Why Atomos Now Builds NDI HX3 Into All Its Network-Enabled Monitor-Recorders

Tier 1 and Tier 2 broadcasters now routinely use NDI to fill the gaps where conventional SDI or ST 2110 IP video is too resource-heavy or overspecified. It is a great fit for spontaneous, ad hoc contribution like news and entertainment. It’s ideal for hidden camera reality TV, where it can support dozens of awkwardly placed or hidden remote cameras. Independent production crews can feed NDI to a live broadcast. NDI is an excellent choice for streamed content - especially niche sports and events with limited budgets.

Why NDI

“Networks change everything” is a headline writer's cliché but perfectly captures the video world before and after networks. The difference is stark and fundamental. With conventional analog or digital video cables, connections are point-to-point. Ten signals require ten cables. Uncompressed video such as ST 2110 imposes brutal loads on networks (e.g. 3 Gbps for 1080p60 and 12Gbps for 4K/UHDp60) but is an effective solution for broadcasters and production facilities that require the network equivalent of SDI video.

In contrast, NDI can use standard networks to move video around. There’s generally no need for special equipment. NDI can often use existing networks and is relatively easy to set up and use. It abstracts the raw complexities of IP video with a software defined architecture. All you have to do is be sensible about network usage; don’t expect flawless performance if you’re sharing the network with thousands of people. It’s always best to have a dedicated network or physical subnet, but with such low costs, that’s easily done.

The true advantage of NDI is its flexibility; it builds virtual connections between end points on a conventional network. NDI caters for everything from small, mobile productions to entire multistudio facilities, and can combine the two. Every network socket is both an input and output - at the same time. Plug a monitor in for one production and a camera in another. With a fast enough network, you could switch an entire multi-camera production with a single ethernet connection. To reconfigure an entire facility, all you have to do is load a new preset in your production software. You can turn a bare Ethernet-equipped room into a professional production gallery and a clearing in a jungle into a production village or live multicam contribution source.

NDI comes in two flavors.

Full NDI

The two types of NDI are known as Full NDI and NDI HX (where HX indicates “High Efficiency”).

Full NDI is the original version. At typically 125-150 Mbps for 1080p60 and 250-400 Mbps for 4K/UHDp60 this version can run over existing networks using low-cost equipment.

Full NDI also has very low latency (the delays that occur when processing and buffering digital video). It uses NDI’s own codec, previously called AirSend, which compresses each individual frame completely, without needing to look at previous or future frames. This makes it easy to process - mostly in software! - and it can achieve remarkable results with very little processing.

Full NDI’s compression is sometimes compared to Apple ProRes, not because it’s technically the same, but because it is a relatively mild form of compression. At these bitrates, it is extremely usable over dedicated networks but could impact (and be impacted by) traffic on a mixed-use network.

To sum up, full bandwidth NDI:

• Uses mild compression for maximum quality and is visually lossless.
• Is easy to process.
• Has very low latency.
• Is comparable in positioning to Apple ProRes.
• Requires a much lower network bandwidth than uncompressed video but still imposes a relatively large network load.

NDI HX

This is a more network-efficient version of NDI. It has a much lower bitrate than Full NDI and so is much kinder to networks. What this means in practice is that you can cram many more video streams or channels into any given network. So, does this affect quality? The latest version, for most broadcast and live production environments, is visually lossless. Let’s look at how it differs from Full NDI, then explain those differences and what they mean operationally.

NDI HX is a clever evolution of NDI designed to fix the bitrate issue. It opts for the well-known H.264 and H.265 codecs that you’ll find embedded in hardware chips in virtually every phone, computer and television. These compressors are significantly better at squeezing digital video into a smaller bitstream. They typically work by not encoding each individual frame, but by looking at a group of frames (or Group of Pictures) and essentially only compressing the parts that move - in other words, the differences between the frames. The latest version is HX3 which, unlike its predecessors HX1 and HX2, can specify single frame (intra-frame) encoding, maximizing quality while keeping the bitrate acceptable and resulting in extremely low latency. The mathematics behind H.264 and H.265 is complex, but the result is simple: lower bitrates and dramatically more simultaneous video channels per network.

Let's zoom in on the quality factor. NDI is all about real-world networking; practical, everyday video transport where a good, clean picture is the priority. NDI HX3 succeeds on all counts. It is visually lossless in virtually all circumstances and reduces latency to a point where it would only be noticeable in a side-by-side comparison with the source.

To sum up, NDI HX3:

• Uses higher compression for remarkably low bitrates while still maintaining excellent image quality.
• Is harder to process in software than Full NDI, but virtually all NDI HX-supporting devices contain dedicated hardware for processing. This makes it very easy and economical to process NDI HX3.
• Has marginally higher latency than Full NDI, but still insignificant in most contexts.
• Uses H.264 and H.265 compression for production-quality video at higher settings.
• Compared to uncompressed video and Full NDI, is much more efficient over networks.
• Supports HD and 4K.
• Supports HDR.
• Supports 10-bit video.

With high-quality H.265 encoding, NDI HX3 is suitable for professional live production.

A Note About NDI, Codecs And Quality

The two types of NDI, Full NDI and NDI HX3, use different compression methods, but that is essentially the only difference between them. Think of NDI (sitting on top of a network) as the transport and administrative system. The compressed video is the payload. NDI HX3’s payload is much lighter and smaller than Full NDI's.

NDI And Atomos: A Productive Path To Video Networking

NDI transforms Atomos devices into portable IP video gateways, bridging traditional cameras and modern network-based production systems.

All current Atomos network-enabled monitor-recorders support NDI HX3 as standard. When you put NDI into the Atomos mix, you don’t just add to the existing capabilities; you multiply them. Everything your Atomos Ninja or Shogun did before, it now does with video over an NDI network. These devices become the physical manifestation of NDI’s virtual connections.

Video sources in an NDI environment are typically fixed installations, most likely remote-operated PTZ cameras. Using a connected Atomos monitor-recorder allows you to turn any DSLR/mirrorless camera, or camcorder, into an NDI source. Both devices can be battery powered and connected via Ethernet cable or wirelessly, for complete freedom of movement.

Atomos devices also provide high-quality monitoring with advanced features like waveform, focus peaking, and color correction tools, ensuring precise control over video output. This enhances real-time confidence monitoring in an NDI workflow, especially in multi-camera setups or live broadcasting, allowing operators to visually monitor streams and adjust on the fly.

A New Way To See And Use Video Networks

NDI’s biggest achievement has been to tame the rough edges of video-over-IP. NDI HX3, the flavor used by Atomos, uses so little bandwidth that you can send multiple production-quality video channels over conventional, budget-friendly networks. It eliminates the hard-to-manage complexity and rawness associated with network configuration. It’s a friendly approach for experts and beginners alike.

Networks can seem very abstract - often because you can’t see what they’re doing. This is precisely what NDI fixes, with simple menus to connect sources and destinations. With NDI, any connection can support cameras, video switchers, recorders, playback systems or displays. It’s an entirely new way of thinking. And with NDI-equipped Atomos products like Ninja and Shogun, you can see what’s on the network in glorious detail and connect video cameras that don’t come with NDI onboard.