Comment puis-je convertir un ensemble de données audio en un fichier wav?

var recLength = 0, recBuffersL = [], recBuffersR = [], sampleRate; this.onmessage = function (e) { switch (e.data.command) { case 'init': init(e.data.config); break; case 'record': record(e.data.buffer); break; case 'exportWAV': exportWAV(e.data.type); break; case 'getBuffer': getBuffer(); break; case 'clear': clear(); break; } }; function init(config) { sampleRate = config.sampleRate; } function record(inputBuffer) { recBuffersL.push(inputBuffer[0]); recBuffersR.push(inputBuffer[1]); recLength += inputBuffer[0].length; } function exportWAV(type) { var bufferL = mergeBuffers(recBuffersL, recLength); var bufferR = mergeBuffers(recBuffersR, recLength); var interleaved = interleave(bufferL, bufferR); var dataview = encodeWAV(interleaved); var audioBlob = new Blob([dataview], { type: type }); this.postMessage(audioBlob); } function getBuffer() { var buffers = []; buffers.push(mergeBuffers(recBuffersL, recLength)); buffers.push(mergeBuffers(recBuffersR, recLength)); this.postMessage(buffers); } function clear() { recLength = 0; recBuffersL = []; recBuffersR = []; } function mergeBuffers(recBuffers, recLength) { var result = new Float32Array(recLength); var offset = 0; for (var i = 0; i < recBuffers.length; i++) { result.set(recBuffers[i], offset); offset += recBuffers[i].length; } return result; } function interleave(inputL, inputR) { var length = inputL.length + inputR.length; var result = new Float32Array(length); var index = 0, inputIndex = 0; while (index < length) { result[index++] = inputL[inputIndex]; result[index++] = inputR[inputIndex]; inputIndex++; } return result; } function floatTo16BitPCM(output, offset, input) { for (var i = 0; i < input.length; i++, offset += 2) { var s = Math.max(-1, Math.min(1, input[i])); output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true); } } function writeString(view, offset, string) { for (var i = 0; i < string.length; i++) { view.setUint8(offset + i, string.charCodeAt(i)); } } function encodeWAV(samples) { var buffer = new ArrayBuffer(44 + samples.length * 2); var view = new DataView(buffer); writeString(view, 0, 'RIFF'); view.setUint32(4, 32 + samples.length * 2, true); writeString(view, 8, 'WAVE'); writeString(view, 12, 'fmt '); view.setUint32(16, 16, true); view.setUint16(20, 1, true); view.setUint16(22, 2, true); view.setUint32(24, sampleRate, true); view.setUint32(28, sampleRate * 4, true); view.setUint16(32, 4, true); view.setUint16(34, 16, true); writeString(view, 36, 'data'); view.setUint32(40, samples.length * 2, true); floatTo16BitPCM(view, 44, samples); return view; } 

usage:

 var AudioContext = win.webkitAudioContext, recorder, audioContext; function recordAudio() { if (!config.stream) { alert('No audio.'); return; } initAudioRecorder(config.audioWorkerPath); audioContext = new AudioContext; var mediaStreamSource = audioContext.createMediaStreamSource(config.stream); mediaStreamSource.connect(audioContext.destination); recorder = new window.Recorder(mediaStreamSource); recorder && recorder.record(); } function stopAudioRecording() { console.warn('Audio recording stopeed'); recorder && recorder.stop(); recorder && recorder.exportWAV(function (blob) { fileType = 'wav'; setBlob(blob); }); recorder && recorder.clear(); } var writer; function setBlob(blob) { blobURL = blob; var config = { blob: blobURL, type: 'audio/wav', fileName: (Math.random() * 1000 << 1000) + '.' + fileType, size: blobURL.length }; writer = RecordRTCFileWriter(config); var reader = new win.FileReader(); reader.readAsDataURL(blobURL); reader.onload = function (event) { blobURL2 = event.target.result; }; } return { stopAudio: stopAudioRecording, stopVideo: stopVideoRecording, recordVideo: recordVideo, recordAudio: recordAudio, save: saveToDisk, getBlob: function () { return blobURL2; }, toURL: function () { return writer.toURL(); } };