近日公司要求实现用户录音并上传的功能，此文不说上传，只说录音。
navigator.getUserMedia
开启录音的方法是 navigator.getUserMedia
此方法有兼容性，且现在早已更名为MediaDevices.getUserMedia
详情参见 MDN，另外，必须在本地服务或者 https 协议下才能够开启录音！否则会报该方法 is not found 的错误。
// 兼容
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
if (navigator.getUserMedia) {
navigator.getUserMedia({ audio: true, video: { width: 1280, height: 720 } },
function(stream) {
var video = document.querySelector('video');
video.src = window.URL.createObjectURL(stream);
video.onloadedmetadata = function(e) {
video.play();
};
},
function(err) {
console.log("The following error occurred: " + err.name);
}
);
} else {
console.log("getUserMedia not supported");
}
recorder.js
摘自此文【前端】vue+recorder实现录音功能
//recorder.js
export default class Recorder {
constructor(stream, config) {
//兼容
window.URL = window.URL || window.webkitURL;
config = config || {};
config.sampleBits = config.sampleBits || 16; //采样数位 8, 16
config.sampleRate = config.sampleRate || 8000; //采样率(1/6 44100)
this.context = new (window.webkitAudioContext || window.AudioContext)();
this.audioInput = this.context.createMediaStreamSource(stream);
this.createScript = this.context.createScriptProcessor || this.context.createJavaScriptNode;
this.recorder = this.createScript.apply(this.context, [4096, 1, 1]);
this.audioData = {
size: 0, //录音文件长度
buffer: [], //录音缓存
inputSampleRate: this.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
let data = new Float32Array(this.size);
let offset = 0;
for (let i = 0; i < this.buffer.length; i++) {
data.set(this.buffer[i], offset);
offset += this.buffer[i].length;
}
//压缩
let compression = parseInt(this.inputSampleRate / this.outputSampleRate);
let length = data.length / compression;
let result = new Float32Array(length);
let index = 0, j = 0;
while (index < length) {
result[index] = data[j];
j += compression;
index++;
}
return result;
},
encodeWAV: function () {
let sampleRate = Math.min(this.inputSampleRate, this.outputSampleRate);
let sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits);
let bytes = this.compress();
let dataLength = bytes.length * (sampleBits / 8);
let buffer = new ArrayBuffer(44 + dataLength);
let data = new DataView(buffer);
let channelCount = 1;//单声道
let offset = 0;
let writeString = function (str) {
for (let 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 (let i = 0; i < bytes.length; i++, offset++) {
let s = Math.max(-1, Math.min(1, bytes[i]));
let val = s < 0 ? s * 0x8000 : s * 0x7FFF;
val = parseInt(255 / (65535 / (val + 32768)));
data.setInt8(offset, val, true);
}
} else {
for (let i = 0; i < bytes.length; i++, offset += 2) {
let 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
start() {
this.audioInput.connect(this.recorder);
this.recorder.connect(this.context.destination);
//音频采集
let self = this;
this.recorder.onaudioprocess = function (e) {
self.audioData.input(e.inputBuffer.getChannelData(0));
};
};
//停止
stop() {
this.recorder.disconnect();
};
//获取音频文件
getBlob() {
this.stop();
return this.audioData.encodeWAV();
};
//回放
play(audio) {
audio.src = window.URL.createObjectURL(this.getBlob());
};
//清理缓存的录音数据
clear(audio) {
this.audioData.buffer = [];
this.audioData.size = 0;
audio.src = ''
};
static checkError(e) {
const { name } = e;
let errorMsg = '';
switch (name) {
case 'AbortError': errorMsg = '录音设备无法被使用'; break;
case 'NotAllowedError': errorMsg = '用户已禁止网页调用录音设备'; break;
case 'PermissionDeniedError': errorMsg = '用户已禁止网页调用录音设备'; break; // 用户拒绝
case 'NotFoundError': errorMsg = '找不到指定媒体类型'; break;
case 'DevicesNotFoundError': errorMsg = '录音设备未找到'; break;
case 'NotReadableError': errorMsg = '录音设备无法使用'; break;
case 'NotSupportedError': errorMsg = '不支持录音功能'; break;
case 'MandatoryUnsatisfiedError': errorMsg = '无法发现指定的硬件设备'; break;
default: errorMsg = '录音调用错误'; break;
}
return { error: errorMsg }
};
static get(callback, config) {
const constrains = { audio: true, video: false };
if (callback) {
if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
navigator.mediaDevices.getUserMedia(constrains).then((stream) => {
let rec = new Recorder(stream, config);
callback(rec);
}).catch((e) => {
callback(Recorder.checkError(e));
})
} else {
// 兼容
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
navigator.getUserMedia(constrains, function(stream) {
let rec = new Recorder(stream, config);
callback(rec);
}, function(err) {
callback(Recorder.checkError(err));
})
}
}
};
}
vue page
我们在 vue 页面中使用 recorder.js
import Recorder from "@/utils/recorder";
// 开始录音
Recorder.get(rec => {
if (rec.error) return console.log(rec.error);
this.curRecorder = rec;
this.curRecorder.start();
this.$toast("开始录音");
});
// 停止录音并获取文件
const blobFile = this.curRecorder.getBlob();
这样我们就实现了录音的功能了