Video: SMPTE Technical Primers

The Broadcast Knowledge exists to help individuals up-skill whatever your starting point. Videos like this are far too rare giving an introduction to a large number of topics. For those starting out or who need to revise a topic, this really hits the mark particularly as there are many new topics.

John Mailhot takes the lead on SMPTE 2110 explaining that it’s built on separate media (essence) flows. He covers how synchronisation is maintained and also gives an overview of the many parts of the SMPTE ST 2110 suite. He talks in more detail about the audio and metadata parts of the standard suite.

Eric Gsell discusses digital archiving and the considerations which come with deciding what formats to use. He explains colour space, the CIE model and the colour spaces we use such as 709, 2100 and P3 before turning to file formats. With the advent of HDR video and displays which can show bright video, Eric takes some time to explain why this could represent a problem for visual health as we don’t fully understand how the displays and the eye interact with this type of material. He finishes off by explaining the different ways of measuring the light output of displays and their standardisation.

Yvonne Thomas talks about the cloud starting by explaining the different between platform as a service (PaaS), infrastructure as a service (IaaS) and similar cloud terms. As cloud migrations are forecast to grow significantly, Yvonne looks at the drivers behind this and the benefits that it can bring when used in the right way. Using the cloud, Yvonne shows, can be an opportunity for improving workflows and adding more feedback and iterative refinement into your products and infrastructure.

Looking at video deployments in the cloud, Yvonne introduces video codecs AV1 and VVC both, in their own way, successors to HEVC/h.265 as well as the two transport protocols SRT and RIST which exist to reliably send video with low latency over lossy networks such as the internet. To learn more about these protocols, check out this popular talk on RIST by Merrick Ackermans and this SRT Overview.

Rounding off the primer is Linda Gedemer from Source Sound VR who introduces immersive audio, measuring sound output (SPL) from speakers and looking at the interesting problem of forward speakers in cinemas. The have long been behind the screen which has meant the screens have to be perforated to let the sound through which interferes with the sound itself. Now that cinema screens are changing to be solid screens, not completely dissimilar to large outdoor video displays, the speakers are having to move but now with them out of the line of sight, how can we keep the sound in the right place for the audience?

This video is a great summary of many of the key challenges in the industry and works well for beginners and those who just need to keep up.

Watch now!
Speakers

John Mailhot John Mailhot
Systems Architect for IP Convergence,
Imagine Communications
Eric Gsell Eric Gsell
Staff Engineer,
Dolby Laboratories
Linda Gedemer, PhD Linda Gedemer, PhD
Technical Director, VR Audio Evangelist
Source Sound VR
Yvonne Thomas Yvonne Thomas
Strategic Technologist
Digital TV Group

Video: The 7th Circle of Hell; Making Facility-Wide Audio-over-IP Work

audio-over-ip

When it comes to IP, audio has always been ahead of video. Whilst audio often makes up for it in scale, its relatively low bandwidth requirements meant computing was up to the task of audio-over-IP long before uncompressed video-over-IP. Despite the early lead, audio-over-IP isn’t necessarily trivial. However, this talk aims to give you a heads up to the main hurdles so you can address them right from the beginning.

Matt Ward, Head of Video for UK-based Jigsaw24, starts this talk revising the reasons to go audio over IP (AoIP). The benefits vary for each company. For some, reducing cabling is a benefit, many are hoping it will be cheaper, for others achievable scale is key. Matt’s quick to point out the drawbacks we should be cautious of, not least of which are complexity and skill gaps.

Matt fast-tracks us to better installations by hitting a list of easy wins some of which are basic, but a disproportionately important as the project continues i.e. naming paths and devices and having IP addresses in logical groups. Others are more nuanced like ensuring cable performance. For CAT6 cabling, it’s easy to get companies to test each of your cables to ensure the cable and all terminations are still working at peak performance.

Planning your timing system is highlighted as next on the road to success with smaller facilities more susceptible to problems if they only have one clock. But any facility has to be carefully considered and Matt points out that the Best Master Clock Algorithm (BMCA).

Network considerations are the final stop on the tour, underlining that audio doesn’t have to run in its own network as long as QoS is used to maintain performance. Matt details his reasons to keep Spanning Tree Protocol off, unless you explicitly know that you need it on. The talk finishes by discussing multicast distribution and IGMP snooping.

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Speaker

Matt Ward Matt Ward
Head of Audio,
Jigsaw24

Video: Avoiding Traps and Pitfalls When Designing SMPTE 2059-2 Networks

As the industry gains more and more experience in implementing PTP, AKA SMPTE 2059-2, timing systems it’s natural to share the experiences so we can all find the best way to get the job done.

Thomas Kernen is a staff architect at Mellanox with plenty of experience under his belt regarding PTP so he’s come to the IP Showcase at IBC 2019 to explain.

The talk starts by discussing what good timing actually is and acknowledging everyone’s enthusiasm going into a project for a well designed, fully functioning system. But, importantly, Thomas then looks at a number of real-world restrictions that come into projects which compromise our ability to deliver a perfect system.

Next Thomas looks at aspects of a timing strategy to be careful of. The timing strategy outlines how the timing of your system is going to work, whether that is message rates or managing hierarchy amongst many other possibilities.

The network design itself, of course, has an important impact on your system. This starts at the basics of whether you build a network which is, itself, PTP aware. In general, Thomas says, it should be PTP aware. However, for smaller networks, it may be practical to use without.

Security gets examined next, talking about using encrypted transports, access control lists, ensuring protect interfaces etc. with the aim of preventing unintended access, removing the ability to access physically – much of this is standard IT security, but it’s so often ignored that it’s important to point it out.

PTP is a system, it’s not a signal like B&B so monitoring is important. How will you know the health of your PTP distribution? You need to monitor on the network side, from the point of view of the deices themselves but also analyse the timing signals themselves, for instance, by comparing the timing signals between the main and reserve.

Finally, Thomas warns about designing redundancy systems since “Redundancy in PTP doesn’t exist.” and then finishes with some notes on properly completing a PTP project.

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Speaker

Thomas Kernen Thomas Kernen
Staff Architect,
Mellanox Technologies

Video: Using PTP & SMPTE 2059 A Practical Experience Perspective

NAB 2019 saw another IP Showcase with plenty of talks on the topic on many people’s minds: PTP and timing in IP systems. It seems there’s a lot which needs to be considered and, truth be told, a lot of people don’t feel they have the complete list of questions to be asking and certainly don’t know all the answers.

So, here, Greg Shay from Telos talks about the learnings from his extensive experience with timing IP signals and with PTP under SMPTE 2059. He hits the following topics;

  • Must you always have a GPS reference for the PTP master?
  • Are PTP-aware switches always necessary?
  • Can you safely not use PTP Peer Delay requests / responses?
  • What is the effect of internal oscillator tolerance and stability when designing PTP client equipment?

To my ears, these are 4 well placed questions because I’ve heard these asked; they are current in the minds of people who are grappling with current and prospective IP installations.

Greg treats gives each one of these due time and we see some interesting facts come out:
You don’t always need a time-synchronised PTP master (pretending to be in 1970 can work just fine).
Compensating for PTP Peer Delay can make things worse – which seems counter-intuitive to the point of PTP Peer Delay requests.
We also see why PTP-aware switches matter and a statistical method of managing without.

This is a talk which exemplifies IP talks which ‘go deeper’ than simply explaining the point of standards. Implementation always takes thought – not only in basic architecture but in use-cases and edge-cases. Here we learn about both.

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Speakers

Greg Shay Greg Shay
CTO,
The Telos Alliance