HTML5怎么实现录音和播放功能

html:

[html] view plain copy
<span style="white-space:pre">        </span><audio controls autoplay></audio>  
        <input type="button" value="开始录音" onclick="startRecording()"/>  
        <input type="button" value="获取录音" onclick="obtainRecord()"/>  
        <input type="button" value="停止录音" onclick="stopRecord()"/>  
        <input type="button" value="播放录音" onclick="playRecord()"/>  
          
        <video id="video1" width="320px" height="240px" controls autoplay ></video>  
        <video id="video2" width="320px" height="240px" controls autoplay ></video>  
        <canvas id="canvas1" width="320" height="240"></canvas>  
        <input type="button" value="拍摄" onclick="scamera()"/>  
        <input type="button" value="播放视频" onclick="playVideo()"/>  
js文件:
[javascript] view plain copy
(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)  
  
          
        //创建一个音频环境对象  
        audioContext = window.AudioContext || window.webkitAudioContext;  
        var context = new audioContext();  
  
        //将声音输入这个对像  
        var audioInput = context.createMediaStreamSource(stream);  
          
        //设置音量节点  
        var volume = context.createGain();  
        audioInput.connect(volume);  
  
        //创建缓存，用来缓存声音  
        var bufferSize = 4096;  
  
        // 创建声音的缓存节点，createScriptProcessor方法的  
        // 第二个和第三个参数指的是输入和输出都是双声道。  
        var recorder = context.createScriptProcessor(bufferSize, 2, 2);  
  
        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) {  
        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('<a href="http://www.it165.net/edu/ewl/" target="_blank" class="keylink">浏览器</a>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<a href="http://www.it165.net/edu/ewl/" target="_blank" class="keylink">浏览器</a>不支持录音功能。'); return;  
            }  
        }  
    };  
    window.HZRecorder = HZRecorder;  
  
})(window);  
页面调用 js：
[javascript] view plain copy
/* 音频 */  
            var recorder;  
            var audio = document.querySelector('audio');  
              
            function startRecording() {  
                HZRecorder.get(function (rec) {  
                    recorder = rec;  
                    recorder.start();  
                });  
            }  
              
              
            function obtainRecord(){  
                var record = recorder.getBlob();  
                debugger;  
            };  
              
            function stopRecord(){  
                recorder.stop();  
            };  
              
            function playRecord(){  
                recorder.play(audio);  
            };  
              
            /* 视频 */  
            function scamera() {  
                var videoElement = document.getElementById('video1');  
                var canvasObj = document.getElementById('canvas1');  
                var context1 = canvasObj.getContext('2d');  
                context1.fillStyle = "#ffffff";  
                context1.fillRect(0, 0, 320, 240);  
                context1.drawImage(videoElement, 0, 0, 320, 240);  
            };  
              
            function playVideo(){  
                var videoElement1 = document.getElementById('video1');  
                var videoElement2 = document.getElementById('video2');  
                videoElement2.setAttribute("src", videoElement1);