HTML5声音录制/播放功能的实现代码

                                    
                                                                        
            
        
                            var recorder;            var audio = document.querySelector('audio');            function startRecording() {                HZRecorder.get(function(rec) {                    recorder = rec;                    recorder.start();                }, {                    sampleBits: 16,                    sampleRate: 16000                });            }            function stopRecording() {                recorder.stop();                var blob = recorder.getBlob();                var url = URL.createObjectURL(blob);                var p = document.createElement('p');                var au = document.createElement('audio');                var hf = document.createElement('a');                au.controls = true;                au.src = url;                hf.href = url;                hf.download = new Date().toISOString() + '.wav';                hf.innerHTML = hf.download;                p.appendChild(au);                p.appendChild(hf);                recordingslist.appendChild(p);            }            function playRecording() {                recorder.play(audio);            }            function uploadAudio() {                recorder.upload("Handler1.ashx", function(state, e) {                    switch(state) {                        case 'uploading':                            //var percentComplete = Math.round(e.loaded * 100 / e.total) + '%';                            break;                        case 'ok':                            //alert(e.target.responseText);                            alert("上传成功");                            break;                        case 'error':                            alert("上传失败");                            break;                        case 'cancel':                            alert("上传被取消");                            break;                    }                });            }            

(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);