path: root/manual/xml/midi_configuration.xml

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<section id="sn-midi-configuration">
	<title>Midi Configuration</title>
	<para>
		Although at this time Ardour does not support
		<glossterm linkend="gt-midi">MIDI</glossterm> sequencing, it does support a
		fairly rich set of interactions via MIDI with other devices. In particular:
	</para>

	<itemizedlist>
		<listitem>
			<para>
				Ardour can function as MIDI Time Code (MTC) master or slave
			</para>
		</listitem>
		<listitem>
			<para>
				Ardour can control or be controlled by other devices using MIDI Machine
				Control (MMC)
			</para>
		</listitem>
		<listitem>
			<para>
				Ardour can bind all gain faders, panners, mute/solo/rec-enable buttons and
				all plugin parameters to be controlled by MIDI Continuous Controller (CC)
				or Note On/Off messages.
			</para>
		</listitem>
		<listitem>
			<para>
				Ardour can send MIDI "feedback" whenever gain, pan or plugin state
				changes, so that external motorized control surfaces can reflect parameter
				changes caused by automation etc.
			</para>
		</listitem>
	</itemizedlist>

	<section id="specifying-midi-ports">
		<title>Specifying MIDI ports</title>
		<para>
			Ardour does not attempt to discover what MIDI ports exist on your system.
			This is a complex issue, and on systems like Linux and OS X that permit
			virtual ports to be created at any time, it is not trivial to get right
			(although future versions of Ardour may try).
		</para>

		<para>
			Instead, the MIDI ports that are available for Ardour to use are defined in
			your <filename>ardour.rc</filename> file. These port definitions are not
			session specific, on the assumption that your system's MIDI hardware
			probably doesn't change much from session to session. The default version
			of this file contains a single port that can be used for inter-application
			MIDI routing as well as MIDI I/O to whatever physical MIDI ports might be
			available on your computer. In many cases, you will not need to change
			them.
		</para>

		<para>
			When you first use Ardour, the
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			<filename>ardour.rc</filename> file that you will have contains a single
			port definition. It defines a port that is almost guaranteed to be usable
			on your system ((Linux/ALSA users may need to ensure that the
			<filename>snd-seq</filename> kernel module gets loaded - many distributions
			do not do this by default)). This port is a "virtual port" it isn't
			actually a hardware MIDI port, but instead is a software port that can be
			connected to other software ports or to whatever hardware MIDI ports you
			have (see <xref linkend="midi-making-connections"/>).
		</para>
	</section>
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	<section id="defining-additional-midi-ports">
		<title>Defining additional MIDI ports</title>
		<para>
			To define additional ports, find the line in <filename>ardour.rc</filename>
			that looks roughly like this:
		</para>
<screen>
&lt;MIDI-port tag="hw:0" device="/dev/snd/midiC1D0" type="alsa/raw" mode="duplex"/&gt;
		</screen>
		<para>
			On OSX/CoreMIDI it would look more like:
		</para>
<screen width="50">
&lt;MIDI-port tag="coremidi" device="ardour" type="coremidi" mode="duplex"/&gt;
		</screen>
		<para>
			You can then add another line right after it that looks similar but
			contains a different port definition.
		</para>

		<para>
			You will see there are 4 pieces of information required to define a MIDI
			port for use within Ardour. Your port definition
		</para>

		<section id="midi-tag">
			<title>Tag</title>
			<para>
				This is just a name of your own choosing. It is how the port will be
				referred to within Ardour. You could use a name that describes what is
				plugged into the port (e.g. "1600x", "Novation"), or a name that describes
				the computer device/system that provides the port (e.g. "HDSP",
				"Sequencer"), or a whimsical name of your own choice (e.g. "bowtie",
				"merlin").
			</para>
		</section>

		<section id="midi-type">
			<title>Type</title>
			<para>
				This is an operating system specific identifier that defines what kind of
				port this is. It can be set to one of three values:
			</para>

			<itemizedlist>
				<listitem>
					<para>
						<literal>alsa/raw</literal> - the port corresponds to a physical MIDI
						port that is accessed directly without involving the ALSA MIDI routing
						subsystem.
					</para>
				</listitem>
				<listitem>
					<para>
						<literal>alsa/sequencer</literal> - the port is a virtual port that can
						send and receive MIDI data via the ALSA MIDI routing subsystem.
					</para>
				</listitem>
				<listitem>
					<para>
						<literal>coremidi</literal> - the port is a virtual port that can send
						and receive MIDI data via the CoreMidi inter-application MIDI routing
						subsystem.
					</para>
				</listitem>
			</itemizedlist>
		</section>

		<section id="midi-device">
			<title>Device</title>
			<para>
				This is an operating specific and MIDI subsystem-specific name that
				actually identifies the device to be used for MIDI I/O.
			</para>

			<itemizedlist>
				<listitem>
					<para>
						for a raw ALSA hardware port, it is the name of the device file
						corresponding to the hardware MIDI port. A typical value might be
						<filename>/dev/snd/midiC0D0/</filename>.
					</para>
				</listitem>
				<listitem>
					<para>
						for an ALSA sequencer port, it is an arbitrary name for the port that
						will appear as part of the ALSA MIDI routing system
					</para>
				</listitem>
				<listitem>
					<para>
						for a CoreMIDI port, it is an arbitrary name for the port that will
						appear as in any CoreMIDI port selection dialogs.
					</para>
				</listitem>
			</itemizedlist>
		</section>

		<section id="midi-mode">
			<title>Mode</title>
			<para>
				This specifies whether the port is available for input, output or both:
			</para>

			<itemizedlist>
				<listitem>
					<para>
						<literal>read</literal> - the port is available for input only
					</para>
				</listitem>
				<listitem>
					<para>
						<literal>write</literal> - the port is available for output only
					</para>
				</listitem>
				<listitem>
					<para>
						<literal>duplex</literal> - the port is available for input and output
					</para>
				</listitem>
			</itemizedlist>

			<para>
				You should probably always use <literal>duplex</literal> here. It is rare to need to open a
				port for unidirectional communication only.
			</para>
		</section>
	</section>

	<section id="midi-removing-ports">
		<title>Removing Midi Ports</title>
		<para>
			To remove a MIDI port, simply delete the line in your
			<filename>ardour.rc</filename> file that defines it.
		</para>
	</section>

	<section id="midi-making-connections">
		<title>Making Connections</title>
		<para>
			If you use actual physical hardware MIDI ports, then establishing
			connections to other MIDI equipment is simply a matter of connecting cables
			correctly. However, if you use "virtual ports" such as those offered by the
			ALSA router/sequencer or CoreMIDI, making connections is slightly more
			involved.
		</para>

		<para>
			Ardour does not come with any way of establishing MIDI connections from/to
			other software MIDI ports. This is a difficult task to get right, and
			Ardour may offer something in the future. For now, you need to use an
			external tool that is dedicated to this purpose, much the same way you
			would use a patchbay (audio/MIDI) with physical equipment.
		</para>

		<section id="midi-connections-alsa">
			<title>Linux/ALSA</title>
			<para>
				<application>qjackctl</application> (the same program that is recommended
				for controlling JACK) also includes an excellent MIDI connection manager.
				You could also use command line tools such as
				<application>aconnect</application>.
			</para>
		</section>

		<section id="midi-connection-osx">
			<title>OSX/CoreMIDI</title>
			<para>
				On OSX/CoreMIDI you need to connect the MIDI ports with a patchbay tool
				such as the excellent MIDI Patchbay from
				<ulink url="http://pete.yandell.com/software/">Pete Yandell</ulink>
			</para>
		</section>
	</section>

	<section id="midi-using-midi-ports">
		<title>Using MIDI ports</title>
		<para>
			Each port that is defined in <filename>ardour.rc</filename> can be used for
			any of the following functions:
		</para>

		<itemizedlist>
			<listitem>
				<para>
					MTC input and output
				</para>
			</listitem>
			<listitem>
				<para>
					MMC input and output
				</para>
			</listitem>
			<listitem>
				<para>
					MIDI CC/Note input and output
				</para>
			</listitem>
		</itemizedlist>
	</section>
</section>