SDI vs IP: Current trends and future outcomes


When looking at the current broadcast technology landscape, it appears that there are several simultaneous pathways to the future in play. When it comes to the selection of SDI or IP video, both customers and manufacturers are locked into decisions by circumstances beyond their control, or an economic reality that is hard to overcome. In the short term, we will see lots of hybrid facilities and implementations, but ultimately IP and IT-based solutions are the end-game for the industry.

The IP video movement

The maturity of IT technology, the necessity of having higher bandwidth transport for 4K/Ultra HD (UHD), 8K, and beyond, along with a desire for more connectivity between products than SDI can offer, led trade alliance groups and SMPTE to work on the IP standard now designated as ST 2110. Several of the 2110 suite of standards were ratified in September of 2017, unlocking some of the industry paralysis to begin making purchasing decisions.

Two years prior to the ratification of SMPTE 2110, NewTek introduced NDI (Network Device Interface), a free software IP video standard. Based on a decade of work to bring baseband video onto computer networks, NDI became an early option for broadcasters wanting to make the move to IP. Several other manufacturers, including Evertz and Sony, had IP formats in the running, but deployments were confined to a small set of customers.

The economic reality for broadcasters

The decision to go to IP or stick with SDI is largely driven by economics for today’s broadcasters. For many, SMPTE 2110 may be too expensive with all-new IT infrastructure, new IP products, and additional human resources to manage it all. As largely a replacement for SDI today, many of the benefits of 2110 are still forthcoming. With this current reality, some top-tier broadcasters will implement the SMPTE standard, but mid-level and regional broadcasters may have a hard time justifying the cost.

NDI is an alternative option for broadcasters who want to move to IP more affordably. It works on existing network infrastructure, and supports SDI and 2110 I/O for hybrid environments. For others, staying with SDI may make sense, depending on what type of production is required and how “future-proof” they want to be.

12G – a brief saviour for SDI?

The rush to 4K/UHD in Asia-Pacific with government initiatives in South Korea, Japan and China within the past few years has forced broadcasters to move ahead with their plans despite the state of IP video at the time. Mobile/outside broadcast (OB) trucks also need a way to do 4K/UHD simply, without using four quad-link cables for each video source, which adds a lot of weight and dollars. These factors and a few more have created a market of unknown size for 12G SDI. While requiring new cabling and routing, 12G SDI operates like video always has in the past, making it less of a paradigm shift than going to IP.

In contrast, 4K IP signals using SMPTE 2110 require 40GbE and 100GbE networks for the large streams, at least until some form of mezzanine compression is ratified. Using IP standards for 4K is a bit simpler and more cost-effective. 4K/UHD IP can travel over existing 1GbE and 10GbE networks, and uses mDNS for auto discovery, cutting configuration time to almost nothing. So, it appears that 12G-SDI does have some momentum right now. The question remains as to whether this is only temporary, or if there will be a move to IP by these 12G customers in the future.

The manufacturer perspective

Hardware manufacturers who have spent years building SDI products face an even tougher proposition with IP — redesign the entire product line or add IP conversion to and from their baseband video products. Most have chosen the latter, meaning that there are no new efficiencies or bandwidth improvements by using IP with their products, just increased cost to customers in most cases. For these companies, adding 12G-SDI to their product mix makes sense as an incremental change to their manufacturing processes. In the end, they are still processing baseband SDI video, just with a different interface. This situation does create a short-term market for standalone 12G-SDI and IP converters, but manufacturers will have to make hay while the sun shines to recoup their costs and make some money.

Software-based products, on the other hand, are much more flexible with IP. If there is a software version of the IP available, everything can exists in the computer and network domains using native IP streams. Things like virtualisation become very easy at this point.

Data centres and the cloud

Many in the industry, including myself, believe that the future of video is software, computers and networks. Much of our current interaction with top broadcasters revolves around the migration of video production from proprietary hardware and video equipment rooms to software-only solutions and data centers.

Whether it is a virtualised local cloud deployment or a full public cloud implementation that industry leaders are contemplating, the result is a 100% IT and IP-centric approach to the future. Scalability, flexibility, redundancy, backup and overall cost savings are reasons for the move in this direction, building a powerful case for those broadcasters trying to make the most of their business. This leaves very little room for SDI in the long-term future of the industry.

An industry thought leader has predicted another 25 years of SDI — I do not see that as a real possibility. The sooner customers embrace the IT/IP world, the better off they will be in the long run.


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