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Streaming Video on Demand with nginx and RTMP Module

In this tutorial we will show a simple way to stream different types of video files using the Nginx server and RTMP modules.

Before starting the work, we will try to offer a small overview over the advantages of using RTMP versus HTTP video delivery.

Real Time Messaging Protocol (RTMP) was initially developed by Macromedia, for streaming on-demand and live media to Adobe Flash applications. It is a TCP-based protocol which maintains persistent connections and is defined as a “stateful” protocol. This means that from the first time a client connects until the time it disconnects, the streaming server keeps track of the client’s actions. On the other side, HTTP is a “stateless” application protocol used to deliver hypermedia information across the Internet worldwide.

Advantages of HTTP over RTMP:

  • Less likely to be blocked by firewalls at different levels in the network; RTMP uses default port 1935, which can be blocked sometimes, especially within corporate firewalls
  • Supported by more CDNs (it supports easier mirroring and edge caching)
  • More expertise in customizing HTTP

Advantages of RTMP over HTTP:

  • Ability to provide multicast support
  • Security and IP protection, using TLS/SSL or RTMPE
  • Seeking: particularly advantageous for long-duration content because the viewer doesn’t have to wait for the video file to load before jumping ahead, as is the case for HTTP-delivered video
  • Reconnect: if there is a network disruption, the client can re-establish a connection, while the video continues to play from the buffer; when the client re-connects, the buffer will begin filling to avoid any disruption in video or audio flow

And now, let’s start to build our streaming server.

To achieve this, we will compile the Nginx source code together with RTMP modules on a Ubuntu 12.04 box.

Logged in as root:

cd ~
mkdir nginx
cd nginx

Install the necessary software and dependencies:

# for compiler and git
apt-get install git gcc make

#for the HTTP rewrite module which requires the PCRE library
apt-get install libpcre3-dev

# for SSL modules
apt-get install libssl-dev

Clone Nginx RTMP module source code from Github:

git clone https://github.com/arut/nginx-rtmp-module

Download the Nginx source code and extract it from the archive. At the time when we are writing this blog post, the current version is 1.4.3:

wget http://nginx.org/download/nginx-1.4.3.tar.gz
tar zxpvf nginx-1.4.3.tar.gz
cd nginx-1.4.3

Let’s compile Nginx:

./configure --add-module=/root/nginx/nginx-rtmp-module/ --with-http_ssl_module --prefix=/usr/local/nginx-streaming/
make
make install

Now it is the time to create a configuration file for Nginx. Go to:

cd /usr/local/nginx-streaming/conf
mv nginx.conf nginx.cong.bkp
nano nginx.conf

and paste the configuration below. This configuration is suggested by the documentation of the RTMP module.

worker_processes  1;

events {
    worker_connections  1024;
}

rtmp {
    server {
        listen 1935;

        chunk_size 4000;

        # video on demand for flv files
        application vod {
            play /var/flvs;
        }

        # video on demand for mp4 files
        application vod2 {
            play /var/mp4s;
        }
    }
}

# HTTP can be used for accessing RTMP stats
http {
    access_log /var/log/nginx/access-streaming.log;
    error_log /var/log/nginx/error-streaming.log;

    server {
        # in case we have another web server on port 80
        listen      8080;

        # This URL provides RTMP statistics in XML
        location /stat {
            rtmp_stat all;
            rtmp_stat_stylesheet stat.xsl;
        }

        location /stat.xsl {
            # XML stylesheet to view RTMP stats.
            # Copy stat.xsl wherever you want
            # and put the full directory path here
            root /var/www/;
        }

        location /hls {
            # Serve HLS fragments
            types {
                application/vnd.apple.mpegurl m3u8;
                video/mp2t ts;
            }
            alias /tmp/app;
            expires -1;
        }
    }
}

To be able to see some nice statistics about the streaming, we must to copy stats.xml in the folder specified in the configuration above.

mkdir /var/www
cp /root/nginx/nginx-rtmp-module/stat.xsl /var/www/

And (re)start the Nginx server with:

/usr/local/nginx-streaming/sbin/nginx

It’s time to play!

As we defined in the Nginx configuration, the server can find some mp4 files in /var/mp4s or flv files in /var/flvs.

You can download an mp4 file here, right click and save it in /var/mp4s with the name sample.mp4.

Now, if you have a video player which supports RTMP protocol (eg: VLC), you can play it directly there.

From the VLC menu, Media->Open Network Stream.

In the URL field we input:

rtmp://<IP_OF_THE_SERVER>:1935/vod2/sample.mp4

Where <IP_OF_THE_SERVER> is the IP or the hostname of the server where we installed Nginx.

vlc

And click play.

play

If you want to show this video on a website, you can use a flash player as Flowplayer or JW Player.

Below we will show how to use Flowplayer to achieve this. First we need to download flowplayer.rtmp-3.2.12.swf (see the download link at the bottom of the page).

The html code below shows how to implement RTMP using Flowplayer. You should just replace the /path/to/background.png, the <IP_OF_THE_SERVER> and the /path/to/flowplayer.rtmp-3.2.12.swf.

<html>
<head>
    <!-- flowplayer javascript component -->
    <script src="http://releases.flowplayer.org/js/flowplayer-3.2.12.min.js"></script>
</head>

<body>
<div id="player" style="width:644px;height:276px;margin:0 auto;text-align:center">
    <img src="/path/to/background.png" height="260" width="489" /></div>
<script>

$f("player", "http://releases.flowplayer.org/swf/flowplayer-3.2.16.swf", {
    clip: {
        url: 'sample.mp4',
        scaling: 'fit',
        provider: 'hddn'
    },

    plugins: {
        hddn: {
            url: "/path/to/flowplayer.rtmp-3.2.12.swf",

            // netConnectionUrl defines where the streams are found
            netConnectionUrl: 'rtmp://<IP_OF_THE_SERVER>:1935/vod2'
        }
    },
    canvas: {
        backgroundGradient: 'none'
    }
});
</script>
</body>
</html>

That’s all.

Of course the solution presented in the post above is minimalist and if you need to scale globally with your Video on Demand product, probably you need a CDN solution.

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