NDI Capture
NDI® (Network Device Interface) is a network video transport over standard Ethernet. NDI Capture brings live NDI streams into WATCHOUT as a capture source — cameras, switchers, graphics systems, other media servers, anything publishing NDI on the network can become a media input for a show.
For sending display output as NDI, see NDI Output. For NDI infrastructure (discovery, cross-subnet routing, bandwidth, firewall), see NDI Video Sources in the network setup chapter.
Adding an NDI Source
- In the Devices window, click Add → Capture Device (or select an existing capture device).
- In Capture Sources, click Add NDI Source.
- Pick the stream from the Stream dropdown. WATCHOUT continuously discovers NDI sources on the network and populates this list automatically. If a known source is missing, see NDI Video Sources for discovery troubleshooting and cross-subnet (Extra IPs) configuration.
- Configure the source properties:
| Property | Behavior |
|---|---|
| Stream | The NDI source name as advertised on the network. |
| Audio Channels | Number of audio channels to capture: 0 (no audio), 1, 2, 4, or 8. |
| Color Space | How the NDI stream's color is interpreted. Auto follows the NDI specification: streams above 1920×1080 use Rec. 2020, streams above 720×576 use Rec. 709, smaller streams use Rec. 601. Rec. 601, Rec. 709, and Rec. 2020 are explicit overrides for sources that do not follow the specification. |
| Sync Mode | Off — this source picks its own latency. Maintain — NDI sources of the same frame rate share latency estimation, so multiple feeds from the same sender stay frame-aligned with each other. |
| Audio Latency | Audio buffer size in milliseconds. Available only when Audio Channels > 0. Preset values: 20, 40, 80, 100, 200, 1000. Higher values increase reliability on congested networks at the cost of additional delay. |
- If Audio Channels > 0, configure the Audio Route grid that appears below — maps incoming NDI audio channels to the show's audio buses. The
cueVolumedefault routes the channel through the cue's volume control. - Click OK.
Audio Constraints
Channel count, color space, sync mode, audio latency, and the routing matrix can all be changed later — open the source in the Devices window and click Update. Two constraints to be aware of:
- PCM audio only. NDI capture supports PCM (uncompressed) audio. Compressed audio carried by the NDI stream (MP3, AAC, etc.) is ignored.
- Audio is local-only. NDI-captured audio can only be played by an audio device on the same node that hosts the capture. You cannot route NDI-captured audio to an audio device on a different node.
Resolution Behavior
The NDI receiver delivers frames at the sender's native resolution. See Capture Resolution for how the capture's Width × Height relates to the source.
Multiple Sources
NDI streams are reachable over the network from any node, so a single NDI source in the capture device's list is enough for all rendering nodes. You only need more than one source when the same capture device also has to cover hardware inputs on specific nodes (for example an NDI primary plus a webcam fallback bound to one particular operator node). See Capture Devices → How Capture Devices Work for the full model.
Troubleshooting
For NDI Capture symptoms and fixes (stream not listed, black or frozen capture, wrong colors, missing audio, audio dropouts), see Capture Issues → NDI Capture.
Related
- NDI Output — publish WATCHOUT's rendered output as an NDI stream.
- NDI Video Sources — network-side reference: discovery, Extra IPs, infrastructure, bandwidth.
- Capture Devices — capture model and multi-node source distribution.
NDI® is a registered trademark of Vizrt NDI AB.