/**
* File : media/MidiAudioPlayer.js
* Created : 11/10/2018
* By : Francesc Busquets <francesc@gmail.com>
*
* JClic.js
* An HTML5 player of JClic activities
* https://projectestac.github.io/jclic.js
*
* @source https://github.com/projectestac/jclic.js
*
* @license EUPL-1.2
* @licstart
* (c) 2000-2020 Educational Telematic Network of Catalonia (XTEC)
*
* Licensed under the EUPL, Version 1.1 or -as soon they will be approved by
* the European Commission- subsequent versions of the EUPL (the "Licence");
* You may not use this work except in compliance with the Licence.
*
* You may obtain a copy of the Licence at:
* https://joinup.ec.europa.eu/software/page/eupl
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the Licence is distributed on an "AS IS" basis, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* Licence for the specific language governing permissions and limitations
* under the Licence.
* @licend
* @module
*/
/* global window */
import MidiPlayer from '@francesc/basic-midi-player-js';
import { log } from '../Utils';
// TODO: Use multiple instruments, at least one for each track
// TODO: Use multiple midi channels (currently flattened to a single channel)
// TODO: Use of channel 10 for percussion instruments
// TODO: ... build a real MIDI player!!
/**
* A simple MIDI player based on MidiPlayerJS
* https://github.com/grimmdude/MidiPlayerJS
* See also: http://www.midijs.net (https://github.com/babelsberg/babelsberg-js/tree/master/midijs)
*/
export class MidiAudioPlayer {
/**
* MidiAudioPlayer constructor
* @param {external:ArrayBuffer} data - The MIDI file content, in ArrayBuffer format
* @param {object} [options={}] - Optional params related to the type of soundfont used. Valid options inside this object are:<br>
* - `MIDISoundFontObject`: An object containing the full soundfont data. When this param is provided, no other one will be used.
* - `MIDISoundFontBase`: The URL used as base for the current collection of MIDI soundfonts. Defaults to `https://clic.xtec.cat/dist/jclic.js/soundfonts/MusyngKite`
* - `MIDISoundFontName`: The MIDI instrument name. Defaults to `acoustic_grand_piano`. See [MIDI.js Soundfonts](https://github.com/gleitz/midi-js-soundfonts) for full lists of MIDI instrument names.
* - `MIDISoundFontExtension`: An extension to be added to `MIDISoundFontName` in order to build the full file name of the soundfont JS file. Defaults to `-mp3.js`
*/
constructor(data, options = {}) {
const AudioContext = window && (window.AudioContext || window.webkitAudioContext);
if (AudioContext) {
// Build instrument on first call to constructor
MidiAudioPlayer.prepareInstrument(options, new AudioContext());
this.data = data;
this.player = new MidiPlayer.Player(ev => this.playEvent(ev));
if (this.player)
this.player.loadArrayBuffer(data);
}
}
/**
* Initializes the soundfont instrument, loading data from GitHub
* NOTE: This will not work when off-line!
* TODO: Provided a basic, simple, static soundfont
* @param {object} options - Optional param with options related to the MIDI soundfont. See details in `constructor` description.
* @param {external:AudioContext} audioContext - The AudioContext object (see: https://developer.mozilla.org/en-US/docs/Web/API/AudioContext)
*/
static prepareInstrument(options = {}, audioContext) {
if (MidiAudioPlayer.loadingInstrument === false) {
MidiAudioPlayer.loadingInstrument = true;
MidiAudioPlayer.audioContext = audioContext;
MidiPlayer.Soundfont.instrument(
MidiAudioPlayer.audioContext,
options.MIDISoundFontObject || MidiAudioPlayer.MIDISoundFontObject ||
`${options.MIDISoundFontBase || MidiAudioPlayer.MIDISoundFontBase}/${options.MIDISoundFontName || MidiAudioPlayer.MIDISoundFontName}${options.MIDISoundFontExtension || MidiAudioPlayer.MIDISoundFontExtension}`)
.then(instrument => {
log('info', 'MIDI soundfont instrument loaded');
MidiAudioPlayer.instrument = instrument;
})
.catch(err => {
log('error', `Error loading soundfont base instrument: ${err}`);
});
}
}
/**
* Pauses the player
*/
pause() {
if (this.player) {
this.player.pause();
this.startedNotes = [];
}
}
/**
* Starts or resumes playing
*/
play() {
if (this.player) {
this.startedNotes = [];
this.player.play();
}
}
/**
* Gets the ' paused' state of the current player
* @returns boolean
*/
get paused() {
return this.player && !this.player.isPlaying();
}
/**
* Checks if the current player has ended or is already playing
* @returns boolean
*/
get ended() {
return this.player && this.player.getSongTimeRemaining() <= 0;
}
/**
* Gets the current time
* @returns number
*/
get currentTime() {
return this.player && (this.player.getSongTime() * 1000) || 0;
}
/**
* Sets the current time of this player (in milliseconds)
* @param {number} time - The time position where the player pointer must be placed
*/
set currentTime(time) {
if (this.player)
this.player.skipToSeconds(time / 1000);
}
/**
* Plays a MIDI event
* @param {object} ev - The event data. See http://grimmdude.com/MidiPlayerJS/docs/index.html for details
*/
playEvent(ev) {
if (this.player && MidiAudioPlayer.instrument) {
// Check for specific interval
if (this.playTo > 0 && this.currentTime >= this.playTo)
this.pause();
// Set main volume
else if (ev.name === 'Controller Change' && ev.number === 7)
this.mainVolume = ev.value / 127;
// Process 'Note on' messages. Max gain set to 2.0 for better results with the used soundfont
else if (ev.name === 'Note on' && ev.velocity > 0)
this.startedNotes[ev.noteNumber] = MidiAudioPlayer.instrument.play(ev.noteName, MidiAudioPlayer.audioContext.currentTime, { gain: 2 * (this.mainVolume * ev.velocity / 100) });
// Process 'Note off' messages
else if (ev.name === 'Note off' && ev.noteNumber && this.startedNotes[ev.noteNumber]) {
this.startedNotes[ev.noteNumber].stop();
delete (this.startedNotes[ev.noteNumber]);
}
}
}
}
Object.assign(MidiAudioPlayer.prototype, {
/**
* The MIDI file data used by this MIDI player
* @name module:media/MidiAudioPlayer.MidiAudioPlayer#data
* @type {external:ArrayBuffer} */
data: null,
/**
* The grimmdude's MidiPlayer used by this player
* @name module:media/MidiAudioPlayer.MidiAudioPlayer#player
* @type {external:MidiPlayerJS} */
player: null,
/**
* When >0, time position at which the music must end
* @name module:media/MidiAudioPlayer.MidiAudioPlayer#playTo
* @type {number} */
playTo: 0,
/**
* Main volume of this track (set with a MIDI message of type `Controller Change` #7)
* @name module:media/MidiAudioPlayer.MidiAudioPlayer#mainVolume
* @type {number} */
mainVolume: 1.0,
/**
* This array is used when processing 'Note off' events to stop notes that are currently playing.
* It contains a collection of 'instrument.play' instances, one for each active note
* @name module:media/MidiAudioPlayer.MidiAudioPlayer#startedNotes
* @type {function[]} */
startedNotes: [],
});
/**
* The {@link external:AudioContext} used by this MIDI player.
* @type {external:AudioContext}
*/
MidiAudioPlayer.audioContext = null;
/**
* The "Instrument" object used by this MIDI player.
* See: https://github.com/danigb/soundfont-player
* @type {external:Instrument}
*/
MidiAudioPlayer.instrument = null;
/**
* A flag used to avoid re-entrant calls to {@link module:media/MidiAudioPlayer.MidiAudioPlayer#prepareInstrument prepareInstrument}
* @type {boolean}
*/
MidiAudioPlayer.loadingInstrument = false;
/**
* An object containing the full soundfont data used by {@link module:media/MidiAudioPlayer.MidiAudioPlayer#instrument instrument}
* When this member is set, no other settings related to the sounfFont will be used.
* This value can be overwritten by the global parameter `MIDISoundFontObject`
* @type {object}
*/
MidiAudioPlayer.MIDISoundFontObject = null;
/**
* The URL used as base for the current collection of MIDI soundfonts.
* This value can be overwritten by the global parameter `MIDISoundFontBase`
* @type {string}
*/
MidiAudioPlayer.MIDISoundFontBase = 'https://clic.xtec.cat/dist/jclic.js/soundfonts/MusyngKite';
// Alternative sites are:
// 'https://clic.xtec.cat/dist/jclic.js/soundfonts/FluidR3_GM'
// 'https://raw.githubusercontent.com/gleitz/midi-js-soundfonts/gh-pages/FluidR3_GM'
// 'https://raw.githubusercontent.com/gleitz/midi-js-soundfonts/gh-pages/MusyngKite'
/**
* The MIDI instrument name.
* This value can be overwritten by the global parameter `MIDISoundFontName`
* See [MIDI.js Soundfonts](https://github.com/gleitz/midi-js-soundfonts) for full lists of MIDI instrument names.
* @type {string}
*/
MidiAudioPlayer.MIDISoundFontName = 'acoustic_grand_piano';
/**
* An extension to be added to `MIDISoundFontName` in order to build the full file name of the soundfont JS file.
* Current valid options are `-mp3.js` and `-ogg.js`
* This value can be overwritten by the global parameter `MIDISoundFontExtension`
* @type {string}
*/
MidiAudioPlayer.MIDISoundFontExtension = '-mp3.js';
export default MidiAudioPlayer;