WebRTC 服务器之Janus视频会议插件信令交互

1.基础知识回顾

WebRTC 服务器之Janus概述和环境搭建-CSDN博客

WebRTC 服务器之Janus架构分析-CSDN博客

2.插件使用流程

我们要使⽤janus的功能时，通常要执⾏以下操作：

1. 在你的⽹⻚引入 Janus.js 库，即是包含janus.js；

<!-- 网页头部或 body 底部引入 -->
<script src="https://your-cdn-path/janus.js"></script>

2. 初始化 Janus 库，并传递其依赖项(依赖项可选)；

Janus.init({debug: true,    // 开启调试日志dependencies: {// 可选依赖（如 adapter.js 用于跨浏览器兼容）adapter: adapter},callback: function() {console.log("Janus 库初始化完成");// 初始化完成后连接服务器connectToJanusServer();}
});

3. 连接服务器 & 创建会话 连接到janus server并创建create⼀个会话session；

let janusSession;function connectToJanusServer() {const serverUrl = "wss://your-janus-server:8989/janus";new Janus({server: serverUrl,success: function(session) {janusSession = session;console.log("会话创建成功:", session.getId());// 创建插件句柄（例如加入视频房间）attachToVideoRoomPlugin();},error: function(error) {console.error("连接失败:", error);}});
}

4. 创建插件句柄 (Handle) 创建⼀个或多个handle 以attach到插件(plugin)（例如videoroom、videocall等插件）；

let pluginHandle;function attachToVideoRoomPlugin() {janusSession.attach({plugin: "janus.plugin.videoroom",  // 插件名称success: function(handle) {pluginHandle = handle;console.log("成功附加到插件，句柄 ID:", handle.getId());// 发送加入房间请求joinVideoRoom();},error: function(error) {console.error("附加插件失败:", error);}});
}

5. 信令交互示例 - 加入视频房间 与创建交互（发送/接收消息，协商PeerConnection）；

function joinVideoRoom() {const joinMsg = {request: "join",room: 1234,       // 房间 IDptype: "publisher",display: "用户1"};pluginHandle.send({ message: joinMsg });
}// 处理服务器事件（如房间通知）
pluginHandle.on("message", (msg, jsep) => {console.log("收到服务器消息:", msg);if (msg["videoroom"] === "joined") {console.log("成功加入房间!");// 处理媒体协商（如创建 Offer）startWebRTCNegotiation();}
});

6. WebRTC 协商流程

function startWebRTCNegotiation() {// 创建媒体配置const mediaConfig = {audio: true,video: true,data: true};// 准备 PeerConnectionpluginHandle.createOffer({media: mediaConfig,success: function(sdp) {// 发送 SDP OfferpluginHandle.sendSDP(sdp);},error: function(error) {console.error("创建 Offer 失败:", error);}});
}// 处理 ICE Candidate
pluginHandle.on("ice", (candidate) => {// 发送候选到服务器pluginHandle.trickle(candidate);
});

7. 最后关闭所有的handles并关闭相关的相应的PeerConnections；消耗destroy会话session。

function cleanup() {// 1. 销毁插件句柄if (pluginHandle) {pluginHandle.detach();pluginHandle = null;}// 2. 销毁会话if (janusSession) {janusSession.destroy();janusSession = null;}
}// 页面关闭时触发清理
window.onbeforeunload = cleanup;

完整流程总结

初始化
Janus.init({ debug: true, callback: createJanusSession });
会话与插件
创建会话 (createSession) → 创建插件句柄 (createHandle) → 注册事件监听 (eventHandler).
信令交互
发送消息 (sendMessage) 加入房间 → 接收服务器事件 (handleEvent).
WebRTC 协商
创建 Offer (createOffer) → 发送 SDP (sendSDP) → 接收 Answer → 创建 Answer (createAnswer).
收发av数据
资源释放
销毁句柄 (destroyHandle) → 销毁会话 (destroySession).

2.1 协议基本类型

"janus"后⾯的字符串代表消息的类型，主要有：

create：创建⼀个Janus会话命令；
attach：attach⼀个插件到Janus会话命令；
success：⼀个命令的成功结果；
error：⼀个命令的失败结果；
ack：⼀个命令的ack，因为不能直接返回结果，先回ack，后续的结果通过event返回；
event：推送给客户端的异步事件，主要由插件发出，这些事件需要插件来⾃⼰定义；
message：客户端发给插件的消息，message和event就构成了应⽤协议；
trickle：客户端发送的candidate，会传递给ICE句柄；
keepalive：客户端发送的⼼跳；
webrtcup：ICE成功建⽴通道的通知；
media：⾳频、视频媒体的接收通知；
slowlink：链路恶化通知；
hangup：挂断通知；
detached：插件从Janus会话detach的通知，释放了⼀个插件句柄。

3.videoroom插件信令交互分析

Janus中所有插件都遵循以下基本数据流程：

客户端发送create创建一个Janus会话；
Janus回复success返回Janus会话句柄；
客户端发送attach命令在Janus会话上attach指定插件；
Janus回复success返回插件的句柄；
客户端给指定的插件发送message进行信令控制；
Janus上的插件发送event通知事件给客户端；
客户端收集candidate并通过trickle消息发送给插件绑定的ICE通道；
Janus发送webrtcup通知ICE通道建立；
客户端发送媒体数据；
Janus发送media消息通知媒体数据的第一次到达；
Janus进行媒体数据转发。

3.总体逻辑

Janus客户端->Janus网关: Janus客户端发送create请求创建会话
- ```
JBJ-WEBSOCKET RECV: {"janus":"create","transaction":"aAMxRfsTsVVQ"}
```

Janus网关–>>Janus客户端: Janus网关创建会话，并返回会话IDJ

JBJ-WEBSOCKET responses:Sending Janus API response(
{"janus": "success","transaction": "aAMxRfsTsVVQ","data": {"id": 5109637625847547}
}
) to janus.transport.websockets (0x7f5cd400d3c0)

Janus客户端->Janus网关: 客户端发送attach命令在Janus会话上attach指定插件；

JBJ-WEBSOCKET RECV: {"janus": "attach","plugin": "janus.plugin.videoroom","opaque_id": "videoroomtest-jIAzP2ZkPUrn","transaction": "2kuM6pzfX4Zh","session_id": 5109637625847547
}

Janus网关–>>Janus客户端: Janus回复success返回插件的句柄；


JBJ-WEBSOCKET responses:Sending Janus API response({"janus": "success","session_id": 5109637625847547,"transaction": "2kuM6pzfX4Zh","data": {"id": 6769547295474368}
}) to janus.transport.websockets (0x7f5cd400d3c0)

Janus客户端->Janus网关: Janus客户端给指定插件发送message（Join）

JBJ-WEBSOCKET RECV: {"janus": "message","body": {"request": "join","room": 1234,"ptype": "publisher","display": "321"},"transaction": "11JDzIbsbK91","session_id": 5109637625847547,"handle_id": 6769547295474368
}

JBJ-WEBSOCKET responses:Sending Janus API response({"janus": "ack","session_id": 5109637625847547,"transaction": "11JDzIbsbK91"
}) to janus.transport.websockets (0x7f5cd400d3c0)

Janus网关–>>Janus客户端: Janus网关处理message，并将结果通过event事件发送给客户端

Preparing JSON event as a reply
JBJ-video.room.event: [6769547295474368] Sending event is: {"janus": "event","session_id": 5109637625847547,"transaction": "11JDzIbsbK91","sender": 6769547295474368,"plugindata": {"plugin": "janus.plugin.videoroom","data": {"videoroom": "joined","room": 1234,"description": "Demo Room","id": 6538458198168085,"private_id": 1041514801,"publishers": []}}} to transport...
Sending event to janus.transport.websockets (0x7f5cd400d3c0)>> 0 (Success)

Janus客户端->Janus网关: Janus客户端给指定插件发送message（Configure & offer）

####################Configure & offer
JBJ-WEBSOCKETRECV: {"janus": "message","body": {"request": "configure","audio": true,"video": true},"transaction": "MHTliRCHqY5y","jsep": {"type": "offer","sdp": "v=0\r\no=- 6239954181818903803 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE 0 1\r\na=extmap-allow-mixed\r\na=msid-semantic: WMS 900722df-7e7a-4951-b1bf-1902cb7fe6e0\r\nm=audio 9 UDP/TLS/RTP/SAVPF 111 63 9 0 8 13 110 126\r\nc=IN IP4 0.0.0.0\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:eHT/\r\na=ice-pwd:aAxznBSHiqTXMkZAzJs5xv3B\r\na=ice-options:trickle\r\na=fingerprint:sha-256 75:80:26:F9:EB:47:14:51:61:D3:CD:8B:60:C1:5E:F5:67:53:1E:88:9C:45:53:3B:32:D0:D2:5F:CD:45:63:7F\r\na=setup:actpass\r\na=mid:0\r\na=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\na=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid\r\na=sendonly\r\na=msid:900722df-7e7a-4951-b1bf-1902cb7fe6e0 9718362e-2152-4c32-9e79-da62a8a609c5\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:111 opus/48000/2\r\na=rtcp-fb:111 transport-cc\r\na=fmtp:111 minptime=10;useinbandfec=1\r\na=rtpmap:63 red/48000/2\r\na=fmtp:63 111/111\r\na=rtpmap:9 G722/8000\r\na=rtpmap:0 PCMU/8000\r\na=rtpmap:8 PCMA/8000\r\na=rtpmap:13 CN/8000\r\na=rtpmap:110 telephone-event/48000\r\na=rtpmap:126 telephone-event/8000\r\na=ssrc:2665350871 cname:+3Rknr5a6Axa5msx\r\na=ssrc:2665350871 msid:900722df-7e7a-4951-b1bf-1902cb7fe6e0 9718362e-2152-4c32-9e79-da62a8a609c5\r\nm=video 9 UDP/TLS/RTP/SAVPF 96 97 103 104 107 108 109 114 115 116 117 118 39 40 45 46 98 99 100 101 119 120 123 124 125\r\nc=IN IP4 0.0.0.0\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:eHT/\r\na=ice-pwd:aAxznBSHiqTXMkZAzJs5xv3B\r\na=ice-options:trickle\r\na=fingerprint:sha-256 75:80:26:F9:EB:47:14:51:61:D3:CD:8B:60:C1:5E:F5:67:53:1E:88:9C:45:53:3B:32:D0:D2:5F:CD:45:63:7F\r\na=setup:actpass\r\na=mid:1\r\na=extmap:14 urn:ietf:params:rtp-hdrext:toffset\r\na=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=extmap:13 urn:3gpp:video-orientation\r\na=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type\r\na=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing\r\na=extmap:8 http://www.webrtc.org/experiments/rtp-hdrext/color-space\r\na=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid\r\na=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id\r\na=extmap:11 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id\r\na=sendonly\r\na=msid:900722df-7e7a-4951-b1bf-1902cb7fe6e0 d97d2702-4a0f-4693-8499-71c66f8c03fe\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:96 VP8/90000\r\na=rtcp-fb:96 goog-remb\r\na=rtcp-fb:96 transport-cc\r\na=rtcp-fb:96 ccm fir\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=rtpmap:103 H264/90000\r\na=rtcp-fb:103 goog-remb\r\na=rtcp-fb:103 transport-cc\r\na=rtcp-fb:103 ccm fir\r\na=rtcp-fb:103 nack\r\na=rtcp-fb:103 nack pli\r\na=fmtp:103 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42001f\r\na=rtpmap:104 rtx/90000\r\na=fmtp:104 apt=103\r\na=rtpmap:107 H264/90000\r\na=rtcp-fb:107 goog-remb\r\na=rtcp-fb:107 transport-cc\r\na=rtcp-fb:107 ccm fir\r\na=rtcp-fb:107 nack\r\na=rtcp-fb:107 nack pli\r\na=fmtp:107 level-asymmetry-allowed=1;packetization-mode=0;profile-level-id=42001f\r\na=rtpmap:108 rtx/90000\r\na=fmtp:108 apt=107\r\na=rtpmap:109 H264/90000\r\na=rtcp-fb:109 goog-remb\r\na=rtcp-fb:109 transport-cc\r\na=rtcp-fb:109 ccm fir\r\na=rtcp-fb:109 nack\r\na=rtcp-fb:109 nack pli\r\na=fmtp:109 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f\r\na=rtpmap:114 rtx/90000\r\na=fmtp:114 apt=109\r\na=rtpmap:115 H264/90000\r\na=rtcp-fb:115 goog-remb\r\na=rtcp-fb:115 transport-cc\r\na=rtcp-fb:115 ccm fir\r\na=rtcp-fb:115 nack\r\na=rtcp-fb:115 nack pli\r\na=fmtp:115 level-asymmetry-allowed=1;packetization-mode=0;profile-level-id=42e01f\r\na=rtpmap:116 rt
}JBJ-video.room.event: [6769547295474368] Sending event is: {"janus": "event","session_id": 5109637625847547,"transaction": "MHTliRCHqY5y","sender": 6769547295474368,"plugindata": {"plugin": "janus.plugin.videoroom","data": {"videoroom": "event","room": 1234,"configured": "ok","audio_codec": "opus","video_codec": "vp8"}},"jsep": {"type": "answer","sdp": "v=0\r\no=- 6239954181818903803 2 IN IP4 117.72.13.81\r\ns=VideoRoom 1234\r\nt=0 0\r\na=group:BUNDLE 0 1\r\na=msid-semantic: WMS janus\r\nm=audio 9 UDP/TLS/RTP/SAVPF 111\r\nc=IN IP4 117.72.13.81\r\na=recvonly\r\na=mid:0\r\na=rtcp-mux\r\na=ice-ufrag:0pFN\r\na=ice-pwd:wGcEE+9WQLoHULcXGP8KFn\r\na=ice-options:trickle\r\na=fingerprint:sha-256 C7:C1:43:EE:67:07:A0:6D:42:33:6A:CA:4E:EA:95:E0:55:17:03:CB:88:FD:B6:37:AB:1C:7B:85:65:9A:95:C6\r\na=setup:active\r\na=rtpmap:111 opus/48000/2\r\na=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\na=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid\r\na=msid:janus janusa0\r\na=ssrc:3338353236 cname:janus\r\na=ssrc:3338353236 msid:janus janusa0\r\na=ssrc:3338353236 mslabel:janus\r\na=ssrc:3338353236 label:janusa0\r\na=candidate:1 1 udp 2013266431 117.72.13.81 53576 typ host\r\na=candidate:2 1 udp 1677722111 117.72.13.81 53576 typ srflx raddr 172.16.0.4 rport 53576\r\na=candidate:3 1 udp 503316991 172.16.0.4 54497 typ relay raddr 172.16.0.4 rport 53576\r\na=end-of-candidates\r\nm=video 9 UDP/TLS/RTP/SAVPF 96 97\r\nc=IN IP4 117.72.13.81\r\na=recvonly\r\na=mid:1\r\na=rtcp-mux\r\na=ice-ufrag:0pFN\r\na=ice-pwd:wGcEE+9WQLoHULcXGP8KFn\r\na=ice-options:trickle\r\na=fingerprint:sha-256 C7:C1:43:EE:67:07:A0:6D:42:33:6A:CA:4E:EA:95:E0:55:17:03:CB:88:FD:B6:37:AB:1C:7B:85:65:9A:95:C6\r\na=setup:active\r\na=rtpmap:96 VP8/90000\r\na=rtcp-fb:96 ccm fir\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtcp-fb:96 goog-remb\r\na=rtcp-fb:96 transport-cc\r\na=extmap:13 urn:3gpp:video-orientation\r\na=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid\r\na=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id\r\na=extmap:11 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=msid:janus janusv0\r\na=ssrc:3467980833 cname:janus\r\na=ssrc:3467980833 msid:janus janusv0\r\na=ssrc:3467980833 mslabel:janus\r\na=ssrc:3467980833 label:janusv0\r\na=ssrc:3074101642 cname:janus\r\na=ssrc:3074101642 msid:janus janusv0\r\na=ssrc:3074101642 mslabel:janus\r\na=ssrc:3074101642 label:janusv0\r\na=candidate:1 1 udp 2013266431 117.72.13.81 53576 typ host\r\na=candidate:2 1 udp 1677722111 117.72.13.81 53576 typ srflx raddr 172.16.0.4 rport 53576\r\na=candidate:3 1 udp 503316991 172.16.0.4 54497 typ relay raddr 172.16.0.4 rport 53576\r\na=end-of-candidates\r\n"}
}#######################trickle
JBJ-WEBSOCKET RECV: {"janus": "trickle","candidate": {"candidate": "candidate:980779705 1 udp 2122260223 192.168.126.1 60475 typ host generation 0 ufrag eHT/ network-id 2","sdpMid": "0","sdpMLineIndex": 0},"transaction": "0WWSoZXbCxhA","session_id": 5109637625847547,"handle_id": 6769547295474368
}JBJ-WEBSOCKET RECV: {"janus": "trickle","candidate": {"candidate": "candidate:3993315412 1 udp 2122194687 192.168.248.1 60476 typ host generation 0 ufrag eHT/ network-id 3","sdpMid": "0","sdpMLineIndex": 0},"transaction": "DddvxlDlWuZN","session_id": 5109637625847547,"handle_id": 6769547295474368
}
JBJ-WEBSOCKET RECV: {"janus": "trickle","candidate": {"candidate": "candidate:2923601174 1 udp 2122129151 172.25.0.107 60477 typ host generation 0 ufrag eHT/ network-id 1 network-cost 10","sdpMid": "0","sdpMLineIndex": 0},"transaction": "HCdvw7ihHaaZ","session_id": 5109637625847547,"handle_id": 6769547295474368
}

Janus网关–>>Janus客户端: Janus网关返回ack消息

JBJ-WEBSOCKET responses:Sending Janus API response({"janus": "ack","session_id": 5109637625847547,"transaction": "MHTliRCHqY5y"
}) to janus.transport.websockets (0x7f5cd400d3c0)JBJ-WEBSOCKET responses:Sending Janus API response({"janus": "ack","session_id": 5109637625847547,"transaction": "0WWSoZXbCxhA"
}) to janus.transport.websockets (0x7f5cd400d3c0)JBJ-WEBSOCKET responses:Sending Janus API response({"janus": "ack","session_id": 5109637625847547,"transaction": "DddvxlDlWuZN"
}) to janus.transport.websockets (0x7f5cd400d3c0)

学习资料分享

0voice · GitHub