(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();
// Compressor
// Create the instance of DynamicsCompressorNode
var compressor = context.createDynamicsCompressor();
// Initialize parameters for Compressor
compressor.threshold.value = document.getElementById('range-compressor-threshold').valueAsNumber;
compressor.knee.value = document.getElementById('range-compressor-knee').valueAsNumber;
compressor.ratio.value = document.getElementById('range-compressor-ratio').valueAsNumber;
compressor.attack.value = document.getElementById('range-compressor-attack').valueAsNumber;
compressor.release.value = document.getElementById('range-compressor-release').valueAsNumber;
// Display "reduction" property in DynamicsCompressorNode
var canvas = document.querySelector('canvas');
var canvasContext = canvas.getContext('2d');
var timerid = null;
var draw = function(x, y) {
var TOTAL_TIME = 10000; // 10 sec
var INTERVAL = 10; // 10 msec
var MIN_DECIBEL = -100; // dB
var MAX_DECIBEL = 0; // dB
var RANGE = MAX_DECIBEL - MIN_DECIBEL; // dB
var width = canvas.width;
var height = canvas.height;
var paddingTop = 20;
var paddingBottom = 20;
var paddingLeft = 30;
var paddingRight = 30;
var innerWidth = width - paddingLeft - paddingRight;
var innerHeight = height - paddingTop - paddingBottom;
var innerBottom = height - paddingBottom;
var isDrawGrid = true;
// Draw reduction (dB)
canvasContext.beginPath();
if ((x === 0) || (x > (innerWidth + paddingLeft))) {
// Clear previous data
canvasContext.clearRect(0, 0, canvas.width, canvas.height);
// Move start point
if (x === 0) {
canvasContext.moveTo(paddingLeft, paddingTop);
} else {
canvasContext.moveTo(paddingLeft, y);
}
// Update x
x = paddingLeft;
} else {
// Move start point
canvasContext.moveTo(x, y);
// Update x
x += INTERVAL * (innerWidth / TOTAL_TIME);
isDrawGrid = false;
}
var y = paddingTop;
// Compressor ON ?
if (document.getElementById('toggle-effect').checked) {
if (compressor.reduction.value === undefined) {
y = Math.floor(-1 * ((compressor.reduction) / RANGE) * innerHeight) + paddingTop;
} else {
y = Math.floor(-1 * ((compressor.reduction.value) / RANGE) * innerHeight) + paddingTop;
}
}
canvasContext.lineTo(x, y);
canvasContext.strokeStyle = 'rgba(0, 0, 255, 1.0)';
canvasContext.lineWidth = 3;
canvasContext.lineCap = 'round';
canvasContext.lineJoin = 'miter';
canvasContext.stroke();
if (isDrawGrid) {
// Draw grid and text (X) every 1000 msec (1 sec)
for (var i = 0; i <= TOTAL_TIME; i += INTERVAL) {
if ((i % 1000) !== 0) {
continue;
}
var gx = Math.floor(i * (innerWidth / TOTAL_TIME)) + paddingLeft;
var text = i + ' msec';
// Draw grid (X)
canvasContext.fillStyle = 'rgba(255, 0, 0, 1.0)';
canvasContext.fillRect(gx, paddingTop, 1, innerHeight);
// Draw text (X)
canvasContext.fillStyle = 'rgba(255, 255, 255, 1.0)';
canvasContext.font = '12px "Times New Roman"';
canvasContext.textAlign = 'center';
canvasContext.fillText(text, gx, (height - 3));
}
// Draw grid and text (Y)
for (var i = MIN_DECIBEL; i <= MAX_DECIBEL; i += 10) {
var gy = Math.floor(-1 * ((i - MAX_DECIBEL) / RANGE) * innerHeight) + paddingTop;
// Draw grid (Y)
canvasContext.fillStyle = 'rgba(255, 0, 0, 1.0)';
canvasContext.fillRect(paddingLeft, gy, innerWidth, 1);
// Draw text (Y)
canvasContext.fillStyle = 'rgba(255, 255, 255, 1.0)';
canvasContext.font = '12px "Times New Roman"';
canvasContext.textAlign = 'left';
canvasContext.fillText((i + ' dB'), 3, gy);
}
}
timerid = window.setTimeout(function() {
draw(x, y);
}, INTERVAL);
};
// 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);
// Clear connection
source.disconnect(0);
compressor.disconnect(0);
if (document.getElementById('toggle-effect').checked) {
// Compressor ON
// Connect nodes for effect (Compressor) sound
// AudioBufferSourceNode (Input) -> DynamicsCompressorNode (Compressor) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(compressor);
compressor.connect(gain);
} else {
// Compressor OFF
// AudioBufferSourceNode (Input) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(gain);
}
// Start audio
source.start(0);
// Start drawing "reduction"
draw(0, 0);
// Set Callback
source.onended = function(event) {
// Remove event handler
source.onended = null;
document.onkeydown = null;
// Stop audio
source.stop(0);
// Stop previous drawing
if (timerid !== null) {
window.clearTimeout(timerid);
timerid = null;
}
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);
// Toggle Effect
document.getElementById('toggle-effect').addEventListener(EventWrapper.CLICK, function() {
if (!(source instanceof AudioBufferSourceNode)) {
return;
}
// Clear connection
source.disconnect(0);
compressor.disconnect(0);
if (this.checked) {
// Compressor ON
// Connect nodes for effect (Compressor) sound
// AudioBufferSourceNode (Input) -> DynamicsCompressorNode (Compressor) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(compressor);
compressor.connect(gain);
} else {
// Compressor OFF
// AudioBufferSourceNode (Input) -> GainNode (Master Volume) (-> AudioDestinationNode (Output))
source.connect(gain);
}
}, false);
// Control threshold
document.getElementById('range-compressor-threshold').addEventListener('input', function() {
var min = compressor.threshold.minValue || -100;
var max = compressor.threshold.maxValue || 0;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
compressor.threshold.value = this.valueAsNumber;
document.getElementById('output-compressor-threshold').textContent = this.value;
}
}, false);
// Control knee
document.getElementById('range-compressor-knee').addEventListener('input', function() {
var min = compressor.knee.minValue || 0;
var max = compressor.knee.maxValue || 40;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
compressor.knee.value = this.valueAsNumber;
document.getElementById('output-compressor-knee').textContent = this.value;
}
}, false);
// Control ratio
document.getElementById('range-compressor-ratio').addEventListener('input', function() {
var min = compressor.ratio.minValue || 1;
var max = compressor.ratio.maxValue || 20;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
compressor.ratio.value = this.valueAsNumber;
document.getElementById('output-compressor-ratio').textContent = this.value;
}
}, false);
// Control attack
document.getElementById('range-compressor-attack').addEventListener('input', function() {
var min = compressor.attack.minValue || 0;
var max = compressor.attack.maxValue || 1;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
compressor.attack.value = this.valueAsNumber;
document.getElementById('output-compressor-attack').textContent = this.value;
}
}, false);
// Control release
document.getElementById('range-compressor-release').addEventListener('input', function() {
var min = compressor.release.minValue || 0.01;
var max = compressor.release.maxValue || 1;
if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) {
compressor.release.value = this.valueAsNumber;
document.getElementById('output-compressor-release').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;
})();