关于音视频:基于-Web-SDK-实现视频通话场景-声网-SDK-教程

声网视频 SDK 被广泛应用于多种实时互动场景中，例如视频会议、视频通话、音视频社交、在线教育等。为了让刚刚接触声网 SDK 的开发者，能够更顺畅地实现根底的视频通话性能，咱们基于声网 Web SDK 4.x 版本梳理了本篇教程。
在本文末，会提供相应 Demo 、文档地址供大家参考应用。同时，欢送点击此处注册声网账号体验。声网每个月会为开发者提供 10000 分钟的收费额度。
本文为「声网 SDK 教程」系列内容

01 Demo 体验

咱们在 GitHub 上提供一个开源的根底视频通话示例我的项目，在开始开发之前你能够通过该示例我的项目体验音视频通话成果。Demo 与线上体验地址，可在文末获取。

02 入手实际

实际工作

从 Web 前端页面引入声网 SDK，发动视频通话。

开发环境

声网 SDK 的兼容性良好，对硬件设施和软件系统的要求不高，开发环境和测试环境满足以下条件即可：

Chrome
Firefox
Safari
Edge

以下是本文的开发环境和测试环境：

开发环境

MacBook Pro (13-inch, M1, 2020)
Visual Studio Code (1.67.1)

测试环境

Chrome (101.0.4951.64)

如果你此前还未接触过声网 SDK，那么你还须要做以下筹备工作：

注册一个声网账号，进入后盾创立 AppID、获取 Token；
下载声网官网最新的视频 SDK。

我的项目设置

文件组织构造

实现视频通话之前，参考如下步骤设置你的我的项目：

如需创立新我的项目，能够在 Visual Studio Code 里 File > New Window，创立 Web 我的项目。残缺的目录构造如下，依据集体教训会有所变动。

.├── index.css # 用于设计 Web 利用的用户界面款式├── index.html # 用于设计 Web 利用的用户界面├── index.js # 通过 AgoraRTCClient 实现具体应用逻辑的代码。└── vendor # 第三方前端插件，辅助页面布局和交互，本教程中是下载到本地应用，你也能够应用 CDN 的形式    ├── bootstrap.bundle.min.js    ├── bootstrap.min.css    └── jquery-3.4.1.min.js

集成声网 SDK

能够下载到本地应用，也能够间接应用声网的 CDN 引入，本文举荐应用 CDN 形式集成声网 SDK。

在 index.html 中增加以下代码

<!DOCTYPE html>...  <link rel="stylesheet" href="./vendor/bootstrap.min.css">  <link rel="stylesheet" href="./index.css">...  <script src="./vendor/jquery-3.4.1.min.js"></script>  <script src="./vendor/bootstrap.bundle.min.js"></script>  <script src="https://download.agora.io/sdk/release/AgoraRTC_N.js"></script>  <script src="./index.js"></script>...

最终残缺代码为

能够间接复制运行。

<!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>Basic Video Call -- Agora</title>  <link rel="stylesheet" href="./vendor/bootstrap.min.css">  <link rel="stylesheet" href="./index.css"></head><body>  <div class="container-fluid banner">    <p class="banner-text">Basic Video Call</p>    <a style="color: rgb(255, 255, 255);fill: rgb(255, 255, 255);fill-rule: evenodd; position: absolute; right: 10px; top: 4px;"      class="Header-link " href="https://github.com/AgoraIO-Community/AgoraWebSDK-NG/tree/master/Demo">      <svg class="octicon octicon-mark-github v-align-middle" height="32" viewBox="0 0 16 16" version="1.1" width="32" aria-hidden="true"><path fill-rule="evenodd" d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0016 8c0-4.42-3.58-8-8-8z"></path></svg>    </a>  </div>    <div id="success-alert" class="alert alert-success alert-dismissible fade show" role="alert">    <strong>Congratulations!</strong><span> You can invite others join this channel by click </span><a href="" target="_blank">here</a>    <button type="button" class="close" data-dismiss="alert" aria-label="Close">      <span aria-hidden="true">&times;</span>    </button>  </div>  <div id="success-alert-with-token" class="alert alert-success alert-dismissible fade show" role="alert">    <strong>Congratulations!</strong><span> Joined room successfully. </span>    <button type="button" class="close" data-dismiss="alert" aria-label="Close">      <span aria-hidden="true">&times;</span>    </button>  </div>  <div id="success-alert-with-token" class="alert alert-success alert-dismissible fade show" role="alert">    <strong>Congratulations!</strong><span> Joined room successfully. </span>    <button type="button" class="close" data-dismiss="alert" aria-label="Close">      <span aria-hidden="true">&times;</span>    </button>  </div>     <div class="container">    <form id="join-form">      <div class="row join-info-group">          <div class="col-sm">            <p class="join-info-text">AppID</p>            <input id="appid" type="text" placeholder="enter appid" required>            <p class="tips">If you don`t know what is your appid, checkout <a href="https://docs.agora.io/en/Agora%20Platform/terms?platform=All%20Platforms#a-nameappidaapp-id">this</a></p>          </div>          <div class="col-sm">            <p class="join-info-text">Token(optional)</p>            <input id="token" type="text" placeholder="enter token">            <p class="tips">If you don`t know what is your token, checkout <a href="https://docs.agora.io/en/Agora%20Platform/terms?platform=All%20Platforms#a-namekeyadynamic-key">this</a></p>          </div>          <div class="col-sm">            <p class="join-info-text">Channel</p>            <input id="channel" type="text" placeholder="enter channel name" required>            <p class="tips">If you don`t know what is your channel, checkout <a href="https://docs.agora.io/en/Agora%20Platform/terms?platform=All%20Platforms#channel">this</a></p>          </div>      </div>       <div class="button-group">        <button id="join" type="submit" class="btn btn-primary btn-sm">Join</button>        <button id="leave" type="button" class="btn btn-primary btn-sm" disabled>Leave</button>      </div>    </form>     <div class="row video-group">      <div class="col">        <p id="local-player-name" class="player-name"></p>        <div id="local-player" class="player"></div>      </div>      <div class="w-100"></div>      <div class="col">        <div id="remote-playerlist"></div>      </div>    </div>  </div>   <script src="./vendor/jquery-3.4.1.min.js"></script>  <script src="./vendor/bootstrap.bundle.min.js"></script>  <script src="https://download.agora.io/sdk/release/AgoraRTC_N.js"></script>  <script src="./index.js"></script></body></html>

视频通话逻辑

实现视频通话逻辑

下图展现视频通话的 API 调用时序,留神图中的办法是对不同的对象调用的。

参考以下步骤实现音视频通话的逻辑：

1.调用 createClient 办法创立 AgoraRTCClient 对象。

2.调用 join 办法退出一个 RTC 频道，你须要在该办法中传入 App ID 、用户 ID、Token、频道名称。

3.先调用 createMicrophoneAudioTrack 通过麦克风采集的音频创立本地音频轨道对象，调用 createCameraVideoTrack 通过摄像头采集的视频创立本地视频轨道对象；而后调用 publish 办法，将这些本地音视频轨道对象当作参数即可将音视频公布到频道中。

4.当一个远端用户退出频道并公布音视频轨道时：

a.监听 client.on("user-published") 事件。当 SDK 触发该事件时，在这个事件回调函数的参数中你能够获取远端用户 AgoraRTCRemoteUser 对象。

b.调用 subscribe 办法订阅远端用户 AgoraRTCRemoteUser 对象，获取远端用户的远端音频轨道 RemoteAudioTrack 和远端视频轨道 RemoteVideoTrack 对象。

c.调用 play 办法播放远端音视频轨道。

注：以下代码都将在 index.js 中增加**

初始化client

var client = AgoraRTC.createClient({ mode: "rtc", codec: "vp8" });

退出RTC 频道并创立本地音频轨道

// Join a channel and create local tracks. Best practice is to use Promise.all and run them concurrently.[ options.uid, localTracks.audioTrack, localTracks.videoTrack ] = await Promise.all([  // Join the channel.  client.join(options.appid, options.channel, options.token || null, options.uid || null),  // Create tracks to the local microphone and camera.  AgoraRTC.createMicrophoneAudioTrack(),  AgoraRTC.createCameraVideoTrack()]);

播放本地视频

// Play the local video track to the local browser and update the UI with the user ID.localTracks.videoTrack.play("local-player");

公布本地音视频到频道中

// Publish the local video and audio tracks to the channel.await client.publish(Object.values(localTracks));

监听远端用户音视频

// Add an event listener to play remote tracks when remote user publishes.client.on("user-published", handleUserPublished);client.on("user-unpublished", handleUserUnpublished); function handleUserPublished(user, mediaType) {  const id = user.uid;  remoteUsers[id] = user;  subscribe(user, mediaType);} function handleUserUnpublished(user, mediaType) {  if (mediaType === 'video') {    const id = user.uid;    delete remoteUsers[id];    $(`#player-wrapper-${id}`).remove();  }}  async function subscribe(user, mediaType) {  const uid = user.uid;  // subscribe to a remote user  await client.subscribe(user, mediaType);  console.log("subscribe success");  if (mediaType === 'video') {    const player = $(`      <div id="player-wrapper-${uid}">        <p class="player-name">remoteUser(${uid})</p>        <div id="player-${uid}" class="player"></div>      </div>    `);    $("#remote-playerlist").append(player);    user.videoTrack.play(`player-${uid}`);  }   if (mediaType === 'audio') {    user.audioTrack.play();  }}

来到频道

async function leave() {  for (trackName in localTracks) {    var track = localTracks[trackName];    if(track) {      track.stop();      track.close();      localTracks[trackName] = undefined;    }  }   // Remove remote users and player views.  remoteUsers = {};  $("#remote-playerlist").html("");   // leave the channel  await client.leave(); }

最终残缺的代码

// create Agora clientvar client = AgoraRTC.createClient({ mode: "rtc", codec: "vp8" });  var localTracks = {  videoTrack: null,  audioTrack: null};var remoteUsers = {};// Agora client optionsvar options = {  appid: null,  channel: null,  uid: null,  token: null}; // the demo can auto join channel with params in url$(() => {  var urlParams = new URL(location.href).searchParams;  options.appid = urlParams.get("appid");  options.channel = urlParams.get("channel");  options.token = urlParams.get("token");  if (options.appid && options.channel) {    $("#appid").val(options.appid);    $("#token").val(options.token);    $("#channel").val(options.channel);    $("#join-form").submit();  }}) $("#join-form").submit(async function (e) {  e.preventDefault();  $("#join").attr("disabled", true);  try {    options.appid = $("#appid").val();    options.token = $("#token").val();    options.channel = $("#channel").val();    await join();    if(options.token) {      $("#success-alert-with-token").css("display", "block");    } else {      $("#success-alert a").attr("href", `index.html?appid=${options.appid}&channel=${options.channel}&token=${options.token}`);      $("#success-alert").css("display", "block");    }  } catch (error) {    console.error(error);  } finally {    $("#leave").attr("disabled", false);  }}) $("#leave").click(function (e) {  leave();}) async function join() {   // add event listener to play remote tracks when remote user publishs.  client.on("user-published", handleUserPublished);  client.on("user-unpublished", handleUserUnpublished);   // join a channel and create local tracks, we can use Promise.all to run them concurrently  [ options.uid, localTracks.audioTrack, localTracks.videoTrack ] = await Promise.all([    // join the channel    client.join(options.appid, options.channel, options.token || null),    // create local tracks, using microphone and camera    AgoraRTC.createMicrophoneAudioTrack(),    AgoraRTC.createCameraVideoTrack()  ]);     // play local video track  localTracks.videoTrack.play("local-player");  $("#local-player-name").text(`localVideo(${options.uid})`);   // publish local tracks to channel  await client.publish(Object.values(localTracks));  console.log("publish success");} async function leave() {  for (trackName in localTracks) {    var track = localTracks[trackName];    if(track) {      track.stop();      track.close();      localTracks[trackName] = undefined;    }  }   // remove remote users and player views  remoteUsers = {};  $("#remote-playerlist").html("");   // leave the channel  await client.leave();   $("#local-player-name").text("");  $("#join").attr("disabled", false);  $("#leave").attr("disabled", true);  console.log("client leaves channel success");} async function subscribe(user, mediaType) {  const uid = user.uid;  // subscribe to a remote user  await client.subscribe(user, mediaType);  console.log("subscribe success");  if (mediaType === 'video') {    const player = $(`      <div id="player-wrapper-${uid}">        <p class="player-name">remoteUser(${uid})</p>        <div id="player-${uid}" class="player"></div>      </div>    `);    $("#remote-playerlist").append(player);    user.videoTrack.play(`player-${uid}`);  }  if (mediaType === 'audio') {    user.audioTrack.play();  }} function handleUserPublished(user, mediaType) {  const id = user.uid;  remoteUsers[id] = user;  subscribe(user, mediaType);} function handleUserUnpublished(user) {  const id = user.uid;  delete remoteUsers[id];  $(`#player-wrapper-${id}`).remove();}

运行成果

[外链图片转存失败,源站可能有防盗链机制,倡议将图片保留下来间接上传(img-qHpzqvtR-1658572023354)(data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVQImWNgYGBgAAAABQABh6FO1AAAAABJRU5ErkJggg==)]在浏览器开两个tab运行网页，应用两个用户退出同一个频道，如果能看见两个本人，阐明你胜利了。

03 残缺代码下载

拜访声网文档核心，依据下图所示门路，下载对应 SDK 压缩包。压缩包中蕴含残缺代码。

参考链接

1.Github 源码

https://github.com/AgoraIO/API-Examples-Web/tree/main/Demo/basicVideoCall

2.线上体验Demo

https://webdemo.agora.io/basicVideoCall/index.html

3.声网文档核心

https://docs.agora.io/cn/Video/downloads?platform=Web