Implementation of HTML5 sound recording and playback functions

(function (window) { //兼容 window.URL = window.URL || window.webkitURL; navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia; var HZRecorder = function (stream, config) { config = config || {}; config.sampleBits = config.sampleBits || 8 //采样数位 8, 16 config.sampleRate = config.sampleRate || (44100 / 6); //采样率(1/6 44100) var context = new (window.webkitAudioContext || window.AudioContext)(); var audioInput = context.createMediaStreamSource(stream); var createScript = context.createScriptProcessor || context.createJavaScriptNode; var recorder = createScript.apply(context, [4096, 1, 1]); var mp3ReceiveSuccess, currentErrorCallback; var audioData = { size: 0 //录音文件长度 , buffer: [] //录音缓存 , inputSampleRate: context.sampleRate //输入采样率 , inputSampleBits: 16 //输入采样数位 8, 16 , outputSampleRate: config.sampleRate //输出采样率 , oututSampleBits: config.sampleBits //输出采样数位 8, 16 , input: function (data) { this.buffer.push(new Float32Array(data)); this.size += data.length; } , compress: function () { //合并压缩 //合并 var data = new Float32Array(this.size); var offset = 0; for (var i = 0; i < this.buffer.length; i++) { data.set(this.buffer[i], offset); offset += this.buffer[i].length; } //压缩 var compression = parseInt(this.inputSampleRate / this.outputSampleRate); var length = data.length / compression; var result = new Float32Array(length); var index = 0, j = 0; while (index < length) { result[index] = data[j]; j += compression; index++; } return result; } , encodeWAV: function () { var sampleRate = Math.min(this.inputSampleRate, this.outputSampleRate); var sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits); var bytes = this.compress(); var dataLength = bytes.length * (sampleBits / 8); var buffer = new ArrayBuffer(44 + dataLength); var data = new DataView(buffer); var channelCount = 1;//单声道 var offset = 0; var writeString = function (str) { for (var i = 0; i < str.length; i++) { data.setUint8(offset + i, str.charCodeAt(i)); } } // 资源交换文件标识符 writeString('RIFF'); offset += 4; // 下个地址开始到文件尾总字节数,即文件大小-8 data.setUint32(offset, 36 + dataLength, true); offset += 4; // WAV文件标志 writeString('WAVE'); offset += 4; // 波形格式标志 writeString('fmt '); offset += 4; // 过滤字节,一般为 0x10 = 16 data.setUint32(offset, 16, true); offset += 4; // 格式类别 (PCM形式采样数据) data.setUint16(offset, 1, true); offset += 2; // 通道数 data.setUint16(offset, channelCount, true); offset += 2; // 采样率,每秒样本数,表示每个通道的播放速度 data.setUint32(offset, sampleRate, true); offset += 4; // 波形数据传输率 (每秒平均字节数) 单声道×每秒数据位数×每样本数据位/8 data.setUint32(offset, channelCount * sampleRate * (sampleBits / 8), true); offset += 4; // 快数据调整数 采样一次占用字节数 单声道×每样本的数据位数/8 data.setUint16(offset, channelCount * (sampleBits / 8), true); offset += 2; // 每样本数据位数 data.setUint16(offset, sampleBits, true); offset += 2; // 数据标识符 writeString('data'); offset += 4; // 采样数据总数,即数据总大小-44 data.setUint32(offset, dataLength, true); offset += 4; // 写入采样数据 if (sampleBits === 8) { for (var i = 0; i < bytes.length; i++, offset++) { var s = Math.max(-1, Math.min(1, bytes[i])); var val = s < 0 ? s * 0x8000 : s * 0x7FFF; val = parseInt(255 / (65535 / (val + 32768))); data.setInt8(offset, val, true); } } else { for (var i = 0; i < bytes.length; i++, offset += 2) { var s = Math.max(-1, Math.min(1, bytes[i])); data.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true); } } return new Blob([data], { type: 'audio/wav' }); } }; //开始录音 this.start = function () { audioInput.connect(recorder); recorder.connect(context.destination); } //停止 this.stop = function () { recorder.disconnect(); } //获取音频文件 this.getBlob = function () { this.stop(); return audioData.encodeWAV(); } //回放 this.play = function (audio) { audio.src = window.URL.createObjectURL(this.getBlob()); } //上传 this.upload = function (url, callback) { var fd = new FormData(); fd.append("audioData", this.getBlob()); var xhr = new XMLHttpRequest(); if (callback) { xhr.upload.addEventListener("progress", function (e) { callback('uploading', e); }, false); xhr.addEventListener("load", function (e) { callback('ok', e); }, false); xhr.addEventListener("error", function (e) { callback('error', e); }, false); xhr.addEventListener("abort", function (e) { callback('cancel', e); }, false); } xhr.open("POST", url); xhr.send(fd); } //音频采集 recorder.onaudioprocess = function (e) { audioData.input(e.inputBuffer.getChannelData(0)); //record(e.inputBuffer.getChannelData(0)); } }; //抛出异常 HZRecorder.throwError = function (message) { alert(message); throw new function () { this.toString = function () { return message; } } } //是否支持录音 HZRecorder.canRecording = (navigator.getUserMedia != null); //获取录音机 HZRecorder.get = function (callback, config) { if (callback) { if (navigator.getUserMedia) { navigator.getUserMedia( { audio: true } //只启用音频 , function (stream) { var rec = new HZRecorder(stream, config); callback(rec); } , function (error) { switch (error.code || error.name) { case 'PERMISSION_DENIED': case 'PermissionDeniedError': HZRecorder.throwError('用户拒绝提供信息。'); break; case 'NOT_SUPPORTED_ERROR': case 'NotSupportedError': HZRecorder.throwError('浏览器不支持硬件设备。'); break; case 'MANDATORY_UNSATISFIED_ERROR': case 'MandatoryUnsatisfiedError': HZRecorder.throwError('无法发现指定的硬件设备。'); break; default: HZRecorder.throwError('无法打开麦克风。异常信息:' + (error.code || error.name)); break; } }); } else { HZRecorder.throwErr('当前浏览器不支持录音功能。'); return; } } } window.HZRecorder = HZRecorder; })(window);