mediaDevices-MediaRecorder流媒体处理
濮阳烨然
参考:https://www.cnblogs.com/Wayou/p/js_audio_recorder.html
转载:https://developer.mozilla.org/zh-CN/docs/Web/API/MediaRecorder
MediaRecorder 是 MediaStream Recording API 提供的用来进行媒体轻松录制的接口, 他需要通过调用 MediaRecorder() 构造方法进行实例化.
if (navigator.mediaDevices) {
console.log('getUserMedia supported.');
var constraints = { audio: true };
var chunks = [];
navigator.mediaDevices.getUserMedia(constraints)
.then(function(stream) {
var mediaRecorder = new MediaRecorder(stream);
visualize(stream);
record.onclick = function() {
mediaRecorder.start();
console.log(mediaRecorder.state);
console.log("recorder started");
record.style.background = "red";
record.style.color = "black";
}
stop.onclick = function() {
mediaRecorder.stop();
console.log(mediaRecorder.state);
console.log("recorder stopped");
record.style.background = "";
record.style.color = "";
}
mediaRecorder.onstop = function(e) {
console.log("data available after MediaRecorder.stop() called.");
var clipName = prompt('Enter a name for your sound clip');
var clipContainer = document.createElement('article');
var clipLabel = document.createElement('p');
var audio = document.createElement('audio');
var deleteButton = document.createElement('button');
clipContainer.classList.add('clip');
audio.setAttribute('controls', '');
deleteButton.innerHTML = "Delete";
clipLabel.innerHTML = clipName;
clipContainer.appendChild(audio);
clipContainer.appendChild(clipLabel);
clipContainer.appendChild(deleteButton);
soundClips.appendChild(clipContainer);
audio.controls = true;
var blob = new Blob(chunks, { 'type' : 'audio/ogg; codecs=opus' });
chunks = [];
var audioURL = URL.createObjectURL(blob);
audio.src = audioURL;
console.log("recorder stopped");
deleteButton.onclick = function(e) {
evtTgt = e.target;
evtTgt.parentNode.parentNode.removeChild(evtTgt.parentNode);
}
}
mediaRecorder.ondataavailable = function(e) {
chunks.push(e.data);
}
})
.catch(function(err) {
console.log('The following error occured: ' + err);
})
}
案例
const recordBtn = document.querySelector(".record-btn");
const player = document.querySelector(".audio-player");
if (navigator.mediaDevices.getUserMedia) {
var chunks = [];
const constraints = { audio: true };
navigator.mediaDevices.getUserMedia(constraints).then(
stream => {
console.log("授权成功！");
const mediaRecorder = new MediaRecorder(stream);
recordBtn.onclick = () => {
if (mediaRecorder.state === "recording") {
mediaRecorder.stop();
recordBtn.textContent = "record";
console.log("录音结束");
} else {
mediaRecorder.start();
console.log("录音中...");
recordBtn.textContent = "stop";
}
console.log("录音器状态：", mediaRecorder.state);
};
mediaRecorder.ondataavailable = e => {
chunks.push(e.data);
};
mediaRecorder.onstop = e => {
var blob = new Blob(chunks, { type: "audio/ogg; codecs=opus" });
chunks = [];
var audioURL = window.URL.createObjectURL(blob);
player.src = audioURL;
};
},
() => {
console.error("授权失败！");
}
);
} else {
console.error("浏览器不支持 getUserMedia");
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>audio record</title>
</head>
<body>
<div class="app">
<button class="record-btn">record</button>
<audio controls class="audio-player"></audio>
</div>
<script src="./recorder.js"></script>
</body>
</html>
录音
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta name="apple-mobile-web-capable" content="yes">
<title>录音并传递给后台</title>
</head>
<body>
<button id="intercomBegin">开始对讲</button>
<button id="intercomEnd">关闭对讲</button>
</body>
<script type="text/javascript">
var begin = document.getElementById('intercomBegin');
var end = document.getElementById('intercomEnd');
var ws = null; //实现WebSocket
var record = null; //多媒体对象，用来处理音频
function init(rec) {
record = rec;
}
//录音对象
var Recorder = function(stream) {
var sampleBits = 16; //输出采样数位 8, 16
var sampleRate = 8000; //输出采样率
var context = new AudioContext();
var audioInput = context.createMediaStreamSource(stream);
var recorder = context.createScriptProcessor(4096, 1, 1);
var audioData = {
size: 0, //录音文件长度
buffer: [], //录音缓存
inputSampleRate: 48000, //输入采样率
inputSampleBits: 16, //输入采样数位 8, 16
outputSampleRate: sampleRate, //输出采样数位
oututSampleBits: sampleBits, //输出采样率
clear: function() {
this.buffer = [];
this.size = 0;
},
input: function(data) {
this.buffer.push(new Float32Array(data));
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(length);
var index = 0,
j = 0;
while (index < length) {
result[index] = data[j];
j += compression;
index++;
}
return result;
},
encodePCM: function() { //这里不对采集到的数据进行其他格式处理，如有需要均交给服务器端处理。
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(dataLength);
var data = new DataView(buffer);
var offset = 0;
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]);
}
};
var sendData = function() { //对以获取的数据进行处理(分包)
var reader = new FileReader();
reader.onload = e => {
var outbuffer = e.target.result;
var arr = new Int8Array(outbuffer);
if (arr.length > 0) {
var tmparr = new Int8Array(1024);
var j = 0;
for (var i = 0; i < arr.byteLength; i++) {
tmparr[j++] = arr[i];
if (((i + 1) % 1024) == 0) {
ws.send(tmparr);
if (arr.byteLength - i - 1 >= 1024) {
tmparr = new Int8Array(1024);
} else {
tmparr = new Int8Array(arr.byteLength - i - 1);
}
j = 0;
}
if ((i + 1 == arr.byteLength) && ((i + 1) % 1024) != 0) {
ws.send(tmparr);
}
}
}
};
reader.readAsArrayBuffer(audioData.encodePCM());
audioData.clear();//每次发送完成则清理掉旧数据
};
this.start = function() {
audioInput.connect(recorder);
recorder.connect(context.destination);
}
this.stop = function() {
recorder.disconnect();
}
this.getBlob = function() {
return audioData.encodePCM();
}
this.clear = function() {
audioData.clear();
}
recorder.onaudioprocess = function(e) {
var inputBuffer = e.inputBuffer.getChannelData(0);
audioData.input(inputBuffer);
sendData();
}
}
/*
* WebSocket
*/
function useWebSocket() {
ws = new WebSocket("ws://192.168.2.9:8080/websocket");
ws.binaryType = 'arraybuffer'; //传输的是 ArrayBuffer 类型的数据
ws.onopen = function() {
console.log('握手成功');
if (ws.readyState == 1) { //ws进入连接状态，则每隔500毫秒发送一包数据
record.start();
}
};
ws.onmessage = function(msg) {
console.info(msg)
}
ws.onerror = function(err) {
console.info(err)
}
}
/*
* 开始对讲
*/
begin.onclick = function() {
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia;
if (!navigator.getUserMedia) {
alert('浏览器不支持音频输入');
} else {
navigator.getUserMedia({
audio: true
},
function(mediaStream) {
init(new Recorder(mediaStream));
console.log('开始对讲');
useWebSocket();
},
function(error) {
console.log(error);
switch (error.message || error.name) {
case 'PERMISSION_DENIED':
case 'PermissionDeniedError':
console.info('用户拒绝提供信息。');
break;
case 'NOT_SUPPORTED_ERROR':
case 'NotSupportedError':
console.info('浏览器不支持硬件设备。');
break;
case 'MANDATORY_UNSATISFIED_ERROR':
case 'MandatoryUnsatisfiedError':
console.info('无法发现指定的硬件设备。');
break;
default:
console.info('无法打开麦克风。异常信息:' + (error.code || error.name));
break;
}
}
)
}
}
/*
* 关闭对讲
*/
end.onclick = function() {
if (ws) {
ws.close();
record.stop();
console.log('关闭对讲以及WebSocket');
}
}
</script>
</html>
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