开源流媒体服务器SRS学习笔记(2) - rtmp / http-flv / hls 协议配置 及跨域问题

对rtmp/http-flv/hls这三种协议不熟悉的同学,强烈建议先看看网友写的这篇文章科普下:理解RTMP、HttpFlv和HLS的正确姿势 。
 
srs可以同时支持这3种协议,只要修改conf配置文件即可,默认情况下加载的是 /usr/local/srs/conf/srs.conf,参考下图:

修改该文件:

listen              1935;
max_connections     200;
srs_log_tank        file;
srs_log_file        ./objs/srs.log;

http_api {
    enabled         on;
    listen          1985;
}

http_server {
    enabled         on;
    listen          8080;
    dir             ./objs/nginx/html;
}

stats {
    network         0;
    disk            sda sdb xvda xvdb;
}

vhost __defaultVhost__ {
    # http-flv设置
    http_remux{
        enabled    on;
        mount      [vhost]/[app]/[stream].flv;
        hstrs      on;
    }

    # hls设置
    hls{
        enabled       on;
        hls_path      ./objs/nginx/html;
        hls_fragment  10;
        hls_window    60;
    }
}

然后执行:

sudo /etc/init.d/srs reload

让配置即时生效,VLC Player里下列3个地址,应该都可以播放了:

协议 地址
rtmp rtmp://srs_server_ip:1935/live/livestream
http flv http://srs_server_ip:8080/live/livestream.flv
hls http://srs_server_ip:8080/live/livestream.m3u8

 要注意的是:hls是把实时的视频流,分成1个个小的切片,保存在/usr/local/srs/objs/nginx/html/live/ 目录下,参考下图:

不太严谨的话,可以理解为播放的是服务器上已经生成好的视频片段,因此就算在obs把实时视频直播源切断,还是可以播放一段时间的。(实时生成视频切片需要时间,而且每个切片本身是N秒一切割,所以不难理解为啥hls协议延时最大)

 

h5播放hls:

借助video-js项目,可以很容易实现.m3u8的hls播放:

<head>
    <title>video-js HLS demo</title>
    <link href="https://vjs.zencdn.net/7.4.1/video-js.css" rel="stylesheet">
</head>

<body>
    <video id='my-video' class='video-js' controls preload='auto' width='640' height='320' poster='avatar-poster.jpg'
        data-setup='{ "html5" : { "nativeTextTracks" : true } }'>
        <source src='http://10.2.*.*:8080/live/livestream.m3u8' type="application/x-mpegURL">
        <p class='vjs-no-js'>
            To view this video please enable JavaScript, and consider upgrading to a web browser that
            <a href='https://videojs.com/html5-video-support/' target='_blank'>supports HTML5 video</a>
        </p>
    </video>

    <script src='https://vjs.zencdn.net/7.4.1/video.js'></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/videojs-contrib-hls/5.15.0/videojs-contrib-hls.min.js"></script>

    <script>
        var player = videojs('my-video');
        player.play();
    </script>

</body>

但播放时,如果h5页面与.m3u8的视频源不在同一个域名,浏览器会遇到跨域问题。

网上有一种解决办法,是修改srs的源码,增加Access-Control-Alow-Orogin:*,但个人不推荐这种做法,一来把安全性降低了,容易造成盗播等安全问题。二是如果官网以后fix bug了,自己又得改一次。

更好的办法,是在srs前面放一个nginx,做转发来解决跨域问题。通常h5页面,是通过nginx来访问的,可以在nginx里,把特定视频源路径,转发到后端srs服务器上,参考以下配置:

    location /srs/ {
	proxy_pass http://10.2.*.*:8080/;
 	add_header Cache-Control no-cache;
 	add_header Access-Control-Allow-Origin *;
    }

这样,请求http://localhost:81/srs/live/livestream.m3u8的请求,都会转发到http://10.2.X.X:8080/live/livestream.m3u8上,跨域问题解决后,就可以正常播放了,参考下图的效果:

tips: obs+srs支持多路视频源同时直播,上图中阿凡达+本机摄像头,二路视频同时推流/拉流,毫无影响。

 

h5播放http-flv

首先要感谢B站开源的flvjs,可以不依赖于flash player,纯js+html实现flv的播放。
<!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: 640px;
        }

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

        .centeredVideo {
            display: block;
            width: 100%;
            height: 320px;
        }

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

<body>
    <div class="mainContainer">
        <video id="videoElement" class="centeredVideo" controls autoplay width="640" height="320">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="./flv.min.js"></script>
    <script>
        var player = document.getElementById('videoElement');
        if (flvjs.isSupported()) {
            var flvPlayer = flvjs.createPlayer({
                type: 'flv',
                isLive: true,
                enableWorker:true,
                enableStashBuffer:false,
                stashInitialSize:128,
                url: 'http://localhost:81/srs/live/livestream.flv',

            });
            flvPlayer.attachMediaElement(videoElement);
            flvPlayer.load();
            flv_start();
        }

        function flv_start() {
            player.play();
        }

        function flv_pause() {
            player.pause();
        }

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

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

</html>

当然,如果播放端环境可控(比如pc端,且能确定安装并允许支行flash player)直接用flash player播放flv效果更好。

posted @ 2019-04-13 23:02  菩提树下的杨过  阅读(...)  评论(... 编辑 收藏