As OTT streaming rules the viewing landscape, technology vendors are hard at work developing low-latency codecs that can make this content available on-demand to any device in the most reliable way. Contribution is another key application that relies on low latency to successfully deliver content between facilities.

Latency is a loaded word in this on-going discussion, as different applications call for better (or worse) latency to deliver the right mix of content and business model to the right users.

In lieu of the recently cancelled 2021 NAB Show, where TheBroadcastBridge.com would have met with these companies in person to discuss this issue, we’ve brought together some of the main players in the space to get their take on where file-based content delivery is taking advantage of the latest compression algorithms and succeeding.

So, what’s the highest latency that can be tolerated for contribution video?

“This depends on the application,” said Usman Shakeel, Director, M&E Architects, at Amazon Web Services (AWS). “For some customers, latencies of a few seconds are fine while others require sub-second or even sub-frame latency.”

He cited an example that would require near real-time encoding: sports wagering and online betting. AWS services include Amazon Interactive Video Service (Amazon IVS), or AWS Cloud Digital Interface (AWS CDI) and AWS Elemental Media Connect for inter-cloud, low-latency high fidelity video transfer.

At Haivision, they claim that for live broadcast contribution, end-to-end latency can be 1-2 seconds or so depending on the type of encoder and network used, “but ideally it should be kept below 500ms for smooth live broadcast production and bidirectional interviews,” said Mark Horchler, Marketing Director, Products and Solutions, Haivision.

The company’s Makito X4 Encoder supports video resolutions up to 4Kp60 or four simultaneous HD encodes, as well as 4:2:2 chroma subsampling and 10-bit pixel depths for wide color gamuts and HDR, PQ or HLG. Depending on the network and streaming protocol used, latency from encode to streaming can be as low as 55ms. Pairing this with Haivision’s low latency Makito X4 Decoder helps ensure that end-to-end contribution latency is kept as low as possible. Haivision recently introduced slice-based encoding and decoding to further reduce latency by 25 percent, they said.

For the product engineers at Zixi, latency disruption depends on the use case.

“For example a live interview will require very low latencies so you aren’t seeing that “satellite delay,” latencies above 500ms will start to be noticeable to the audience,” said Naytram Deonarain, Technical Partner Manager, Zixi. “Our technology can do ultra-low latencies of 50ms if the underlying hardware can support the connection.”

In other use cases where QoE is important, he said that most broadcasters will choose a higher latency to ensure the video is of pristine quality. Zixi’s software-defined video platform (SDVP) can be leveraged to manage both of these uses cases and we provide the data for our customers to optimize their workflows over unmanaged networks.

Zixi’s SDVP has gained traction within the professional video industry and now says it has partnered with over 300+ hardware vendors “to allow our customers to have a choice when it comes to encoders. All of the major vendors support the Zixi protocol and its ability for ultra-low latency. The SDK requires very little resources allowing encoding partners to use the processing power to achieve ultra-low latencies,” said Deonarain.

Supporting the most popular compression protocols is key to Zixi’s success. Deonarain said the Zixi SDVP is both protocol and codec agnostic, and “we can transport any video signal in an MPEG-TS container whether it’s highly compressed HLS or low compression J2K. Our platform is future proof to support any format today and will be able to support 8K whenever that format becomes widely available.”

The issue of timing and synchronization came up in our discussion regarding how it can affect latency.

“Producing content with IP streams will require highly accurate timing to ensure the video streams are synchronized, and since we’re producing the content before it goes to air it’s more important to ensure the video is synchronized across cameras,” said Deonarain. “Customers can deal with some latency to ensure the content is synchronized when it comes to switching between cameras, and our customers are already adopting the SDVP to manage the transport of numerous streams/cameras in the cloud. For pre-production you’ll need some form of management to ensure all cameras are available and in-sync.”

“Depending on customer requirements, many codec settings can be adjusted to trade off extra buffering and higher quality or less buffering and lower latency,” added AWS’ Shakeel.

“Keeping multiple contribution feeds in sync over an IP network, especially the Internet, can add additional latency,” said Haivision’s Horchler. “Using both SRT and our Stream Sync technology, we can synchronize streams with Makito X and X4 decoders accurate to a single frame while keeping latency as low as possible.”

The key for customers is to figure out how much latency their audience can tolerate, which in turn can determine the success of the project or streaming service.

Here’s these companies’ plans for the 2021 NAB Show that wasn’t:

AWS:
At NAB 2021, Amazon Web Services (AWS) was planning on showcasing AWS and AWS Partner solutions from its AWS for Media and Entertainment (M&E) offering, which aligns the most purpose-built M&E capabilities of any cloud to transform the industry across broadcast, media supply chain and archive, content production, data and analytics, and direct-to-consumer streaming.

Haivision:
The company was going to show the ultra-low latency Makito X4 video encoder and decoder pair with new support for HDR live contribution workflows and slice-based encoding. It was also planning to demonstrate all the new features of its cloud-based video routing solution, Haivision Hub, including agile outputs, preview thumbnails, and much more.

Zixi:
The company planned to show—and is going to show in the Zixi Innovates virtual showcase Zixi Innovates Virtual Showcase 2021, October 11-21—its Intelligent Data Platform and the use of advanced analytics, AI, and Machine Learning to mitigate risk in the broadcast environment. Also, ZEN Master and the integration of AWS Cloud Digital Interface (CDI) and AWS Elemental Link which are expanding the traditional use of ZEN Master. There are also new features and functionality of v15 of the Zixi Broadcaster, and the new Zixi as a Service (ZaaS), a full SaaS offering of the Zixi SDVP. And lastly, the Zixi Content Xchange with access to 10,000+ channels globally and full Saas delivery door to door.