Stream live video using nginx

Written by Solène, on 26 August 2019.
Tags: #openbsd #gaming #nginx

This blog post is about a nginx rtmp module for turning your nginx server into a video streaming server.

The official website of the project is located on github at: https://github.com/arut/nginx-rtmp-module/

I use it to stream video from my computer to my nginx server, then viewers can use mpv rtmp://perso.pw/gaming in order to view the video stream. But the nginx server will also relay to twitch for more scalability (and some people prefer viewing there for some reasons).

The module will already be installed with nginx package since OpenBSD 6.6 (not already out at this time).

There is no package for install the rtmp module before 6.6. On others operating systems, check for something like “nginx-rtmp” or “rtmp” in an nginx context.

Install nginx on OpenBSD:

pkg_add nginx

Then, add the following to the file /etc/nginx/nginx.conf

load_module modules/ngx_rtmp_module.so;
rtmp {
    server {
        listen 1935;
        buflen 10s;
    
        application gaming {
            live on;
            allow publish 176.32.212.34;
            allow publish 175.3.194.6;
            deny publish all;
            allow play all;
    
            record all;
            record_path /htdocs/videos/;
            record_suffix %d-%b-%y_%Hh%M.flv;
    
        }
    }
}

The previous configuration sample is a simple example allowing 172.32.212.34 and 175.3.194.6 to stream through nginx, and that will record the videos under /htdocs/videos/ (nginx is chrooted in /var/www).

You can add the following line in the “application” block to relay the stream to your Twitch broadcasting server, using your API key.

push rtmp://live-ams.twitch.tv/app/YOUR_API_KEY;

I made a simple scripts generating thumbnails of the videos and generating a html index file.

Every 10 minutes, a cron check if files have to be generated, make thumbnails for videos (tries at 05:30 of the video and then 00:03 if it doesn’t work, to handle very small videos) and then create the html.

The script checking for new stuff and starting html generation:

#!/bin/sh
    
cd /var/www/htdocs/videos
    
for file in $(find . -mmin +1 -name '*.flv')
do
        echo $file
        PIC=$(echo $file | sed 's/flv$/jpg/')
        if [ ! -f "$PIC" ]
        then
                ffmpeg -ss 00:05:30 -i "$file" -vframes 1 -q:v 2 "$PIC"
                if [ ! -f "$PIC" ]
                then
                        ffmpeg -ss 00:00:03 -i "$file" -vframes 1 -q:v 2 "$PIC"
                        if [ ! -f "$PIC" ]
                        then
                                echo "problem with $file" | mail user@my-tld.com
                        fi
                fi
        fi
done
cd ~/dev/videos/ && sh html.sh

This one makes the html:

#!/bin/sh
    
cd /var/www/htdocs/videos
    
PER_ROW=3
COUNT=0
    
cat << EOF > index.html
<html>
  <body>
<h1>Replays</h1>
<table>
EOF
    
for file in $(find . -mmin +3 -name '*.flv')
do
        if [ $COUNT -eq 0 ]
        then
                echo "<tr>" >> index.html
                INROW=1
        fi
        COUNT=$(( COUNT + 1 ))
        SIZE=$(ls -lh $file  | awk '{ print $5 }')
        PIC=$(echo $file | sed 's/flv$/jpg/')
    
        echo $file
        echo "<td><a href=\"$file\"><img src=\"$PIC\" width=320 height=240 /><br />$file ($SIZE)</a></td>" >> index.html
        if [ $COUNT -eq $PER_ROW ]
        then
                echo "</tr>" >> index.html
                COUNT=0
                INROW=0
        fi
done
    
if [ $INROW -eq 1 ]
then
        echo "</tr>" >> index.html
fi
    
cat << EOF >> index.html
    </table>
  </body>
</html>
EOF