node-jetson-webcam

With this you can run multiple webcams on a jetson nano dev. simplified.

Setup

• Install gstreamer:

sudo add-apt-repository universe
sudo add-apt-repository multiverse
sudo apt-get update
sudo apt-get install gstreamer1.0-tools gstreamer1.0-alsa gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly gstreamer1.0-libav -y
sudo apt-get install libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libgstreamer-plugins-good1.0-dev libgstreamer-plugins-bad1.0-dev -y 
sudo apt-get install curl make htop ffmpeg v4l-utils icecast2 -y
sudo apt-get upgrade -y

• Install Node

curl -L https://git.io/n-install | bash

• Exit and reopen the console or source it:

. ~/.bashrc

• Change node.js version to 12

n 12

• Create a folder

sudo mkdir /data
sudo chown MYUSER:MYUSER /data

replace MYUSER with your own. getting: echo $USER

• Get the repo:

cd /data
git clone https://github.com/seekwhencer/node-jetson-webcam.git
cd node-jetson-webcam
npm install

Run it

npm run dev

Configure

Edit the default config in: config/default.conf

The [camera] and the [camercontrols] element is the property set of all cameras. [camera_1] and [camera_2] override things from [camera] and [cameracontrols].

check the webcam devices:

ls -la /dev/video*

... and edit the config

Steam Configuration

Edit these config fields for all or a specific camera:

[camera]
source=mjpeg
encoder=vp8
overlay=clock,name,device
output=icecast

• source can be: mjpg or h264 or raw
• encoder can be: vp8 or h264
• overlay can be: clock,name,device or less of them, comma separated
• output can be: tcp or icecast

Camera Capabilities

Check if your cam supports the given source properties. At the moment it is:

mjpeg
30 fps
1280 x 720

This is important! If you give wrong capabilities to width_from, height_from, framerate_from or width,height,framerate (if no _from property was set). Check the capabilities of your cam. v4l2-ctl --list-formats -d /dev/video0 - replace video0 with your device.

Playback

Two ways of streaming:

1. per tcp directly from gstreamer
2. per http from icecast2

open tcp://jetson-ip-or-name:5100
or: http://jetson-ip-or-name:8100/one
replace the name or use the ip and chose a port

API

open http://jetson-ip-or-name:8080/v1

---

All Cameras

GET/cameras

get all cameras

---

GET/cameras/record

start recording for all cameras

---

GET/cameras/stop

stop recording for all cameras

---

GET/cameras/snapshot

make a snapshot

---

One Camera

GET/camera/{camera_id}

get one camera

---

GET/camera/{camera_id}/record

save recording on disk

---

GET/camera/{camera_id}/stop

stop recording

---

GET/camera/{camera_id}/snapshot

make a snapshot

---

GET /camera/{camera_id}/controls

get the camera controls (brightness, contrast etc.)

---

POST /camera/{camera_id}/controls

set the camera controls (brightness, contrast etc.)
multipart form, any property equals a form field

---

POST /camera/{camera_id}/controls/reset

reset to the defaults from config file

---

Desktop Streaming

It is possible to stream the ubuntu gnome desktop - and, if you let it run: a fullscreen browser. I suggest the chromium browser. Simply start the desktop, open a shell, go into the app folder and run: ./desktop.sh.

desktop.sh is actually the simplest way to send the desktop view as stream to the icecast server. But you need to run the script from a terminal from open gnome session - not over SSH. You can reach the desktop stream: http://jetson-ip-or-hostname:8100/desktop !

desktop.sh needs the running node app and the running icecast2 server.

Autostart with the desktop - or: "the kiosk mode"

• edit, replace MYUSER

  nano ~/.config/autostart/MYUSER.desktop
  

• use this:

  [Desktop Entry]
  Type=Application
  Name=Node Jetson Webcam Desktop Stream
  Exec=gnome-terminal -e /data/node-jetson-webcam/desktop.sh
  X-GNOME-Autostart-enabled=true
  

Set autologin to your user. Check the user settings....

Auto start the node app

• install pm2 globally

npm install pm2 -g

• apply as service

pm2 startup

• follow the instructions from pm2 and execute the given commands as sudo
• let pm2 start the app

cd /data/node-jetson-webcam
pm2 start "npm run dev" --name "node-jetson-webcam"
pm2 save

• starting, stopping

pm2 stop 0
pm2 start 0

0 is the pm2 app id.

• get status

pm2 status
pm2 status 0

• logs

pm2 logs 0

Summary:

At the moment the Icecast Stream is stable as hell with a latency of a second or less. Tested over a 300 MBit/s Wifi Network and played with VLC on a Windows Platform. The browser playback in firefox lags a little bit. I don't know why.

The key for a stable and fluid stream was this f***** properties for the webmmuxer: min-cluster-duration and max-cluster-duration

Sharpness: with a cheap webcam under 100 € you have a maximum focus range with the lens of the webcam. This means you can't focus things far far away. The maximum is somewhere at 5 meters ? The normal use case of a webcam is to make a skype call or something. These use cases needs a low focus range.

To hack your webcam, open the cam and rotate the lens with a pliers. BUT: be careful and make a little mark on the lens ring and the fixed holder to turn it back later. That sounds funny? It is.