MidiEvent - abudaan/qambi GitHub Wiki
####MIDI Events
Some MIDI events are only sent over a specific channel, these events are called channel events. Note on and note off events are examples of channel events. By default, all MIDI events are sent to channel 1. You only have to worry about channel numbers if you want to use external soft- or hardware devices for playback or processing of MIDI events.
There are 2 ways you can set a channel for an event: 1) add an extra fifth parameter to the constructor, or 2) add the zero-based value of the channel number to value of the event type. For instance we want to send a C4 note with velocity 100 over channel 5 at ticks position 480:
// with additional fifth parameter
sequencer.createMidiEvent(480, sequencer.NOTE_ON, 60, 100, 5)
// add channel to event type, note: 5 zero-based is 4
sequencer.createMidiEvent(480, sequencer.NOTE_ON + 4, 60, 100)
sequencer.createMidiEvent(480, 148, 60, 100) // same a above
sequencer.createMidiEvent(480, 0x94, 60, 100) // same a above, hexadecimalIn the second way, you pass a so called status byte instead of an event type. A status byte is the sum of a command and a zero-based channel number. This is according to the MIDI standard. The MIDI protocol is very efficient and it doesn't want to use an extra byte for the channel number, so instead the event type (command) and channel number are combined in one single byte:
| NOTE OFF | 128 | 0x80 |
|---|---|---|
| channel 1 | 128 | 0x80 |
| channel 2 | 129 | 0x81 |
| channel 3 | 130 | 0x82 |
| channel 4 | 131 | 0x83 |
| channel 5 | 132 | 0x84 |
| channel 6 | 133 | 0x85 |
| channel 7 | 134 | 0x86 |
| channel 8 | 135 | 0x87 |
| channel 9 | 136 | 0x88 |
| channel 10 | 137 | 0x89 |
| channel 11 | 138 | 0x8A |
| channel 12 | 139 | 0x8B |
| channel 13 | 140 | 0x8C |
| channel 14 | 141 | 0x8D |
| channel 15 | 142 | 0x8E |
| channel 16 | 143 | 0x8F |
| NOTE ON | 144 | 0x90 |
|---|---|---|
| channel 1 | 145 | 0x90 |
| channel 2 | 146 | 0x91 |
| channel 3 | 147 | 0x92 |
| channel 4 | 148 | 0x93 |
| channel 5 | 149 | 0x94 |
| and so on. |
#####Properties
#####.id >String, read only
Unique id of the event. The id start with an M, followed by the event number and the date in milliseconds.
#####.eventNumber >Number, read only
Consecutive number of the event. The number starts at 0 every time the sequencer is initialized.
#####.ticks >Number, read only
Position of the event in ticks
#####.type >Number, read only
MIDI type of the event, see Sequencer
#####.data1 >Number, read only
The data1 byte of the MIDI event.
#####.data2 >Number, read only
The data2 byte of the MIDI event.
#####.muted >Boolean, read & write
Mutes or unmutes the event.
- - - *only available for channel events:*
#####.channel
Number, read only
The MIDI channel that this event gets sent to during playback. Has only effect if you send event to an external soft- or hardware MIDI device.
#####.command >Number, read only
Has the same value a type.
#####.status >Number, read only
The sum of command and channel, for example if you create a note on event for channel 3, the value of status will be 144 + 3 = 147.
- - - *only available for note on and note off events:* - - -
#####.note >Object, read only
A Note object based on the event's note number
#####.noteName >String, read only
The full note name of event's note, e.g. C4
#####.noteNumber >Number, read only
The note number, same as data1
#####.velocity >Number, read only
The velocity, same as data1
#####.octave >Number, read only
The octave of the event's note.
#####.frequency >Float, read only
The frequency of the event's note.
- - - *only available for tempo events:* - - -
#####.tempo >Number, read only
The tempo in BPM of the tempo event
- - - *only available for time signature events:* - - -
#####.nominator >Number, read only
The nominator of the new time sigature, e.g. 6/8
#####.denominator >Number, read only
The denominator of the new time sigature, e.g. 6/8
#####Methods
#####.clone()
Returns a clone of the MidiEvent. All members are copied to a new MidiEvent instance, so id and eventNumber of the clone are unique.
#####.move(ticks) >Number
Set the add or subtracts ticks from the ticks value of the event.
#####.moveTo(...position) >Position
Sets the ticks value of the event to the ticks value of the provided position. See position. You can only use this method on events that already have been added to a song. This is because calculating the position depends on the song's tempo and time-signature events.
let event = sequencer.createMidiEvent(0, sequencer.NOTE_ON, 60, 100);
// move event to the first beat of the fifth bar
event.moveTo('barsandbeats', 5, 1, 1, 0)#####.transpose(semitones) >Number
Transposes the event by the provided number of semitones. Float values are rounded to whole numbers. You can provide both negative and positive numbers.
#####.setPitch(noteNumber) >Number
Transposes the event to the provided MIDI note number.
#####.reset([fromPart=true, fromTrack=true, fromSong=true]) >[Boolean, Boolean, Boolean]
If an event is added to a part, that part is referenced by the member part of the event. If the part is added to a track, that track is referenced by the member track of the event. And if the track is added to a song, that song is referenced by the song member of the event. With the method reset you can clear these references. The method is called automatically as soon as you remove the event from a part, a track or a song, so you shouldn't have to use this method very often.