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Kiloview N40/N40 Plus with Callaba: NDI workflow, SRT bridge, multiview and recording

May 16, 2026
Iurii Pakholkov, founder of Callaba

Written by Iurii Pakholkov

Founder of Callaba. Building cloud video tools for SRT, RTMP, WebRTC, NDI, live routing, monitoring, recording, and production workflows.

Release: Callaba 8.4

Kiloview N40 and N40 Plus are HDMI to NDI High Bandwidth bi-directional converters. That detail matters because the clean N40 workflow is NDI-first, not direct SRT-first.

If you searched for Kiloview N40 SRT, the practical answer is: do not treat N40 like an all-protocol SRT encoder. Use it as an HDMI ↔ NDI device. If the stream needs to enter Callaba Gateway as SRT, add an NDI-to-SRT bridge or choose a direct SRT-capable device such as N50 or N60.

This guide is written for the search intent behind Kiloview N40 SRT, Kiloview N40 Plus SRT, Kiloview N40 multiview, Kiloview N40 recorder, Kiloview N40 playback, Kiloview N40 NDI and Callaba SRT Gateway.

Quick answer: can I connect Kiloview N40 directly to Callaba Gateway over SRT?

Kiloview N40/N40 Plus is an NDI device, not the right device to configure as a native SRT-TS pusher in the standard workflow. To use it with Callaba Gateway over SRT, create a bridge: N40/N40 Plus → NDI → NDI-to-SRT bridge, for example Callaba Engine → Callaba Gateway. If you need native device-side SRT, use a direct SRT-capable model such as N50, N60 or E3.

Kiloview N40 and N40 Plus with Callaba workflows Infographic showing Kiloview N40 and N40 Plus as 4K HDMI to NDI bi-directional converters, with Callaba Gateway used for SRT ingest, multiview, recording and playback after a bridge or alternate SRT device. Kiloview N40 / N40 Plus + Callaba NDI HDMI converter workflow, with SRT handled by bridge or gateway path N40 / N40 Plus HDMI ↔ NDI High Bandwidth NDI first SRT needs bridge Callaba Gateway SRT ingest, monitor, record, play NDI device SRT bridge Recorder Multiview
N40/N40 Plus is best understood as an NDI device. The SRT part belongs to the bridge or to another SRT-capable device.

What this setup does

This workflow connects an HDMI source or HDMI destination to an NDI network using Kiloview N40 or N40 Plus. If the same source needs to be handled by Callaba Gateway as SRT, do not look for direct SRT settings on N40 first. Use an intermediate NDI-to-SRT bridge or another SRT-capable device.

  • N40/N40 Plus: HDMI input or output in an NDI High Bandwidth workflow.
  • NDI-to-SRT bridge: converts the NDI source into SRT for cloud contribution.
  • Callaba Gateway: receives SRT, then enables browser multiview, cloud recording, playback, routing and downstream delivery.

N40/N40 Plus role: NDI first, SRT second

The main mistake is to configure N40 like an SRT hardware encoder. It is better to treat it as the NDI part of a larger workflow. That keeps the article useful and honest for people who already bought the device and now need a Callaba path.

Kiloview N40 and N40 Plus role map for Callaba workflows Infographic showing Kiloview N40 and N40 Plus as HDMI to NDI High Bandwidth converters, and showing how Callaba SRT workflows need an NDI to SRT bridge or a direct SRT-capable device. N40 is an NDI converter first Good for HDMI ↔ NDI. Not the same setup path as N50 or N60 all-protocol SRT devices. N40 / N40 Plus HDMI input or output NDI High Bandwidth encode/decode Use inside an NDI network. HDMI ↔ NDI Callaba Gateway SRT contribution, monitoring, recording, playback and routing. Needs SRT source or bridge. SRT workflow
N40/N40 Plus solves the HDMI-to-NDI or NDI-to-HDMI part. Callaba solves the cloud SRT workflow after a suitable SRT source exists.

Important distinction: if you need direct SRT from the device to Callaba, N40/N40 Plus is usually not the right Kiloview choice. Use the N40 when the source or destination is NDI. Use N50, N60 or another all-protocol encoder/decoder when the device itself must send or receive SRT.

Before you start

Decide whether the job is NDI-only or Callaba SRT ingest. This choice decides the rest of the setup.

N40 role Decide whether N40 is encoding HDMI to NDI or decoding NDI to HDMI.
NDI discovery Confirm that the NDI source is visible on the intended network before adding SRT.
Bridge location Decide where NDI will be converted to SRT: local workstation, cloud VM, gateway appliance or production system.
Callaba SRT listener Create a Callaba SRT input only after you know which device or bridge will send SRT.
Resolution first test Start with 1080p30 before 4Kp60. This makes bridge and SRT troubleshooting easier.
Audio Confirm HDMI or analog audio on the N40 side, then confirm audio after the bridge and in Callaba.

Bridge workflow: NDI to SRT to Callaba

Use this path when the source starts as HDMI, N40 turns it into NDI, and the production needs that source inside a Callaba SRT workflow.

N40 NDI to Callaba SRT bridge workflow Infographic showing HDMI source to Kiloview N40 or N40 Plus, NDI output to an NDI to SRT bridge, then SRT ingest into Callaba Gateway for multiview, recording, playback and routing. Bridge workflow: N40 NDI to Callaba SRT Use this when the HDMI source starts in NDI but the cloud workflow expects SRT. HDMI source camera or output N40 / N40+ HDMI ↔ NDI NDI → SRT bridge or adapter Callaba SRT ingest + workflow HDMI NDI SRT record/play
The key step is the bridge. Callaba receives SRT from the bridge, not the local NDI source directly in this SRT Gateway workflow.

A typical Callaba SRT listener URL for the bridge output can look like this:

Command 
srt://YOUR_CALLABA_IP:10180?mode=caller&latency=200&streamid=kiloview-n40-bridge-main

Use this as a field-format example only. The bridge, not the N40 itself, sends this SRT stream to Callaba.

Settings table

This table helps keep the NDI side and SRT side separate.

Kiloview N40 NDI and Callaba SRT settings table Infographic listing settings for a Kiloview N40 or N40 Plus workflow with Callaba: NDI device mode, bridge, SRT listener, UDP port, codec, resolution, frame rate, audio and monitoring. Settings to check before going live N40 settings are NDI-side. Callaba settings are SRT-side. Field N40 / N40 Plus Callaba side Why Device roleNDI encoder/decoderSRT input/output routedirection ProtocolNDI High BandwidthSRT after bridgecompatibility Bridgeoutputs NDI streamreceives SRT streamcloud ingest UDP portnot used by NDIopen SRT listenerfirewall Resolution/FPSup to 4Kp60 HDMImatch bridge outputsync CodecNDI streamH.264/H.265 SRTplayer path AudioHDMI / analog pathdetected after bridgemonitoring MultiviewNDI source localbrowser board after SRToperations Recordingsource-side optionalcloud recordingproof
N40 settings are NDI-side. Callaba settings become relevant after a bridge or SRT-capable device exists.
Setting N40 / N40 Plus Callaba side Why it matters
Protocol NDI High Bandwidth SRT after bridge Do not confuse the NDI device with the SRT ingest endpoint.
Device role NDI encoder or decoder SRT input or output route Direction decides the whole workflow.
UDP port Not used by NDI device setup Open SRT listener port The bridge, not N40 itself, sends SRT to this port.
Resolution / FPS Up to 4Kp60 HDMI workflow Match bridge SRT output A bridge can change format, bitrate or codec.
Audio HDMI or analog audio path Detected after SRT ingest Audio must be confirmed after the bridge, not only on the NDI side.

N40 multiview workflow with Callaba

N40 can create or receive an NDI source, but Callaba multiview becomes relevant after the feed reaches Callaba as a supported live input. In an SRT Gateway workflow, that means the NDI source must first be bridged into SRT.

Interactive check: open the Callaba multiview demo to see how a received source can look after cloud ingest. Your N40 source would appear there only after it enters Callaba through a bridge or a supported ingest path.

N40 recorder workflow: NDI source vs Callaba cloud recording

The N40 side and the Callaba side protect different points in the workflow. N40 handles the HDMI ↔ NDI conversion. Callaba records what actually arrived after the NDI-to-SRT bridge or another ingest path.

Layer What it verifies Use case
NDI/source-side check That HDMI reached the NDI network correctly. Use during local setup and source validation.
Callaba cloud recording That the bridged SRT stream actually reached Callaba. Use when you need cloud-side proof of the received workflow.

N40 playback workflow with Callaba

Playback also has two meanings. N40 can decode NDI to HDMI inside the local NDI network. Callaba playback means browser player, HLS output, embed link or a cloud route after Callaba receives the stream.

Install steps 
HLS playlist after Callaba ingest:
https://YOUR_CALLABA_DOMAIN/hls/kiloview-n40-bridge-main/playlist.m3u8

Player or embed page:
https://YOUR_CALLABA_DOMAIN/embed/kiloview-n40-bridge-main

Where the links come from: Callaba generates these links after you create a web player or HLS packaging path for the incoming bridged stream. Depending on your configuration, links may include temporary tokens or authorization parameters.

Troubleshooting

Most issues come from mixing up NDI and SRT responsibilities. Check the NDI side first, then the bridge, then Callaba.

Kiloview N40 to Callaba troubleshooting path Troubleshooting path for Kiloview N40 and N40 Plus workflows with Callaba: check whether the workflow is NDI or SRT, verify HDMI signal, NDI discovery, bridge output, SRT listener, codec, audio and Callaba preview. Debug N40 + Callaba in this order First prove NDI. Then prove the bridge. Then prove SRT ingest in Callaba. 1. Protocol NDI or SRT path? 2. HDMI input / output 3. NDI discovery / source 4. Bridge NDI→SRT 5. SRT listener / port 6. Media codec and audio 7. Callaba preview / record / route
Do not debug Callaba first if the NDI source is not visible. Prove the local NDI path, then prove SRT ingest.

1. No SRT connection in Callaba

  • Confirm the SRT sender is the bridge or another SRT-capable device, not the N40 itself.
  • Confirm Callaba is listening on the expected UDP port.
  • Check stream ID, passphrase and latency on the SRT sender.

2. NDI source is not visible

  • Confirm N40/N40 Plus is in the correct encoding or decoding mode.
  • Check HDMI signal, NDI discovery and network segment.
  • Confirm the bridge can see the same NDI source.

3. Connected, but no picture in Callaba

  • Check the NDI-to-SRT bridge output codec.
  • Start with H.264 and 1080p30 before testing 4Kp60.
  • Check audio mapping after the bridge, not only on the HDMI or NDI side.

Official references used for this guide

Use these if you need exact N40/N40 Plus device role, NDI behavior, HDMI limits, firmware notes or SRT background before configuring a production workflow.

FAQ

Can Kiloview N40 send SRT directly to Callaba Gateway?

Treat N40/N40 Plus as an NDI High Bandwidth HDMI converter, not as the normal direct SRT device in this workflow. To use Callaba SRT Gateway, add an NDI-to-SRT bridge or choose a direct SRT-capable Kiloview device.

Can I use N40 with Callaba multiview?

Yes, but not by sending NDI directly into an SRT listener. The N40 source must first become a supported Callaba input, for example through an NDI-to-SRT bridge. After Callaba receives the stream, it can be placed in browser multiview.

Can Callaba record a Kiloview N40 source?

Yes, after the N40 source enters Callaba through a supported ingest path. In an SRT Gateway workflow, this usually means the NDI output is bridged into SRT first.

How do I bridge N40 NDI to Callaba SRT?

Use a Callaba Engine instance, OBS/FFmpeg test bridge, or another NDI-to-SRT bridge. The bridge receives the N40 NDI source and sends SRT to a Callaba Gateway listener.

Should I use N40 or N50/N60 for direct SRT?

Use N40/N40 Plus when the job is HDMI ↔ NDI. Use N50, N60 or another all-protocol device when the hardware itself must send or receive SRT directly.

Final practical rule

Do not force N40 into the wrong role. Use N40/N40 Plus for HDMI ↔ NDI. Use Callaba Gateway for SRT ingest, monitoring, recording and playback after the stream becomes SRT through Callaba Engine, another NDI-to-SRT bridge, or direct SRT-capable hardware.

Last updated: May 16, 2026

Try Callaba Gateway with your NDI-to-SRT workflow

Create an SRT listener in Callaba, send your bridged N40/N40 Plus source to the gateway, and monitor the feed before routing it to recording, restreaming, multiview, playback or player delivery.

See SRT server setup Open multiview demo Explore NDI workflows