erhabor-fona/midi_util

a pure dart library that allows one to write multi-track Musical Instrument Digital Interface (MIDI) files from within dart programs

midi_util

Inspired by the python library -MIDIUtil written by Mark Conway Wirt, midi_util is a pure dart library that allows one to create MIDI files (Musical Instrument Digital Interface) within a dart program with minimum fuss, and supports both format 1 and 2 files. Due to the large documentation as well as the organic growth of the MIDI files specifications, midi_util has been made to effectively implement aspects of this specifications that are commonly used and are in high demand. The midi_util package is properly structured to give anyone with a good understanding of the MIDI file format, and demonstrates a good understanding of object oriented programming with dart the ability to extend the library -Henc all of these makes this package easy to understand

import 'dart:io';

import 'package:midi_util/midi_util.dart';

void main() {
  List notes = [60, 62, 64, 65, 67, 69, 71, 72]; //  # MIDI note number
  var track = 0;
  var channel = 0;
  var time = 0; //    # In beats
  var duration = 0.5; //    # In beats
  var tempo = 60; //   # In BPM
  var volume = 100; //  # 0-127, as per the MIDI standard

  MIDIFile myMIDI = MIDIFile(numTracks: 2);
  myMIDI.addTempo(
    track: track,
    time: time,
    tempo: tempo,
  );
  myMIDI.addKeySignature(
      track: track,
      time: time,
      no_of_accidentals: 0,
      accidental_mode: AccidentalMode.MAJOR,
      accidental_type: AccidentalType.SHARPS);

  List.generate(notes.length, (i) {
    myMIDI.addNote(
        track: track,
        channel: channel,
        pitch: notes[i],
        time: time + i,
        duration: duration,
        volume: 100);
  });

  var outputFile = File('c_scale.mid');
  myMIDI.writeFile(outputFile);
}

There are several additional event types that can be added and there are various options available for creating the MIDIFile object, but the above is sufficient to begin using the library and creating note sequences. The above code is found in machine-readable form in the examples directory. A detailed class reference and documentation describing how to extend the library is provided in the documentation directory.