瀏覽器HTML5錄音功能

時間 2019-12-07

原文原文鏈接

1、瀏覽器HTML5錄音功能

2、業務代碼

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title></title>
</head>
<body>
    <div>
        <audio controls autoplay></audio>
        <input onclick="startRecording()" type="button" value="錄音" />
        <input onclick="stopRecording()" type="button" value="中止" />
        <input onclick="playRecording()" type="button" value="播放" />
        <input onclick="uploadAudio()" type="button" value="提交" />
        <input onclick="cancelAudio()" type="button" value="取消" />
    </div>

    <script type="text/javascript" src="record.js"></script>


    <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 cancelAudio(){
            recorder.stop();
            recorder.clear();
        }

        function uploadAudio() {
            recorder.upload("/upload", function (state, e) {
                switch (state) {
                    case 'uploading':
                        //var percentComplete = Math.round(e.loaded * 100 / e.total) + '%';
                        break;
                    case 'ok':
                        //alert(e.target.responseText);
                        alert("上傳成功");
                        break;
                    case 'error':
                        alert("上傳失敗");
                        break;
                    case 'cancel':
                        alert("上傳被取消");
                        break;
                }
            });
        }

    </script>

</body>
</html>

3、錄音文件javascript

//兼容
window.URL = window.URL || window.webkitURL;
//獲取計算機的設備：攝像頭或者錄音設備
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;

var HZRecorder = function (stream, config) {
    config = config || {};
    config.sampleBits = config.sampleBits || 8;      //採樣數位 8, 16
    config.sampleRate = config.sampleRate || (44100 / 6);   //採樣率(1/6 44100)

    //建立一個音頻環境對象
    var audioContext = window.AudioContext || window.webkitAudioContext;
    var context = new audioContext();
    var audioInput = context.createMediaStreamSource(stream);
    // 第二個和第三個參數指的是輸入和輸出都是單聲道,2是雙聲道。
    var recorder = context.createScriptProcessor(4096, 1, 1);

    var audioData = {
        size: 0          //錄音文件長度
        , buffer: []     //錄音緩存
        , inputSampleRate: context.sampleRate    //輸入採樣率
        , inputSampleBits: 16       //輸入採樣數位 8, 16
        , outputSampleRate: config.sampleRate    //輸出採樣率
        , outputSampleBits: config.sampleBits       //輸出採樣數位 8, 16
        , input: function (data) {
            this.buffer.push(new Float32Array(data));
            this.size += data.length;
        }
        , compress: function () { //合併壓縮
            //合併
            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;
            }
            //壓縮
            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.outputSampleBits);
            var bytes = this.compress();
            var dataLength = bytes.length * (sampleBits / 8);
            var buffer = new ArrayBuffer(44 + dataLength);
            var data = new DataView(buffer);

            var channelCount = 1;//單聲道
            var offset = 0;

            var writeString = function (str) {
                for (var i = 0; i < str.length; i++) {
                    data.setUint8(offset + i, str.charCodeAt(i));
                }
            }

            // 資源交換文件標識符
            writeString('RIFF'); offset += 4;
            // 下個地址開始到文件尾總字節數,即文件大小-8
            data.setUint32(offset, 36 + dataLength, true); offset += 4;
            // WAV文件標誌
            writeString('WAVE'); offset += 4;
            // 波形格式標誌
            writeString('fmt '); offset += 4;
            // 過濾字節,通常爲 0x10 = 16
            data.setUint32(offset, 16, true); offset += 4;
            // 格式類別 (PCM形式採樣數據)
            data.setUint16(offset, 1, true); offset += 2;
            // 通道數
            data.setUint16(offset, channelCount, true); offset += 2;
            // 採樣率,每秒樣本數,表示每一個通道的播放速度
            data.setUint32(offset, sampleRate, true); offset += 4;
            // 波形數據傳輸率 (每秒平均字節數) 單聲道×每秒數據位數×每樣本數據位/8
            data.setUint32(offset, channelCount * sampleRate * (sampleBits / 8), true); offset += 4;
            // 快數據調整數 採樣一次佔用字節數 單聲道×每樣本的數據位數/8
            data.setUint16(offset, channelCount * (sampleBits / 8), true); offset += 2;
            // 每樣本數據位數
            data.setUint16(offset, sampleBits, true); offset += 2;
            // 數據標識符
            writeString('data'); offset += 4;
            // 採樣數據總數,即數據總大小-44
            data.setUint32(offset, dataLength, true); offset += 4;
            // 寫入採樣數據
            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/mp3' });
        }
    };

    //開始錄音
    this.start = function () {
        audioInput.connect(recorder);
        recorder.connect(context.destination);
    }

    //中止
    this.stop = function () {
        recorder.disconnect();
    }

    //獲取音頻文件
    this.getBlob = function () {
        this.stop();
        return audioData.encodeWAV();
    }

    //回放
    this.play = function (audio) {
        audio.src = window.URL.createObjectURL(this.getBlob());
    }
    //清除
    this.clear = function(){
        audioData.buffer=[];
        audioData.size=0;
    }

    //上傳
    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);
    }

    //音頻採集
    recorder.onaudioprocess = function (e) {
        audioData.input(e.inputBuffer.getChannelData(0));
        //record(e.inputBuffer.getChannelData(0));
    }

};
//拋出異常
HZRecorder.throwError = function (message) {
    alert(message);
    throw new function () { this.toString = function () { return message; } }
}
//是否支持錄音
HZRecorder.canRecording = (navigator.getUserMedia != null);
//獲取錄音機
HZRecorder.get = function (callback, config) {
    if (callback) {
        if (navigator.getUserMedia) {
            navigator.getUserMedia(
                { audio: true } //只啓用音頻
                , function (stream) {
                    var rec = new HZRecorder(stream, config);
                    callback(rec);
                }
                , function (error) {
                    switch (error.code || error.name) {
                        case 'PERMISSION_DENIED':
                        case 'PermissionDeniedError':
                            HZRecorder.throwError('用戶拒絕提供信息。');
                            break;
                        case 'NOT_SUPPORTED_ERROR':
                        case 'NotSupportedError':
                            HZRecorder.throwError('瀏覽器不支持硬件設備。');
                            break;
                        case 'MANDATORY_UNSATISFIED_ERROR':
                        case 'MandatoryUnsatisfiedError':
                            HZRecorder.throwError('沒法發現指定的硬件設備。');
                            break;
                        default:
                            HZRecorder.throwError('沒法打開麥克風。異常信息:' + (error.code || error.name));
                            break;
                    }
                });
        } else {
            HZRecorder.throwErr('當前瀏覽器不支持錄音功能。'); return;
        }
    }
};