Zero configuration in AV signal distribution

One of the biggest issues in AV distribution in the IP world is that equipment is not identifiable by its physical connection. In networking, every connected device needs to have a unique address so another device, hardware, and applications can reach it.

However, the network physical connection is dynamic and not related at all to the equipment address. For that reason, in a large network with hundreds (or thousands) of devices with addresses, it becomes difficult to find and interconnect equipment. NDI offers two different options for a zero-configuration discovery and registration: mDNS and Discovery Service.

This White Paper offers a compressed overview of NDI: its fundamental principles, technological features, protocols, and settings. It is updated in real-time by the NDI team to reflect the most recent developments to our Core Tech Platform. The current version of NDI is 6.3

Introduction to NDI

NDI stands for Network Device Interface. It is a widely adopted video connectivity standard based on proprietary IP networking specifications. NDI enables multimedia systems to identify and communicate with one another over IP and to encode, transmit, and receive many streams of high-quality, low latency, frame-accurate video and audio, and exchange metadata in real-time.

NDI operates bi-directionally, with many streams on a shared connection. Its encoding algorithm is resolution and frame-rate-independent, supporting 4K resolutions and beyond, along with unlimited floating-point audio channels and custom metadata. NDI can be integrated and/or supported by any network-connected product, including video cameras, graphics systems, video mixers, capture cards, multimedia players, video editing applications, and many other devices and software. NDI

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🚩News

Feb 17, 2026

NDI 6.3.1

Jan 21, 2026

is now available! NDI 6.3 expands our discovery, monitoring, and control architecture bringing real-time insight and management to mid-to-large NDI networks. Review the for specific details

Dec 31, 2025

We are sunsetting our HX License Upgrade program. Please see this page for more details

Oct 1, 2025

Sep 11, 2025

Windows has a released a patch for the unexpected drop in traffic on . The patch is currently available for both Windows 10 and 11. Please see our article for more information about the original issue. You can also find more information on the

Sep 14, 2025

We’ve made the tough call to discontinue NDI Remote and take the service offline. This decision comes after identifying performance issues that can’t be quickly addressed. That said, we’re already exploring a more reliable way to bring Remote back in the future. We’ll share updates as soon as we have them. If you have questions or need a hand planning a workaround, please reach out through the proper channel. Our team’s here to help!

🆕Release Notes

NDI 6.3.1

Fixed

• Potential deadlock issue in the new discovery server with sources for older versions

• Rare rash in on Mac when enabling NDI output and allowing network access

• Issue where fails to auto launch at starup if the selected source is unavailable

NDI 6.3.0

NDI Tools

Sender Monitoring Enhancements: The now includes sender discovery and monitoring on both Windows and macOS.

Default Sender Monitoring Support: Enabled by default in existing sender-based NDI Tools apps.

• : NDI Test Patterns, NDI Screen Capture, NDI Screen Capture HX, NDI VLC Plugin.

• : NDI Test Patterns, NDI Scan Converter.

NDI Discovery Server Improvements: Enhanced capabilities. The NDI server utility is now available as a standalone installer for Windows and Linux and can run as a service. See for setup details.

Fixed

• Fixed an issue in the NDI plugin for Adobe Premiere where the field sequence was incorrectly displayed when playing SpeedHQ progressive clips in interlaced sequences.

• Resolved poor NDI HX encoding performance on AMD GPU/CPU systems in and .

• Fixed NDI Virtual Input on macOS failing to receive video when connected via and .

NDI SDK

New APIs: Introduced APIs for , designed for integration with the NDI Discovery Server. See documentation for details.

Performance Improvements: Enhanced codec quality across multiple generations.

Enabled passthrough of the NDI capabilities message from NDI receiver to the NDI sender.

Enhanced Receiver Passthrough Control: Introduced per-codec passthrough override control via receiver creation JSON in the NDI Advanced SDK, enabling selective decompression of compressed formats. Please refer to the SDK documentation for details.

Improvements to . Please refer to the files for more details.

MAC (Media Access Control) address refers to a unique physical address identifying a network node. Sending and receiving video streams across an IP network requires applications that support video and can discover receiving applications that are looking for video.

NDI resolves host names to IP addresses over the LAN and does so automatically. When you start an application that sends NDI, the devices that can receive NDI become aware instantaneously. While this is a typical function on almost all networks, there are some cases where it is important to know how this works to properly configure networks utilizing managed data flow protocols.

NDI is designed for use with standard consumer off-the-shelf (COTS) network infrastructure devices. Looking closely at the network topology and configuration will help to ensure that the maximum possible bandwidth is available.

When selecting a network switch, it is important to check the throughput speeds. Ensure that each port is full duplex (i.e., bi-directional communication) and that each port's upstream and downstream data speeds are at least 1 Gigabit per second (Gbps). In some cases, it is best to force the ports on managed switches to utilize 1 Gbps in contrast with Auto-Negotiation. The use of Auto-Negotiation can sometimes (mostly because non fully compatible Network Interfaces) result in 100Mb connections or even lower, which does not renegotiate until the port is flooded with traffic for some time. Also, poor termination of RJ-45 connectors can impact Auto-Negotiation.

The same suggestion applies when considering network switches that include 10 Gigabit per second ports. Many switches manufactured at the time of writing may share bandwidth across the backplane of multiple ports. Since these ports are generally reserved for linking to other switches, the specification for throughput may be listed differently than the Gigabit port section in the product documentation.

It is best to use switches from the same manufacturer, or ideally, the same model of switch, throughout a single subnet. This will simplify configuration and lessen the chances of compatibility and configuration issues.

Video, just like voice data in VoIP systems, is a very demanding data stream and will immediately expose a weakness in a network. The network must support multiple video, audio, and data streams in a reliable, synchronized manner without disruption. When delay, packet loss, and jitter reach thresholds where the video is impacted visually, the usefulness of that video drops to zero. It is important to understand the complexities of video in IP data networks to mitigate these factors.

Networks that are designed to move NDI video streams should be thought of as being primarily utilized for video. IP networks are, by their very nature, “best effort delivery” systems and were originally developed for the transport of data. By contrast to video, data services can function happily with packet retransmissions, lost packets, and even packets arriving out of order.

Video streams, while still composed of data, are much more rigid in their requirements. With the use of modern networking equipment and proper configuration, video can move across networks whilst still obtaining low latency, frame accuracy, and high-quality requirements necessary for live video production.

Audio is at the heart of countless applications, from media production to live broadcasting, and understanding the principles behind its digital transformation is key to unlocking its full potential.

This guide explores how NDI leverages digital audio technology to enable seamless, high-quality audio transmission over IP networks. Beginning with the fundamentals of digital audio, we'll delve into the technical aspects of NDI audio, its real-world use cases, and the innovative products driving this revolution. Whether you're an audio engineer or a curious enthusiast, this guide will provide a comprehensive look at the role of NDI in reshaping modern audio workflows.

Contents

Our certified devices are tested to ensure interoperability with all other certified produces. Please check the Product Finder on our website to search for products that have been certified.

NDI operates most efficiently in a dedicated network with high bandwidth and high availability. This contrasts with unmanaged environments such as the public Internet or networks where video rides along with data without priority.

Gigabit (1000 Mbps) networks are essential in production workflows. A typical NDI stream consisting of 1080 60P video yields a data rate up to 150 Mbps per stream. This extremely efficient stream is designed to have very low latency and allows multiple streams to be stacked together on a single Gigabit network. Even so, a production environment may require more capacity based on a simultaneous number of NDI streams required.

The following tables are intended to calculate bandwidth needs based on video resolutions and frame rates. It should be noted, however, that NDI is not deterministic. The bandwidth needed for NDI should be based on the determination of the average utilization required.

One approach to manually interconnect NDI devices is to specify the IP address of the transmitter in the receiver.

In Windows and MacOS, this can be achieved using the NDI Access Manager in the External Sources feature. Several NDI hardware decoders also support this functionality.

For Linux, the IP addresses of NDI senders can be added manually in the NDI configuration file called "ndi-config.v1.json." This file is in the home directory of the user currently logged in.

Specifying the IP address of an NDI source allows the receiver to receive NDI sources that are in a different

NDI groups enhance the efficiency and management of NDI-based workflows by providing a structured way to organize and control the visibility and access of NDI sources and destinations within a network.

NDI devices support two different kinds of Groups: Send and Receive.

A device can be part of different Groups, some Groups only in the Send or Receive mode:

The ways in which NDI is currently utilized — and can continue to be utilized — to connect are virtually limitless. This is primarily due to two factors: (1) our ongoing development of the features and capabilities of our Core Technology and (2) our community of users exploring and implementing NDI-based solutions. From professional broadcast studios to homemade streaming setups, NDI can be applied in any situation where a multimedia connection is needed. Despite the wide range of scenarios, users are consistently seeking certain performance standards, such as high-quality audio and video, low latency, and plug-and-play setups.

Learning how to use multicast is one of the most frequently explored topics within our community. To support this interest, we've gathered a collection of resources to learn more about implementing multicast with NDI. Whether you're just starting to explore multicast or looking to refine your existing setup you can check out the section in our , the guide for , or our articles on how to use NDI multicast with offer in-depth information and practical advice. You can also ask questions in the forums or take our NDI basics course via the . These resources are tailored to help you achieve optimal performance, ensuring high-quality audio and video, minimal latency, and seamless integration into your workflows.

This space includes a variety of reference guides, best practice documents, and step-by-step tutorials for using NDI. Our goal is to offer valuable information for anyone looking to connect their setups and workflows with NDI. We are committed to continuously updating this resource and adding new educational content to reflect the latest developments in our technology and its application within our community.

Today, millions of professional and amateur users leverage NDI-enabled devices and software to maximize IP for audio and video connectivity. In addition to developing the core technology that provides the connectivity features and infrastructure for this ecosystem of products, we recognized the importance of facilitating the operation of NDI workflows and setups.

Hence, we created NDI Tools, a collection of simple yet powerful free software applications designed to introduce anyone, from end users to professional installers, to the world of NDI connectivity and video over IP.

NDI tools work on most computers and are . Our team is committed to improving all our tools by releasing that make each tool even more powerful and valuable. This space contains all documentation and educational content related to NDI Tools. We continuously review it to reflect the most recent developments and updates.

NDI is designed to enable successful video transport using the default configuration of network interface drivers; however, most recent network interface drivers do support the configuration of advanced properties that can help optimize NDI transmission.

Consider the following adjustments but note that adjusting individual adapters can significantly affect performance and reliability positively and negatively. It is important to consider testing performance with a network analyzer before and after each setting change. The following adjustments are intended to help; however, performance will depend on network and usage (names and available settings vary between vendors, adapter models, and even between different driver versions):

Speed and Duplex

NDI Utilities are standalone applications designed for specific purposes within NDI-based workflows or for integrating our technology into products. Unlike the NDI Tools, which feature a closed user interface (UI), these Utilities are meant for more flexible uses and exploration. Some of them may only be operated through a command-line terminal.

By default, an NDI Sender has the capability to generate two types of streams: a full-quality stream and a proxy stream. A receiver can readily activate the . A simple way to visualize a proxy stream is by utilizing NDI Studio Monitor and enabling the Low Bandwidth mode within the Video settings menu.

The Proxy stream serves as a means for an application to enhance the efficiency of NDI distribution across the network. For instance, an NDI-based Video Mixer can leverage the proxy stream for sources that are intended for use in a preview monitor rather than an actual output. Then, when a source is transitioned to an output, the application can seamlessly switch from the proxy stream to the full bandwidth stream.

This approach empowers receivers to effectively manage a more significant number of NDI sources while utilizing less network bandwidth.

The NDI Glossary provides clear definitions and explanations of key terms and concepts related to NDI technology as well as more general industry standard terms for AV over IP. We provided this to serve as a reference to help you navigate and understand the terminology used throughout the NDI ecosystem.

NDI offers a range of plugins designed to integrate our powerful connectivity technology seamlessly into popular creative applications. These plugins include NDI for After Effects, Premiere Pro, Output for Final Cut Pro, NDI for VLC, and Audio Direct. Each plugin enhances the flexibility and efficiency of your production pipeline, bringing the power of NDI directly into the tools you use every day.

Reliable UDP – NDI 5

In NDI version 5 the default communication mechanism is a Reliable UDP protocol that represents the state-of-the-art communication protocol that is implemented by building upon all the experience we have seen in the real world with NDI across a massive variety of different installations

Reliable UDP, also known as RUDP, is a transport protocol that combines the advantages of UDP's low latency and simplicity with the reliability of TCP (Transmission Control Protocol). It is designed specifically for real-time multimedia applications, where maintaining the timeliness of data is crucial.

In the context of NDI, Reliable UDP is employed to ensure that video and audio streams are delivered reliably and with minimal delay. It achieves this by implementing several mechanisms:

Sequencing: Reliable UDP assigns a sequence number to each packet it sends. This allows the receiving end to detect missing or out-of-order packets and request retransmissions if necessary.

Retransmissions: If a packet is lost or arrives out of order, the receiving end can request a retransmission of the missing packet(s) using the sequence number information.

Flow control: Reliable UDP incorporates flow control mechanisms to manage the rate of data transmission. This prevents overwhelming the network or the receiving device with more data than it can handle, ensuring a smoother streaming experience.

Congestion control: RUDP also includes congestion control algorithms to prevent network congestion and avoid unnecessary packet loss. It dynamically adjusts the transmission rate based on network conditions, maintaining optimal throughput without overwhelming the network.

Multipath TCP – NDI 4

This protocol permits transport across multiple NICs and all network paths, it is intended to use hardware-accelerated network adapters with adaptive bandwidth sharing across NICs.

Multipath TCP is a transmission protocol that offers advantages such as maximizing throughput, optimizing resource usage, and enhancing network redundancy. It can seamlessly integrate multiple network pathways, including wireless and mobile networks. It is especially efficient when used with NDI equipment that utilizes multiple Gigabit connections to exchange a large number of NDI streams.

However, in scenarios where 10Gbit interfaces are connected with 1Gbit interfaces, Multipath TCP's efficiency is compromised. This is primarily due to network switches being unable to effectively manage network congestion in such situations. As a result, the protocol may not perform optimally in these specific network configurations.

UDP with Forward Error Correction – NDI 3

This alternative protocol to TCP is used when reliable delivery of data packets is not required. UDP is typically used for applications where timeliness is of higher priority than accuracy, such as streaming media, teleconferencing, and voice-over-IP (VoIP). Forward error correction (FEC) is a method of obtaining error control in data transmission in which the source (transmitter) sends redundant data to the destination (receiver).

UDP (User Datagram Protocol) with Forward Error Correction (FEC) is a beneficial approach when the network is prone to errors or not entirely reliable. It provides a solution for error correction when data packets get lost or corrupted during transmission.

However, it's important to note that using UDP with FEC requires additional computational processing on the receiver side. The receiver needs to implement algorithms and mechanisms to manage the error correction process. This involves decoding the received data and applying error correction techniques to recover any lost or corrupted packets.

Single TCP – NDI 1

This network communications protocol enables two host systems to establish a connection, exchange data packets, and ensure data is delivered intact to the correct destination. TCP is typically grouped with IP (Internet Protocol) and is collectively known as TCP/IP.

Single-TCP is supported on all NDI versions. While the other transmission modes are likely to perform better, this mode offers baseline compatibility for all NDI clients.

What is digital audio?

Digital audio refers to the representation of sound in a digital format, wherein audio signals are converted into a series of binary numbers that can be stored, transmitted, and manipulated by electronic devices such as computers and audio processors.

Unlike analog audio, represented by continuously varying electrical signals, digital audio breaks down sound into discrete samples at regular intervals, typically measured in thousands of samples per second (expressed as KHz). Each sample captures the amplitude of the audio waveform at a specific point in time, allowing for precise reproduction and manipulation of sound.

Digital audio has revolutionized how we record, edit, transmit, and reproduce sound, enabling unprecedented levels of fidelity, flexibility, and convenience in a wide range of applications, from music production and broadcasting to telecommunications and multimedia entertainment.

Conversion process

Recording or converting sound into a digital format involves two primary steps: sampling and quantization.

Sampling

Sound is a continuous analog wave. To digitize this sound, it is sampled at discrete intervals. The sampling rate, measured in Hertz (Hz), defines how many times per second the sound is sampled. A common sampling rate for CD-quality audio is 44.1 kHz, meaning the audio is sampled 44,100 times per second.

In broadcast video production, the sample rate is 48 kHz; for high-quality audio recording and mastering, the sample rate can be up to 768 kHz.

Quantization

Once sampled, each snapshot of the sound's amplitude is converted into a digital value. This process is known as quantization. The bit depth determines the resolution of this conversion, with higher bit depths allowing a more precise representation of the sound's amplitude. Common bit depths include 16-bit, 24-bit, and 32-bit.

Audio formats

In addition to the fundamental concepts of sampling and quantization, understanding digital audio involves familiarity with various audio file formats. These formats can be categorized into two main types: uncompressed and compressed.

Uncompressed Formats

These formats store digital audio data without any compression, preserving the original quality of the audio. Common uncompressed audio formats include:

WAV (Waveform Audio File Format): Developed by IBM and Microsoft, it's a standard format for storing audio on PCs.

AIFF (Audio Interchange File Format): Developed by Apple, similar in quality and structure to WAV, commonly used on Mac computers.

Compressed Formats

Compressed formats store audio data using algorithms that eliminate redundant or less audible information to reduce file size. Compressed formats can be lossless or lossy.

Lossless Formats: These compress audio data without losing any information, allowing the original audio to be perfectly reconstructed from the compressed data. Examples include FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec).

An NDI Bridge executable can also be launched using the following command line arguments:

/verbose Generates extensive log entries in Windows Event Logs, with the event source labeled as "NDI Bridge."

/host Initiates Bridge in host mode.

/join Launches Bridge in join mode.

/local Starts Bridge in local mode.

/autorun Minimizes Bridge window upon startup.

/noui Suppresses the display of any user interface elements and prevents the creation of a taskbar icon.

For example, you can use /local /autorun to initiate the Bridge in local mode and minimize it. Similarly, /local /noui will start the Bridge in local mode without any user interface. If you use /autostart without specifying /host, /join, or /local, the Bridge will start in the last selected mode.

If you prefer to configure Bridge using a configuration file, you can find the settings in AppData\Local\NDI\Application.NDI.Bridge.UI\bridge_settings.json.

Most setting names are self-explanatory, except for "selected_tab," which serves as an index field to indicate the last selected tab (mode) the user used (0 = host, 1 = join, 2 = local).

All settings for each mode are present in the same file, so you may need to adjust your logic to target the correct settings for the appropriate mode (e.g., "host_model," "local_model," "join_model").

NDI transmitters and receivers do not require any specific synchronization method to connect and function. An NDI infrastructure can operate “sync-free”, avoiding the complexity and cost of network systems that support synchronization layers. However, for specific use cases, developers and hardware manufacturers have several approaches to achieve synchronization.

When processing multiple video streams in production workflows, it may be necessary to synchronize all video streams to the same frame rate, with their frame start times aligned.

For physical video sources (e.g., cameras or video output cards) that have a fundamental native video timebase, synchronization is achieved through genlocking the internal video timebase to a reference signal, typically a blackburst signal.

For software-only implementations (e.g., character generators, DDR playback, graphics rendering engines) that lack an inherent internal video timebase, multiple platforms can maintain the same frame rate by locking system clocks using NTP, PTP, or similar protocols. However, even with locked system clocks, frame start times will not align across different applications since each application initializes its frame processing independently.

NDI Genlock

NDI Genlock provides a solution for software applications that lack an internal video timebase by allowing them to use an NDI signal as a timing reference. The Genlock instance connects to any visible NDI sender on the network and synchronizes the frame rate and frame start times to the selected source. The NDI source can reside on a local network, a remote network, or in the cloud.

To ensure proper operation of an NDI source as a Genlock reference, the following conditions must be met:

NDI Version Compatibility

It is strongly recommended that the NDI source stream originates from NDI version 5 or higher, which includes significant enhancements for genlock support. Older NDI streams may not fully comply with NDI genlock operations.

Network Bandwidth

The NDI source must have sufficient network bandwidth to provide the genlock stream to all NDI receivers. Configuring the source with multicast may help optimize bandwidth usage.

Cross-Frame-Rate Locking

NDI Genlock supports cross-frame-rate locking, where, for instance, a 60Hz signal can synchronize to a 30Hz sender. However, this is not a recommended workflow and should be avoided if possible.

Irregular Frame Streams

Some NDI sources, like the Test Pattern Generator and NDI Screen Capture, may not send a regular frame stream. These sources optimize CPU usage and save network bandwidth by skipping frames, making them unsuitable as genlock references.

Fallback Mechanism

If the NDI Genlock clock cannot successfully synchronize with the NDI sender, it will automatically fall back to using the system clock. While this fallback is not as precise, it allows video processing to continue with reasonable performance.

Setting up an NDI-based video production in a Virtual Private Cloud is quite easy; the first step is to define how to make NDI Discovery and Registration work in a VPC. Cloud providers allow the creation of a multicast domain; multicast is required to use mDNS-based discovery and registration. This setup requires the creation of a transit gateway with multicast enabled. Enabling multicast in the cloud might require specific knowledge; for this reason, the easiest solution to enable NDI Discovery and registration is to set up a Discovery Service. NDI Discovery Service requires just a basic Windows or Linux-based instance to run.

Looking for the OBS plugin? While NDI does not have an official OBS plugin you can download the unofficial one following the directions from our Getting Started with OBS guide.

NDI supports multicast-based video sources using UDP with forward error correction. Multicasting allows a single NDI source to be delivered to multiple receivers by replicating the NDI packets from the sender to any number of receivers.

For successful multicasting, IGMP is mandatory. IGMP allows the receiving NDI systems to request access to the sender. Without IGMP querying and snooping, Multicast traffic is treated the same as broadcast transmission, resulting in packet forwarding to all ports on the network. With IGMP snooping, multicast NDI traffic is forwarded only to the receivers that subscribe to the multicast NDI stream.

NDI subscribes to a multicast group and will unsubscribe when that stream is no longer needed. A routing querier on the network handles the management of multicast subscriptions. If multicast is enabled on the sender, the receiver is going to prioritize multicast receive over unicast.

While video and audio data are delivered to the network via multicast delivery, each receiver also connects to the sender via a unicast TCP connection for bi-directional communication of metadata (e.g., PTZ control, tally, etc.)

Basic multicast settings can be enabled in the NDI Access Manager on Windows and Mac machines.

In Linux, Multicast can be configured in the NDI configuration file located in the home directory of the effective user: "ndi-config.v1.json"

Here is the way to set up Multicast in the configuration file:

When multicast receiving is enabled, and a sender is available in the same local network, the receiver can negotiate for a multicast stream to be sent. If the sender is not on the same local network, this negotiation does not occur (since it could lead to a multicast stream being sent but never able to arrive at the receiver).

Suppose the network is correctly configured and can ensure a multicast stream to route reliably from a different network to the receiver’s local network. In that case, it is possible to specify the sender’s subnet in the “subnets” setting of the "ndi-config.v1.json" to allow multicast negotiation to occur.

These settings pertain to the multicast NDI setting on this machine. The first setting determines whether multicast sending is enabled or not.

By default, multicast sending is disabled. Next is the IP address prefix and mask. In this example, multicast IP addresses will be chosen in the range 239.255.0.0 - 239.255.255.255. NDI will attempt to use different multicast addresses to ensure that the streams can be filtered efficiently by the network adapter.

NDI senders need a range of multicast addresses available.

The TTL value controls how many “hops” the multicast sending traffic will take, allowing it to move outside the local network.

Live Streaming and Broadcasting (Sports, News, etc.) commentary and comms

There are several use cases in the production of live events, such as sports and news, where NDI Audio can be utilized with great benefits. In sporting events, for example, the entire audio flow for commentary, where neither latency nor synchronization represents a real problem, could be managed using NDI with the advantage of distributing all the service video signals using the same technology. Another example of its use is audio communications like Intercoms. In this case, NDI also offers the advantage of infrastructure simplicity and, above all, the ability to be supported by software applications rather than dedicated hardware. Moreover, NDI works on wireless networks, thanks to NDI Bridge over WAN.

Webinars and Remote Training

In these use cases, neither latency nor synchronization are blocking issues. What's essential are the ease of use and the ability of NDI to operate over the internet and wireless networks. NDI-based devices, such as the Mackie DLZ Creator, are excellent examples of products designed for these markets.

Remote Production (REMI) and Cloud Production

In these use cases, the features of NDI are of immense value:

• With , multichannel audio streams can be distributed and shared over the Internet. NDI is natively unicast, which is the perfect solution for the cloud.

• NDI does not require strong synchronization technology; PTP cannot operate over the Internet or in the cloud.

Even in these use cases, a technology allowing software-only solutions represents a significant advantage over competing technologies.

Furthermore, NDI also supports video and metadata, enabling the creation of a complete workflow with a single technology.

Public Address (PA) System

In this case, NDI's achievable latency does not represent a problem, and thanks to multicast's support, NDI can be easily implemented to provide audio streams to many receivers.

Another immense advantage of NDI in this market is its operation over wireless networks, a unique feature compared to other technologies that allow for the distribution of audio signals where a wired infrastructure is not possible.

Home Entertainment (High Fidelity Audio)

NDI is extremely plug-and-play. The audio quality is perfectly compatible with high and very high-quality digital entertainment systems.

Discovery and Registration, especially based on the NDI Discovery Server, are much more efficient and reliable than other mDNS solutions.

In NDI, the receiver defines which source to use, which is exactly like a radio tuned to a broadcasting station. This is consistent with the normal user experience. Furthermore, no transmitter can unexpectedly connect to a receiver, a very common problem with AoIP for home entertainment solutions used today.

Wireless Audio

NDI Audio represents a winning solution in all applications with a wireless connection. Compared to other Audio Over IP technologies, NDI is less sensitive to the Wi-Fi network jitter and does not require a synchronization like PTP that can’t work over wireless connections.

With NDI, multiple audio channels can be multiplexed into a single transmission while maintaining synchronization. This is a huge advantage over other AoIP technologies.

NDI Discovery is a tool that enables you set up and manage Discovery Servers within workflows. We cover the capabilities of Discovery Service in depth in our White Paper.

Accessing NDI Discovery

. After installing it, access NDI Discovery from the or your applications folder.

Once you've installed Discovery check out our guide. For high level introduction on how Discovery works read on Receiver Discoverability, Monitoring, and Control.

Senders

Displays all NDI sources (“senders”) that have registered with the Discovery Server. Each sender entry shows its device name/hostname, the network address, and port it is streaming from. Devices appear grouped by hostname. This tab helps you quickly see which NDI devices are currently available to provide streams on your network.

As of NDI 6.3, this view also includes senders registered using the new NDI Sender Advertiser APIs. These APIs extend discovery support to senders, coexist with the legacy advertisement system, and enable improved visibility into sender properties and events when used with the Discovery Server.

Receivers

Shows all NDI receivers (endpoints listening for NDI streams) recognized by the Discovery Server. Devices are also grouped by hostname under receivers. This is especially useful when troubleshooting or confirming which machines are actively listening for NDI streams.

Settings

You can configure or change the Discovery Server IP and port. You can also see whether the application is connected to a Discovery Server and at which IP/port.

For first time set up, when using with for the first time be sure to select the Allow Receiver Advertising and Allow Receiver Control from the settings

(2) A VCU, or Video Codec Unit, is a specialized hardware module or component designed to handle the encoding and decoding of video streams. Note that the term VCU seems to be mainly used by AMD for their Zynq series of FPGAs. For instance, other SoCs such as Ambarella just call it a codec. The primary function of a VCU is to efficiently compress (encode) raw video data to reduce its size for storage or transmission and decompress (decode) video data for playback. By performing these operations in hardware, a VCU can significantly speed up video processing tasks, reduce CPU load, and decrease power consumption, which is especially beneficial in devices where power efficiency and high-performance video processing are critical. Integrating a VCU within a System on Chip (SoC) or as part of a dedicated video processing card allows for efficient handling of video content, making it a critical component for multimedia applications and devices in today's video-centric digital world.

(3) An FPGA-based encoder/decoder requires an SoC to be able to offer the user interface, the memory, the network interface of the system, etc.

Apple has turned off a feature called "legacy camera support" however it can be re-enabled in Recovery Mode by following these steps from Apple: https://support.apple.com/en-us/HT213969

When you restore these legacy settings, the camera privacy indicator won't display in the menu bar while a camera with older software is in use.

1. Restart your Mac into Recovery Mode:

   • Use macOS Recovery on a Mac with Apple silicon

2. Click the Options button, then click Continue.

3. From the Utilities menu, choose Terminal.

4. Enter this command: system-override legacy-camera-plugins-without-sw-camera-indication=on

5. Press Return. Depending on your system configuration, you might be prompted to complete additional steps.

6. Quit Terminal.

7. From the Apple menu, choose Restart.

To change back to the default settings, follow the steps again and enter this command:

system-override legacy-camera-plugins-without-sw-camera-indication=off

As a technology designed to connect video, ensuring interoperability across all NDI products—both hardware and software—is one of the fundamental principles that NDI strives to uphold for its growing user community.

In this guide, we will explore how NDI can connect video while maintaining interoperability and consistent performance at the heart of any workflow. We will cover some of the basics of digital video and explain the various ways NDI-enabled devices and NDI formats can work together to create a seamless networking environment.

Contents

On Mac

1. You will first need to insure that you have installed the NDI SDK. By default it will install to Library

2. If you did not change the install location, open on MacOS and enter the following command:

1. A separate Terminal window will open with NDI Discovery Service running. If a different directory was chosen to install the NDI SDK to, replace 'Library' with your chosen directory path.

1. On the NDI Sender, open , and enter the IP address of your Mac and the Port Number

NDI Scan Converter is an application designed to effortlessly share your computer's desktop video and audio with any other device on your network through an NDI stream.

Whether you're conducting broadcasts and presentations, collaborating on projects, creating tutorials, or engaging in media playback, Screen Capture provides a valuable solution.

Accessing NDI Scan Converter

and run NDI Scan Converter from the or your applications list.

Sharing Your Screen

The tool will appear in your system tray with the NDI logo. Upon launch, your computer's desktop video and audio are viewable from any NDI-enabled device on your network.

Viewing on NDI-Enabled Devices

View the output of Screen Capture on another NDI-enabled device using an application like

Right-click on the screen and select the device name and corresponding NDI stream.

Desktop or Application Selection:

• On the File top level menu, you can select which will be the source of your NDI stream. Select either Desktop to capture your entire desktop or choose a specific application window.

System Audio Input Configuration:

You can mute audio capture by clicking Mute Audio, which can be found on the Settings top-level menu.

Choose the desired system audio input for capturing sound along with your video in your MacOS Sound settings.

MacOS System Audio not Captured via NDI Scan Converter

1. Install or update:

   • OBS Studio 30 or newer

   • Distro AV NDI plug‑in for OBS

   • NDI Tools 6.1.1 for Mac — be sure to tick “Virtual Input” during setup and allow its Camera and Microphone extensions when macOS asks.

2. In OBS open Tools then NDI Output Settings, enable Main Output, give it a name, and click OK.

3. Launch NDI Virtual Input (in Applications > NDI). From its menu‑bar icon choose the OBS feed. Restart the app if you just approved permissions.

4. Open Zoom (or Google Meet, Teams, etc.).

   • Pick NDI Video for camera.

   • Pick NDI Audio (or “NDI Virtual Input”) for microphone. If the virtual mic is missing, reinstall NDI Tools and reboot.

Issue: When using by itself, the video signal is transmitted over NDI, but the audio is silent or only captures the system microphone. This is expected behavior.

Solution: Use an audio loopback tool to route system audio into the NDI stream:

• (deprecated)

After installation:

1. Follow the tool’s instructions to route system output to a virtual input.

2. Launch .

3. Ensure audio is not muted in the Scan Converter menu.

1. Download and Install OBS Studio

   1. Install OBS Studio version 30.0.0 or later (Qt6, x64/ARM64/AppleSilicon) on all relevant machines from https://obsproject.com.

2. Install the NDI plug in for OBS

   1. Download the DistroAV NDI plugin from .

   2. Before installing, remove any old versions of the OBS-NDI plugin to prevent conflicts.

   3. Install the plugin after OBS Studio is installed.

3. Install NDI Runtime

   1. Download and install the NDI Runtime version 6 or later as shown here: .

4. Enable NDI Output in OBS (on the source computer)

   1. Open OBS Studio

   2. Navigate to Tools > Distro AV NDI® Settings

NDI HX3 stream specifications:

GOP size must be 20 frames Glass-to-Glass latency, less than 100ms I Frame request response, less than 80ms

In more complex networking cases, ports may need your attention.

To extend beyond the local network, applications (such as NDI Bridge) use network communication ports. Connecting to a local application from an external network requires targeting the correct port, and that your network router is set up to accept traffic at that port.

This is much like an office with one main telephone number, but many extensions. On a WAN like the Internet, the ‘public IP number’ corresponds to the main telephone number. Your firm provides a list of extension numbers, each matching one phone. Likewise, your network router exposes certain ports for external access. Connecting to a network router is impossible if it doesn’t expose a port.

The NDI Bridge Host finds your public IP address automatically and listens for traffic arriving at the port you specify in its configuration app. It cannot, however, automatically configure the router to allow traffic from the WAN to reach that port. (By default, routers expose a limited set of common ports, and are manually configured to use other ports for specific purposes.)

Port Forwarding

To configure port forwarding, you need to know the internal port you will use, and how to access your router settings.

• NDI Bridge defaults to port 5990 but lets you specify a different ‘internal port’.

• Router settings are often available on a webpage published on your local network, though this can vary. Your router documentation will provide details and login information for the router. Alternatively, an Internet search for “port forwarding” locates countless detailed guides (such as ). A network administrator may handle this task for you in more complex environments.

Once you have this information, you can access the port forwarding section of your router settings to enter the internal and external ports. Port forwarding options are often found under either “Applications and Gaming” or “Firewall”.) If a Protocol option is provided, select “Both”, or “UDP”.

NDI Test Patterns is a tool designed to facilitate precise audio and video calibration on NDI-enabled devices within your network.

With a range of test patterns and audio tones, this tool ensures accurate color properties and optimal sound levels.

Accessing NDI Test Patterns

and run NDI Test Patterns from the or your applications list.

Immediate NDI Signal Sharing

Upon launching, NDI Test Patterns will instantly share an NDI signal across your network, viewable on other NDI-enabled devices using software like Studio Monitor.

Viewing the NDI Signal

To receive the signal from NDI Test Patterns, right-click on the tool, select the device's name, and choose Test Patterns.

Test Pattern Variety

Explore a variety of test patterns by scrolling down the page and selecting the one that best suits your calibration needs.

Custom Image With Embedded Alpha

Click the plus button at the bottom of the screen to add custom images to the list of patterns in NDI Test Patterns.

NDI Test Patterns supports images with embedded alpha, allowing you to load most 32-bit image file formats and use them as sources for overlays in your program.

Audio Calibration

Enable a one-kilohertz tone accompanying the NDI test pattern signal to test your audio equipment. Choose from various decibel levels to suit your audio calibration requirements.

NDI Router is a tool that enables the routing of NDI video and audio streams to a diverse array of destinations. This tool enables users to:

• assign NDI sources to named router outputs quickly.

• create presets for recalling router layouts for different shows or sites with just one click.

NDI Webcam Input is a tool that enables you to use any NDI video and audio signal on your network as a webcam source.

This is particularly beneficial for enhancing your video conferencing experience on platforms like Zoom, Microsoft Teams, Skype, and more. By replacing your conventional webcam with professional video production NDI-enabled equipment and software, you can bring graphics, virtual sets, and other visual enhancements to your virtual meetings.

Audio over IP refers to the transmission of digital audio across IP networks. This technology enables high-quality audio streams to be sent between devices and locations with minimal latency. AoIP can be used for broadcasting, live sound reinforcement, recording studios, and more.

Key concepts

NDI Access Manager is a tool designed to give you control over the visibility and discoverability of NDI sources within your network. This tool allows you to manage precisely who can see specific NDI sources through the utilization of .

NDI Studio Monitor is a tool that allows you to effortlessly view video and audio signals transmitted over your network through an NDI stream.

Studio Monitor is a valuable tool for anyone involved in video monitoring, digital signage, KVM control, recording, PTZ operation, or more.

NDI Test Patterns is a tool designed to facilitate precise audio and video calibration on NDI-enabled devices within your network.

With a range of test patterns and audio tones, this tool ensures accurate color properties and optimal sound levels.

NDI Virtual Input is a tool that enables you to use any NDI video and audio signal on your network as a webcam source.

This is particularly beneficial for enhancing your video conferencing experience on platforms like Zoom, Microsoft Teams, Skype, and more. By replacing your conventional webcam with professional video production NDI-enabled equipment and software, you can bring graphics, virtual sets, and other visual enhancements to your virtual meetings.

Overview

In modern networked media environments, efficient discovery and management of NDI® audio and video sources are essential for scalable, low-latency workflows.

The NDI Discovery Service is an OS-managed background process that runs the NDI Discovery Server the centralized registry for NDI sources and receivers and exposes its proprietary API for client access.

It provides a more predictable and scalable method for registering and locating NDI sources and receivers. It is especially valuable in networks where multicast traffic is restricted or discouraged, such as cloud-hosted or enterprise environments.

NDI Router is a tool that enables the routing of NDI video and audio streams to a diverse array of destinations. This tool enables users to:

• assign NDI sources to named router outputs quickly.

• create presets for recalling router layouts for different shows or sites with just one click.

Starting in NDI version 5, this lists all the network adapters that will be used for network transmission.

One or more NICs can be used to transmit and receive video and audio data. This capability can be used to ensure that the NDI primary stream data remains on a particular group of network adapters, for instance, allowing you to ensure that dedicated audio is on a separate network card from the NDI video. It is generally preferred that you let NDI select the network adapters automatically, which can smartly select which to use and how to choose the ones that result in the best bandwidth.

While in some modes, NDI can automatically balance bandwidth across multiple NICs, it usually is better for you to use NIC teaming at a machine configuration level which can result in much better performance than what is possible in software. If this setting is misconfigured to specify NICs that might not exist, then NDI might fail to function correctly.

Also, please note that the operation of computer systems that are separately on entirely different networks with different IP address ranges is often not handled robustly by the operating system, and NDI might not fully function in these configurations.

NDI Access Manager is a tool designed to give you control over the visibility and discoverability of NDI sources within your network. This tool allows you to manage precisely who can see specific NDI sources through the utilization of . Ideal for enhancing content-sharing workflows, NDI Access Manager is available for free as part of the NDI Tools package.

NDI for Adobe After Effects is a groundbreaking plugin that seamlessly integrates your laptop or workstation into your live production workflow. (Available for Windows and Mac)

By enabling you to send an NDI stream directly from your After Effects timeline, it simplifies the review and approval process, streamlines collaboration between remote teams, and accelerates live-to-air editing workflows.

The NDI Launcher is a platform where you can access all the tools you have on your computer. By clicking on any card, you'll open that specific tool. Alternatively, you can find all the tools within your selected folder (by default, they will be installed in the Applications folder).

Register your NDI Tools

Annex-B

This format specifies that each NAL unit must be prefixed with a start code (usually a sequence of bytes like 0x000001). This start code helps the decoder identify the beginning of each unit.

The NDI Discovery Server is a command-line application available for Windows, macOS, and Linux. It allows you to replace mDNS-based automatic discovery with a centralized registry of NDI sources.

This can be very helpful for installations where you wish to avoid having significant mDNS traffic for a large number of sources. It can also be useful when multicast is not possible or desirable; it is very common for cloud computing services not to allow multicast traffic. When using the Discovery Service, NDI can operate entirely in unicast mode and thus in almost any installation. The Discovery server supports all NDI functionality, including NDI groups. Clients should be configured to connect with the Discovery Service instead of using mDNS to locate sources.

When there is a Discovery server, NDI applications will use both mDNS and the Discovery server to find and receive sources on the local network that are not on machines configured to use discovery.

For senders, if a Discovery Service is specified, then mDNS will not be used; these sources will only be visible to other finders and receivers configured to use the Discovery server.

NDI Discovery is a tool that enables you set up and manage Discovery Servers within workflows. We cover the capabilities of in depth in our .

NDI Screen Capture is an application designed to effortlessly share your computer's desktop video and audio with any other device on your network through an NDI stream.

Whether you're conducting broadcasts and presentations, collaborating on projects, creating tutorials, or engaging in media playback, Screen Capture provides a valuable solution.

The following list presents some products that make use of NDI connectivity technology for Audio over IP networking. It will be updated over time, as more relevant products enter the market.

NDI Audio Direct is a collection of VST audio plugins for MS Windows designed to integrate seamlessly with virtually any audio software application, allowing you to harness the power of NDI. (Available for Windows only)

This innovative tool empowers users to select, receive, and generate multichannel audio with exceptional quality and minimal latency.

It facilitates easy Audio over IP, supporting workflow both on-premises and in virtual or cloud environments, and it's compatible with any digital audio workstation through VST plugins.

NDI Apps bring the power of NDI technology directly to your everyday devices. From mobile phones and tablets to desktop computers, these applications make it possible to capture, send, and receive high-quality video and audio across standard networks without the need for specialized hardware.

Whether you’re streaming a live event, collaborating remotely, or extending the reach of your production setup, NDI Apps are designed to make professional-grade connectivity accessible anywhere. By turning consumer devices into fully functional NDI sources and receivers, these apps help bridge the gap between professional broadcast environments and everyday creative workflows.

Capture (coming soon)

NDI for Adobe Premiere Pro is a powerful plugin that accelerates live-to-air editing workflows with real-time renderless playback and preview over your network via NDI. (Available for Windows and Mac)

By enabling you to send an NDI stream directly from your Premiere Pro timeline, it simplifies the review and approval process, streamlines collaboration between remote teams, and accelerates live-to-air editing workflows.