Live IP: A practical view.November 18, 2016
By Willem Vermost and Felix Poulin
For many years now, we have taken for granted that the future of content production lies with IP, and how it promises many benefits.
The exciting news is that we are now passing from theory to practice. One of the most significant proofs-of-concept, titled LiveIP, has been delivered at Belgium’s national broadcaster VRT. It involved building and operating a live TV production studio with state-of-the-art IP-enabled equipment, using available interoperable, open standards. The project is the result of great collaboration between VRT, the European Broadcasting Union (EBU) and a group of innovative broadcast technology partners including Axon, D&MS, DWESAM, EVS, Genelec, Grass Valley, Imagine Communications, Lawo, Nevion, Tektronix, Trilogy and Vizrt.
Today’s digital environment has a clear impact on audiences. Consumers want to be able to consume more media anytime, anywhere and on any device. This obliges media organisations to provide new formats, and to package their content for different media delivery platforms.
This ongoing business transformation would be difficult to achieve using traditional SDI-based technology, as it is not flexible enough to adapt to the continuous and rapid changes. While IP is often said to be the technology best placed to support that transformation, there are many questions in the industry about its readiness for live production. Can it, in its present state, bring to professional live media the transformation seen in other areas such as telecoms or media post production?
How to change?
The best way to answer these questions is to actually test this new technology in a real environment. The LiveIP project was designed with many short phases, built around typical workflows: single camera, multi camera, remote production, a live TV show. During the summer months in Europe, the set-up was used for a daily production and at IBC 2016, the kit was used to produce IBC TV.
What technology is being used?
This project started in spring 2015. The design of the system was based on the technology that was available at the time, and that vendors had committed to providing working implementations during the course of the project.
The topology used for the IP network is the so-called Spine-Leaf architecture. It is a software-defined network, based upon the OpenFlow standard, which deals with the routing of the media streams. To transport the uncompressed video, SMPTE ST 2022-6 was used. As in many SDI-based television studios, audio is usually carried separately from the video. A combination of AES67 and the Ravenna standard was used.
Just like in a traditional SDI-based studio, an SDI-over-IP studio requires the end-devices to be precisely synchronised. IEEE 1588-2008, or Precision Time Protocol (PTP), is the recognised way to achieve sufficiently precise time distribution over a network. Not all video equipment was already capable of using PTP during the project.
PTP includes several parameters, which are constrained in profiles that are specific to certain applications. In this project, two PTP profiles were used by the different devices: the profile for video applications as described in SMPTE ST 2059-2:2015 and the profile as described in AES67 for professional audio applications. From an operational point of view, one profile for video and audio would be beneficial.
What about interoperability?
The transition to IP video transport and IT architectures is a fundamental change for our industry. It brings more flexibility and modularity, but also adds complexity. The technology is also new to users, as well as to many vendors. This being said, we found that users have a baseline expectation: they want the same level of interoperability as with SDI, which gives them the liberty of building systems from best-of-breed components.
Therefore, there is a real advantage in bringing together technology pioneers on the premises of a broadcaster to interconnect their hardware and software to address a real use case — all while the technology is still evolving. Within this “safe haven”, engineers can cross company boundaries and work together on the interoperability between their products, without being burdened by commercial concerns. Moreover, the findings from this project are contributing to the international standardisation of the technology.
What to conclude?
From the LiveIP experience, we can conclude that it is possible today to build a live IP-based studio. No real roadblocks were encountered throughout the entire project. The set-up has proved to be particularly flexible due to the fact that there is more emphasis on configuration than cabling.
In order to help EBU members, who are Europe’s public service broadcasters, an EBU working group has drawn up what it believes will be the evolution of the technology over the coming years. The roadmap, which you can read more about at https://tech.ebu.ch/news/2016/08/ip-production-infrastructure—is-it-ready-for-take-off, was welcomed by many organisations and has been adopted by the Joint Task Force on Networked Media (JT-NM).
To unlock all the possibilities that IT-based systems can provide, further development is needed. Aspects to be explored include elementary flows, discovery and registration, capability management, and virtualisation.
The next big step towards IP-based live production would be to have a new open standard based on all current efforts and the VSF recommendations TR-03 and TR-04. The SMPTE drafting group is using these recommendations as a foundation for a new open standard that will be known as SMPTE SD-2110. This will enable separate video, audio and metadata essence in an open, interoperable fashion. The publication is to be expected very soon!