Streaming

NDI for churches: a beginner's guide

If your church streams, you've probably seen "NDI" mentioned in vMix, OBS or a graphics tool and wondered what it actually is. The short version: NDI lets you send video and graphics between computers over your ordinary network cable — no capture cards, no HDMI runs across the building. Here's what that means for your church, in plain English.

What NDI actually is

NDI (Network Device Interface) is a free technology for carrying high-quality video over a standard Ethernet network. Instead of running a physical HDMI or SDI cable from one device to another, the "sender" puts its video onto the network, and any "receiver" on the same network can pick it up — just by choosing it from a list by name.

Why churches use it

• No capture cards — feed a graphics PC's output into your streaming switcher without buying and wiring capture hardware.
• Fewer cables — send video room-to-room over the network you already have.
• Flexible layout — your lyrics PC, camera, and lower-third graphics can all live on different machines and still reach the switcher.
• It's free — the NDI tools and most church software's NDI support cost nothing extra.

What you need to get started

• A wired gigabit network — NDI works best over wired Ethernet. Avoid Wi-Fi for anything important; a cheap gigabit switch is worth it.
• NDI-capable software on both ends — a sender (a camera, a graphics tool, a lyrics program) and a receiver (usually your streaming switcher).
• Everything on the same network — senders and receivers need to see each other on the LAN.

A typical church setup

The most common use is getting graphics — like an automatically-detected Bible verse — onto the stream without extra hardware:

1. The senderA tool like TajiCast outputs a full-width lower-third over NDI.
2. The networkThat video travels over your wired gigabit LAN.
3. The receiverYour switcher (vMix or OBS) adds it as an NDI source and overlays it on the program.

NDI vs HDMI/SDI

HDMI and SDI are point-to-point: one cable, one destination, and you need capture hardware to bring them into a computer. NDI is network-based: one sender can be received by many machines, and it arrives inside software directly — no capture card. For most church graphics and inter-PC video, NDI is simpler and cheaper. (Cameras and long broadcast runs still often use SDI.)

Handy tips

• Name your sources clearly — "Graphics-PC (TajiCast)" beats "Desktop 2".
• Match resolution — set the sender's resolution to your switcher's canvas so overlays fit edge to edge.
• Mind bandwidth — several full-quality NDI streams add up; gigabit wired keeps it smooth.

Related: TajiCast for vMix · TajiCast for OBS · For live-streaming churches