(function() {
var onDOMContentLoaded = function() {
window.AudioContext = window.AudioContext || window.webkitAudioContext;
try {
// Create the instance of AudioContext
var context = new AudioContext();
} catch (error) {
window.alert(error.message + ' : Please use Chrome or Safari.');
return;
}
// for the instance of AudioBufferSourceNode
var source = null;
// for legacy browsers
context.createGain = context.createGain || context.createGainNode;
// Create the instance of GainNode (for Master Volume)
var gain = context.createGain();
// Phaser
// Create the instance of OscillatorNode (for LFO)
var lfo = context.createOscillator();
// for leagcy browsers
lfo.start = lfo.start || lfo.noteOn;
lfo.stop = lfo.stop || lfo.noteOff;
var MAXIMUM_STAGES = 24;
var filters = new Array(MAXIMUM_STAGES);
for (var i = 0; i < MAXIMUM_STAGES; i++) {
// Create the instance of BiquadFilterNode
filters[i] = context.createBiquadFilter();
// All-Pass Filter
filters[i].type = (typeof filters[i].type === 'string') ? 'allpass' : 7;
// Initialize parameters for All-Pass Filter
filters[i].frequency.value = document.getElementById('range-phaser-frequency').valueAsNumber;
filters[i].Q.value = Math.SQRT1_2;
filters[i].gain.value = 0; // Not used
}
// for Phaser parameters
var numberOfStages = 0;
var depthRate = 0; // This value must be less than or equal to 1.0 (100%)
var depth = context.createGain();
var rate = lfo.frequency;
var mix = context.createGain();
var feedback = context.createGain();
// Initialize parameters for Phaser
numberOfStages = document.forms['form-phaser-stage'].elements['radio-phaser-stage'][1].value;
depthRate = document.getElementById('range-phaser-depth').valueAsNumber / 100;
depth.gain.value = document.getElementById('range-phaser-frequency').valueAsNumber * depthRate;
rate.value = document.getElementById('range-phaser-rate').valueAsNumber;
mix.gain.value = document.getElementById('range-phaser-mix').valueAsNumber;
feedback.gain.value = document.getElementById('range-phaser-feedback').valueAsNumber;
// Trigger 'ended' event
var trigger = function() {
var event = document.createEvent('Event');
event.initEvent('ended', true, true);
if (source instanceof AudioBufferSourceNode) {
source.dispatchEvent(event);
}
};
// This funciton is executed after getting ArrayBuffer of audio data
var startAudio = function(arrayBuffer) {
// The 2nd argument for decodeAudioData
var successCallback = function(audioBuffer) {
// The 1st argument (audioBuffer) is the instance of AudioBuffer
// If there is previous AudioBufferSourceNode, program stops previous audio
if ((source instanceof AudioBufferSourceNode) && (source.buffer instanceof AudioBuffer)) {
// Execute onended event handler
trigger();
source = null;
}
// Create the instance of AudioBufferSourceNode
source = context.createBufferSource();
// for legacy browsers
source.start = source.start || source.noteOn;
source.stop = source.stop || source.noteOff;
// Set the instance of AudioBuffer
source.buffer = audioBuffer;
// Set parameters
source.playbackRate.value = document.getElementById('range-playback-rate').valueAsNumber;
source.loop = document.querySelector('[type="checkbox"]').checked;
// GainNode (Master Volume) -> AudioDestinationNode (Output);
gain.connect(context.destination);
// Connect nodes for original audio
// AudioBufferSourceNode (Input) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(gain);
if (numberOfStages > 0) {
// Phaser ON
// Connect nodes for effect (Phaser) sound
// AudioBufferSourceNode (Input) -> BiquadFilterNode (All-Pass Filter) x N -> GainNode (Mix) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(filters[0]);
for (var i = 0; i < numberOfStages; i++) {
if (i < (numberOfStages - 1)) {
filters[i].connect(filters[i + 1]);
} else {
filters[i].connect(mix);
// Connect nodes for Feedback
// (AudioBufferSourceNode (Input) ->) BiquadFilterNode (All-Pass Filter) x N -> GainNode (Feedback) -> BiquadFilterNode (All-Pass Filter) x N -> ...
filters[i].connect(feedback);
feedback.connect(filters[0]);
}
}
mix.connect(gain);
} else {
// Phaser OFF
}
// Connect nodes for LFO that changes frequency in BiquadFilterNode (All-Pass Filter) periodically
// OscillatorNode (LFO) -> GainNode (Depth) -> frequency (AudioParam) x N
lfo.connect(depth);
for (var i = 0; i < MAXIMUM_STAGES; i++) {
depth.connect(filters[i].frequency);
}
// Start audio
source.start(0);
// Start LFO
lfo.start(0);
// Set Callback
source.onended = function(event) {
// Remove event handler
source.onended = null;
document.onkeydown = null;
// Stop audio
source.stop(0);
// Stop LFO
var type = lfo.type;
var frequency = lfo.frequency.value;
var detune = lfo.detune.value;
lfo.stop(0);
// for next start
lfo = context.createOscillator();
// for leagcy browsers
lfo.start = lfo.start || lfo.noteOn;
lfo.stop = lfo.stop || lfo.noteOff;
// Set parametres
lfo.type = type;
lfo.frequency.value = frequency;
lfo.detune.value = detune;
// Change reference
rate = lfo.frequency;
console.log('STOP by "on' + event.type + '" event handler !!');
// Audio is not started !!
// It is necessary to create the instance of AudioBufferSourceNode again
// Cannot replay
// source.start(0);
};
// Stop audio
document.onkeydown = function(event) {
// Space ?
if (event.keyCode !== 32) {
return;
}
// Execute onended event handler
trigger();
return false;
};
};
// The 3rd argument for decodeAudioData
var errorCallback = function(error) {
if (error instanceof Error) {
window.alert(error.message);
} else {
window.alert('Error : "decodeAudioData" method.');
}
};
// Create the instance of AudioBuffer (Asynchronously)
context.decodeAudioData(arrayBuffer, successCallback, errorCallback);
};
/*
* File Uploader
*/
document.getElementById('file-upload-audio').addEventListener('change', function(event) {
var uploader = this;
var progressArea = document.getElementById('progress-file-upload-audio');
// Get the instance of File (extends Blob)
var file = event.target.files[0];
if (!(file instanceof File)) {
window.alert('Please upload file.');
} else if (file.type.indexOf('audio') === -1) {
window.alert('Please upload audio file.');
} else {
// Create the instance of FileReader
var reader = new FileReader();
reader.onprogress = function(event) {
if (event.lengthComputable && (event.total > 0)) {
var rate = Math.floor((event.loaded / event.total) * 100);
progressArea.textContent = rate + ' %';
}
};
reader.onerror = function() {
window.alert('FileReader Error : Error code is ' + reader.error.code);
uploader.value = '';
};
// Success read
reader.onload = function() {
var arrayBuffer = reader.result; // Get ArrayBuffer
startAudio(arrayBuffer);
uploader.value = '';
progressArea.textContent = file.name;
};
// Read the instance of File
reader.readAsArrayBuffer(file);
}
}, false);
// Control Master Volume
document.getElementById('range-volume').addEventListener('input', function() {
var min = gain.gain.minValue || 0;
var max = gain.gain.maxValue || 1;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
gain.gain.value = this.valueAsNumber;
document.getElementById('output-volume').textContent = this.value;
}
}, false);
// Control playbackRate
document.getElementById('range-playback-rate').addEventListener('input', function() {
if (source instanceof AudioBufferSourceNode) {
var min = source.playbackRate.minValue || 0;
var max = source.playbackRate.maxValue || 1024;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
source.playbackRate.value = this.valueAsNumber;
}
}
document.getElementById('output-playback-rate').textContent = this.value;
}, false);
// Toggle loop
document.querySelector('[type="checkbox"]').addEventListener(EventWrapper.CLICK, function() {
if (source instanceof AudioBufferSourceNode) {
source.loop = this.checked;
}
}, false);
// Select the number of All-Pass Filters
document.getElementById('form-phaser-stage').addEventListener('change', function() {
for (var i = 0, len = this.elements['radio-phaser-stage'].length; i < len; i++) {
if (this.elements['radio-phaser-stage'][i].checked) {
numberOfStages = parseInt(this.elements['radio-phaser-stage'][i].value);
if (!(source instanceof AudioBufferSourceNode)) {
return;
}
// Clear connection
source.disconnect(0);
for (var i = 0; i < MAXIMUM_STAGES; i++) {
filters[i].disconnect(0);
}
mix.disconnect(0);
// Connect nodes for original audio
// AudioBufferSourceNode (Input) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(gain);
if (numberOfStages > 0) {
// Phaser ON
// Connect nodes for effect (Phaser) sound
// AudioBufferSourceNode (Input) -> BiquadFilterNode (All-Pass Filter) x N -> GainNode (Mix) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(filters[0]);
for (var i = 0; i < numberOfStages; i++) {
if (i < (numberOfStages - 1)) {
filters[i].connect(filters[i + 1]);
} else {
filters[i].connect(mix);
// Connect nodes for Feedback
// (AudioBufferSourceNode (Input) ->) BiquadFilterNode (All-Pass Filter) x N -> GainNode (Feedback) -> BiquadFilterNode (All-Pass Filter) x N -> ...
filters[i].connect(feedback);
feedback.connect(filters[0]);
}
}
mix.connect(gain);
} else {
// Phaser OFF
}
break;
}
}
}, false);
// Control frequency
document.getElementById('range-phaser-frequency').addEventListener('input', function() {
for (var i = 0; i < MAXIMUM_STAGES; i++) {
filters[i].frequency.value = this.valueAsNumber;
}
document.getElementById('output-phaser-frequency').textContent = this.value;
}, false);
// Control Phaser Depth
document.getElementById('range-phaser-depth').addEventListener('input', function() {
depth.gain.value = document.getElementById('range-phaser-frequency').valueAsNumber * (this.valueAsNumber / 100);
depthRate = this.valueAsNumber / 100;
document.getElementById('output-phaser-depth').textContent = this.value;
}, false);
// Control Phaser Rate
document.getElementById('range-phaser-rate').addEventListener('input', function() {
rate.value = this.valueAsNumber;
document.getElementById('output-phaser-rate').textContent = this.value;
}, false);
// Control Phaser Mix
document.getElementById('range-phaser-mix').addEventListener('input', function() {
var min = mix.gain.minValue || 0;
var max = mix.gain.maxValue || 1;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
mix.gain.value = this.valueAsNumber;
document.getElementById('output-phaser-mix').textContent = this.value;
}
}, false);
// Control Phaser Feedback
document.getElementById('range-phaser-feedback').addEventListener('input', function() {
var min = feedback.gain.minValue || 0;
var max = feedback.gain.maxValue || 1;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
feedback.gain.value = this.valueAsNumber;
document.getElementById('output-phaser-feedback').textContent = this.value;
}
}, false);
};
if ((document.readyState === 'interactive') || (document.readyState === 'complete')) {
onDOMContentLoaded();
} else {
document.addEventListener('DOMContentLoaded', onDOMContentLoaded, true);
}
})();
function EventWrapper(){
}
(function(){
var click = '';
var start = '';
var move = '';
var end = '';
// Touch Panel ?
if (/iPhone|iPad|iPod|Android/.test(navigator.userAgent)) {
click = 'click';
start = 'touchstart';
move = 'touchmove';
end = 'touchend';
} else {
click = 'click';
start = 'mousedown';
move = 'mousemove';
end = 'mouseup';
}
EventWrapper.CLICK = click;
EventWrapper.START = start;
EventWrapper.MOVE = move;
EventWrapper.END = end;
})();