Copyright © 2025 - Mark Lasersohn

NDI™ is a registered trademark of Vizrt NDI AB

This is an example of creating a NDI stream in concert with OpenCV, allowing you to turn any USB camera like most webcams, or any video file, into a NDI stream and pump the video through your network to any NDI client, like CowCam or OBS Studio (with a NDI plugin, of course).

Compile with:

g++ -Wno-write-strings cow_ndi.cpp -o cow_ndi -I/usr/local/include/ndi `pkg-config --cflags --libs opencv`
(or simply use the included script: mkit)

You must have the OpenCV and NDISDK development libraries installed as this program uses both. It is helpful to have a program like CowCam or OBS Studio (with a NDI plugin) installed so as to view the created NDI stream.

Syntax: cow_ndi camera_path [ndi_stream_name] [video_format]
      camera_path is the path to the camera. This may be a device, such as as USB device, in the /dev directory, or it may be a video file. It can be any file OpenCV can use as a capture device.
      The optional argument ndi_stream_name is the name listed by NDI™ for the video stream.
      The optional argument video_format, is an integer ranging from 0 to 4, used to specify the NDI™ video format for the stream:
         0 = BGRX
         1 = RGBX
         2 = I420
         3 = UYVA
         4 = UYVY
        I420 is the default.

Examples:
      cow_ndi /dev/video0 ; Stream name defaults to 'Cow NDI' and frame format to I420
      cow_ndi /dev/video0 MyStreamName ; Frame format defaults to I420
      cow_ndi /dev/video0 MyStreamName 3 ; Stream will use UYVA video frame format