How to Set Up NDI Lower Thirds in OBS for Seamless Scripture Overlays

Livestream viewers expect clear, legible scripture references that integrate naturally over a pastor’s live camera feed without obscuring the sanctuary stage. Traditional methods like green-screen chroma keying or secondary HDMI capture cards often produce jagged text edges, color bleed, and messy hardware setups.

Network Device Interface (NDI) solves this challenge by sending broadcast-grade video with native transparency (alpha channel) over a local Ethernet network. This guide provides a step-by-step walkthrough to configure NDI lower thirds in OBS Studio for clean, latency-free church livestream scripture overlays.

What Is NDI and Why Is It Best for Scripture Overlays?

NDI is a royalty-free software protocol developed by NewTek that enables video-compatible hardware and software to transmit high-definition video, audio, and alpha transparency channels over a standard local area network (LAN).

When displaying scripture on a church livestream, alpha channel support is critical. An alpha channel transmits transparency data alongside standard red, green, and blue (RGB) color channels. This allows OBS Studio to composite lower third graphics—such as Bible verses, speaker names, and sermon notes—directly on top of camera footage with smooth semi-transparent backgrounds and anti-aliased text.

Using NDI eliminates the need for physical HDMI capture cards or green-screen filters in OBS. Video signals travel instantly between your church presentation computer and your OBS streaming machine over a single Cat6 Ethernet cable.

System Requirements and Prerequisites

To set up NDI scripture overlays in OBS Studio, your church AV environment requires the following components:

• A dedicated Gigabit Local Area Network (LAN): Both the presentation computer and the OBS streaming computer must connect to the same router or network switch via Cat5e or Cat6 Ethernet cables. Wi-Fi connections cause dropped frames and packet loss.
• OBS Studio: Version 29.0 or newer installed on your broadcast machine.
• The obs-ndi Plugin: The official plugin that allows OBS Studio to recognize and decode NDI video streams.
• NDI 5 or NDI 6 Core Runtime: The background runtime engine required by your operating system to process NDI network packets.
• NDI-Enabled Church Presentation Software: Software capable of outputting a dedicated lower third theme with alpha transparency, such as ProPresenter, Kairos, or EasyWorship.

Step 1: Configure Alpha Output in Your Presentation Software

Before OBS can receive scripture overlays, your presentation software must output a transparent video feed.

1. Open your presentation software settings and navigate to the Screens or Outputs menu.
2. Create a new screen output and set the output type to NDI.
3. Set the resolution to match your livestream canvas (typically 1920x1080 at 30fps or 60fps).
4. Select a color format that supports alpha transparency, such as RGBA or NDI with Alpha.
5. Apply a lower third template to this output. Ensure the background color of the scripture slide is set to transparent (0% opacity) rather than black or green.

Step 2: Install the OBS-NDI Plugin

If you have not already installed NDI support inside OBS Studio, complete these installation steps on your streaming computer:

1. Download the latest release of the obs-ndi installer from its official GitHub repository.
2. Download and install the corresponding NDI Runtime for Windows or macOS.
3. Run the installers and restart your computer to ensure all background system drivers register properly.
4. Launch OBS Studio. Click the + button under the Sources dock. If the installation was successful, NDI™ Source will appear in the list of available sources.

Step 3: Add and Position the NDI Source in OBS Studio

With both systems running and connected to the local network, you can now link the scripture feed into your livestream scene.

1. Open OBS Studio and select the scene containing your main camera feed.
2. In the Sources panel, click + and select NDI™ Source.
3. Name the source Scripture Lower Third and click OK.
4. Open the Source name dropdown menu. OBS will automatically scan your local network and list available NDI feeds. Select the NDI output generated by your presentation software.
5. Set the Bandwidth setting to Highest to preserve full resolution and text sharpness.
6. Leave Sync set to Network for local setups with low network jitter.
7. Ensure the Scripture Lower Third source is placed above your camera video capture source in the OBS source layer stack.

Once added, your scripture lower thirds will immediately overlay your camera shot whenever a slide is triggered on the presentation computer.

Troubleshooting Common NDI Scripture Overlay Issues

• Black Background Instead of Transparency: If the background appears solid black rather than see-through, verify that your presentation software is outputting in RGBA mode and that slide background layers have opacity set to 0%.
• Network Latency or Stuttering: Ensure neither machine is on Wi-Fi. Verify that both computers connect through a Gigabit switch with Quality of Service (QoS) enabled.
• Source Not Appearing in OBS: If the NDI source dropdown in OBS is blank, check the Windows Defender Firewall or macOS Network Security settings. Grant full local network permissions to both OBS Studio and your presentation application.

Conclusion

Deploying NDI lower thirds in OBS Studio provides church livestreams with crisp typography, professional transparency, and zero hardware clutter. By leveraging high-bandwidth network video rather than clumsy workarounds, your media team can display Bible verses cleanly and keep online congregants engaged throughout every sermon.