nginx-hls-server

Table of Contents

• Objective
• Prerequisites
• Setup
  • Create ffmepg HLS stream
  • Set up NGINX
• Test
• Optional
• Troubleshooting
  • Cannot find correct input device
  • ffmpeg cannot access video input device

Objective

To create a video stream and serve as a HLS endpoint via NGINX.

Prerequisites

The steps listed here should work for most *nix devices, as long as ffmpeg & nginx are supported & installed.

ffmpeg

sudo apt-get install ffmpeg     # Debain-based
sudo pacman -S ffmpeg           # Arch-based
yum install ffmpeg              # RHEL/Fedora
brew install ffmpeg             # macos

NGINX

As we need to use the RTMP Module in NGINX, which might not be present in certain build, we will clone the git repo and compile nginx:

cd /path/to/build/dir
git clone https://github.com/arut/nginx-rtmp-module.git
git clone https://github.com/nginx/nginx.git
cd nginx
./auto/configure --add-module=../nginx-rtmp-module
make
sudo make install

This will install NGINX in /usr/local/nginx.

Setup

1. Create ffmepg HLS stream

Here is an example to set up a HLS stream at /tmp/hls/ with following settings:

Input

• Input device: /dev/video0
• Resoltuion: 1280x720
• Framerate: 30

HLS stream

• Encoding preset: superfast
• Target (average) bit rate: 5000k
• Codec: h264
• Segment time interval: 6 seconds
• Playlist size: 10 segments
• Wrap limit: 40 segements
• HLS flag: delete_segments
• Segement deletion threshold: 1

ffmpeg -video_size 1280x720 \
       -framerate 30 \
       -i /dev/video0 \
       -f hls \
       -preset superfast \
       -c:v libx264 \
       -b:v 5000k \
       -hls_time 6 \
       -hls_list_size 10 \
       -hls_wrap 40 \
       -hls_delete_threshold 1 \
       -hls_flags delete_segments \
       /tmp/hls/stream.m3u8

You can run it with & or other tools (e.g. screen or nohup) to make it run in background.

2. Set up NGINX

Modify /usr/local/nginx/conf/nginx.conf so that it serves contents in /tmp/hls as HLS stream:

worker_processes  1;
user	pi;

events {
    worker_connections  1024;
}
 
http { 
    default_type application/octet-stream;
 
    server { 
        listen 80; 
        location /live { 
            alias /tmp/hls/; 
        } 
    }
 
    types {
        application/vnd.apple.mpegurl m3u8;
        video/mp2t ts;
        text/html html;
    } 
}

Test the config file by running:

/usr/local/nginx/sbin/nginx -t

Start the nginx server:

/usr/local/nginx/sbin/nginx

Note: You may need to run with root access. i.e. run it with sudo.

Test

Open VLC player and connect to http://<ip-address>/live/stream.m3u8.

Optional

Add RTMP functionality to the server so that it can accept RTMP streams and process into HLS stream.

rtmp { 
    server { 
        listen 1935; 
        application live { 
            live on; 
            interleave on;
 
            hls on; 
            hls_path /tmp/hls/; 
            hls_fragment 15s; 
        } 
    } 
} 

Troubleshooting

Cannot find correct input device

If you have difficulties in finding the right device/config/parameters, you can view the details device info by using v4l2-ctl.

To use v4l2-ctl, you need to have v4l-utils installed. Please install it using package manager of your distro.

For example:

sudo apt install v4l-utils

Then you can list all of the device details using the following command:

v4l2-ctl --all

or

v4l2-ctl --list-devices

ffmpeg cannot access video input device

[video4linux2,v4l2 @ 0x5567bd2739c0] Cannot open video device /dev/video0: Operation not permitted
/dev/video0: Operation not permitted

In some distros, there are restrictions on which devices certain softwares can access to. Thus in order to let ffmpeg to access to the camera e.g. /dev/video0, you will need to explicitly grant permission to ffmpeg

Here is an example on Ubuntu:

snap connect ffmpeg:camera