The Unofficial Guide to NDI - IP Video Production

NDI stands for Network Device Interface and it is a high quality, low latency, IP video transmission standard popular for video production. You can think about NDI as an easy way to connect live video sources between computers. The NDI video connection standard was initially adopted by the live video production industry in software such as: Wirecast, vMix, LiveStream Studio, OBS (via a plugin), xSplit, and the NewTek TriCaster. Today, NDI is used in a wide variety of video applications including broadcast, distance learning, and video communications. There are so many software and hardware integrations it’s easy to use NDI with almost any project that uses video on a computer.

Most NDI users start their journey with NDI by seeking a new way of connecting video sources beyond the traditional HDMI and SDI cable types. Traditional video cables such as HDMI and SDI have obvious limitations such as cable distance and resolution. NDI offers much greater flexibility compared to traditional video cables because it leverages network connections that are already in place for most computer systems. Getting started can be as easy as downloading the free NDI tools which can be used to send and receive video over a standard LAN (Local Area Network). Over the years, NDI tools have grown to include NDI video viewing applications, screen capture software, virtual webcam inputs, remote camera controls and KVM solutions. There are even apps for iOS and Android devices that can turn a smartphone into a camera or presentation tool using NDI. NDI Tools allow anyone to get started using IP video and easily leapfrog old technologies that used to require expensive capture cards and hardware video switchers.

All NDI-enabled software and hardware become part of a larger ecosystem where all sources are visible and available to other computers on the network. In this way, NDI video sources open up a new world of connectivity that is far beyond traditional point-to-point video cabling. While IP video is not a new concept, NDI has brought ease of use and flexibility to the complex world of network video. With thousands of developers using the royalty-free NDI standard video production professionals are able to find new and innovative ways to use the solution all the time. At its core, NDI has made the ability to quickly discover, send and connect IP video sources incredibly easy and reliable. NDI users will tell you that “it just works” which is in part due to the discovery system which allows software and hardware systems to easily find each other on a local area network.

Over the years, NDI has also released new connectivity options such as NDI|HX which stands for “High Efficiency.” NDI High Efficiency was announced in 2017 and it provides additional flexibility for bandwidth control when sending video over your local area network. NDI HX has also made the use of NDI video over WiFi and other bandwidth-constrained networks possible. In 2020, NDI|HX2 was announced with a slew of new improvements that optimize NDI. Other important tools that you will learn about in this book, include NDI Studio Monitor which allows users to quickly browse and control video sources on any Mac or PC computer, and NDI Access Manager which provides security and network management for IT professionals.

IP Video is a term used to describe a video that is distributed on an IP network. The “IP” in IP Video stands for Internet Protocol, which is a set of standards for communicating over computer networks. IP Video devices can include cameras, hardware or software switchers, graphic workstations, and displays. NDI is just one type of IP Video that has become a popular standard for live streaming and video production.

Advantages of IP Video

IP video offers many advantages over standard cable connection options. One benefit is scalability. As demands grow, adding additional cameras and other sources can become complicated when you are using traditional HDMI or SDI cabling. Hardware switchers can quickly run out of inputs, and many computers are limited on the number of capture cards or boxes that can be connected. With IP video, a single ethernet cable can handle a large number of sources, and there is no additional expense in terms of capture cards and hardware video switchers.

Note: Traditional video HDMI and SDI sources can be connected to a computer and converted into NDI video sources. This can be accomplished by using NDI Connect and other software solutions. Magewell for example offers a free NDI Bridge which converts all video sources connected to Magewell hardware into NDI outputs to accommodate modern IP video workflows.

Another advantage of IP video is the possibility of decentralized distribution. With a standard hardware switcher, all sources are routed to one location. With IP Video, sources are available anywhere on the network and can easily be sent to any other location on the network. This opens up a multitude of production and distribution possibilities.

IP Video also breaks the distance barrier of standard cabling options. While SDI connections can offer much greater lengths than more limited HDMI cables, they still face limits based on cable quality and capabilities. For example, an Ethernet cable can be used for video, control capabilities, and powering a device whereas an SDI or HDMI cable can only handle video. While there are limitations as to the length of individual ethernet cables, these cables only need to make it to the nearest router or switch, not all the way from the camera to the switcher.

Perhaps the most compelling advantage of IP video for many people is affordability. Most hardware video production solutions are expensive when compared to software alternatives. The prime example of this is capture card hardware. Before IP video, all video sources had to be run directly from the source to a capture device in order to be used with a video production solution. Today, NDI removes the need for expensive capture cards and makes it possible to capture video directly through a computer's network interface.

IP Video Considerations

Before making the switch to an IP video solution such as NDI, also consider the challenges you may face with implementation. The biggest challenges may come to those who are comfortable with video standards but not with networking. A simple setup may be manageable by someone with no networking experience. However, more complex configurations may require a higher level of understanding when it comes to networking or access to someone with the required knowledge. In this book and included online course, you will gain a basic understanding of the networking skills necessary to manage an NDI network for video production.

Key Takeaways:

1. NDI is not the only IP video standard available today. It is however one of the most popular IP video technologies used for live video production and communications.

2. IP video technology is helping to modernize video production.

3. IP video is helping to make live video production more affordable.

Once you have stepped into the NDI ecosystem, you will find a growing number of tools, both hardware, and software available to improve your production workflow and offer new creative possibilities. Due to the nature of NDI, there are many software tools that can do as much or more than previous hardware options. NDI has always offered many resources to developers to add NDI functionality to their software and hardware systems. The NDI SDK (Software Development Kit) has helped many developers implement NDI into their products over the years since it’s release. In this chapter, you will learn about the most popular tools and software solutions available to use with NDI.

The StreamGeeks have been using NDI in a variety of ways to produce video content, live streams and high-powered webinars. In this chapter, you can learn some simple, realistic ways to use NDI. You will see how the team at StreamGeeks leverages NDI to capture presentation materials, Zoom meeting participants, social media comments, and of course cameras. Each NDI use case will be presented in this chapter in a practical “get the job done” scenario starting with capturing presentation slides.

Simple Presentation Slides

During most live streams and video recordings, the team at StreamGeeks creates a presentation. This presentation is made with Google Slides and then runs on a laptop computer in the studio. This laptop is then connected to an HDMI monitor so that it can be easily seen from any camera angle in the studio. Using NDI Screen Capture, the “Presentation Laptop” is easily able to send the presentation slides directly to the “Live Streaming Computer.”

The live streaming computer uses vMix to produce the live stream. Inside of vMix, there are multiple NDI camera inputs, an audio input, and a variety of other media assets. One of these media assets is a PNG file that is used to organize a live camera view and the presentation slides. You can see in the screenshot below how vMix is used to layer together two NDI video sources.

As you can see the video production above is built out of multiple media sources. Local to the computer there is a PNG file and a lower third. Underneath the transparent PNG file there are two NDI video sources that are connected over the network. This allows the producer the flexibility to create a scene where viewers can see the speaker next to their presentation but also cut to a full screen view of either the camera or the presentation at any time.

Capturing a Zoom Meeting

The beauty of IP Video is scalability. Take a look at this next diagram where four NDI cameras have been added along with a second NDI Screen Capture. It’s now quite normal to have a Zoom Meeting going during the StreamGeeks live streams. This allows the team to connect with viewers in real-time in order to answer questions and collaborate. Just like the presentation slides, the Zoom Meeting is captured in a Grid View and made available to the producer.

As you can see, NDI video sources can easily be added to your LAN in order to provide your productions with more options. The NDI capture of Zoom Meetings has become very popular. During a normal live stream, the StreamGeeks will also use NDI Webcam Input to bring NDI video back into Zoom for guests to view who are not watching the live stream. To take this NDI Zoom capture project one step further, you can see the diagram below includes two different video capture methods in the same Zoom Meeting. How is this possible? Using multiple computers, the StreamGeeks will often connect to the same Zoom meeting to display the content in various ways.

During certain live streams, it’s nice to be able to show the active speaker in a larger window. It’s also nice as a producer to have the active speaker in the Zoom Meeting available as its own input to take full screen. Here you can see the active speaker is actually captured by regular screen capture. This means that vMix (or another software) is simply capturing a screen that is connected to the computer directly (without NDI). While this does take up precious monitor space, our team will often use NDI on a separate computer to capture the active speak view.

Working with a Team

One great way NDI has helped the team at StreamGeeks grow is through the ability to share responsibilities. Now that our studio is 100% NDI enabled, the ability to share video sources and production-related responsibilities has opened up. One way that our team shares responsibilities is by managing who is responsible for which specific NDI video feed that is being sent to the production. The presentation slides are one example, but another is the management of social media content and in studio displays.

To manage social media comments the team uses vMix Social. There is a main vMix social application that is used to authenticate accounts with social media platforms such as Twitter, Facebook, Twitch and YouTube. Once set up, this application has a web interface that can be used by anyone on the LAN. The web interface will show all social media comments coming in from the connected social media networks. From here, the user is able to select a comment to show on screen. While vMix Social is a great tool, it’s too much for our producer to manage while also running the live stream. Therefore, a second social media manager is necessary.

This diagram above shows how the social media manager is able to manage a separate vMix instance and connect that video to the main live streaming computer using NDI. Running a second instance of a video production software like vMix, OBS or Wirecast allows a secondary live streaming operator to make contributions to the production. This can look like a simple lower third, or a full screen of video. In fact, the social media manager also controls the video on an LCD inside of the studio. To do this, they are able to remotely control Studio Monitor using the web control interface. This allows the social media manager the ability to switch between a grid view of the Zoom audience and other content that may be beneficial to the production. In practice, this is often used to seamlessly switch between social media comments and the audience.

Using NDI in this way is an ideal way for many organizations who seek to add volunteers to their team. NDI will allow anyone with a computer and some technical skills to contribute to video production.

Key Takeaways:

1. NDI is a technology that makes it easier to accomplish video production projects.

2. The StreamGeeks use NDI in most live video productions from their studio.

3. NDI can make it easier to work with a team and allow others to contribute content.

The purpose of this chapter will be to provide a basic understanding of how IP networks are set up as it applies to video production. In this chapter, you will be challenged to think outside the box about how to plan out live streaming and video production systems in the world of IP. Using standard networking infrastructure, NDI will enable you to think about video technology in a new way.

At this point, you may be thinking, what’s the catch? The main bottleneck most NDI users deal with is a limitation of bandwidth on the network infrastructure. Three areas where bandwidth can be limited include the ethernet cabling, networking equipment (router, switch, or wireless access point) and the NIC (Network Interface Card) port on the computer. Ethernet cables are therefore at the heart of many IP-based video production systems. Ethernet cables do not usually extend beyond 328 feet (100 meters), though they come in a variety of quality types noted below.

Most video production setups that use ethernet for video connectivity require CAT 5e cabling or greater because regular Category 5 cabling only supports up to 100 megabits per second of data transmission. CAT 5e supports a full gigabit, or 1,000 Megabits, of data transmission. Higher-end CAT cabling can offer up to 25 gigabits of data per second.

Ethernet connections are easy and convenient to use for a variety of applications. For one thing, you can use network-connected devices that can provide bi-directional connectivity to send and receive communications. You can also connect all the devices on your network to the internet, opening up many possibilities for connectivity around the world. Most commonly installed networking equipment supports gigabit connectivity but higher bandwidth networking gear is becoming more common every day. Unfortunately, if you have 10/100 networking infrastructure, you will have a hard time using it for IP-based video production. There simply isn’t enough bandwidth on these older networking systems to support video transmission in HD quality.

The good news is that gigabit networking equipment has become the industry standard and there is a good chance this is the type of technology you already have installed. A gigabit network switch with a full throughput backplane can send approximately 1,000 megabits of data to each device on your network. You should never use 100% of the available bandwidth on your network because you need to reserve “headroom” to avoid network congestion and failure. Network bandwidth headroom recommendations can vary widely but generally; most IT professionals recommend 30% - 60% depending on what the network is utilized for. You should consider consulting your network administrator before adding IP video traffic to your local area network. NewTek suggests “NDI traffic should not take up more than 75% of the bandwidth of any network link” (NewTek, 2016).

Knowing how important bandwidth is to any NDI project, it’s nice to know that you do have some options to optimize bandwidth. The chart above shows the two main types of NDI video: NDI and NDI|HX. NDI is considered the full bandwidth version of NDI which can take a 3 gigabit, fully uncompressed video signal, and compress it down to 125-200 megabits without producing noticeable digital artifacting. This type of compression is what makes IP video production possible on a gigabit network infrastructure. The compression effect is “unnoticeable” to the human eye in most cases and seeing the video side by side is a worthwhile experience. The final destination for many live video sources is a content delivery network like Facebook and YouTube and therefore users already plan on compressing the entire video stream with RTMP or SRT before it reaches the end viewers.

OBS stands for Open Broadcaster Software. OBS is an open source video production software project that has become the most popular live streaming and video production solution in the world. The software provides an open workspace for creating, recording and streaming video in a live production environment. OBS is totally free, yet it supports an unlimited number of sources and scenes (assuming your computer can handle it) which is partially why it has become so popular. OBS has become the standard for live streaming video gaming, but also many other types of live productions including worship services, live sports, talk shows and more.

While many production software packages and hardware switchers have some built-in graphics generation, many productions need more power and control. In professional, fast-moving environments, graphic creation needs to be done at a separate workstation. In some cases, multiple workstations are used to keep up with on-the-fly graphic design and editing.

With NDI, graphics and titles can be generated anywhere on the network and immediately used as a production source. Using an additional computer for graphics and title generation allows small teams to work together in a live production environment. It also spreads the workload away from the technical director or switcher operator who often have more tasks then they can handle on their own. A dedicated graphics operator can create and manage graphics, and they can be ready to go when needed by a producer on the same network using NDI.