文章目录

  • 1. 简介
  • 2. 安装ffmpeg
  • 3. 安装nginx
  • 3.1 安装nginx依赖
  • 3.1.1 pcre
  • 3.1.2 zlib
  • 3.1.3 openssl
  • 3.2 编译nginx
  • 3.2.1 下载nginx
  • 3.2.2 下载nginx-http-flv-module
  • 3.2.3 编译
  • 4. 配置nginx
  • 4.1 重点配置介绍
  • 4.2 完整配置(方便复制粘贴)
  • 5. ffmpeg推流
  • 5.1 海康威视网络摄像机推流命令
  • 5.2 rtsp视频流公共测试地址
  • 6. flvjs播放
  • 6.1 关键代码说明
  • 6.2 完整代码(方便复制粘贴)
  • 7. 其他问题
  • 7.1 累积时延问题
  • 7.2 自动播放问题
  • 7.3 flvjs播放器要主动销毁
  • 7.4 同时在后台启动多个推流


1. 简介

大部分网络摄像机,比如海康威视都支持rtsp协议视频流,但是web一般是无法直接播放rtsp协议视频流的,需要在服务器上把rtsp视频流转换成web其他协议。本篇博客介绍利用ffmpeg、nginx、flvjs实现web浏览rtsp视频流。主要参考了文章【入门】无插件web直播解决方案,ffmpeg+nginx-http-flv-module+flv.js、Nginx+FFmpeg 海康、大华NVR实现rtsp转flv实时预览+录像回放 所用到的服务器操作系统为ubuntu20.04。

2. 安装ffmpeg

sudo apt update && sudo apt install ffmpeg

3. 安装nginx

nginx需要安装nginx-http-flv-module以支持flv格式视频流,需要下载该模块,并从源码重新编译nginx,在编译nginx前还需要下载一些必要的依赖,以下参考了nginx源码编译教程

3.1 安装nginx依赖

3.1.1 pcre

教程中给的pcre下载链接无法使用,我更换成了以下链接https://ftp.pcre.org/pub/pcre/pcre-8.44.tar.gz

wget https://ftp.pcre.org/pub/pcre/pcre-8.44.tar.gz
tar -zxf pcre-8.44.tar.gz
cd pcre-8.44
./configure
make
sudo make install

3.1.2 zlib

wget http://zlib.net/zlib-1.2.11.tar.gz
tar -zxf zlib-1.2.11.tar.gz
cd zlib-1.2.11
./configure
make
sudo make install

3.1.3 openssl

再次按照该文档编译时,发现编译nginx执行configure命令无法找到编译的openssl(经测试发现–prefix=/usr改为–prefix=/usr/local即可),改为用sudo apt-get install libssl-dev 直接安装,以下为原来的编译教程

教程中./Configure darwin64-x86_64-cc --prefix=/usr配置后有问题,我参考stackoverflow解决方案,做了更改

wget http://www.openssl.org/source/openssl-1.1.1g.tar.gz
tar -zxf openssl-1.1.1g.tar.gz
cd openssl-1.1.1g
./Configure LIST | grep -i linux
./Configure linux-x86_64 --prefix=/usr/local
make
sudo make install

3.2 编译nginx

3.2.1 下载nginx

wget https://nginx.org/download/nginx-1.18.0.tar.gz
tar zxf nginx-1.18.0.tar.gz

3.2.2 下载nginx-http-flv-module

git clone https://github.com/winshining/nginx-http-flv-module.git

3.2.3 编译

下方/path/to应该修改成你的nginx-http-flv-module文件夹的位置,比如我在home目录hfy下执行的git clone命令,nginx-http-flv-module文件夹位于我的家目录中,配置命令应该写成./configure --add-module=/home/hfy/nginx-http-flv-module

cd nginx-1.18.0
./configure --add-module=/path/to/nginx-http-flv-module
make
sudo make install

4. 配置nginx

sudo vi /usr/local/nginx/conf/nginx.conf 打开nginx配置文件,删除原来的配置内容,替换为nginx-http-flv-module github readme最后给出的example configuration

4.1 重点配置介绍

...
 
http {
    include       mime.types;
    default_type  application/octet-stream;
 
    keepalive_timeout  65;
 
    server {
        listen       80; #http-flv的拉流端口
 
        ...
        
        # http-flv的相关配置
        location /live {
            flv_live on; #打开HTTP播放FLV直播流功能
            chunked_transfer_encoding on; #支持'Transfer-Encoding: chunked'方式回复
 
            add_header 'Access-Control-Allow-Origin' '*'; #添加额外的HTTP头
            add_header 'Access-Control-Allow-Credentials' 'true'; #添加额外的HTTP头
        }
 
        ...
    }
}
 
rtmp_auto_push on;
rtmp_auto_push_reconnect 1s;
rtmp_socket_dir /tmp;
 
rtmp {
    out_queue           4096;
    out_cork            8;
    max_streams         128;
    timeout             15s;
    drop_idle_publisher 15s;
 
    log_interval 5s; #log模块在access.log中记录日志的间隔时间,对调试非常有用
    log_size     1m; #log模块用来记录日志的缓冲区大小
 
    server {
        listen 1935;
        server_name www.test.*; #用于虚拟主机名后缀通配
 
        #ffmpeg推流的application 
        application myapp {
            live on;
            gop_cache on; #打开GOP缓存,减少首屏等待时间 on时第一帧加载快,off时第一帧加载慢 
            # @StringKai 在博客提到on时延高,off时延低,不过我在测试时并没有感觉出时延的差别
        }
 
       ...
    }
 
   ...
}

4.2 完整配置(方便复制粘贴)

worker_processes  1; #should be 1 for Windows, for it doesn't support Unix domain socket
#worker_processes  auto; #from versions 1.3.8 and 1.2.5

#worker_cpu_affinity  0001 0010 0100 1000; #only available on FreeBSD and Linux
#worker_cpu_affinity  auto; #from version 1.9.10

error_log logs/error.log error;

#if the module is compiled as a dynamic module and features relevant
#to RTMP are needed, the command below MUST be specified and MUST be
#located before events directive, otherwise the module won't be loaded
#or will be loaded unsuccessfully when NGINX is started

#load_module modules/ngx_http_flv_live_module.so;

events {
    worker_connections  4096;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    keepalive_timeout  65;

    server {
        listen       80;

        location / {
            root   /var/www;
            index  index.html index.htm;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

        location /live {
            flv_live on; #open flv live streaming (subscribe)
            chunked_transfer_encoding  on; #open 'Transfer-Encoding: chunked' response

            add_header 'Access-Control-Allow-Origin' '*'; #add additional HTTP header
            add_header 'Access-Control-Allow-Credentials' 'true'; #add additional HTTP header
        }

        location /hls {
            types {
                application/vnd.apple.mpegurl m3u8;
                video/mp2t ts;
            }

            root /tmp;
            add_header 'Cache-Control' 'no-cache';
        }

        location /dash {
            root /tmp;
            add_header 'Cache-Control' 'no-cache';
        }

        location /stat {
            #configuration of streaming & recording statistics

            rtmp_stat all;
            rtmp_stat_stylesheet stat.xsl;
        }

        location /stat.xsl {
            root /var/www/rtmp; #specify in where stat.xsl located
        }

        #if JSON style stat needed, no need to specify
        #stat.xsl but a new directive rtmp_stat_format

        #location /stat {
        #    rtmp_stat all;
        #    rtmp_stat_format json;
        #}

        location /control {
            rtmp_control all; #configuration of control module of rtmp
        }
    }
}

rtmp_auto_push on;
rtmp_auto_push_reconnect 1s;
rtmp_socket_dir /tmp;

rtmp {
    out_queue           4096;
    out_cork            8;
    max_streams         128;
    timeout             15s;
    drop_idle_publisher 15s;

    log_interval 5s; #interval used by log module to log in access.log, it is very useful for debug
    log_size     1m; #buffer size used by log module to log in access.log

    server {
        listen 1935;
        server_name www.test.*; #for suffix wildcard matching of virtual host name

        application myapp {
            live on;
            gop_cache on; #open GOP cache for reducing the wating time for the first picture of video
        }

        application hls {
            live on;
            hls on;
            hls_path /tmp/hls;
        }

        application dash {
            live on;
            dash on;
            dash_path /tmp/dash;
        }
    }

    server {
        listen 1935;
        server_name *.test.com; #for prefix wildcard matching of virtual host name

        application myapp {
            live on;
            gop_cache on; #open GOP cache for reducing the wating time for the first picture of video
        }
    }

    server {
        listen 1935;
        server_name www.test.com; #for completely matching of virtual host name

        application myapp {
            live on;
            gop_cache on; #open GOP cache for reducing the wating time for the first picture of video
        }
    }
}

5. ffmpeg推流

5.1 海康威视网络摄像机推流命令

ffmpeg推流命令主要参考了文章:Nginx+FFmpeg 海康、大华NVR实现rtsp转flv实时预览+录像回放,详细介绍了如何使用ffmpeg对海康威视网络摄像机推流

ffmpeg -rtsp_transport tcp -i  rtsp://user:password@ip:port/Streaming/channels/101  -c copy -f flv rtmp://127.0.0.1:1935/myapp/mystream

参数解析
-rtsp_transport tcp: 固定写法
user:用户名
password:密码
ip:摄像头或NVR的IP地址
port:摄像头或NVR的RTSP端口,默认是554,具体的RTSP取流规则可以百度
-c copy: 输出直接复制,不转换格式
-f flv:转成flv
rtmp://127.0.0.1:1935/myapp/mystream:根据Nginx配置文件生成,端口号1935与nginx配置中的listen 1935对应;myapp对应配置文件中的application myapp;mystream名字不固定,会在后续用flvjs取流时用到

附海康威视网络摄像机rtsp取流地址

【新版本】
URL规定:
rtsp://username:password@[address]:[port]/Streaming/Channels/[id](?parm1=value1&parm2-=value2…)
注:VLC可以支持解析URL里的用户名密码,实际发给设备的RTSP请求不支持带用户名密码。
详细描述:
举例说明:
通道01主码流:
rtsp://admin:abc12345@172.6.22.234:554/Streaming/Channels/101?transportmode=unicast
通道01子码流:
rtsp://admin:abc12345@172.6.22.234:554/Streaming/Channels/102?transportmode=unicast(单播)
rtsp://admin:abc12345@172.6.22.106:554/Streaming/Channels/102?transportmode=multicast (多播)
rtsp://admin:abc12345@172.6.22.106:554/Streaming/Channels/102 (?后面可省略,默认单播)
通道01第3码流:
rtsp://admin:abc12345@172.6.22.234:554/Streaming/Channels/103?transportmode=unicast
零通道主码流(零通道无子码流):

rtsp://admin:12345@172.6.22.106:554/Streaming/Channels/001

注:新版本URL,通道号全部按顺序从1开始。

5.2 rtsp视频流公共测试地址

如果手头没有现成的网络摄像头供测试,可以使用公共的rtsp视频测试地址
rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mov 相应的推流命令如下

ffmpeg -rtsp_transport tcp -i rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mov  -c copy -f flv rtmp://127.0.0.1:1935/myapp/mystream

6. flvjs播放

flvjs是哔哩哔哩开源的web播放器,使用方法可以参考官方demo。但是官方给出的demo代码比较多,如果只是想简单实现的话可以参考下方的完整代码,注意flvjs是通过bootcdn引入的。

6.1 关键代码说明

var flvPlayer = flvjs.createPlayer({
                type: 'flv',
                enableWorker: true,     //浏览器端开启flv.js的worker,多进程运行flv.js
                isLive: true,           //直播模式
                hasAudio: true,        //开启音频             
                hasVideo: true,
                stashInitialSize: 128,  
                enableStashBuffer: false, //播放flv时,设置是否启用播放缓存,只在直播起作用。
                url: ''
            })

url格式 http://example.com:80/live?port=1935&app=myapp&stream=mystream
example.com:80中的80端口与nginx配置中listen 80对应,后面的三个get参数port=1935&app=myapp&stream=mystream是固定格式,1935与nginx配置listen 1935对应,myapp与nginx配置中application myapp对应,mystream与ffmpeg推流命令最后的rtmp://127.0.0.1:1935/myapp/mystream 对应

6.2 完整代码(方便复制粘贴)

<!DOCTYPE html>
<html>

<head>
    <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
    <title>flv.js demo</title>
    <style>
        .mainContainer {
            display: block;
            width: 1024px;
            margin-left: auto;
            margin-right: auto;
        }

        .urlInput {
            display: block;
            width: 100%;
            margin-left: auto;
            margin-right: auto;
            margin-top: 8px;
            margin-bottom: 8px;
        }

        .centeredVideo {
            display: block;
            width: 100%;
            height: 576px;
            margin-left: auto;
            margin-right: auto;
            margin-bottom: auto;
        }

        .controls {
            display: block;
            width: 100%;
            text-align: left;
            margin-left: auto;
            margin-right: auto;
        }
    </style>
</head>

<body>
    <div class="mainContainer">
        <video id="videoElement" class="centeredVideo" controls width="1024" height="576">Your browser is too old which doesn't support HTML5 video.</video>
    </div>
    <br>
    <div class="controls">
        <button onclick="flv_start()">开始</button>
        <button onclick="flv_pause()">暂停</button>
        <button onclick="flv_destroy()">停止</button>
        <input style="width:100px" type="text" name="seekpoint" />
        <button onclick="flv_seekto()">跳转</button>
    </div>
    <script src="https://cdn.bootcdn.net/ajax/libs/flv.js/1.5.0/flv.js"></script>
    <script>
        var vElement = document.getElementById('videoElement');
        if (flvjs.isSupported()) {
            var flvPlayer = flvjs.createPlayer({
                type: 'flv',
                enableWorker: true,     //浏览器端开启flv.js的worker,多进程运行flv.js
                isLive: true,           //直播模式
                hasAudio: true,        //关闭音频             
                hasVideo: true,
                stashInitialSize: 128,  
                enableStashBuffer: false, //播放flv时,设置是否启用播放缓存,只在直播起作用。
                url: 'http://example.com/live?port=1935&app=myapp&stream=mystream'
            });
            flvPlayer.attachMediaElement(vElement)
            flvPlayer.load() //加载
        }
        
        setInterval(function () {
            vElement.playbackRate = 1
            console.log("时延校正判断");
            if (!vElement.buffered.length) {
                return
            }
            var end = vElement.buffered.end(0)
            var diff = end - vElement.currentTime
            console.log(diff)
            if (5 <= diff && diff <=60) {
                console.log("二倍速")
                vElement.playbackRate = 2
            }
            if (diff > 60) {
                console.log("跳帧")
                vElement.currentTime = end
            }
        }, 2500)

        function flv_start() {
            flvPlayer.play()
        }

        function flv_pause() {
            flvPlayer.pause()
        }

        function flv_destroy() {
            flvPlayer.pause()
            flvPlayer.unload()
            flvPlayer.detachMediaElement()
            flvPlayer.destroy()
            flvPlayer = null
        }

        function flv_seekto() {
            player.currentTime = parseFloat(document.getElementsByName('seekpoint')[0].value)
        }
        
    </script>
</body>
</html>

7. 其他问题

至此已经完成了整个实现过程,但是还有一些问题需要注意。

7.1 累积时延问题

由于网络波动或者网页切换到后台等原因,flvjs播放会有累积时延,这在摄像头监控画面中是无法忍受的,主要参考了github issues以及【入门】无插件web直播解决方案,ffmpeg+nginx-http-flv-module+flv.js给出的解决方案:video对象可以获取currentTime以及endTime,设置一个定时器比较一下二者时间差,时间差小于60s时倍速播放,大于60s时直接跳帧,因为视频监控的用户更关心最近的画面,代码已经在6.2中给出,如下:

setInterval(function () {
            vElement.playbackRate = 1
            console.log("时延校正判断");
            if (!vElement.buffered.length) {
                return
            }
            var end = vElement.buffered.end(0)
            var diff = end - vElement.currentTime
            console.log(diff)
            if (5 <= diff && diff <=60) {
                console.log("二倍速")
                vElement.playbackRate = 2
            }
            if (diff > 60) {
                console.log("跳帧")
                vElement.currentTime = end
            }
        }, 2500)

7.2 自动播放问题

有时候可能一个web页面需要展示好几个监控视频画面,让用户依次点击开始播放不太方便,需要在video标签中加入autoplay 属性实现自动播放,但是一些浏览器比如chrome禁止音频内容的自动播放,可以在video标签中加入muted属性,如下:
<video id="videoElement" class="centeredVideo" muted autoplay width="1024" height="576">Your browser is too old which doesn't support HTML5 video.</video>

7.3 flvjs播放器要主动销毁

该问题是我在使用Vue进行前端开发时遇到的,在离开某个Vue页面后并没有主动销毁flvjs的播放器,后台仍然在接受数据,导致再次回到该页面时无法重复创建flvjs播放器,加载不出监控画面。解决方法是在离开页面的回调函数中写入销毁的函数

function flv_destroy() {
            flvPlayer.pause()
            flvPlayer.unload()
            flvPlayer.detachMediaElement()
            flvPlayer.destroy()
            flvPlayer = null
        }

7.4 同时在后台启动多个推流

当需要同时在后台启动多个推流命令时,使用screen可能比较麻烦。可以创建一个start_live.sh的脚本,内容如下:

# start_live.sh
nohup ffmpeg -rtsp_transport tcp -i rtsp://a.com/vod/mp4:BigBuckBunny_115k.mov  -c copy -f flv rtmp://127.0.0.1:1935/myapp/mystream1 &
nohup ffmpeg -rtsp_transport tcp -i rtsp://b.com/vod/mp4:BigBuckBunny_115k.mov  -c copy -f flv rtmp://127.0.0.1:1935/myapp/mystream2 &
nohup ffmpeg -rtsp_transport tcp -i rtsp://c.com/vod/mp4:BigBuckBunny_115k.mov  -c copy -f flv rtmp://127.0.0.1:1935/myapp/mystream3 &

为了防止在nohup.out中写入巨量的日志信息,可以在ffmpeg推流命令中加入-loglevel quiet参数。