一个简单的WebRtc的例子

创建项目

// 创建项目
// 1. 进入发布目录 ,这里要进入自己设置的发布路径
cd public 
// 创建项目
mkdir demo01
cd demo01
// 创建 两文件 css 和 js ，用来对html 界面进行渲染
mkdir css js
// 返回上一级目录，书写html文件
cd ..
vim index.html

// index.html 
<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>一个简单WebRTC例子</title>
		<!--  引入外来的css文件 -->
		<link href="./css/main.css" rel="stylesheet" />
	</head>
	<body>
		
		<div>
			<div>
				<!--  打开摄像头服务 -->
				<button type="button" id="start">Start</button>
				<!-- 同一个主机的两个窗口建立连接 -->
				<button type="button" id="call">Call</button>
				<!-- 关闭连接操作 -->
				<button id="hangup" disabled>HangUp</button>	
			</div>
			<div id="preview">
				<div id="preview">
								<div >
									<!--  模拟本地 -->
									<h2>Local:</h2>
									<video id="localvideo" autoplay playsinline></video>
									<h2>Local SDP:</h2>
									<textarea id="offer"></textarea>
								</div>
								<div>
									<!-- 模拟远端 -->
									<h2>Remote:</h2>
									<video id="remotevideo" autoplay playsinline></video>
									<h2>Remote SDP:</h2>
									<textarea id="answer"></textarea>
							</div>
					</div>
			</div>
		</div>
			<!--  解决 浏览器适配问题 -->
			<script src="https://webrtc.github.io/adapter/adapter-latest.js"></script> 
			<!-- 进行WebRTC通信的关键代码 -->
			<script src="js/main.js"></script>
	</body>
</html>

// main.css
/*
 *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.
 */

button {
  margin: 0 20px 25px 0;
  vertical-align: top;
  width: 134px;
}

textarea {
  color: #444;
  font-size: 0.9em;
  font-weight: 300;
  height: 20.0em;
  padding: 5px;
  width: calc(100% - 10px);
}

div#getUserMedia {
  padding: 0 0 8px 0;
}

div.input {
  display: inline-block;
  margin: 0 4px 0 0;
  vertical-align: top;
  width: 310px;
}

div.input > div {
  margin: 0 0 20px 0;
  vertical-align: top;
}

div.output {
  background-color: #eee;
  display: inline-block;
  font-family: 'Inconsolata', 'Courier New', monospace;
  font-size: 0.9em;
  padding: 10px 10px 10px 25px;
  position: relative;
  top: 10px;
  white-space: pre;
  width: 270px;
}

div#preview {
  border-bottom: 1px solid #eee;
  margin: 0 0 1em 0;
  padding: 0 0 0.5em 0;
}

div#preview > div {
  display: inline-block;
  vertical-align: top;
  width: calc(50% - 12px);
}

section#statistics div {
  display: inline-block;
  font-family: 'Inconsolata', 'Courier New', monospace;
  vertical-align: top;
  width: 308px;
}

section#statistics div#senderStats {
  margin: 0 20px 0 0;
}

section#constraints > div {
  margin: 0 0 20px 0;
}

h2 {
  margin: 0 0 1em 0;
}


section#constraints label {
  display: inline-block;
  width: 156px;
}

section {
  margin: 0 0 20px 0;
  padding: 0 0 15px 0;
}

video {
  background: #222;
  margin: 0 0 0 0;
  --width: 100%;
  width: var(--width);
  height: 225px;
}

@media screen and (max-width: 720px) {
  button {
    font-weight: 500;
    height: 56px;
    line-height: 1.3em;
    width: 90px;
  }

  div#getUserMedia {
    padding: 0 0 40px 0;
  }

  section#statistics div {
    width: calc(50% - 14px);
  }

}

// main.js
'use strict'

var localVideo = document.querySelector('video#localvideo');
var remoteVideo = document.querySelector('video#remotevideo');

var btnStart = document.querySelector('button#start');
var btnCall = document.querySelector('button#call');
var btnHangup = document.querySelector('button#hangup');

var offerSdpTextarea = document.querySelector('textarea#offer');
var answerSdpTextarea = document.querySelector('textarea#answer');

var localStream;
var pc1;
var pc2;

function getMediaStream(stream){
	localVideo.srcObject = stream;
	localStream = stream;
}

function handleError(err){
	console.error('Failed to get Media Stream!', err);
}

function start(){

	if(!navigator.mediaDevices ||
		!navigator.mediaDevices.getUserMedia){
		console.error('the getUserMedia is not supported!');
		return;
	}else {
		var constraints = {
			video: true,
			audio: false
		}
		navigator.mediaDevices.getUserMedia(constraints)
					.then(getMediaStream)
					.catch(handleError);

		btnStart.disabled = true;
		btnCall.disabled = false;
		btnHangup.disabled = true;
	}
}

function getRemoteStream(e){
	remoteVideo.srcObject = e.streams[0];
}

function handleOfferError(err){
	console.error('Failed to create offer:', err);
}

function handleAnswerError(err){
	console.error('Failed to create answer:', err);
}

function getAnswer(desc){
	pc2.setLocalDescription(desc);
	answerSdpTextarea.value = desc.sdp

	//send desc to signal
	//receive desc from signal
	
	pc1.setRemoteDescription(desc);
}

function getOffer(desc){
	pc1.setLocalDescription(desc);
	offerSdpTextarea.value = desc.sdp

	//send desc to signal
	//receive desc from signal
	
	pc2.setRemoteDescription(desc);

	pc2.createAnswer()
		.then(getAnswer)
		.catch(handleAnswerError);

}

function call(){
	
	pc1 = new RTCPeerConnection();
	pc2 = new RTCPeerConnection();

	pc1.onicecandidate = (e)=>{
		pc2.addIceCandidate(e.candidate);	
	}

	pc2.onicecandidate = (e)=>{
		pc1.addIceCandidate(e.candidate);	
	}

	pc2.ontrack = getRemoteStream;

	localStream.getTracks().forEach((track)=>{
		pc1.addTrack(track, localStream);	
	});

	var offerOptions = {
		offerToRecieveAudio: 0,
		offerToRecieveVideo: 1
	}

	pc1.createOffer(offerOptions)
		.then(getOffer)
		.catch(handleOfferError);

	btnCall.disabled = true;
	btnHangup.disabled = false;
}

function hangup(){
	pc1.close();
	pc2.close();
	pc1 = null;
	pc2 = null;

	btnCall.disabled = false;
	btnHangup.disabled = true;
}

btnStart.onclick = start;
btnCall.onclick = call;
btnHangup.onclick = hangup;