提示：局域网socket版，一对多
文章目录
前言
WebRTC（Web Real-Time Communication）是一种实时通讯技术，允许网络应用或站点在不借助中间媒介的情况下，建立浏览器之间的点对点（Peer-to-Peer）连接，实现视频流、音频流或其他任意数据的传输。WebRTC的核心功能包括音视频的采集、编解码、网络传输和显示等
WebRTC的技术特点1、实时通信：WebRTC专注于实时通信，包括音频、视频和其他数据传输。
2、点对点通信：WebRTC支持点对点通信，即两个浏览器之间直接建立连接，无需通过中间服务器。
3、多媒体引擎：WebRTC包含一个多媒体引擎，处理音频和视频流，并提供丰富的API和协议。
4、NAT穿越：WebRTC提供机制，使得在NAT（Network Address Translation）和防火墙等网络设备背后进行通信更为容易。
5、TURN服务器：当P2P连接无法建立时，WebRTC会利用TURN服务器进行数据中转，确保通信的稳定性
一、教程
二、webrtc工作流程
// 推流拉流过程
/**
* 推流端获取视频stream
* 推流端生成offer
* 推流端通过offer设置推流LocalDescription
* 推流端发送offer给(拉)流端
* (拉)流端接收offer
* (拉)流端通过offer设置(拉)流端RemoteDescription
* (拉)流端生成answer
* (拉)流端通过answer设置(拉)流端LocalDescription
* (拉)流端发送answer给推流端
* 推流端接收answer设置推流端RemoteDescription
* 推流端发送candidate(video,audio各一次)
* (拉)流端接收candidate
* (拉)流端发送candidate(video,audio各一次)
* 推流端接收candidate
* **/三、推流端
一个拉流RTCPeerConnection，对应一个推流RTCPeerConnection
X 个拉流RTCPeerConnection，对应X 个推流RTCPeerConnection
push.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>推流</title>
</head>
<body>
<video id="webrtcVideo" autoplay></video>
<script>
const video = document.getElementById('webrtcVideo');
// webscoket
const ws = new WebSocket('ws://127.0.0.1:1990'); // 可换成局域网ip地址
let videoStream;
// 一个拉流RTCPeerConnection对应一个推流RTCPeerConnection，xx个拉流RTCPeerConnection，对应xx个推流RTCPeerConnection
const pushPool = {};
// rtc connection
let pushRtcCon;
// 打开摄像头，video标签播放视频流
const getStream = async () => {
if(!navigator.mediaDevices||!navigator.mediaDevices.getUserMedia)console.log('不支持：getUserMedia');
const stream = await navigator.mediaDevices.getUserMedia({video:true});
video.srcObject = stream;
videoStream = stream;
}
getStream();
// 开始推流
const startPush = (pullId) => {
if(!pushPool[pullId])pushPool[pullId] = pushRtcCon = new RTCPeerConnection();
// rtc connection 添加track
videoStream.getVideoTracks().forEach(track => {
pushRtcCon.addTrack(track,videoStream);
});
// 监听icecandidate
pushRtcCon.onicecandidate = (event)=>{
if(event.candidate)ws.send(JSON.stringify({type:'candidate',candidate:event.candidate,id:pullId}))
}
// 创建offer
pushRtcCon.createOffer().then(offer=>{
console.log(offer)
// 设置推流LocalDescription
pushRtcCon.setLocalDescription(offer).then(()=>{ console.log('推流设置LocalDescription成功');});
// offer信息发送给拉流
ws.send(JSON.stringify({type:'offer',id:pullId,offer}))
});
}
// 开启websocket服务
ws.addEventListener('open',()=>{
// 初始化推流通道
ws.send(JSON.stringify({type:'push_init'}))
console.log('websocket连接成功')
});
// 接收wenbscoket信息
ws.addEventListener('message', (event) => {
let data = JSON.parse(event.data);
console.log(data)
// 接收到拉流传来的answer 设置推流RemoteDescription
if(data.type == 'answer')pushRtcCon.setRemoteDescription(data.answer).then(()=>{ console.log('推流设置RemoteDescription成功');});
// 接收拉流candidate 推流rtc connection 添加IceCandidate
if(data.type == 'candidate'&&data.candidate)pushRtcCon.addIceCandidate(data.candidate).then(()=>{ console.log('推流添加candidate成功');});
// 接收拉流开启消息 开始推流
if(data.type == 'pull_start')startPush(data.id);
})
</script>
</body>
</html>四、拉流
pull.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<video id="pullVideo" autoplay preload muted></video>
<div id="pullBtn">拉流</div>
<script>
const pullBtn = document.getElementById('pullBtn');
// 开始拉流
const startPll = () =>{
let ws = new WebSocket('ws://127.0.0.1:1990'); // 可换成局域网ip地址
const pullVideo = document.getElementById('pullVideo');
let pullStrem;
// 拉流rtc connection
const pullRtcCon = new RTCPeerConnection();
const pullID = new Date().getTime()+'io'+Math.round(Math.random()*10000);
// 拉流监听icecandidate
pullRtcCon.onicecandidate = (event)=>{
// 接收到icecandidate 发送candidate给推流端
if(event.candidate)ws.send(JSON.stringify({type:'candidate',candidate:event.candidate,num:1,id:pullID}))
}
// 监听track
pullRtcCon.addEventListener('track' ,(event) => {
pullStrem = event.streams[0];
pullVideo.srcObject = event.streams[0];
})
// 打开webscoket
ws.addEventListener('open',async ()=>{
await ws.send(JSON.stringify({type:'pull_init',id:pullID}));
// 通知推流端，开始推流
ws.send(JSON.stringify({type:'pull_start',id:pullID}));
console.log('websocket连接成功')
});
// 监听webscoket消息
ws.addEventListener('message',(event)=>{
let data = JSON.parse(event.data);
// 接收到推流端offer
console.log(data,'????')
if(data.type == 'offer'){
// 设置拉流端 RemoteDescription
pullRtcCon.setRemoteDescription(data.offer).then(()=>{
console.log('拉流设置RemoteDescription成功')
// 创建answer
pullRtcCon.createAnswer(data.offer).then((answer)=>{
// 设置拉流的LocalDescription
pullRtcCon.setLocalDescription(answer).then(()=>{
console.log('拉流设置LocalDescription成功')
});
// 发送answer到推流端
ws.send(JSON.stringify({type:'answer',answer,id:pullID}))
});
});
}
// 接收推流端candidate 拉流端添加IceCandidate
if(data.type == 'candidate')pullRtcCon.addIceCandidate(data.candidate).then(()=>{ console.log('拉流添加candidate成功');});
})
}
// 拉流按钮点击事件
pullBtn.addEventListener('click',startPll)
</script>
</body>
</html>五、socket服务
安装依赖
npm init
npm install nodejs-websocket -Sindex.js
const ws = require('nodejs-websocket');
const port = '1990';
// 推流通道 拉流通道
let wsPush,wsPull,pullPool={};
const server = ws.createServer((connection)=>{
// websocket 连接接收数据
connection.on('text',(msg)=>{
let data = JSON.parse(msg);
// 初始化推流websocket
if(data.type == 'push_init')wsPush = connection;
// 初始化拉流websocket
if(data.type == 'pull_init')if(!pullPool[data.id]) pullPool[data.id] = connection;
// 接收推流消息 发送给拉流
if(connection == wsPush&&pullPool[data.id])pullPool[data.id].send(msg);
// 接收拉流消息 发送给推流
for(let key in pullPool){
if(connection == pullPool[key]&&wsPush)wsPush.send(msg);
}
})
// websocket 关闭
connection.on('close',()=>{
wsPush = null;wsPull = null;
console.log('通道关闭')
})
// websocket 报错
connection.on('err',(err)=>{
wsPush = null;wsPull = null;
console.log('通道报错：'+err)
})
})
server.listen(port,console.log('ws启动成功，127.0.0.1:'+port));六、效果
推流端
拉流端（点击拉流按钮）
七、备注
1、socket地址可换成局域网IP地址访问
2、pull来流请求地址可换成局域网IP地址访问
总结
踩坑路漫漫长@~@