近日公司要求實現(xiàn)用戶錄音并上傳的功能经宏，此文不說上傳傻寂，只說錄音佩捞。
navigator.getUserMedia
開啟錄音的方法是 navigator.getUserMedia
此方法有兼容性甥绿，且現(xiàn)在早已更名為MediaDevices.getUserMedia
詳情參見 MDN字币，另外，必須在本地服務(wù)或者 https 協(xié)議下才能夠開啟錄音共缕！否則會報該方法 is not found 的錯誤洗出。
// 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
//recorder.js
export default class Recorder {
constructor(stream, config) {
//兼容
window.URL = window.URL || window.webkitURL;
config = config || {};
config.sampleBits = config.sampleBits || 16; //采樣數(shù)位 8, 16
config.sampleRate = config.sampleRate || 8000; //采樣率(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, //錄音文件長度
buffer: [], //錄音緩存
inputSampleRate: this.context.sampleRate, //輸入采樣率
inputSampleBits: 16, //輸入采樣數(shù)位 8, 16
outputSampleRate: config.sampleRate, //輸出采樣率
oututSampleBits: config.sampleBits, //輸出采樣數(shù)位 8, 16
input: function (data) {
this.buffer.push(new Float32Array(data));
this.size += data.length;
},
compress: function () { //合并壓縮
//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;
}
//壓縮
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;//單聲道
let offset = 0;
let writeString = function (str) {
for (let 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(jié)數(shù),即文件大小-8
data.setUint32(offset, 36 + dataLength, true);
offset += 4;
// WAV文件標志
writeString('WAVE');
offset += 4;
// 波形格式標志
writeString('fmt ');
offset += 4;
// 過濾字節(jié),一般為 0x10 = 16
data.setUint32(offset, 16, true);
offset += 4;
// 格式類別 (PCM形式采樣數(shù)據(jù))
data.setUint16(offset, 1, true);
offset += 2;
// 通道數(shù)
data.setUint16(offset, channelCount, true);
offset += 2;
// 采樣率,每秒樣本數(shù),表示每個通道的播放速度
data.setUint32(offset, sampleRate, true);
offset += 4;
// 波形數(shù)據(jù)傳輸率 (每秒平均字節(jié)數(shù)) 單聲道×每秒數(shù)據(jù)位數(shù)×每樣本數(shù)據(jù)位/8
data.setUint32(offset, channelCount * sampleRate * (sampleBits / 8), true);
offset += 4;
// 快數(shù)據(jù)調(diào)整數(shù) 采樣一次占用字節(jié)數(shù) 單聲道×每樣本的數(shù)據(jù)位數(shù)/8
data.setUint16(offset, channelCount * (sampleBits / 8), true);
offset += 2;
// 每樣本數(shù)據(jù)位數(shù)
data.setUint16(offset, sampleBits, true);
offset += 2;
// 數(shù)據(jù)標識符
writeString('data');
offset += 4;
// 采樣數(shù)據(jù)總數(shù),即數(shù)據(jù)總大小-44
data.setUint32(offset, dataLength, true);
offset += 4;
// 寫入采樣數(shù)據(jù)
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' });
}
};
}
//開始錄音
start() {
this.audioInput.connect(this.recorder);
this.recorder.connect(this.context.destination);
//音頻采集
let self = this;
this.recorder.onaudioprocess = function (e) {
self.audioData.input(e.inputBuffer.getChannelData(0));
};
};
//停止
stop() {
this.recorder.disconnect();
};
//獲取音頻文件
getBlob() {
this.stop();
return this.audioData.encodeWAV();
};
//回放
play(audio) {
audio.src = window.URL.createObjectURL(this.getBlob());
};
//清理緩存的錄音數(shù)據(jù)
clear(audio) {
this.audioData.buffer = [];
this.audioData.size = 0;
audio.src = ''
};
static checkError(e) {
const { name } = e;
let errorMsg = '';
switch (name) {
case 'AbortError': errorMsg = '錄音設(shè)備無法被使用'; break;
case 'NotAllowedError': errorMsg = '用戶已禁止網(wǎng)頁調(diào)用錄音設(shè)備'; break;
case 'PermissionDeniedError': errorMsg = '用戶已禁止網(wǎng)頁調(diào)用錄音設(shè)備'; break; // 用戶拒絕
case 'NotFoundError': errorMsg = '找不到指定媒體類型'; break;
case 'DevicesNotFoundError': errorMsg = '錄音設(shè)備未找到'; break;
case 'NotReadableError': errorMsg = '錄音設(shè)備無法使用'; break;
case 'NotSupportedError': errorMsg = '不支持錄音功能'; break;
case 'MandatoryUnsatisfiedError': errorMsg = '無法發(fā)現(xiàn)指定的硬件設(shè)備'; break;
default: errorMsg = '錄音調(diào)用錯誤'; 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
我們在 vue 頁面中使用 recorder.js
import Recorder from "@/utils/recorder";
// 開始錄音
Recorder.get(rec => {
if (rec.error) return console.log(rec.error);
this.curRecorder = rec;
this.curRecorder.start();
this.$toast("開始錄音");
});
// 停止錄音并獲取文件
const blobFile = this.curRecorder.getBlob();
這樣我們就實現(xiàn)了錄音的功能了
