How to get the most out of an NDI encoder

Network bandwidth

The first step when using NDI is to assess the available bandwidth on your local network. Regardless of the NDI encoder’s make, model, or features, the encoding can only be performed to its full potential if the local network can transport the signals.

At a minimum, the workflow should be running on a Gigabit network – throughput speeds, full duplex ports, and upstream and downstream data speeds must all be capable of transferring the data. Insufficient bandwidth can negatively affect the final product – dropped frames, frozen video, audio glitches, and sudden disconnection.

The general rule of thumb is to reserve 25 percent of bandwidth for headroom so that the signal transmission remains smooth should there be any unaccounted for traffic while your production is underway. So, if a Gigabit network isn’t doing the trick, consider upgrading to a 10 Gigabit network.

A typical High Bandwidth NDI stream at 1920×1080p@30 fps needs approximately 100 Mbps per stream. But the bandwidth required to use NDI effectively will vary depending on the number of video sources, the resolutions, and the frame rates. Ultimately, the bandwidth required is unique to the video production at hand, making it wise to test the network if possible.

In 2016, one year after High Bandwidth NDI was released, a high-efficiency version of the IP-based solution called NDI|HX was released. It was specifically designed to work on low-bandwidth networks.

One 1920×1080p@30 fps NDI|HX stream needs approximately 24 Mbps, making it highly versatile. However, the efficient compression used by NDI|HX does add some latency to the stream. The added latency varies depending on the device, frame rate, and resolution, but it’s typically not more than one or two frames of delay – hardly noticeable to the eye or ear.

NDI and NDI|HX bandwidth recommendations

Hardware over software

When choosing any encoder – and NDI encoders are no different – we always face the same question: hardware or software?

Software encoders have their benefits in certain situations, but the performance and reliability hardware encoders offer compared to software alternatives are essential for an NDI production. Software encoding can be resource-intensive, requiring very powerful computers with state-of-the-art GPUs and plenty of memory to run effectively in an NDI workflow.

Unless one or several computers already meet the requirements of processing NDI’s high-quality, low-latency video, encoding software can crash mid-record or stream. At best, the software encoder will add latency to the NDI feeds, undermining one of the biggest benefits of the solution. Determining a system’s requirements to run an NDI software encoder effectively may be challenging as it can vary depending on the content being produced.

A hardware NDI encoder is an investment in performance and reliability. Optimized from the ground up to encode video, acquiring high-quality and audio inputs with no added latency and no other competing programs makes hardware a wise choice.

Multi-encoding support

Multi-encoding is the process of encoding one or more inputs multiple times with different settings. As a result, you have a wealth of redundancy by capturing all your assets simultaneously at different resolutions, bitrates, and frame rates. For example, you can send a 720p@30 fps live stream to a media server while saving a 1080p@30 fps recording to the device’s internal storage.

Depending on the encoder, multi-encoding support can offer far greater depth than just encoding at different settings. Hardware encoders that feature multiple programs or channels can encode assets independently of the content being shared. For example, if your hardware encoder allows for content to be mixed and switched within the device, you could have several layouts streaming a 720p@30 fps to a media server in one channel, a 1080@30 fps recording saved to internal storage, and ISOs of each video asset recorded in separate channels as additional backups.

This is particularly useful any time you are streaming live events where there are no second chances. Should the stream stutter or fail, you have the recorded backup with its layouts, but you can also work off individual camera feeds to create a produced broadcast.

Input versatility

While NDI has many advantages, keeping your options open and having plan B’s readily available is always a good idea in video production. When searching for an NDI encoder, a device that can accept networked signals and physical cables ensures you can create the best possible video in any circumstance.

When an encoder can accept HDMI, SDI, and NDI or NDI|HX equally, you can stream and record your content regardless of the network’s condition. Plus, you eliminate the need to add converters for any incompatible hardware. But the most significant benefit is that physically connecting certain devices can help keep the network clear to acquire the essential NDI signals with greater reliability. On the other hand, putting every device on the same network could cause network congestion.

Be prepared for any situation with an NDI encoder that works with everything.

Remote device management

An NDI encoder sits at the heart of your workflow. As such, if it’s interrupted in any way, it can grind your video production to a halt.

Whether dealing with a single or several NDI encoders, it’s essential to have the chance to access it from anywhere and mitigate any downtime. Remote device management is an extraordinary asset for any NDI encoder.

By accessing it in the cloud or receiving customized alerts from 24/7 monitoring, you can take corrective action immediately and begin troubleshooting from anywhere.

When a device malfunctions, it’s stressful for all stakeholders. Giving yourself the convenience and flexibility to manage the device remotely in these high-pressure situations is insurance against production interruptions.

Interoperability

On top of delivering high-quality video with greater convenience, NDI’s rise to prominence can also be attributed to its interoperability. As an open standard protocol, it’s publicly available to anyone, allowing any hardware manufacturer to implement it.

When choosing an NDI encoder, selecting a device that shares NDI’s commitment to compatibility will make it a seamless fit in almost any situation.

Integrations with content management systems like Kaltura or automation controls like Creston or Q-SYS can make your productions vastly more efficient and easier to use. Devices with an open API allow owners to customize the hardware to suit their exact needs, further optimizing the exact workflow.

Investing in an NDI encoder that can’t complement the systems already in place, either with built-in integrations or through the open API, can lead to frustration, downtime, and even the complete overhaul of video tech stacks.

To take full advantage of the quality NDI offers, a device that works with virtually everything, like NDI itself, is a huge boon for integrators.

The best NDI encoders: Epiphan Pearl-2 and Pearl Mini

The award-winning Epiphan Pearl production systems, known for their reliability and versatility, can be featured at the center of your NDI workflows.

Pearl Mini accepts two NDI|HX inputs, allowing you to connect high-quality, low-latency video more efficiently over your local networks.

Pearl-2 allows users to receive up to six NDI|HX, up to three High Bandwidth NDI inputs, and output 1080p@30 fps High Bandwidth NDI or one 4K@30 fps High Bandwidth NDI stream.

Discover what Pearl can do for your NDI workflows.