A good SFU - Janus gateway

Posted on Sun 02 May 2021 in Journal

概述

Janus是由Meetecho设计和开发的一种开源通用WebRTC服务器。该版本的服务器专为Linux系统量身定制，尽管它也可以为MacOS机器编译和安装。现在暂不支持Windows，不过可以在Windows 10上的“ Linux的Windows子系统”中运行。

Janus 由 Janus CORE、Janus Plugin 以及信令接口三部分组成。

信令接口，Janus 支持的信令协议比较多，如 HTTP、WebSocket、RabbitMQ 等。这些信令协议使得 Janus 具有非常好的接入性。因为很多公司喜欢各种不同的协议，如有的喜欢 websocket，有的喜欢http，proto等。因此 Janus 在信令接入方面具有很大的优势。
Janus Plugin，Janus 的业务管理是按照 Plugin 的方式管理的，因此你可以在Janus中根据自己的需要实现自己的业务插件。实际上，对于一般性的需求 Janus 已经相关的插件。如：
VideoRoom，用于多人音视频互动，像音视频会议，在线教育都可以通过该插件来实现。
VideoCall，用于 1:1 的音视频通信。
SIP，用于与传统电话设备对接。
Streaming，用于广播，也就是我们通常所说的一人共享，多人观看的直播模式。
TextRoom，它是一个聊天室，通过它可以进行文本聊天。
RecordPlay，用于录制和回放。

Janus Core 是Janus的核心，其作用是处理流的转发，各种协议的接入。以浏览器为例，要想让浏览器接入到 WebRTC 流媒体服务器上，那流媒体服务器必须要支持 STUN、DTLS、SRTP、ICE 等协议。

Compile and install Janus gateway

refer to https://github.com/meetecho/janus-gateway

install dependency library

sudo apt install libmicrohttpd-dev libjansson-dev \
libssl-dev libsrtp-dev libsofia-sip-ua-dev libglib2.0-dev \
libopus-dev libogg-dev libcurl4-openssl-dev liblua5.3-dev \
libconfig-dev pkg-config gengetopt libtool automake

sudo apt install doxygen graphviz

install libice

sudo apt install meson

sudo apt install python3-pip

meson -v
(it should be 0.58.0)


git clone https://gitlab.freedesktop.org/libnice/libnice
cd libnice
meson --prefix=/usr build && ninja -C build && sudo ninja -C build install

install libsrtp

wget https://github.com/cisco/libsrtp/archive/v2.2.0.tar.gz
tar xfv v2.2.0.tar.gz
cd libsrtp-2.2.0
./configure --prefix=/usr --enable-openssl
make shared_library && sudo make install

install libwebsocket

git clone https://libwebsockets.org/repo/libwebsockets
cd libwebsockets
# If you want the stable version of libwebsockets, uncomment the next line
# git checkout v3.2-stable
mkdir build
cd build
# See https://github.com/meetecho/janus-gateway/issues/732 re: LWS_MAX_SMP
# See https://github.com/meetecho/janus-gateway/issues/2476 re: LWS_WITHOUT_EXTENSIONS
cmake -DLWS_MAX_SMP=1 -DLWS_WITHOUT_EXTENSIONS=0 -DCMAKE_INSTALL_PREFIX:PATH=/usr -DCMAKE_C_FLAGS="-fpic" ..
make && sudo make install

compile

git clone https://github.com/meetecho/janus-gateway.git
cd janus-gateway
Then just use:
sh autogen.sh
to generate the configure file. After that, configure and compile as usual to start the whole compilation process:
./configure --prefix=/opt/janus --enable-docs
make
sudo make install
sudo make configs

cat /opt/janus/etc/janus/janus.jcfg
cd /opt/janus
mkdir logs
./bin/janus —help
./bin/janus -b -L /opt/janus/logs/janus.log

check

$ netstat -anp|grep janus
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
tcp        0      0 0.0.0.0:8188            0.0.0.0:*               LISTEN      6588/./bin/janus
tcp6       0      0 :::8088                 :::*                    LISTEN      6588/./bin/janus
udp6       0      0 :::5002                 :::*                                6588/./bin/janus
udp6       0      0 :::5004                 :::*                                6588/./bin/janus
unix  3      [ ]         STREAM     CONNECTED     53056548 6588/./bin/janus
unix  3      [ ]         STREAM     CONNECTED     53056547 6588/./bin/janus

示例

EchoTest

This Echo Test demo just blindly sends you back whatever you send to it. You're basically attached to yourself, and so your audio and video you send to Janus are echoed back to you. The same is done for RTCP packets as well, with the information properly updated.

client:

open http://10.224.85.233/demos/echotest.html by firefox

Janus Object init

1) POST /janus * response: sessionId is the data.id

    {
    "janus": "success",
    "transaction": "iqHi029hsJF3",
    "data": {
        "id": 1730150663723177
    }
    }

JSEP

```

[
{
    "janus": "event",
    "session_id": 76377000668057,
    "transaction": "AlvApIFrqWBE",
    "sender": 4176087136988668,
    "plugindata": {
        "plugin": "janus.plugin.echotest",
        "data": {
            "echotest": "event",
            "result": "ok"
        }
    },
    "jsep": {
        "type": "answer",
        "sdp": "v=0\r\n
        o=mozilla...THIS_IS_SDPARTA-63.0.3 1603271024498389 1 IN IP4 10.224.85.233\r\n
        s=-\r\n
        t=0 0\r\n
        a=group:BUNDLE 0 1\r\n
        a=msid-semantic: WMS janus\r\n
        m=audio 9 UDP/TLS/RTP/SAVPF 109\r\n
        c=IN IP4 10.224.85.233\r\n
        a=sendrecv\r\n
        a=mid:0\r\n
        a=rtcp-mux\r\n
        a=ice-ufrag:AUe7\r\n
        a=ice-pwd:XgM3SlRrtjdv+kDY5T1ITI\r\n
        a=ice-options:trickle\r\n
        a=fingerprint:sha-256 44:98:B3:C6:A8:88:ED:50:22:0F:2E:1A:58:65:A3:CB:46:65:2F:8A:AB:E1:BF:D5:32:85:3E:95:9E:CF:48:63\r\n
        a=setup:active\r\na=rtpmap:109 opus/48000/2\r\n
        a=fmtp:109 useinbandfec=1\r\n
        a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\n
        a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid\r\n
        a=msid:janus janusa0\r\n
        a=ssrc:705498670 cname:janus\r\n
        a=ssrc:705498670 msid:janus janusa0\r\n
        a=ssrc:705498670 mslabel:janus\r\n
        a=ssrc:705498670 label:janusa0\r\n
        a=candidate:1 1 udp 2013266431 10.224.85.233 37266 typ host\r\n
        a=end-of-candidates\r\n
        m=video 9 UDP/TLS/RTP/SAVPF 120\r\n
        c=IN IP4 10.224.85.233\r\n
        a=sendrecv\r\n
        a=mid:1\r\n
        a=rtcp-mux\r\n
        a=ice-ufrag:AUe7\r\n
        a=ice-pwd:XgM3SlRrtjdv+kDY5T1ITI\r\n
        a=ice-options:trickle\r\n
        a=fingerprint:sha-256 44:98:B3:C6:A8:88:ED:50:22:0F:2E:1A:58:65:A3:CB:46:65:2F:8A:AB:E1:BF:D5:32:85:3E:95:9E:CF:48:63\r\n
        a=setup:active\r\n
        a=rtpmap:120 VP8/90000\r\n
        a=rtcp-fb:120 ccm fir\r\n
        a=rtcp-fb:120 nack\r\n
        a=rtcp-fb:120 nack pli\r\n
        a=rtcp-fb:120 goog-remb\r\n
        a=rtcp-fb:120 transport-cc\r\n
        a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid\r\n
        a=fmtp:120 max-fs=12288;max-fr=60\r\n
        a=msid:janus janusv0\r\n
        a=ssrc:3463695356 cname:janus\r\n
        a=ssrc:3463695356 msid:janus janusv0\r\n
        a=ssrc:3463695356 mslabel:janus\r\n
        a=ssrc:3463695356 label:janusv0\r\n
        a=candidate:1 1 udp 2013266431 10.224.85.233 37266 typ host\r\n
        a=end-of-candidates\r\n
        m=application 0 UDP/DTLS/SCTP webrtc-datachannel\r\n
        c=IN IP4 10.224.85.233\r\n
        a=inactive\r\n"
    }
}
]

````

server:

code structure

dependencies

To install it, you'll need to satisfy the following dependencies:

Jansson
libconfig
libnice (at least v0.1.16 suggested, master recommended)
OpenSSL (at least v1.0.1e)
libsrtp (at least v2.x suggested)
usrsctp (only needed if you are interested in Data Channels)
libmicrohttpd (at least v0.9.59; only needed if you are interested in REST support for the Janus API)
libwebsockets (only needed if you are interested in WebSockets support for the Janus API)
cmake (only needed if you are interested in WebSockets and/or BoringSSL support, as they make use of it)
rabbitmq-c (only needed if you are interested in RabbitMQ support for the Janus API or events)
paho.mqtt.c (only needed if you are interested in MQTT support for the Janus API or events)
nanomsg (only needed if you are interested in Nanomsg support for the Janus API)
libcurl (only needed if you are interested in the TURN REST API support)

A couple of plugins depend on a few more libraries:

Sofia-SIP (only needed for the SIP plugin)
libopus (only needed for the AudioBridge plugin)
libogg (needed for the VoiceMail plugin and/or post-processor, and optionally AudioBridge and Streaming plugins)
libcurl (only needed if you are interested in RTSP support in the Streaming plugin or in the sample Event Handler plugin)
Lua (only needed for the Lua plugin)

Additionally, you'll need the following libraries and tools:

GLib
zlib
pkg-config
gengetopt

Janus JS API

In general, when using the Janus features, you would normally do the following:

include the Janus JavaScript library in your web page;
initialize the Janus JavaScript library and (optionally) passing its dependencies;
connect to the server and create a session;
create one or more handles to attach to a plugin (e.g., echo test and/or streaming);
interact with the plugin (sending/receiving messages, negotiating a PeerConnection);
eventually, close all the handles and shutdown the related PeerConnections;
destroy the session.

Example

apt install nginx

sudo cp -rf /opt/janus/shar/ janus/demos /var/www/html/

http://localhost/demos/

EchoTest

http://localhost/demos/echotest.html

点击 "start"

Ping: http://10.224.85.233:8188/ping?

代码结构

Janus 主要由三个部分组成：

Core： Janus的核心部分，其作用是处理数据流的转发，以及各种协议的接入，是WebRTC技术的具体实现。
Plugin：Janus插件，Janus的业务管理是按照Plugin的方式管理的，因此开发者可以在Janus中根据自己的需要实现自己的业务插件。实际上，对于一般性的需求，Janus已经有相关的插件。其中，可使用 VideoRoom视频房间插件进行多人音视频互动。
Transport：Janus的信令传输层，Janus并没有限定信令接口使用的信令传输协议，当前支持的协议有HTTP、WebSocket、MQTT、NanoMsg和RabbitMQ。

参考资料

Janus google group: https://groups.google.com/g/meetecho-janus
https://blog.csdn.net/sonysuqin/article/details/84988120

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