webrtc实现点对点视频通讯

「爱情、让人受尽委屈。」 2023-08-17 15:42 122阅读 0赞

html：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

<!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>webrtc</title>
        <style>
            #yours{
                width:300px;
                position:absolute;
                top:200px;
                left:100px;
            }
            #theirs{
                width:300px;
                position:absolute;
                top:200px;
                left:400px;
            }
        </style>
    </head>
    <body>
        <button οnclick="createOffer()">建立连接</button>
        <video id="yours" autoplay></video>
        <video id="theirs" autoplay></video>
    
    </body>
    
    <script src="./lib/jquery.min.js"></script>
    <script src="./lib/webrtc.js"></script>
    
    </html>

webrtc.js

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1 var websocket;
      2 
      3 function randomNum(minNum,maxNum){ 
      4     switch(arguments.length){ 
      5         case 1: 
      6             return parseInt(Math.random()*minNum+1,10); 
      7         break; 
      8         case 2: 
      9             return parseInt(Math.random()*(maxNum-minNum+1)+minNum,10); 
     10         break; 
     11             default: 
     12                 return 0; 
     13             break; 
     14     } 
     15 } 
     16 const userid = 'user' + randomNum(0,100000);
     17 
     18 function hasUserMedia() {
     19     navigator.getUserMedia = navigator.getUserMedia || navigator.msGetUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
     20     return !!navigator.getUserMedia;
     21 }
     22 function hasRTCPeerConnection() {
     23     window.RTCPeerConnection = window.RTCPeerConnection || window.webkitRTCPeerConnection || window.mozRTCPeerConnection || window.msRTCPeerConnection;
     24     return !!window.RTCPeerConnection;
     25 }
     26 
     27 var yourVideo = document.getElementById("yours");
     28 var theirVideo = document.getElementById("theirs");
     29 var Connection;
     30 
     31 
     32 function startPeerConnection() {
     33     //return;
     34     var config = {
     35         'iceServers': [
     36             //{ 'urls': 'stun:stun.xten.com:3478' },
     37             //{ 'urls': 'stun:stun.voxgratia.org:3478' },
     38             { 'url': 'stun:stun.l.google.com:19302' }
     39         ]
     40     };
     41     config = { 
     42         iceServers: [
     43             { urls: 'stun:stun.l.google.com:19302' }, 
     44             { urls: 'stun:global.stun.twilio.com:3478?transport=udp' }
     45         ],
     46         //sdpSemantics: 'unified-plan'
     47     };
     48     // {
     49     //     "iceServers": [{
     50     //         "url": "stun:stun.1.google.com:19302"
     51     //     }]
     52     // };
     53     Connection = new RTCPeerConnection(config);
     54     Connection.onicecandidate = function(e) {
     55         console.log('onicecandidate');
     56         if (e.candidate) {
     57             websocket.send(JSON.stringify({
     58                 "userid":userid,
     59                 "event": "_ice_candidate",
     60                 "data": {
     61                     "candidate": e.candidate
     62                 }
     63             }));
     64         }
     65     }
     66     Connection.onaddstream = function(e) {
     67         console.log('onaddstream');
     68 
     69         //theirVideo.src = window.URL.createObjectURL(e.stream);
     70         theirVideo.srcObject = e.stream; 
     71     }
     72 }
     73 
     74 
     75 createSocket();
     76 startPeerConnection();
     77 
     78 if (hasUserMedia()) {
     79     navigator.getUserMedia({ video: true, audio: false },
     80         stream => {
     81             yourVideo.srcObject = stream; 
     82             window.stream = stream;
     83             Connection.addStream(stream)                
     84         },
     85         err => {
     86             console.log(err);
     87         })
     88 }       
     89 
     90 
     91 function createOffer(){
     92     //发送offer和answer的函数，发送本地session描述
     93     Connection.createOffer().then(offer => {
     94         Connection.setLocalDescription(offer);
     95         websocket.send(JSON.stringify({
     96             "userid":userid,
     97             "event": "offer",
     98             "data": {
     99                 "sdp": offer
    100             }
    101         }));
    102     });
    103 }
    104 
    105 
    106 
    107 function createSocket(){
    108     //websocket = null;
    109     websocket = new WebSocket('wss://www.ecoblog.online/wss');
    110     eventBind();
    111 };
    112 function eventBind() {
    113     //连接成功
    114     websocket.onopen = function(e) {
    115         console.log('连接成功')
    116     };
    117     //server端请求关闭
    118     websocket.onclose = function(e) {
    119       console.log('close')
    120     };
    121     //error
    122     websocket.onerror = function(e) {
    123 
    124     };
    125     //收到消息
    126     websocket.onmessage = (event)=> {
    127         if(event.data == "new user") {
    128             location.reload();
    129         } else {
    130             var json = JSON.parse(event.data);
    131             console.log('onmessage: ', json);
    132             if(json.userid !=userid){
    133                 //如果是一个ICE的候选，则将其加入到PeerConnection中，否则设定对方的session描述为传递过来的描述
    134                 if(json.event === "_ice_candidate"&&json.data.candidate) {
    135                     Connection.addIceCandidate(new RTCIceCandidate(json.data.candidate));
    136                 }else if(json.event ==='offer'){
    137                     Connection.setRemoteDescription(json.data.sdp);
    138                     Connection.createAnswer().then(answer => {
    139                             Connection.setLocalDescription(answer);
    140                             console.log(window.stream)
    141                             websocket.send(JSON.stringify({
    142                                 "userid":userid,
    143                                 "event": "answer",
    144                                 "data": {
    145                                     "sdp": answer
    146                                 }
    147                             }));
    148                     })
    149                 }else if(json.event ==='answer'){
    150                     Connection.setRemoteDescription(json.data.sdp);   
    151                     console.log(window.stream)
    152 
    153                 }
    154             }
    155         }
    156     };
    157 }

建立连接的过程：

1⃣️两个浏览器都打开该页面，连接到同一个socket('wss://www.ecoblog.online/wss')；

注意：webrtc只能在localhost或者https下使用，所以线上环境的话，我们的socket服务以及html页面都必须是要有https证书的；

对于wss，利用代理，在nginx的站点配置下如下配置/wss：

![1220416-20190809003155375-431128215.png][]

正如你所看到的那样，socket服务开在12345端口，所以还要去阿里云网站开一个这个端口的出入站规则；

另外centos的防火墙对该端口开放，或者直接关闭防火墙（自行百度）

socket服务写得比较简陋，但已够用，功能就是把收到的信息发给当前连接的所有c端

![1220416-20190809003706624-311090933.png][]

2⃣️两个c端已经和socket建立连接，然后任意其中一端点击“建立连接”

此时点击建立连接的端就是offer(携带信号源信息)，发给另外一个端，另外一个端收到offer之后，发出响应answer(携带信号源信息)，offer端收到answer端信息进行存储；

这样每个端都有了自己的信息和对方的信息，

3⃣️candidata信息的发送

其实这块，网上有的说法是offer发出answer发出后设置了localDescription和remoteDescription后就会触发onicecandidate，但是我测试的时候貌似没有，所以

我这里是在获取摄像头信息后通过

Connection.addStream(stream)

来触发Connection.onicecandidate，在这个事件监听的回调里，发出自身端的candidata给对方，如此一来，双方都有了对方的localDescription、remoteDescription和candidata；

三者齐全之后，就会触发Connection.onaddstream,这样，直接通过：

theirVideo.srcObject = e.stream;

把流写到video里面去，这样就能展示对方的视频信息了：

但是这样，只能在局域网内使用，如果要在公网使用的话，还要一个穿透服务器，网上找的一些免费的好像都不能用了？还是说我写得有问题？

具体的可百度，webrtc搭建stun服务器

转载于:https://www.cnblogs.com/eco-just/p/11324768.html

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[1220416-20190809003706624-311090933.png]: /images/20230810/bb4ec16a1fac433eb988f7d830d24084.png