CS 535 Big Data, Computer Science Department, Colorado State University, Spring 2020

Recording Presentations using OBS (Open Broadcaster S/W)

We will be recording presentations using an open-source software called OBS which is available for Mac, Linux and Windows machines.

1. Installing OBS on personal machine -

Step 1: Download OBS for your Windows/Linux/MacOS machine from here https://obsproject.com/

- If using Mac, install the OBS software using the dmg obs-mac-24.0.6.dmg which you just downloaded

- For Windows, run the following 64-bit executable file OBS-Studio-24.0.3-Full-Installer-x64.exe

- For Linux environment refer to the following page - https://obsproject.com/wiki/install-instructions#linux

Step 2: Drag OBS icon to Applications folder to complete the installation for MacOS. You should see OBS applications in your dock or in Launchpad -> OBS

2. Capturing screen and recording Presentation -

Open the application, on bottom you should see Scenes panel, Sources, Audio Mixer, Scene Transitions window and control buttons

Step 1: Adding Scenes to capture monitor screen and presentation

- Click on + icon under Scenes window

- Give a new name for this scene eg. Scene1. We will use this to capture everything on the machine’s window

- You can also add another scene for slides like in above step

- Create this new scene with any name eg. “Powerpoint”

Step 1 Step 2

CS 535 Big Data, Computer Science Department, Colorado State University, Spring 2020

Step 2: Adding Input Sources for the scenes

- Add the source for Scene1 by clicking on + icon under Scenes panel

- Now, to capture everything on your screen, select Display Capture as the source -> Create New. Rest everything can stay same.

- Next, attach the input source ie your PowerPoint/Keynote presentation for scene “Powerpoint”

- Make sure you open your PPT/Keynote before adding this new source

- Click on + icon again under the Sources and select Window Capture -> Create New -> OK. (Tick on Make Source visible option)

- Inside Properties for this new window capture, pin your OBS window to the ppt/keynote by selecting it from drop down menu and then click OK

CS 535 Big Data, Computer Science Department, Colorado State University, Spring 2020

Step 3: Everything inside the black box above the OBS panels (Sources, Scenes, audio mixer) will be captured. You can also resize and reposition your window to fit this black canvas by dragging the red box as shown below -

Step 4: Select the appropriate Scene and Source to start recording the video

- Now if you don’t want to capture the audio, then you can mute the mic under Audio Mixer

- Click on Start Recording button on extreme Right under controls

- You can also pause and stop recording in similar way

3. Changing storage path and audio/video settings for the recording

Step 1: You can also provide the path where you want all the recordings to be stored

- Simply go to OBS -> Preferences -> Output -> Recordings -> Change the Recording Path

To Mute Click here

CS 535 Big Data, Computer Science Department, Colorado State University, Spring 2020

Step 2: Change Video settings

- We can also specify the Recording Quality as High Quality Medium Sized File and desired recording format (by default mp4)

- You can adjust the size of the screen by again going to Settings -> Video and changing the Base (Canvas) resolution. Make sure your presentation fits inside the black square canvas

Step 3: Change Audio Setting if required

- You can either use OBS to record the voice or you can also use iMovie or similar software for doing the voice over

- For OBS inside settings click on Audio and change Mic/Auxiliary Audio to your machine’s microphone or external microphone whatever you like to record the voice. Rest settings can stay the same

- While recording try to keep the Mic/Aux green bar between -25 to -10 dB. If the green bar reaches the red region indicates that your voice is too loud. Using the slider below Mic/Aux category you can adjust the max/min volume (Keep at 80-85% as shown below)

CS 535 Big Data, Computer Science Department, Colorado State University, Spring 2020

4. Improving voice qualities by adding Filters

To improve the audio quality click on the settings icon near slider under Mic/Aux -> Filters and click on + icon on bottom left corner

The choice of filters you want to add depends on what microphone you are using or what place are you recording. However, we will add these three basic filters -

1. Add Noise Suppression

- To reduce the background noises, adjust the Suppression Level (dB) by moving slider to get desired effect

- If there is too much background noise, then you can reduce this value to around -30 dB. If there is less background noise, then you can bring it up to -20

- If you go below -30/-40, then you may face issues such as microphone might not pick up the desired audio

2. Add Noise Gate

- This will try to reduce noice when you have pauses while recording the audio

- So, when you are silent in your audio, this filter will try to make it complete silent

- You can adjust the Close Threshold and Open threshold to the values which works best for you

3. Add Compressor filter, this in general will improve your voice quality

This is the basic setup which you can use to record the presentations. Lastly, to see the recorded videos click on File -> Show Recordings