Telestream Archives – The Broadcast Knowledge

Video: Cloud Services for Media and Entertainment – Processing, Playout and Distribution

Posted on 24th May 2021 by Russell Trafford-Jones

What are the options for moving your playout, processing and distribution into the cloud? What will the workflows look like and what are the options for implementing them? This video covers the basics, describes many of the functions available like subtitle generation and QC then leads you through to harnessing machine learning,

SMPTE’s New York section has brought together Evan Statton and Liam Morrison from AWS, Alex Emmermann from Telestream, Chris Ziemer & Joe Ashba from Imagine Communications and Rick Phelps from Brklyn Media to share their knowledge on the topic. Rick kicks off proceedings with a look at the principles of moving to the cloud. He speaks about the need to prepare your media before the move by de-duplicating files, getting the structure and naming correct and checking your metadata is accurate. Whilst deduplicating data reduces your storage costs, another great way to do this is to store in IMF format. IMF, the Interoperable Media Format, is related to MXF and stores essences separately. By using pointers to the right media, new versions of files can re-use media from other files. This further helps reduce storage costs.

Rick finishes by running through workflow examples covering INgest, Remote Editing using PCoIP, Playout and VoD before running through the pros and cons of Public, Private and Hybrid cloud.

Next on the rosta are Chris & Joe outlining their approach to playout in the cloud. They summarise the context and zoom in to look at linear channels and their Versio product. An important aspect of bringing products to the cloud, explains Joe, is to ensure you optimise the product to take advantage of the cloud. Where a software solution on-prem will use servers running the storage, databases, proxy generation and the like, in the cloud you don’t want to simply set up EC2 instances to run these same services. Rather, you should move your database into AWS’s database service, use AWS storage and use a cloud-provided proxy service. This is when the value is maximised.

Alex leads with his learnings about calculating the benefits of cloud deployment focussing on the costs surrounding your server. You have to calculate the costs of the router port it’s connected to and the rest of the network infrastructure. Power and aircon is easy to calculate but don’t forget, Alex says, about the costs of renting the space in a data centre and the problems you hit when you have to lease another cage because you have become full. Suddenly and extra server has led to a two-year lease on datacentre space. He concludes by outlining Telestream’s approach to delivering transcode. QC, playback and stream monitoring in their Telestream Cloud offering.

Evan Statton talks about the reasons that AWS created CDI and they merged the encoding stages for DTH transmission and OTT into one step. These steps came from customers’ wishes to simplify cloud worksflows or match their on-prem experiences. JPEG-XS, for isntance, is there to ensure that ultra low-latency video can flow in and out of AWS with CDI allowing almost zero delay, uncompressed video to flow within the cloud. Evan then looks through a number of workflows: Playout, stadium connectivity, station entitlement and ATSC 3.0.

Liam’s presenation on machine learning in the cloud is the last of this section meeting. Liam focuses he comments and demos on machine learning for video processing. He explains how ML fits into the Articifical Intelligence banner and looks to where the research sector is heading. Machine learning is well suited to the cloud because of the need to have big GPU-heavy servers to manage large datasets and high levels of compute. the G4 series of EC2 servers is singled out as the machine learning instances of choice.

Liam shows demos of super resolution and frame interpolation the later being used to generate slow motion clips, increasing the framerate of videos, improving the smoothness of stop-motion animations and more. Bringing this together, he finishes by showing some 4K 60fps videos created from ancient black and white film clips.

The extensive Q&A looks at a wide range of topics:
The need for operational change management since however close you get the cloud workflows to match what your staff are used to, there will be issues adjusting to the differences.
How to budget due to the ‘transactional’ nature of AWS cloud microservices
Problems migrating TV infrastructure to the cloud
How big the variables are between different workflow designs
When designing cloud workflows, what are the main causes of latency? When fighting latency what are the trade-offs?
How long ML models for upconverting or transcoding take finish training?

Watch now!
Speakers

	Liam Morrison Principal Architect, Machine Learning, Amazon Web Services (AWS)
	Alex Emmermann Cloud Business Development, Telestream
	Joe Ashba Senior Solutions Architect, Imagine Communications
	Chris Ziemer VP Strategic Accounts & Partnerships, Imagine Communications
	Rick Phelps Founder, Brklyn Media
	Evan Statton Principal Architect, Amazon Web Services (AWS)
	Moderator: Ed DeLauter

Video: PTP/ST 2059 Best Practices developed from PTP deployments and experiences

Posted on 8th April 2021 by Russell Trafford-Jones

PTP is foundational for SMPTE ST 2110 systems. It provides the accurate timing needed to make the most out of almost zero-latency professional video systems. In the strictest sense, some ST 2110 workflows can work without PTP where they’re not combining signals, but for live production, this is almost never the case. This is why a lot of time and effort goes into getting PTP right from the outset because making it work perfectly from the outset gives you the bedrock on which to build your most valuable infrastructure upon.

In this video, Gerard Phillips from Arista, Leigh Whitcomb from Imagine Communications and Telestream’s Mike Waidson join forces to run down their top 15 best practices of building a PTP infrastructure you can rely on.

Gerard kicks off underlining the importance of PTP but with the reassuring message that if you ‘bake it in’ to your underlying network, with PTP-aware equipment that can support the scale you need, you’ll have the timing system you need. Thinking of scale is important as PTP is a bi-directional protocol. That is, it’s not like the black and burst and TLS that it replaces which are simply waterfall signals. Each endpoint needs to speak to a clock so understanding how many devices you’ll be having and where is important to consider. For a look a look at PTP itself, rather than best practices, have a look at this talk free registration required or this video with Meinberg.

Gerard’s best practices advice continues as he recommends using a routed network meaning having multiple layer 2 networks with layer 3 routing between This reduces the broadcast domain size which, in turn, increases stability and resilience. JT-NM TR-1001 can help to assist in deployments using this network architecture. Gerard next cautions about layer 2 IGMP snoopers and queriers which should exist on every VLAN. As the multicast traffic is flooded to the snooping querier in layer 2, it’s important to consider traffic flows.

When Gerard says PTP should be ‘baked in’, it’s partly boundary clocks he’s referring to. Use them ‘everywhere you can’ is the advice as they bring simplicity to your design and allow for easier debugging. Part of the simplicity they bring is in helping the scalability as they shed load from your GM, taking the brunt of the bi-directional traffic and can reduce load on the endpoints.

It’s long been known that audio devices, for instance, older versions of Dante before v4.2, use version one of PTP which isn’t compatible with SPMTE ST 2059’s requirement to use PTP v2. Gerard says that, if necessary, you should buy a version 1 to version 2 converter from your audio vendor to join the v1 island to your v2 infrastructure. This is linked to best practice point 6; All GMs must have the same time. Mike makes the point that all GMs should be locked to GPS and that if you have multiple sites, they should all have an active, GPS-locked GM even if they do send PTP to each other over a WAN as that is likely to deliver less accurate timing even if it is useful as a backup.

Even if you are using physically separate networks for your PTP and ST 2110 main and backup networks, it’s important to have a link between the two GMs for ST 2022-7 traffic so a link between the two networks just for PTP traffic should be established.

The next 3 points of advice are about the ongoing stability of the network. Firstly, ST 2059-2 specifies the use of TLV messages as part of a mechanism for media notes to generate drop-frame timecode. Whilst this may not be needed day 1, if you have it running and show your PTP system works well with it on, there shouldn’t be any surprises in a couple of years when you need to introduce an end-point that will use it. Similarly, the advice is to give your PTP domain a number which isn’t a SMPTE or AES default for the sole reason that if you ever have a device join your network which hasn’t been fully configured, if it’s still on defaults it will join your PTP domain and could disrupt it. If, part of the configuration of a new endpoint is changing the domain number, the chances of this are notably reduced. One example of a configuration item which could affect the network is ‘ptp role master’ which will stop a boundary clock from taking part in BCMA and prevents unauthorised end-points taking over.

Gerard lays out the ways in which to do ‘proper commissioning’ which is the way you can verify, at the beginning, that your PTP network is working well-meaning you have designed and built your system correctly. Unfortunately, PTP can appear to be working properly when in reality it is not for reasons of design, the way your devices are acting, configuration or simply due to bugs. To account for this, Gerard advocates separate checklists for GM switches and media nodes with a list of items to check…and this will be a long list. Commissioning should include monitoring the PTP traffic, and taking a packet capture, for a couple of days for analysis with test and measurement gear or simply Wireshark.

Leigh finishes up the video talking about verifying functionality during redundancy switches and on power-up. Commissioning is your chance to characterise the behaviour of the system in these transitory states and to observe how equipment attached is affected. His last point before summarising is to implement a PTP monitoring solution to capture the critical parameters and to detect changes in the system. SMPTE RP 2059-15 will define parameters to monitor, with the aim that monitoring across vendors will provide some sort of consistent metrics. Also, a new version of IEEE-1588, version 2.1, will add monitoring features that should aid in actively monitoring the timing in your ST 2110 system.

This Arista white paper contains further detail on many of these best practices.

Watch now!
Speakers

	Gerard Phillips Solutions Engineer, Arista
	Leigh Whitcomb Principal Engineer. Imagine
	Mike Waidson Application Engineer, Telestream

Video: Keeping Time with PTP

Posted on 4th November 2020 by Russell Trafford-Jones

Different from his talk of the same name we covered last week, Mike Waidson from Telestream explains the fundamentals of PTP joined by Leigh Whitcomb from Imagine Communications and Robert Welch from Arista. Very few PTP talks include a live BCMA quiz plus, with more time than the IP Showcase talks, this is a well-paced, deep look into the basics.

Mike starts by reviewing how the measurement of time has been more and more accurately measured with us now, typically using atomic clocks. In the TV-domain analogue video used signals for B&B which gave frequency information in the subcarrier and allowed frequency locking and to keep in sync with other signals. NTP has allowed computers and routers on IP networks to keep lock allowing sub-millisecond synchronisation over LANs. Now we have IEEE 1588 PTP which harnesses hardware for maximum precision providing sub-microsecond precision.

Traditionally an SPG would create many different synchronising signals, distributed by DAs. With PTP however, the idea is creating a single time signal on to the network (as well as older signals if necessary). Although, the important thing to remember is that PTP both sends and receives data from the endpoints. GPS is made from 31 active satellites of which only 4 are needed for a lock. But other systems such as the Russian GLONASS, the Chinese BAIDU Navigational system or the European Galileo can also be used, sometimes in conjunction with each other to improve locking speed or give resilience.

Mike and his co-hosts give an overview of the standards that make all this possible, starting with the PTP standard itself IEEE 1588-2019 which is added to by SMPTE 2059. The latter is two standards that, together ensure broadcast devices can usefully harness PTP which is a general, cross-industry standard and track all signals back to a single point in time in 1970. Whilst this may seem extreme, the benefit of doing this is that if we know that all possible types of signal were in-phase at this one point in time, we can extrapolate how each signal should be phased now and use that information to synchronise the system. Upcoming to PTP, we hear, are standardised ways to monitor PTP plus additional security around the standard.

The next section looks at the types of Grandmaster and the fact that each clock works in its own domain. Typically, all your system will be in the same domain, but if you have incompatible situations such as older Dante networks or if you want to have a testing environment, you can use domains to separate your equipment. The standard, as defined by SMPTE 2059 is 127.

Mike then looks at the different types of PTP Message types: Announce, Sync & Follow up, Delay Request, Delay Response and Management Messages (broadcast information, drop second, time zone etc.) He then brings some of these up in Wireshark and talks us through the structure and what can be found within.

The most original part of the talk is the live walkthrough of three different scenarios where Leigh and Robert talk through their thinking on which clock will be the grandmaster and for what reason. This comes down to their understanding of the order of precedence of the metrics such as the manually-allotted priority, then the class of clock, clock accuracy and other values. One value worth remembering is that if your clock is locked to GPS it will have a class of 6, but if it then loses lock, it will become 7.

PTP talks are not complete without an explanation of the sync message exchanges needed to actually determine the time (and the relative delays in order to compute it) as well as the secondary clock types, boundary and transparent. Boundary clocks take on much of the two-way traffic in PTP protecting the grandmasters from having to speak directly to all the, potentially, thousands of devices. Transparent switches, simply update the time announcements with the delay for the message to move through the switch. Whilst this is useful in keeping the timing accurate, it provides no protection for the grandmasters.

Before the talk finishes with a Q&A, the team finish by explaining the difference between operating in unicast and multicast, prioritising PTP traffic using the differentiated services protocol and adding redundancy to the PTP system.

Watch now!
Free registration required
Speakers

	Robert Welch Technical Solultions Lead, Arista
	Leigh Whitcomb Principal Engineer. Imagine
	Mike Waidson Application Engineer, Telestream

Video: Keeping Time with PTP

Posted on 23rd October 2020 by Russell Trafford-Jones

The audio world has been using PTP for years, but now there is renewed interest thanks to its inclusion in SMPTE ST 2110. Replacing the black and burst timing signal (and for those that used it, TLS), PTP changes the way we distribute time. B&B was a waterfall distribution, PTP is a bi-directional conversation which, as a system, needs to be monitored and should be actively maintained.

Michael Waidson from Telestream (who now own Tektronix) brings us the foundational basics of PTP as well as tips and tricks to troubleshoot your PTP system. He starts by explaining. the types of messages which are exchanged between the clock and the device as well as why all these different messages are necessary. We see that we can set the frequency at which the announce, sync and follow-up messages. The sync and follow-up messages actually contain the time. When a device receives one of these messages, it needs to respond with a ‘delay request’ in order to work out how much of a delay there is between it and the grand master clock. This will result in it receiving a delay response. On top of these basic messages, there is a periodic management message which can contain further information such as daylight savings time or drop-frame information.

Michael moves on to looking at troubleshooting highlighting the four main numbers to check: The domain value, grandmaster ID, message rates and the communication mode. PTP is a global standard used in many industries. To make PTP most useful to the broadcast industry, SMPTE ST 2059 defines values to use for message repetition (4 per second for announce messages, 8 for sync, delay request and delay response). ST 2059 also defines how devices can determine the phase of any broadcast signal for any given time which is the fundamental link needed to ensure all devices keep synchronicity.

Another good tip from Michael is if you see the grandmaster MAC changing between the grandmasters on the system, this indicates it’s no receiving any announce messages so is initiating the Best Master Clock Algorithm (BMCA) and trying the next grandmaster. Some PTP monitoring equipment including from Meinberg and from Telestream can show the phase lag of the PTP timing as well as the delay between the primary and secondary grandmaster – the lower the better.

A talk on PTP can’t avoid mentioning boundary clocks and transparent switches. Boundary clocks take on much of the two-way traffic in PTP protecting the grandmasters from having to speak directly to all the, potentially, thousands of devices. Transparent switches, simply update the time announcements with the delay for the message to move through the switch. Whilst this is useful in keeping the timing accurate, it provides no protection for the grandmasters. He finishes video ends with a look at how to check PTP messages on the switch.

Watch now!
Speakers

Michael Waidson
Application Engineer
Telestream (formerly Tektronix)

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