Pointing a camera at the projector screen works, but the words come out blurry and washed out. A capture card works better, but it costs money and ties the stream computer to the projection computer with a cable. NDI is a third way. It sends video over your ordinary church network, and streaming software like OBS, vMix and Streamlabs can receive it.
Crater has NDI built in on Windows.
What you need#
- Crater on Windows on the projection computer.
- NDI Tools, free from ndi.video/tools, installed on the Crater computer.
- Streaming software that receives NDI. OBS Studio needs the DistroAV plugin (formerly obs-ndi). vMix and Streamlabs have NDI input built in.
- Both computers on the same network. A wired connection is the most reliable.
Setting it up#
- Install NDI Tools on the Crater computer and restart Crater. An NDI button appears in the top bar.
- Click NDI to start the stream. The button turns cyan.
- In your streaming software, add an NDI source and pick the one named after the Crater computer, like CHURCH-PC (Crater Live).
- Put a verse on the screen in Crater and check it arrives.
The NDI guide covers every setting, including what each colour of the NDI button means.
Give the stream its own look#
Full-screen lyrics look right on a projector but cover the camera shot on a stream. Turn on Dual output mode in Crater’s NDI settings, then set a separate song theme and scripture theme for the stream, such as a lower third. The projector keeps its full-screen look and the stream gets the words across the bottom of the picture.
Handy during the service#
- Hide NDI blanks the stream without touching the projector, for a private prayer time or a notice you don’t want online.
- Hide pictures and video keeps lyrics and scripture on the stream but blanks videos you don’t have the rights to broadcast.
- On a slow laptop, on-demand rendering only sends a new frame when something changes.
No projector at all?#
The NDI stream works whether or not the projection window is open. A church that only streams can run Crater on one laptop and send the words straight to the stream.