Applied Technology: Encoding and Transcoding in Today’s Complex Broadcast Environment

Broadcasters used to predominantly deliver SD and HD linear content. Today, consumer expectations for high-quality video on every screen, including on-demand, have propelled the industry toward adopting a more flexible and efficient approach to video production and distribution.

This article will take a look at several new approaches to video encoding/transcoding designed to help broadcasters quickly distribute compelling content, such as Ultra HD (UHD), on a wide range of devices, while lowering operational complexity and costs.

Software-Based Encoding and Virtualization

A growing number of broadcasters are moving away from bespoke broadcast hardware in favor of a software-based approach to encoding, particularly for linear programming. Compared with a hardware-based infrastructure, a software-based encoding solution allows broadcasters to more quickly adapt to new devices, codec technologies, formats, and business models. Furthermore, software-based encoding provides broadcasters with a seamless path to a virtualized video infrastructure.

The idea behind virtualizing broadcast and multiscreen processing is to liberate it from the underlying hardware, enabling those functions in the video chain to be realized as software that can run on standard IT equipment within a data center, as well as on a private or a public cloud.

With virtualization, broadcasters can dramatically reduce investment and maintenance costs while increasing the speed with which they are able to deploy new services, such as UHD.

There will certainly be a transition period when it comes to virtualization. Luckily, broadcasters have options when it comes to making that transition, either by adopting a fully virtualized encoder today, or implementing an appliance-based encoder that allows them to easily migrate in the future, when ready.

Visitor's portal viewpoint into Televisa control room.

Visitor's portal viewpoint into Televisa control room.

Cloud-based Transcoding

For multiscreen delivery, cloud-based transcoding has emerged as a quick and affordable way for broadcasters to convert high-quality video into an array of media formats. There are a few different methods that broadcasters can take when it comes to cloud transcoding, such as hosting all final assets in the cloud, or implementing a hybrid approach where workflow orchestration is in the cloud and more processor-intensive transcoding workloads are either on-premises or in the cloud.

The overall benefits of cloud-based transcoding are reduced delivery times and costs. With the hybrid approach, hosting transcoding on-premises has certain advantages as well, including increased asset security and economics, in terms of the ability to depreciate computer infrastructure over time.

One approach that is gaining traction around the world is creating content in a mezzanine format, like UHD, and then relying on cloud-based service operators to do the transcoding. This method is quite a significant change within the broadcast market compared with the laborious act of distributing content in all formats for all screens. Using a mezzanine format rather than transcoding in a wide range of media formats (e.g., SD, HD, UHD) and standards (e.g., HLS, HDS, DASH, etc.) broadcasters can save a significant amount of time and money. In fact, some of the formats broadcasters are distributing in are tied to broadband IP consumption; thus, it makes sense to disperse transcoding capabilities in the same way that audio transcoding is done for voice services.

As ABR consumption grows, we are also seeing cloud-based service providers, such as Encoding.com, making the transition from being solely file-based server operators to extending capability to cater for full blown live streaming. This move is essential for two reasons, to track viewing demographics, which favor streaming over linear scheduled services and the continual pressure on DTH services to relinquish spectrum for mobile usage.

Delivering UHD ABR Content Via HEVC and MPEG-DASH

Over the last year, we’ve seen UHD services being rolled out by video service providers like DIRECTV, Amazon and Netflix. According to the Consumer Electronics Association (CEA), shipments of 4K UHD displays are projected to reach 4 million units in 2015, a 208 percent increase over the year 2014.Clearly, streaming quality is important to today’s television viewers, but there are a couple of challenges that broadcasters face in delivering high-quality ABR content. One issue is bandwidth.

Inevitably, delivering UHD content results in higher bandwidth utilization. From an encoding standpoint, broadcasters need a solution that provides better video compression than MPEG-2 or AVC. Given the rate at which technology advances, it’s also important to choose a solution that is flexible, one that can easily be updated to support future video codecs and standards via a software or license upgrade.

Encoding with HEVC, the next-generation compression format, has emerged as the solution to broadcasters’ bandwidth woes — for now. With HEVC, broadcasters can significantly reduce the data rate needed for high-quality video coding. This makes it possible to deliver higher quality video services, like UHD, using the same amount of bandwidth.

The other challenge broadcasters’ face relates to packaging, storage, and delivery. The industry is really pushing for UHD channels to be part of a multiscreen service. Yet, preparing content in a variety of ABR formats (e.g. Apple HLS, Microsoft Smooth Streaming, and Adobe HDS) would be too costly and time-consuming, creating scalability issues that would in turn reduce the quality of streaming video content for viewers.

Adopting a transcoding solution that supports MPEG-DASH would eliminate the need to create a duplicate infrastructure for UHD ABR streaming. Using the DASH standard, broadcasters can package, store, and deliver a single piece of content just once.

Harmonic's Pure Compression Engine is part of the Harmonic VOS, a software-based, fully virtualized platform that unifies the entire media processing chain, from ingest to delivery.

Harmonic's Pure Compression Engine is part of the Harmonic VOS, a software-based, fully virtualized platform that unifies the entire media processing chain, from ingest to delivery.

Conclusion

Given the recent changes in consumer demand from linear scheduled programming to VOD content, the move from SD and HD to UHD, and broadcast to multiscreen and ABR delivery, broadcasters require more flexibility in the headend. Today there is considerable pressure on the broadcast spectrum, which is pushing the operators of previous free-to-air DTH services to reinvent how content is distributed. More and more, we’re seeing broadcast operators relying on broadband to deliver DTH services, particularly for long-tail content.

The good news is that broadcast equipment is evolving toward software-based solutions that offer increased flexibility, scalability, and cost savings, enabling operators to leverage the IT economics of off-the-shelf servers. Harmonic offers a superior approach to software-based encoding/transcoding, enabling broadcasters to take incremental steps toward the virtualized environment.

Harmonic's Pure Compression Engine is at the heart of this Electra X software-based encoder.

Harmonic's Pure Compression Engine is at the heart of this Electra X software-based encoder.

The flexibility that is provided by a virtualized video delivery platform like Harmonic VOS is exactly what broadcasters require in order to deliver competitive services, enabling broadcasters to make a seamless transition from SD MPEG-2 to HEVC UHD without having to completely replace their infrastructure.

Ian Trow, Senior Director of Emerging Technology and Strategy at Harmonic.

Ian Trow, Senior Director of Emerging Technology and Strategy at Harmonic.

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