godot/doc/classes/InputEventMIDI.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="InputEventMIDI" inherits="InputEvent" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
	<brief_description>
		Represents a MIDI message from a MIDI device, such as a musical keyboard.
	</brief_description>
	<description>
		InputEventMIDI stores information about messages from [url=https://en.wikipedia.org/wiki/MIDI]MIDI[/url] (Musical Instrument Digital Interface) devices. These may include musical keyboards, synthesizers, and drum machines.
		MIDI messages can be received over a 5-pin MIDI connector or over USB. If your device supports both be sure to check the settings in the device to see which output it is using.
		By default, Godot does not detect MIDI devices. You need to call [method OS.open_midi_inputs], first. You can check which devices are detected with [method OS.get_connected_midi_inputs], and close the connection with [method OS.close_midi_inputs].
		[codeblocks]
		[gdscript]
		func _ready():
		    OS.open_midi_inputs()
		    print(OS.get_connected_midi_inputs())

		func _input(input_event):
		    if input_event is InputEventMIDI:
		        _print_midi_info(input_event)

		func _print_midi_info(midi_event):
		    print(midi_event)
		    print("Channel ", midi_event.channel)
		    print("Message ", midi_event.message)
		    print("Pitch ", midi_event.pitch)
		    print("Velocity ", midi_event.velocity)
		    print("Instrument ", midi_event.instrument)
		    print("Pressure ", midi_event.pressure)
		    print("Controller number: ", midi_event.controller_number)
		    print("Controller value: ", midi_event.controller_value)
		[/gdscript]
		[csharp]
		public override void _Ready()
		{
		    OS.OpenMidiInputs();
		    GD.Print(OS.GetConnectedMidiInputs());
		}

		public override void _Input(InputEvent inputEvent)
		{
		    if (inputEvent is InputEventMIDI midiEvent)
		    {
		        PrintMIDIInfo(midiEvent);
		    }
		}

		private void PrintMIDIInfo(InputEventMIDI midiEvent)
		{
		    GD.Print(midiEvent);
		    GD.Print($"Channel {midiEvent.Channel}");
		    GD.Print($"Message {midiEvent.Message}");
		    GD.Print($"Pitch {midiEvent.Pitch}");
		    GD.Print($"Velocity {midiEvent.Velocity}");
		    GD.Print($"Instrument {midiEvent.Instrument}");
		    GD.Print($"Pressure {midiEvent.Pressure}");
		    GD.Print($"Controller number: {midiEvent.ControllerNumber}");
		    GD.Print($"Controller value: {midiEvent.ControllerValue}");
		}
		[/csharp]
		[/codeblocks]
		[b]Note:[/b] Godot does not support MIDI output, so there is no way to emit MIDI messages from Godot. Only MIDI input is supported.
	</description>
	<tutorials>
		<link title="MIDI Message Status Byte List">https://www.midi.org/specifications-old/item/table-2-expanded-messages-list-status-bytes</link>
		<link title="Wikipedia General MIDI Instrument List">https://en.wikipedia.org/wiki/General_MIDI#Program_change_events</link>
		<link title="Wikipedia Piano Key Frequencies List">https://en.wikipedia.org/wiki/Piano_key_frequencies#List</link>
	</tutorials>
	<members>
		<member name="channel" type="int" setter="set_channel" getter="get_channel" default="0">
			The MIDI channel of this message, ranging from [code]0[/code] to [code]15[/code]. MIDI channel [code]9[/code] is reserved for percussion instruments.
		</member>
		<member name="controller_number" type="int" setter="set_controller_number" getter="get_controller_number" default="0">
			The unique number of the controller, if [member message] is [constant MIDI_MESSAGE_CONTROL_CHANGE], otherwise this is [code]0[/code]. This value can be used to identify sliders for volume, balance, and panning, as well as switches and pedals on the MIDI device. See the [url=https://en.wikipedia.org/wiki/General_MIDI#Controller_events]General MIDI specification[/url] for a small list.
		</member>
		<member name="controller_value" type="int" setter="set_controller_value" getter="get_controller_value" default="0">
			The value applied to the controller. If [member message] is [constant MIDI_MESSAGE_CONTROL_CHANGE], this value ranges from [code]0[/code] to [code]127[/code], otherwise it is [code]0[/code]. See also [member controller_value].
		</member>
		<member name="instrument" type="int" setter="set_instrument" getter="get_instrument" default="0">
			The instrument (also called [i]program[/i] or [i]preset[/i]) used on this MIDI message. This value ranges from [code]0[/code] to [code]127[/code].
			To see what each value means, refer to the [url=https://en.wikipedia.org/wiki/General_MIDI#Program_change_events]General MIDI's instrument list[/url]. Keep in mind that the list is off by 1 because it does not begin from 0. A value of [code]0[/code] corresponds to the acoustic grand piano.
		</member>
		<member name="message" type="int" setter="set_message" getter="get_message" enum="MIDIMessage" default="0">
			Represents the type of MIDI message (see the [enum MIDIMessage] enum).
			For more information, see the [url=https://www.midi.org/specifications-old/item/table-2-expanded-messages-list-status-bytes]MIDI message status byte list chart[/url].
		</member>
		<member name="pitch" type="int" setter="set_pitch" getter="get_pitch" default="0">
			The pitch index number of this MIDI message. This value ranges from [code]0[/code] to [code]127[/code].
			On a piano, the [b]middle C[/b] is [code]60[/code], followed by a [b]C-sharp[/b] ([code]61[/code]), then a [b]D[/b] ([code]62[/code]), and so on. Each octave is split in offsets of 12. See the "MIDI note number" column of the [url=https://en.wikipedia.org/wiki/Piano_key_frequencies]piano key frequency chart[/url] a full list.
		</member>
		<member name="pressure" type="int" setter="set_pressure" getter="get_pressure" default="0">
			The strength of the key being pressed. This value ranges from [code]0[/code] to [code]127[/code].
			[b]Note:[/b] For many devices, this value is always [code]0[/code]. Other devices such as musical keyboards may simulate pressure by changing the [member velocity], instead.
		</member>
		<member name="velocity" type="int" setter="set_velocity" getter="get_velocity" default="0">
			The velocity of the MIDI message. This value ranges from [code]0[/code] to [code]127[/code]. For a musical keyboard, this corresponds to how quickly the key was pressed, and is rarely above [code]110[/code] in practice.
			[b]Note:[/b] Some MIDI devices may send a [constant MIDI_MESSAGE_NOTE_ON] message with [code]0[/code] velocity and expect it to be treated the same as a [constant MIDI_MESSAGE_NOTE_OFF] message. If necessary, this can be handled with a few lines of code:
			[codeblock]
			func _input(event):
			    if event is InputEventMIDI:
			        if event.message == MIDI_MESSAGE_NOTE_ON and event.velocity &gt; 0:
			            print("Note pressed!")
			[/codeblock]
		</member>
	</members>
</class>