webaudiofont
Version:
Soundfonts for web. About of 2000 musical instruments. GM MIDI compatible.
323 lines (322 loc) • 10.4 kB
JavaScript
'use strict'
console.log('WebAudioFont Player v2.82 GPL3');
var WebAudioFontLoader = require('./loader');
var WebAudioFontChannel = require('./channel');
var WebAudioFontReverberator = require('./reverberator')
function WebAudioFontPlayer() {
this.envelopes = [];
this.loader = new WebAudioFontLoader(this);
this.onCacheFinish = null;
this.onCacheProgress = null;
this.afterTime = 0.05;
this.nearZero = 0.000001;
this.createChannel = function (audioContext) {
return new WebAudioFontChannel(audioContext);
};
this.createReverberator = function (audioContext) {
return new WebAudioFontReverberator(audioContext);
};
this.limitVolume = function (volume) {
if (volume) {
volume = 1.0 * volume;
} else {
volume = 0.5;
}
return volume;
};
this.queueChord = function (audioContext, target, preset, when, pitches, duration, volume, slides) {
volume = this.limitVolume(volume);
for (var i = 0; i < pitches.length; i++) {
this.queueWaveTable(audioContext, target, preset, when, pitches[i], duration, volume - Math.random() * 0.01, slides);
}
};
this.queueStrumUp = function (audioContext, target, preset, when, pitches, duration, volume, slides) {
pitches.sort(function (a, b) {
return b - a;
});
this.queueStrum(audioContext, target, preset, when, pitches, duration, volume, slides);
};
this.queueStrumDown = function (audioContext, target, preset, when, pitches, duration, volume, slides) {
pitches.sort(function (a, b) {
return a - b;
});
this.queueStrum(audioContext, target, preset, when, pitches, duration, volume, slides);
};
this.queueStrum = function (audioContext, target, preset, when, pitches, duration, volume, slides) {
volume = this.limitVolume(volume);
if (when < audioContext.currentTime) {
when = audioContext.currentTime;
}
for (var i = 0; i < pitches.length; i++) {
this.queueWaveTable(audioContext, target, preset, when + i * 0.01, pitches[i], duration, volume - Math.random() * 0.01, slides);
volume = 0.9 * volume;
}
};
this.queueSnap = function (audioContext, target, preset, when, pitches, duration, volume, slides) {
volume = this.limitVolume(volume);
volume = 1.5 * (volume || 1.0);
duration = 0.05;
this.queueChord(audioContext, target, preset, when, pitches, duration, volume, slides);
};
this.resumeContext = function (audioContext) {
try {
if (audioContext.state == 'suspended') {
if (audioContext.constructor.name == 'AudioContext') {
console.log('audioContext.resume', audioContext);
audioContext.resume();
} else {
//skip
}
}
} catch (e) {
//don't care
}
}
this.queueWaveTable = function (audioContext, target, preset, when, pitch, duration, volume, slides) {
this.resumeContext(audioContext);
volume = this.limitVolume(volume);
var zone = this.findZone(audioContext, preset, pitch);
if (!(zone.buffer)) {
console.log('empty buffer ', zone);
return;
}
var baseDetune = zone.originalPitch - 100.0 * zone.coarseTune - zone.fineTune;
var playbackRate = 1.0 * Math.pow(2, (100.0 * pitch - baseDetune) / 1200.0);
var sampleRatio = zone.sampleRate / audioContext.sampleRate;
var startWhen = when;
if (startWhen < audioContext.currentTime) {
startWhen = audioContext.currentTime;
}
var waveDuration = duration + this.afterTime;
var loop = true;
if (zone.loopStart < 1 || zone.loopStart >= zone.loopEnd) {
loop = false;
}
if (!loop) {
if (waveDuration > zone.buffer.duration / playbackRate) {
waveDuration = zone.buffer.duration / playbackRate;
}
}
var envelope = this.findEnvelope(audioContext, target, startWhen, waveDuration);
this.setupEnvelope(audioContext, envelope, zone, volume, startWhen, waveDuration, duration);
envelope.audioBufferSourceNode = audioContext.createBufferSource();
envelope.audioBufferSourceNode.playbackRate.setValueAtTime(playbackRate, 0);
if (slides) {
if (slides.length > 0) {
envelope.audioBufferSourceNode.playbackRate.setValueAtTime(playbackRate, when);
for (var i = 0; i < slides.length; i++) {
var newPlaybackRate = 1.0 * Math.pow(2, (100.0 * slides[i].pitch - baseDetune) / 1200.0);
var newWhen = when + slides[i].when;
envelope.audioBufferSourceNode.playbackRate.linearRampToValueAtTime(newPlaybackRate, newWhen);
}
}
}
envelope.audioBufferSourceNode.buffer = zone.buffer;
if (loop) {
envelope.audioBufferSourceNode.loop = true;
envelope.audioBufferSourceNode.loopStart = zone.loopStart / zone.sampleRate + zone.delay;
envelope.audioBufferSourceNode.loopEnd = zone.loopEnd / zone.sampleRate + zone.delay;
} else {
envelope.audioBufferSourceNode.loop = false;
}
envelope.audioBufferSourceNode.connect(envelope);
envelope.audioBufferSourceNode.start(startWhen, zone.delay);
envelope.audioBufferSourceNode.stop(startWhen + waveDuration);
envelope.when = startWhen;
envelope.duration = waveDuration;
envelope.pitch = pitch;
envelope.preset = preset;
return envelope;
};
this.noZeroVolume = function (n) {
if (n > this.nearZero) {
return n;
} else {
return this.nearZero;
}
};
this.setupEnvelope = function (audioContext, envelope, zone, volume, when, sampleDuration, noteDuration) {
envelope.gain.setValueAtTime(this.noZeroVolume(0), audioContext.currentTime);
var lastTime = 0;
var lastVolume = 0;
var duration = noteDuration;
var ahdsr = zone.ahdsr;
if (sampleDuration < duration + this.afterTime) {
duration = sampleDuration - this.afterTime;
}
if (ahdsr) {
if (!(ahdsr.length > 0)) {
ahdsr = [{
duration: 0,
volume: 1
}, {
duration: 0.5,
volume: 1
}, {
duration: 1.5,
volume: 0.5
}, {
duration: 3,
volume: 0
}
];
}
} else {
ahdsr = [{
duration: 0,
volume: 1
}, {
duration: duration,
volume: 1
}
];
}
envelope.gain.cancelScheduledValues(when);
envelope.gain.setValueAtTime(this.noZeroVolume(ahdsr[0].volume * volume), when);
for (var i = 0; i < ahdsr.length; i++) {
if (ahdsr[i].duration > 0) {
if (ahdsr[i].duration + lastTime > duration) {
var r = 1 - (ahdsr[i].duration + lastTime - duration) / ahdsr[i].duration;
var n = lastVolume - r * (lastVolume - ahdsr[i].volume);
envelope.gain.linearRampToValueAtTime(this.noZeroVolume(volume * n), when + duration);
break;
}
lastTime = lastTime + ahdsr[i].duration;
lastVolume = ahdsr[i].volume;
envelope.gain.linearRampToValueAtTime(this.noZeroVolume(volume * lastVolume), when + lastTime);
}
}
envelope.gain.linearRampToValueAtTime(this.noZeroVolume(0), when + duration + this.afterTime);
};
this.numValue = function (aValue, defValue) {
if (typeof aValue === "number") {
return aValue;
} else {
return defValue;
}
};
this.findEnvelope = function (audioContext, target, when, duration) {
var envelope = null;
for (var i = 0; i < this.envelopes.length; i++) {
var e = this.envelopes[i];
if (e.target == target && audioContext.currentTime > e.when + e.duration + 0.001) {
try {
e.audioBufferSourceNode.disconnect();
e.audioBufferSourceNode.stop(0);
e.audioBufferSourceNode = null;
} catch (x) {
//audioBufferSourceNode is dead already
}
envelope = e;
break;
}
}
if (!(envelope)) {
envelope = audioContext.createGain();
envelope.target = target;
envelope.connect(target);
envelope.cancel = function () {
if (envelope.when + envelope.duration > audioContext.currentTime) {
envelope.gain.cancelScheduledValues(0);
envelope.gain.setTargetAtTime(0.00001, audioContext.currentTime, 0.1);
envelope.when = audioContext.currentTime + 0.00001;
envelope.duration = 0;
}
};
this.envelopes.push(envelope);
}
return envelope;
};
this.adjustPreset = function (audioContext, preset) {
for (var i = 0; i < preset.zones.length; i++) {
this.adjustZone(audioContext, preset.zones[i]);
}
};
this.adjustZone = function (audioContext, zone) {
if (zone.buffer) {
//
} else {
zone.delay = 0;
if (zone.sample) {
var decoded = atob(zone.sample);
zone.buffer = audioContext.createBuffer(1, decoded.length / 2, zone.sampleRate);
var float32Array = zone.buffer.getChannelData(0);
var b1,
b2,
n;
for (var i = 0; i < decoded.length / 2; i++) {
b1 = decoded.charCodeAt(i * 2);
b2 = decoded.charCodeAt(i * 2 + 1);
if (b1 < 0) {
b1 = 256 + b1;
}
if (b2 < 0) {
b2 = 256 + b2;
}
n = b2 * 256 + b1;
if (n >= 65536 / 2) {
n = n - 65536;
}
float32Array[i] = n / 65536.0;
}
} else {
if (zone.file) {
var datalen = zone.file.length;
var arraybuffer = new ArrayBuffer(datalen);
var view = new Uint8Array(arraybuffer);
var decoded = atob(zone.file);
var b;
for (var i = 0; i < decoded.length; i++) {
b = decoded.charCodeAt(i);
view[i] = b;
}
audioContext.decodeAudioData(arraybuffer, function (audioBuffer) {
zone.buffer = audioBuffer;
});
}
}
zone.loopStart = this.numValue(zone.loopStart, 0);
zone.loopEnd = this.numValue(zone.loopEnd, 0);
zone.coarseTune = this.numValue(zone.coarseTune, 0);
zone.fineTune = this.numValue(zone.fineTune, 0);
zone.originalPitch = this.numValue(zone.originalPitch, 6000);
zone.sampleRate = this.numValue(zone.sampleRate, 44100);
zone.sustain = this.numValue(zone.originalPitch, 0);
}
};
this.findZone = function (audioContext, preset, pitch) {
var zone = null;
for (var i = preset.zones.length - 1; i >= 0; i--) {
zone = preset.zones[i];
if (zone.keyRangeLow <= pitch && zone.keyRangeHigh + 1 >= pitch) {
break;
}
}
try {
this.adjustZone(audioContext, zone);
} catch (ex) {
console.log('adjustZone', ex);
}
return zone;
};
this.cancelQueue = function (audioContext) {
for (var i = 0; i < this.envelopes.length; i++) {
var e = this.envelopes[i];
e.gain.cancelScheduledValues(0);
e.gain.setValueAtTime(this.nearZero, audioContext.currentTime);
e.when = -1;
try {
e.audioBufferSourceNode.disconnect();
} catch (ex) {
console.log(ex);
}
}
};
return this;
}
if (typeof module === 'object' && module.exports) {
module.exports = WebAudioFontPlayer;
}
if (typeof window !== 'undefined') {
window.WebAudioFontPlayer = WebAudioFontPlayer;
}