Video: Is IP Really Better than SDI?

Is SDI so bad? With the industry as a whole avidly discussing and developing IP technology, all the talk of the benefits of IP can seem like a dismissal of SDI. SDI served the broadcast industry very well for decades, so what’s suddenly so wrong with it? Of course, SDI still has a place and even some benefits over IP. Whilst IP is definitely a great technology to take the industry forward, there’s nothing wrong with using SDI in the right place.

Ed Calverley from Q3Media takes an honest look at the pros and cons of SDI. Not afraid to explain where SDI fits better than IP, this is a very valuable video for anyone who has to choose technology for a small or medium project. Whilst many large projects, nowadays, are best done in IP, Ed looks at why that is and, perhaps more importantly, what’s tricky about making it work, highlighting the differences doing the same project in SDI.

This video is the next in IET Media’s series of educational videos and follows on nicely from Gerard Phillips’ talk on Network Design for uncompressed media. Here, Ed recaps on the reasons SDI has been so successful and universally accepted in the broadcast industry as well as looking at SDI routing. This is essential to understand the differences when we move to IP in terms of benefits and compromises.

SDI is a unidirectional technology, something which makes it pleasantly simple, but at scale makes life difficult in terms of cabling. Not only is it unidirectional, but it can only really carry one video at a time. Before IP, this didn’t seem to be much of a restriction, but as densities have increased, cabling was often one limiting factor on the size of equipment – not unlike the reason 3.5mm audio jacks have started to disappear from some phones. Moreover, anyone who’s had to plan an expansion of an SDI router, adding a second one, has come across the vast complexity of doing so. Physically it can be very challenging, it will involve using tie-lines which come with a whole management overhead in and of themselves as well as taking up much valuable I/O which could have been used for new inputs and outputs, but are required for tying the routers together. Ed uses a number of animations to show how IP significantly improves media routing,

In the second part of the video, we start to look at the pros and cons of key topics including latency, routing behaviour, virtual routing, bandwidth management, UHD and PTP. With all this said, Ed concludes that IP is definitely the future for the industry, but on a project-by-project basis, we shouldn’t dismiss the advantages that do exist of SDI as it could well be the right option.

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Speakers

Ed Ed Calverley
Trainer & Consultant
Q3Media.co.uk
Russell Trafford-Jones Moderator: Russell Trafford-Jones
Exec Member, IET Media Technical Network
Editor, The Broadcast Knowledge
Manager, Services & Support, Techex

Video: Network Design for Live Production

The benefits of IP sound great, but many are held back with real-life concerns: Can we afford it? Can we plug the training gap? and how do we even do it? This video looks at the latter; how do you deploy a network good enough for uncompressed video, audio and metadata? The network needs to deal with a large number of flows, many of which are high bandwidth. If you’re putting it to air, you need reliability and redundancy. You need to distribute PTP timing, control and maintain it.

Gerard Philips from Arista talks to IET Media about the choices you need to make when designing your network. Gerard starts by reminding us of the benefits of moving to IP, the most tangible of which is the switching density possible. SDI routers can use a whole rack to switch over one thousand sources, but with IP Gerard says you can achieve a 4000-square router within just 7U. With increasingly complicated workflows and with the increasing scale of some broadcasters, this density is a major motivating factor in the move. Doubling down on the density message, Gerard then looks at the difference in connectivity available comparing SDI cables which have signal per cable, to 400Gb links which can carry 65 UHD signals per link.

Audio is always ahead of video when it comes to IP transitions so there are many established audio-over-IP protocols, many of which work at Layer 2 over the network stack. Using Layer 2 has great benefits because there is no routing which means that discovering everything on the network is as simple as broadcasting a question and waiting for answers. Discovery is very simple and is one reason for the ‘plug and play’ ease of NDI, being a layer 2 protocol, it can use mDNS or similar to query the network and display sources and destinations available within seconds. Layer 3-based protocols don’t have this luxury as some resources can be on a separate network which won’t receive a discovery request that’s simply broadcast on the local network.

Gerard examines the benefits of layer 2 and explains how IGMP multicast works detailing the need for an IGMP querier to be in one location and receiving all the traffic. This is a limiting factor in scaling a network, particularly with high-bandwidth flows. Layer 3, we hear, is the solution to this scaling problem bringing with it more control of the size of ‘failure domains’ – how much of your network breaks if there’s a problem.

The next section of the video gets down to the meat of network design and explains the 3 main types of architecture: Monolithic, Hub and spoke and leaf and spoke. Gerard takes time to discuss the validity of all these architectures before discussing coloured networks. Two identical networks dubbed ‘Red’ and ‘Blue’ are often used to provide redundancy in SMPTE ST 2110, and similar uncompressed, networks with the idea that the source generates two identical streams and feeds them over these two identical networks. The receiver receives both streams and uses SMPTE ST 2022-7 to seamlessly deal with packet loss. Gerard then introduces ‘purple’ networks, ones where all switch infrastructure is in the same network and the network orchestrator ensures that each of the two essence flows from the source takes a separate route through the infrastructure. This means that for each flow there is a ‘red’ and a ‘blue’ route, but overall each switch is carrying a mixture of ‘red’ and ‘blue’ traffic.

The beauty of using IGMP/PIM for managing traffic over your networks is that the network itself decides how the flows move over the infrastructure. This makes for a low-footprint, simple installation. However, without the ability to take into account individual link capacity, the capacity of the network in general, bitrate of individual flows and understanding the overall topology, there is very control over where your traffic is which makes maintenance and fault-finding hard and, more generally, what’s the right decision for one small part of the network is not necessarily the right decision for the flow or for the network as a whole. Gerard explains how Software-Defined Networking (SDN) address this and give absolute control over the path your flows take.

Lastly, Gerard looks at PTP, the Precision Time Protocol. 2110 relies on having the PTP in the flow, in the essence allowing flows of separate audio and video to have good lip-sync and to avoid phase errors when audio is mixed together (where PTP has been used for some time). We see different architectures which include two grandmaster clocks (GMs), discuss whether boundary clocks (BCs) or transparent clocks (TCs) are the way to go and examine the little security that is available to stop rogue end-points taking charge and becoming grandmaster themselves.

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Speakers

Gerard Phillips Gerard Phillips
Systems Engineer,
Arista

Video: The End of Broadcast?

This discussion asks what the limits are of ‘broadcast’ in a world increasingly dominated by streaming. Whilst services like the BBC’s iPlayer have demonstrated how on-demand can sit alongside live streams of linear channels, the growing world of Disney+, Netflix and Apple TV+ is muscling in on the family television bringing with them different ways of accessing video.

Presented by Ian Nock, chair of the IET Media technical network, this is the 2020 John Logie Baird lecture online. First up, is Chris Wood from OTT specialist Spicy Mango who represents the perspective that OTT is the way forward. This isn’t a fight between screen sizes, he starts by saying, but rather about experiences and expectations. A great example of this is how pause and rewind features have made their way into many linear TV offerings. The convenience to pause a video while you leave the room or discuss it was so powerful that when it was possible to bring it into live, it did. This type of feature migration will continue to happen as the types of service merge.

Chris makes the important point that ‘live TV’ often means linear. There is a lot of live streaming available through Twitch, sports providers like DAZN and companies like Amazon Prime which is not captured separately. This makes it hard to understand how much people are still valuing the live feeling. Live TV, he says, is not going away whatever happens to linear RF transmissions because we need live programming, we enjoy it differently.

Source: DTG

Next, representing the UK Digital TV Group (DTG) is Yvonne Thomas who looks at the fragmented landscape with a large variety of types of VoD service available – subscription, advertiser etc. For the younger audience whose experience of video is predominantly over IP, their experiences become quite fragmented meaning it’s hard for a broadcaster to maintain continuity and relevance. Yvonne also talks about the proliferation of IT needed to watch all this content which can lead to families inadvertently exposing their data or compromising their security.

Nigel Walley from Decipher makes the point that some of our intuitions are wrong. As we see trends evolving, whilst the industry was initially discussing the rise of ‘second screens’, it’s important to realise that some of this was driven by the simple fact that the only place you could watch Netflix of YouTube was your second screen. As consumer electronics manufacturers have made space for ‘Netflix’ buttons and we see Google and Apple with their HDMI connected players, we see people have quickly reverted to watching good content on their best screen; their TV.

Another important point made by Nigel is that as much people companies talk about the ability to individually target viewers and deliver highly customised services, there will always be situations with shared viewing whether they may as well not be logged in as customisation takes much more of a back seat.

Source: OMDIA

Maria Rua Aguete from Omdia challenges our assumptions on who the big players in streaming are. They can be ranked both by revenue and by subscribers. Maria shows us that China Telecom, Baidu and Tencent are in positions 2, 3 and 4 when counted by subscribers. Still, one third of the world’s OTT subscribers are held by Amazon, Netflix and Disney+.
Maria continues to deliver a vast range of timely statistics that help us understand the current situation within the pandemic. She covers the popularity of free services with in the UK, recent M&A activity, the consumers’ rising appetite for video and international channels.

The session closes with a 20 minute Q&A.

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Speakers

Maria Rua Aguete
Technology Fellow & Executive Director,
Omdia
Yvonne Thomas Yvonne Thomas
Strategic Technologist
Digital TV Group
Chris Wood Chris Wood
CTO,
Spicy Mango
Nigel Walley Nigel Walley
Managing Director,
Decipher
Ian Nock Moderator: Ian Nock
Chair, IET Media Technical Network

On-Demand Webinar: How to Prove Value with AI and Machine Learning

This webinar is now available online.

We’ve seen AI entering our lives in many ways over the past few years and we know that this will continue. Artificial Intelligence and Machine Learning are techniques that are so widely applicable they will touch all aspects of our lives before too many more years have passed. So it’s natural for us to look at the broadcast industry and ask “How will AI help us?” We’ve already seen machine learning entering into codecs and video processing showing that up/downscaling can be done better by machine learning than with the traditional ‘static’ algorithms such as bicubic, lanczos and nearest neighbour. This webinar examines the other side of things; how can we use the data available within our supply chains and from our viewers to drive efficiencies and opportunities for better monetisation?

There isn’t a strong consensus on the difference between AI and Machine learning. One is that that Artificial Intelligence is a more broad term of smart computing. Others say that AI has a more real-time feedback mechanism compared to Machine Learning (ML). ML is the process of giving a large set of data to a computer and giving it some basic abilities so that it can learn for itself. A great example of this is the AI network monitoring services available that look at all the traffic flowing through your organisation and learn how people use it. It can then look for unusual activity and alert you. To do this without fixed thresholds (which for network use really wouldn’t work) is really not feasible for humans, but computers are up to that task.

For conversations such as this, it usually doesn’t matter how the computer achieves it, AI, ML or otherwise. The points how can you simplify content production? How can you get better insights into the data you have? How can you speed up manual tasks?

David Short from IET Media moderates this session with Steve Callanan who’s company WIREWAX is working to revolutionise video creation, asset management and interactive video services joined by Hanna Lukashevich from Fraunhofer IDMT (Institute for Digital Media Technology) who uses machine learning to understand and create music and sound. Grant Franklin Totten completes the panel with his experience at Al Jazeera who have been working on using AI in broadcast since 2018 as a way to help maintain editorial and creative compliance as well as detecting fake news and bias checking.

Watch now!
Speakers

David Short Moderator: David Short
Vice Chair,
IET Media Technical Network
Steve Callanan Steve Callanan
Founder,
WIREWAX
Hanna Lukashevich Hanna Lukashevich
Head of Semantic Music Technologies,
Fraunhofer IDMT
Grant Franklin Totten Grant Franklin Totten
Head of Media & Emerging Platforms,
Al Jazeera Media Network