(function (window) {  
    //兼容  
    window.URL = window.URL || window.webkitURL;  
    //请求麦克风
    navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;  
  
    var Recorder = function (stream, wsock) {  
        //创建一个音频环境对象  
        audioContext = window.AudioContext || window.webkitAudioContext;  
        var context = new audioContext();  
        
        config =  {};  
        config.channelCount = 1;
        config.numberOfInputChannels = config.channelCount;
        config.numberOfOutputChannels = config.channelCount;
        config.sampleBits = config.sampleBits || 16;      //采样数位 8, 16  
        //config.sampleRate = config.sampleRate || (context.sampleRate / 6);   //采样率(1/6 44100)
        config.sampleRate = config.sampleRate || 8000;   //采样率16K
        //创建缓存，用来缓存声音  
        config.bufferSize = 8192;
        var ws = wsock;
        //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声道数。
        var recorder = context.createScriptProcessor(config.bufferSize, config.channelCount, config.channelCount); 
         
        //用来储存读出的麦克风数据，和压缩这些数据，将这些数据转换为WAV文件的格式
        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 = [];
            	this.size = 0;
                this.buffer.push(new Float32Array(data));  //Float32Array
                this.size += data.length;  
            }  
            , getRawData: 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 getRawDataion = parseInt(this.inputSampleRate / this.outputSampleRate);  
                var length = data.length / getRawDataion;  
                var result = new Float32Array(length);  
                var index = 0, j = 0;  
                while (index < length) {  
                    result[index] = data[j];  
                    j += getRawDataion;  
                    index++;  
                }  
                return result;
            }             
            
            ,closeContext:function(){
                context.close();   //关闭AudioContext否则录音多次会报错。
            }
            ,getPureWavData: function(offset) {
                var sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits)
                var bytes = this.getRawData();  
                var dataLength = bytes.length * (sampleBits / 8);  
                var buffer = new ArrayBuffer(dataLength);  
                var data = new DataView(buffer);
                data = this.reshapeWavData(sampleBits, offset, bytes, data);                
//                var wavd = new Int8Array(data.buffer.byteLength);
//                var pos = 0;
//                for (var i = 0; i < data.buffer.byteLength; i++, pos++) {
//                    wavd[i] = data.getInt8(pos);
//                }                //                return wavd;
				
                //  return new Blob([data], { type: 'audio/wav' });
                return data;

            }            
            ,reshapeWavData: function(sampleBits, offset, iBytes, oData) {
                if (sampleBits === 8) {  
                    for (var i = 0; i < iBytes.length; i++, offset++) {  
                        var s = Math.max(-1, Math.min(1, iBytes[i]));  
                        var val = s < 0 ? s * 0x8000 : s * 0x7FFF;  
                        val = parseInt(255 / (65535 / (val + 32768)));  
                        oData.setInt8(offset, val, true);  
                    }  
                } else {  
                    for (var i = 0; i < iBytes.length; i++, offset += 2) {  
                        var s = Math.max(-1, Math.min(1, iBytes[i]));  
                        oData.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true);  
                    }  
                } 
                return oData;
            }
             
        };  
  
        //开始录音  
        this.start = function () {
            audioInput.connect(recorder);  
            recorder.connect(context.destination);
        };  
  
        //停止  
        this.stop = function () {  
            recorder.disconnect();             
        
            audioData.closeContext();
        }
  
        
        var $bo=$("#inbo");
        var $change=$("#change");
        var width=$bo.width();
        //音频采集  
        recorder.onaudioprocess = function (e) {
            audioData.input(e.inputBuffer.getChannelData(0));
            
            var data = audioData.getPureWavData(0);
            if (ws != null)
            	ws.send(data);
            
            
        };  
  
    };  
    //抛出异常  
    Recorder.throwError = function (message) {  
        throw new function () { this.toString = function () { return message; };};  
    };  
    //是否支持录音  
    Recorder.canRecording = (navigator.getUserMedia != null);  
    //获取录音机  
    Recorder.get = function (callback, wsock) {  
        if (callback) {  
            if (navigator.getUserMedia) {  
                navigator.getUserMedia(  
                    { audio: true } //只启用音频  A
                    , function (stream) {  //stream这个参数是麦克风的输入流，将这个流传递给Recorder
                        var rec = new Recorder(stream, wsock);  
                        callback(rec);  
                    }  
                    , function (error) {  
                        switch (error.code || error.name) {  
                            case 'PERMISSION_DENIED':  
                            case 'PermissionDeniedError':  
                                Recorder.throwError('用户拒绝提供信息。');  
                                break;  
                            case 'NOT_SUPPORTED_ERROR':  
                            case 'NotSupportedError':  
                                Recorder.throwError('浏览器不支持硬件设备。');  
                                break;  
                            case 'MANDATORY_UNSATISFIED_ERROR':  
                            case 'MandatoryUnsatisfiedError':  
                                Recorder.throwError('无法发现指定的硬件设备。');  
                                break;  
                            default:  
                                Recorder.throwError('无法打开麦克风。异常信息:' + (error.code || error.name));  
                                break;  
                        }  
                    });  
            } else {  
                Recorder.throwErr('当前浏览器不支持录音功能。'); return;  
            }  
        }  
    };  
    window.Recorder = Recorder;  
  
})(window);