By Matthew Goldman
We are on the verge of a revolution in how professional media facilities handle audio, video and ancillary data. While this shift — from serial digital interface (SDI) to Internet protocol (IP) — is just as monumental and as significant as the industry’s transition from tape to file-based operations, it can be seamless if engineers plan out the transition carefully.
The end of the SDI era
For the past several decades, the professional media industry has used different variants of SDI to move around high-quality real-time video. SDI (defined by nearly two dozen SMPTE standards) has served us very well — meeting the industry’s “24/7/365” requirements for high image quality, high aural quality, “always on” real time and high availability — and continues to do so as an immensely useful solution.
However, industry-specific interfaces, protocols and infrastructure limit effectiveness in addressing the challenges of modern media production and distribution, including scalability and complexity concerns.
Since the development of SDI those many years ago, we have entered the information technology (IT) age. Because computers are ubiquitous and hundreds of billions of devices are in use worldwide, it has become possible to realise significant economies of scale in working with IT technology. By moving away from the industry-specific interfaces, protocols, and infrastructure of SDI and towards IP, and leveraging off the more scalable and cost-effective interfaces, protocols and infrastructure of IT, professional media facilities have the freedom and agility to rapidly deploy new solutions and quickly realise new capabilities that can simplify operations, reduce costs and improve their competitive potential.
When engineers understand the new standards that support the migration to all-IP operations, producers and on-air talent will not even know something has changed. They will, however, experience its impact in countless ways.
The impact of going all-IP
Following the lead of the networking industry, the broadcast industry is beginning to take advantage of IT: By virtualising operations and shifting to software-defined networking (SDN) and media processing, with the data and control plane functions separate from one another; by leveraging more economical commercial off-the-shelf (COTS) hardware, including servers and switches; and by abstracting video processing capabilities as software from the underlying hardware.
In addition to accelerating development and updating of software solutions to address evolving market needs more quickly and more cost-effectively, the industry’s embrace of IT also enables the transport of professional media over managed IP networks.
Top six reasons for moving to all-IP
1. To enhance the flexibility and agility of the video plant, with “video” meaning professional media, including video, audio and ancillary data.
2. To enable compatibility with network interfaces on COTS Ethernet switches and COTS servers.
3. To achieve the flexible association of streams into desired groups of media.
4. To establish network-based registration and discovery of devices, streams and media capabilities.
5. To realise much greater density than was possible with SDI, over an inherently bidirectional connection.
6. To create a standard suite that is agnostic to the specific video and audio formats that are being carried on it, and which uses the same carriage mechanism regardless of resolution, bit depth, frame rate, number of channels, and so on.
In short, all-IP allows media professionals to do more, and to do it with greater flexibility and speed — and at a lower cost — than ever before. With an understanding of the latest SMPTE standards, facilities can execute their transition and realise these benefits with surprising ease.
The path towards all-IP
Building on advances made earlier by the networking industry, the professional media industry is now writing its own specific software-defined media processing software to ride on COTS servers and switches. In taking this step, we will be enabling the software-oriented virtualised video production plants of the future.
The first phase of achieving this goal is to facilitate the carriage of video, audio and ancillary data essence in a manner consistent with the six aforementioned reasons for embracing IP. We have taken this vital step by creating the SMPTE ST 2110 suite of standards, titled Professional Media Over Managed IP Networks.
The new standards suite describes the carriage of video, audio and ancillary data — all co-timed and related to each other so that everything can stay in sync — while maintaining the flexibility to run on generic IT infrastructure.
Underlying these capabilities is a common time-based system that is precise enough to handle real-time video, and capable of working seamlessly with generic switches. IEEE 1588 Precision Time Protocol (PTP) serves as a common, very precise time base that can be carried point-to-point on IP over Ethernet networks through switches and servers.
By creating a profile for the use of PTP in professional media environments and establishing time-aligned signal generation, another SMPTE standards suite — SMPTE ST 2059 — defines the interoperable use of IP-based media equipment and also permits interoperation with conventional genlocked SDI equipment.
While the combination of SMPTE ST 2059 and ST 2110 lays the foundation for the broadcast migration to all-IP, we already have SDI over IP now, thanks to SMPTE ST 2022-6. Together, all of these standards provide broadcasters with the flexibility to migrate incrementally to IP, using legacy SDI gear along with newer IP-capable systems and equipment, or to make a wholesale shift to all-IP.
We are now beginning to see implementation solutions for doing just that — going all-IP all at once. The viability of this approach has become evident through a series of interoperability demonstrations for professional media over IP. SMPTE is one of eight sponsors of what is known as the IP Showcase, a multi-vendor interoperability demonstration that first took place at IBC 2016 and has continued at key trade shows, including the SMPTE 2017 Annual Technical Conference & Exhibition, with standing-room-only crowds for presentations related to the IP migration.
These standards provide the professional media industry with a toolset for embracing IP. Media technology suppliers can deliver the solutions that facilitate IP operations, and broadcasters and other content creators can deploy IP-based solutions that give them greater agility in providing the timely, engaging and unique content that today’s consumers demand.
Like any major industry-wide advance, the migration to all-IP has called for extensive work in standards development and testing, with input from a wide array of stakeholders. Now, however, a great deal of that work has culminated in standards — and the SMPTE ST 2110 suite, in particular — that pave the way for professional media companies to make a painless, even seamless, shift to the fantastic new world of all-IP.