使用js调用麦克风并录音

<div>
    <audio controls autoplay></audio>
    <input onclick="startRecording()" type="button" value="录音"/>
    <input onclick="stopRecording()" type="button" value="停止"/>
    <input onclick="playRecording()" type="button" value="播放"/>
    <input onclick="uploadAudio()" type="button" value="提交"/>
</div>
<script>
 var recorder;
    var audio = document.querySelector('audio');
    function startRecording() {
        HZRecorder.get(function (rec) {
            recorder = rec;
            recorder.start();
        });
    }
    function stopRecording() {
        recorder.stop();
    }
    function playRecording() {
        recorder.play(audio);
    }
        function uploadAudio() {
        recorder.upload()
    }
</script>

(function (window) {
    //兼容
    window.URL = window.URL || window.webkitURL;
    navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
    window.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext || window.msAudioContext;
    try {
        var audioContext = new window.AudioContext();
    } catch (e) {
        console.log('!Your browser does not support AudioContext');
    }
    var context = context || new AudioContext();

    var HZRecorder = function (stream, config) {
        config = config || {};
        config.sampleBits = config.sampleBits || 16;      //采样数位 8, 16
        config.sampleRate = config.sampleRate || 16000;   //采样率(1/6 44100)
        var audioInput = context.createMediaStreamSource(stream);
        var recorder = context.createScriptProcessor ? context.createScriptProcessor(4096, 1, 1) : context.createJavaScriptNode(4096, 1, 1);
        var audioData = {
            size: 0          //录音文件长度
            , buffer: []   //录音缓存
            , bufferData: []
            , 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));
                for (var i = 0; i < data.length; i++) {
                    this.bufferData.push(data[i]);
                }
                // initEchart(this.buffer);
                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(parseInt(length));
                // 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);
                    }
                }
                // this.bufferData = data;
                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();
            initEchart(audioData.buffer);
        }

        //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());
        }

        //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;
    function cacl(arr, callback) {
        var ret;
        for (var i = 0; i < arr.length; i++) {
            ret = callback(arr[i], ret);
        }
        return ret;
    }

    Array.prototype.sum = function () {
        return cacl(this, function (item, sum) {
            if (typeof (sum) == 'undefined') {
                return Math.abs(item);
            } else {
                return sum += Math.abs(item);
            }
        });
    };
    Array.prototype.avg = function () {
        if (this.length == 0) {
            return 0;
        }
        return this.sum(this) / this.length;
    };

    function randomString(len) {
        len = len || 32;
        var $chars = 'abcdefhijkmnprstwxyz2345678';
        /****默认去掉了容易混淆的字符oOLl,9gq,Vv,Uu,I1****/
        var maxPos = $chars.length;
        var pwd = '';
        for (i = 0; i < len; i++) {
            pwd += $chars.charAt(Math.floor(Math.random() * maxPos));
        }
        return pwd;
    }
})(window);

原文：使用js调用麦克风并录音 | 李二狗的博客 (liergou.vip)