Rodrigo Nascimento
10 years ago
parent
e9134a42ab
commit
13779cc1b5
@ -0,0 +1,32 @@ |
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class @AudioRecorder |
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constructor: (cb) -> |
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window.AudioContext = window.AudioContext or window.webkitAudioContext |
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navigator.getUserMedia = navigator.getUserMedia or navigator.webkitGetUserMedia |
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window.URL = window.URL or window.webkitURL |
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@audio_context = new AudioContext |
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ok = (stream) => |
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@startUserMedia(stream) |
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cb?.call(@) |
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navigator.getUserMedia {audio: true}, ok, (e) -> |
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console.log('No live audio input: ' + e) |
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startUserMedia: (stream) -> |
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input = @audio_context.createMediaStreamSource(stream) |
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@recorder = new Recorder(input, {workerPath: '/recorderWorker.js'}) |
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startRecording: (button) -> |
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@recorder.record() |
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stopRecording: (cb) -> |
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@recorder.stop() |
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if cb? |
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@getBlob cb |
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@recorder.clear() |
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getBlob: (cb) -> |
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@recorder.exportWAV cb |
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@ -0,0 +1,18 @@ |
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function drawBuffer( width, height, context, data ) { |
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var step = Math.ceil( data.length / width ); |
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var amp = height / 2; |
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context.fillStyle = "silver"; |
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context.clearRect(0,0,width,height); |
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for(var i=0; i < width; i++){ |
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var min = 1.0; |
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var max = -1.0; |
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for (j=0; j<step; j++) { |
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var datum = data[(i*step)+j];
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if (datum < min) |
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min = datum; |
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if (datum > max) |
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max = datum; |
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} |
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context.fillRect(i,(1+min)*amp,1,Math.max(1,(max-min)*amp)); |
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} |
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} |
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@ -0,0 +1,92 @@ |
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(function(window){ |
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var WORKER_PATH = 'recorderWorker.js'; |
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var Recorder = function(source, cfg){ |
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var config = cfg || {}; |
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var bufferLen = config.bufferLen || 4096; |
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var numChannels = config.numChannels || 2; |
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this.context = source.context; |
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this.node = (this.context.createScriptProcessor || |
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this.context.createJavaScriptNode).call(this.context, |
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bufferLen, numChannels, numChannels); |
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var worker = new Worker(config.workerPath || WORKER_PATH); |
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worker.postMessage({ |
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command: 'init', |
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config: { |
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sampleRate: this.context.sampleRate, |
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numChannels: numChannels |
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} |
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}); |
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var recording = false, |
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currCallback; |
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this.node.onaudioprocess = function(e){ |
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if (!recording) return; |
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var buffer = []; |
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for (var channel = 0; channel < numChannels; channel++){ |
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buffer.push(e.inputBuffer.getChannelData(channel)); |
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} |
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worker.postMessage({ |
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command: 'record', |
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buffer: buffer |
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}); |
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} |
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this.configure = function(cfg){ |
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for (var prop in cfg){ |
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if (cfg.hasOwnProperty(prop)){ |
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config[prop] = cfg[prop]; |
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} |
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} |
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} |
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this.record = function(){ |
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recording = true; |
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} |
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this.stop = function(){ |
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recording = false; |
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} |
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this.clear = function(){ |
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worker.postMessage({ command: 'clear' }); |
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} |
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this.getBuffer = function(cb) { |
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currCallback = cb || config.callback; |
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worker.postMessage({ command: 'getBuffer' }) |
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} |
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this.exportWAV = function(cb, type){ |
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currCallback = cb || config.callback; |
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type = type || config.type || 'audio/wav'; |
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if (!currCallback) throw new Error('Callback not set'); |
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worker.postMessage({ |
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command: 'exportWAV', |
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type: type |
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}); |
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} |
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worker.onmessage = function(e){ |
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var blob = e.data; |
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currCallback(blob); |
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} |
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source.connect(this.node); |
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this.node.connect(this.context.destination); //this should not be necessary
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}; |
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Recorder.forceDownload = function(blob, filename){ |
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var url = (window.URL || window.webkitURL).createObjectURL(blob); |
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var link = window.document.createElement('a'); |
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link.href = url; |
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link.download = filename || 'output.wav'; |
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var click = document.createEvent("Event"); |
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click.initEvent("click", true, true); |
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link.dispatchEvent(click); |
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} |
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window.Recorder = Recorder; |
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})(window); |
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@ -0,0 +1,147 @@ |
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var recLength = 0, |
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recBuffers = [], |
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sampleRate, |
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numChannels; |
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this.onmessage = function(e){ |
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switch(e.data.command){ |
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case 'init': |
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init(e.data.config); |
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break; |
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case 'record': |
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record(e.data.buffer); |
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break; |
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case 'exportWAV': |
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exportWAV(e.data.type); |
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break; |
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case 'getBuffer': |
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getBuffer(); |
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break; |
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case 'clear': |
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clear(); |
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break; |
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} |
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}; |
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function init(config){ |
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sampleRate = config.sampleRate; |
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numChannels = config.numChannels; |
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initBuffers(); |
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} |
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function record(inputBuffer){ |
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for (var channel = 0; channel < numChannels; channel++){ |
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recBuffers[channel].push(inputBuffer[channel]); |
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} |
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recLength += inputBuffer[0].length; |
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} |
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function exportWAV(type){ |
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var buffers = []; |
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for (var channel = 0; channel < numChannels; channel++){ |
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buffers.push(mergeBuffers(recBuffers[channel], recLength)); |
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} |
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if (numChannels === 2){ |
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var interleaved = interleave(buffers[0], buffers[1]); |
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} else { |
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var interleaved = buffers[0]; |
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} |
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var dataview = encodeWAV(interleaved); |
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var audioBlob = new Blob([dataview], { type: type }); |
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this.postMessage(audioBlob); |
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} |
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function getBuffer(){ |
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var buffers = []; |
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for (var channel = 0; channel < numChannels; channel++){ |
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buffers.push(mergeBuffers(recBuffers[channel], recLength)); |
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} |
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this.postMessage(buffers); |
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} |
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function clear(){ |
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recLength = 0; |
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recBuffers = []; |
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initBuffers(); |
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} |
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function initBuffers(){ |
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for (var channel = 0; channel < numChannels; channel++){ |
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recBuffers[channel] = []; |
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} |
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} |
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function mergeBuffers(recBuffers, recLength){ |
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var result = new Float32Array(recLength); |
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var offset = 0; |
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for (var i = 0; i < recBuffers.length; i++){ |
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result.set(recBuffers[i], offset); |
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offset += recBuffers[i].length; |
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} |
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return result; |
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} |
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function interleave(inputL, inputR){ |
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var length = inputL.length + inputR.length; |
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var result = new Float32Array(length); |
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var index = 0, |
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inputIndex = 0; |
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while (index < length){ |
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result[index++] = inputL[inputIndex]; |
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result[index++] = inputR[inputIndex]; |
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inputIndex++; |
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} |
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return result; |
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} |
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function floatTo16BitPCM(output, offset, input){ |
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for (var i = 0; i < input.length; i++, offset+=2){ |
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var s = Math.max(-1, Math.min(1, input[i])); |
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output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true); |
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} |
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} |
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function writeString(view, offset, string){ |
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for (var i = 0; i < string.length; i++){ |
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view.setUint8(offset + i, string.charCodeAt(i)); |
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} |
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} |
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function encodeWAV(samples){ |
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var buffer = new ArrayBuffer(44 + samples.length * 2); |
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var view = new DataView(buffer); |
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/* RIFF identifier */ |
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writeString(view, 0, 'RIFF'); |
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/* RIFF chunk length */ |
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view.setUint32(4, 36 + samples.length * 2, true); |
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/* RIFF type */ |
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writeString(view, 8, 'WAVE'); |
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/* format chunk identifier */ |
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writeString(view, 12, 'fmt '); |
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/* format chunk length */ |
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view.setUint32(16, 16, true); |
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/* sample format (raw) */ |
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view.setUint16(20, 1, true); |
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/* channel count */ |
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view.setUint16(22, numChannels, true); |
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/* sample rate */ |
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view.setUint32(24, sampleRate, true); |
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/* byte rate (sample rate * block align) */ |
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view.setUint32(28, sampleRate * 4, true); |
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/* block align (channel count * bytes per sample) */ |
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view.setUint16(32, numChannels * 2, true); |
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/* bits per sample */ |
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view.setUint16(34, 16, true); |
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/* data chunk identifier */ |
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writeString(view, 36, 'data'); |
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/* data chunk length */ |
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view.setUint32(40, samples.length * 2, true); |
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floatTo16BitPCM(view, 44, samples); |
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return view; |
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} |
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