Any USB camera connected to a machine running macOS or Linux (from now on the SOURCE machine) can be used as a remote USB camera that streams the video over an Internet connection to different computing units that runs Dragonfly (from now on the CLIENT machine).

1 – Install Gstreamer

We use Gstreamer to stream the video from the SOURCE machine. To install it enter the following commands on your SOURCE machine:

sudo apt-get -y install libgstreamer1.0-dev
sudo apt-get -y install libgstreamer-plugins-base1.0-dev
sudo apt-get -y install gstreamer1.0-libav
sudo apt-get -y install gstreamer1.0-plugins-bad
sudo apt-get -y install gstreamer1.0-tools
sudo apt-get -y install gstreamer1.0-plugins-good
sudo apt-get -y install gstreamer1.0-plugins-ugly
sudo apt-get -y install gstreamer1.0-nice

2 – Activate the streaming

On the SOURCE machine:

1. Connect the USB camera.
2. Launch the following command to list all video devices picked up by Ubuntu in order to find the ID of the USB camera:

   sudo apt-get install v4l-utils
   v4l2-ctl --list-devices

   Why do you see 2 IDs for each camera?
   There is a common bug on Ubuntu 18.04 where 2 indexes are displayed for each USB camera. When configuring the CAM_SOURCE field inside the Configuration tab of the Dragonfly Web user interface please use the first index of the two.
3. Launch one of the following commands to activate the video stream (ip_of_your_device is the local IP address assigned to the SOURCE machine):
   • MJPEG streaming – use this solution if the hardware does not allow live H264 encoding, or if H264 is not satisfying:

     gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,width=640,height=480,framerate=30/1' ! decodebin name=dec ! queue ! videoconvert ! jpegenc ! queue ! multipartmux ! tcpserversink host=ip_of_your_device port=5000

   • H264 streaming – much lower bandwidth requirements than MJPEG, but requires live encoding and some CPUs might not be powerful enough.

     gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,width=640,height=480,framerate=30/1' ! videoconvert ! x264enc tune=zerolatency byte-stream=true ! rtph264pay ! gdppay ! tcpserversink host=ip_of_your_device port=5000 sync=false

   • H264 (accelerated) streaming – same as H264 streaming, but does not require a powerful CPU encoding. However, all platforms are not compatible. Raspberry Pi and Jetson Nano should work fine.

     gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,width=640,height=480,framerate=30/1' ! videoconvert ! omxh264enc ! rtph264pay ! gdppay ! tcpserversink host=ip_of_your_device port=5000 sync=false

3 – Make the video stream available to Dragonfly

1. Launch Dragonfly on the CLIENT machine.
2. Click on the Configuration tab:
   1. Set the CAM_SOURCE parameter to one of the following strings depending on the type of streaming activated on the SOURCE machine (ip_of_your_device is the local IP address assigned to the SOURCE machine):
      • For MJPEG streaming:

        gstreamer:tcpclientsrc host=ip_of_your_device port=5000 ! multipartdemux ! image/jpeg, framerate=30/1 ! jpegparse ! jpegdec ! videoconvert ! appsink sync=false

      • For H264 streaming:

        gstreamer:tcpclientsrc host=ip_of_your_device port=5000 ! gdpdepay ! rtph264depay ! avdec_h264 ! videoconvert ! appsink sync=false

      • For H264 (accelerated) streaming:

        gstreamer:tcpclientsrc host=ip_of_your_device port=5000 ! gdpdepay ! rtph264depay ! avdec_h264 ! videoconvert ! appsink sync=false

3. Click on Save and Restart.