obs

OBS studio is an open-source software for screen-recording available in Windows/Mac/Linux platforms. It can be downloaded from the official website. Below we provide a simple use case scenario of using OBS for recording a pdf/ppt file with the recorder's video (captured through webcam) placed in a smaller window.

Step 1: Download and install OBS. For windows and mac download from the website. For Linux, follow their guide here. Depending on your flavor of linux and version, you may need to use appropriate guide for installing. For Ubuntu users, the simplest path is to use the command

sudo apt install obs-studio ffmpeg

But, for optimal result in Linux, please follow the guide in their website.

Step 2: Once installed, run OBS. It will ask whether you want to perform a common set up. Say yes. Following screens will show up one after another. A suitable choice is made in them, that you can follow.

Optimize for recording, as you will record the lecture. Click Next.

A higher FPS will result in larger size of the video and will consume more CPU power. Click Next.

Verify settings, and if these look ok, select Apply Settings.

You'll be presented with this screen.

Step 3: Now, we'll configure:

  • A particular window (such as a pdf or pptx file) as primary source.

  • Microphone as audio source

  • Webcam as another video source.

These three steps are shown on these three small videos (each 15-20 seconds). Please use higher resolution versions, otherwise the texts may not be visible.

Make sure the window (pdf/ppt file) is already open and not minimized.

In the last video, there are multiple options that can be configured for the webcam. We kept the default options as they were.

Step 4: Now we are ready to record the screen.

Click on the Start Recording button, as marked. It will start recording. You can minimize the OBS windows. Once recording has started, the same button in OBS will have an option to pause the recording or stop the recording. The final video file will appear in your Videos folder.

  • At any point in time, the recording window can be changed (such as pdf to a ppt). This can be done by selecting the window source and clicking the properties, as shown in the picture below.

  • The full desktop can also be captured, by adding 'Display' as a source. It sometimes cause problems.