(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 var gain = context.createGain(); var drawAudio = function(canvas, data, sampleRate) { var canvasContext = canvas.getContext('2d'); 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; // Sampling period var period = 1 / sampleRate; // This value is the number of samples during 50 msec var n50msec = Math.floor(50 * Math.pow(10, -3) * sampleRate); // Clear previous data canvasContext.clearRect(0, 0, width, height); // Draw audio wave canvasContext.beginPath(); for (var i = 0, len = data.length; i < len; i++) { // 50 msec ? if ((i % n50msec) === 0) { var x = Math.floor((i / len) * innerWidth) + paddingLeft; var y = Math.floor(((1 - data[i]) / 2) * innerHeight) + paddingTop; if (i === 0) { canvasContext.moveTo(x, y); } else { canvasContext.lineTo(x, y); } } } canvasContext.strokeStyle = 'rgba(0, 0, 255, 1.0)'; canvasContext.lineWidth = 0.5; canvasContext.lineCap = 'round'; canvasContext.lineJoin = 'miter'; canvasContext.stroke(); }; // 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 // Get audio binary data for drawing wave var channelLs = new Float32Array(audioBuffer.length); var channelRs = new Float32Array(audioBuffer.length); console.log('numberOfChannels : ' + audioBuffer.numberOfChannels); // Stereo ? if (audioBuffer.numberOfChannels > 1) { // Stereo channelLs.set(audioBuffer.getChannelData(0)); channelRs.set(audioBuffer.getChannelData(1)); drawAudio(document.querySelectorAll('canvas')[0], channelLs, audioBuffer.sampleRate); drawAudio(document.querySelectorAll('canvas')[1], channelRs, audioBuffer.sampleRate); } else if (audioBuffer.numberOfChannels > 0) { // Monaural channelLs.set(audioBuffer.getChannelData(0)); drawAudio(document.querySelectorAll('canvas')[0], channelLs, audioBuffer.sampleRate); } else { window.alert('The number of channels is invalid.'); return; } // 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; // AudioBufferSourceNode (Input) -> GainNode (Volume) -> AudioDestinationNode (Output) source.connect(gain); gain.connect(context.destination); // Start audio source.start(0); // Set Callback source.onended = function(event) { // Remove event handler source.onended = null; document.onkeydown = null; // Stop audio source.stop(0); 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 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); }; 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; })();