OBS_Configuration

OBS (Open Broadcaster Software) is free software that allows you to customize your video recording. You can superimpose text and combine multiple video sources, cropping which parts of the video sources are shown. For instance you could use your webcam to show your face, and an additional USB webcam to show your desk, where you can illustrate some point using manipulatives.

A "green screen" is a physical cloth colored background (such as this 6'x9' one for $22) that is used to isolate just part of a video source. For instance you may be interested in adding just the video of your face to your video recordings, as shown below:

greenscreen

You then record two separate sources, both your "talking head" with the green screen background, along with the video of whatever is on your computer screen. For recordings where you are not doing this live, then you don't need OBS and can use other tools such as Camtasia studio or iMovie. After you have made your recording, you can choose to have your "talking head" video superimposed on the rest of the screen, selecting the size and position, using those programs to make the green screen portion of your video transparent, as shown in the image above.

It is a bit trickier if you are trying get the "talking head" live, with a transparent background, for instance to use as input to Zoom or some other video-conferencing software. If you are a PC user then use obs-virtualcam, though I haven't done the installation with this one to give any insight.

Mac users do the following:

  1. If you haven't done so already, download and install OBS.

  2. Download and install the free NewTek NDI/HX driver and Tools, available by scrolling down at ndi.tv/tools . You will first be asked to register your name and email information.

NDI Driver and Tools

  1. First install the NDI/HX driver. Next install NDI Virtual Input, one of the NewTek Tools options. This will (after a few more steps) will allow you to define your OBS output as a virtual webcam.

  2. Create an NDI output from OBS. To do this download and install the Palakis obs-ndi software to create an OBS Tools / NDI Output settings menu option.

Palakis OBS-NDI Software

  1. Note there are two steps:

    1. Download and run obs-ndi-4.9.0-macOS.pkg

    2. Install the NDI 4.5.1 macOS runtime using the installer provided here: https://ndi.palakis.fr/runtime/ndi-runtime-4.5.1-macOS.pkg

  2. Launch OBS. From within the newly created Tools / NDI Output settings menu option:

  1. select Main Output and give it a name (e.g. OBS_NDI_Output).

Create NDI Output Name

  1. (OBS needs to be running for this step to work.) Launch the previously downloaded program NDI Virtual Input:

  1. and then select your virtual video input source created in the previous step (e.g. OBS_NDI_Output) using the Sources menu option at the top of the screen:

Select NDI Source

  1. (Both OBS and NDI need to be running for this step to work.) Within Zoom select NDI Video as the input camera. This will give you your created composite OBS video as your Zoom image.

OBS output through NDI to Zoom

To explore further do a google search on "OBS NDI Tutorial" which gives this video, among others.

This page is one of the resources from the online teaching tools page.