence of MIDI bytes, as hexadecimal values, that make up the message you want to bind. Using this is slightly less efficient than the other variants shown above, but is useful for some oddly designed control devices.

As of Ardour 4.6 it is possible to use multi-event MIDI strings such as two event CC messages, RPN or NRPN.

The sysex= and msg= bindings will only work with function= or action= control addresses. They will not work with the uri= control addresses. Controls used with uri= require a Value which is only available in a known place with channel mode MIDI events.

Control address

A control address defines what the binding will actually control. There are quite a few different things that can be specified here:

Each of the specifications needs an address, which takes various forms too. For track-level controls (solo/gain/mute/recenable), the address is one the following:

For send/insert/plugin controls, the address consists of a track/bus address (as just described) followed by a number identifying the plugin/send (starting from 1). For plugin parameters, there is an additional third component: a number identifying the plugin parameter number (starting from 1).

One additional feature: for solo and mute bindings, you can also add momentary="yes" after the control address. This is useful primarily for NoteOn bindings—when Ardour gets the NoteOn it will solo or mute the targetted track or bus, but then when a NoteOff arrives, it will un-solo or un-mute it.

Bindings to Ardour "functions"

Rather than binding to a specific track/bus control, it may be useful to have a MIDI controller able to alter some part of Ardour's state. A binding definition that does this looks like this:

In this case, a NoteOn message for note number 13 (on channel 1) will start the transport rolling. The following function names are available:

Binding to Ardour "actions"

You can also bind a sysex or arbitrary message to any of the items that occur in Ardour's main menu (and its submenus). The list of actions shows all available values of action-name.

To create a binding between an arbitrary MIDI message (we'll use a note-off on channel 1 of MIDI note 60 (hex) with release velocity 40 (hex)), the binding file would contain:

The general rule, when taken an item from the keybindings file and using it in a MIDI binding is to simply strip the <Action> prefix of the second field in the keybinding definition.

Banks and Banking

Because many modern control surfaces offer per-track/bus controls for far fewer tracks & busses than many users want to control, Ardour offers the relatively common place concept of banks. Banks allow you to control any number of tracks and/or busses easily, regardless of how many faders/knobs etc. your control surface has.
To use banking, the control addresses must be specified using the bank relative format mentioned above ("B1" to identify the first track of a bank of tracks, rather than "1" to identify the first track).

One very important extra piece of information is required to use banking: an extra line near the start of the list of bindings that specifies how many tracks/busses to use per bank. If the device has 8 faders, then 8 would be a sensible value to use for this. The line looks like this:

In addition, you probably want to ensure that you bind something on the control surface to the next-bank and prev-bank functions, otherwise you and other users will have to use the mouse and the GUI to change banks, which rather defeats the purpose of the bindings.

The Selected Strip

Often times one wants to just deal with the strip currently selected by the GUI (or the control surface). In the same way as with banks above the selected strip can be designated with S1.

A Complete (though muddled) Example

<?xml version="1.0" encoding="UTF-8"?>
<ArdourMIDIBindings version="1.0.0" name="pc1600x transport controls">
  <DeviceInfo bank-size="16"/>
  <Binding channel="1" ctl="1"   uri="/route/gain B1"/>
  <Binding channel="1" ctl="2"   uri="/route/gain B2"/>
  <Binding channel="1" ctl="3"   uri="/route/send/gain B1 1"/>
  <Binding channel="1" ctl="4"   uri="/route/plugin/parameter B1 1 1"/>
  <Binding channel="1" ctl="6"   uri="/bus/gain master"/>

  <Binding channel="1" note="1"  uri="/route/solo B1"/>
  <Binding channel="1" note="2"  uri="/route/solo B2" momentary="yes"/>

  <Binding channel="1" note="15"  uri="/route/mute B1" momentary="yes"/>
  <Binding channel="1" note="16"  uri="/route/mute B2" momentary="yes"/>

  <Binding sysex="f0 0 0 e 9 0 5b f7" function="transport-start"/>
  <Binding sysex="f0 7f 0 6 7 f7" function="rec-disable"/>
  <Binding sysex="f0 7f 0 6 6 f7" function="rec-enable"/>
  <Binding sysex="f0 0 0 e 9 0 53 0 0 f7" function="loop-toggle"/>

  <Binding channel="1" note="13" function="transport-roll"/>
  <Binding channel="1" note="14" function="transport-stop"/>
  <Binding channel="1" note="12" function="transport-start"/>
  <Binding channel="1" note="11" function="transport-zero"/>
  <Binding channel="1" note="10" function="transport-end"/>
</ArdourMIDIBindings>

Please note that channel, controller and note numbers are specified as decimal numbers in the ranges 1-16, 0-127 and 0-127 respectively (the channel range may change at some point).