Russell Trafford-Jones, Author at The Broadcast Knowledge

Webinar: RAVENNA and its Relationship to AES67 and SMPTE ST 2110

Posted on 14th April 2020 by Russell Trafford-Jones

This webinar is now available on-demand

This first in a series of webinars, this will have a broad scope covering the history of audio networking in, the development of RAVENNA the the consequent developments of AES67 and ST2110. Whether you’re new to or already familiar with RAVENNA and/or AES67 & ST2110 you’ll benefit from this webinar either as revision or as an excellent starting point for understanding the landscape of Audio-over-IP standards and technologies.

This webinar is presented Andreas Hildebrand who has previously appeared on The Broadcast Knowledge giving insight into The Audio Parts of ST 2110, ST 2110-30 and NMOS IS-08 — Audio Transport and Routing amongst others.

This talk looks at how audio IP works and the benefits of using an IP system. Since the invention of RAVENNA, the AES and SMPTE have moved to using audio over IP so the walk will examine how RAVENNA and SMPTE place the audio data on the network and get that to the decoders. Interoperability between systems is important but can only happen if certain parameters are correct, something that Andreas will mention but will also be a subject for future webinars.

Whether you want to revise the basics from an expert or learn them for the first time, now’s the time to register.

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Speaker

Andreas Hildebrand
Senior Product Manager,
ALC NetworX GmbH

Video: How CBS Sports Digital streams live events at scale

Posted on 9th April 2020 by Russell Trafford-Jones

Delivering high scale in streaming really exposes the weaknesses of every point of your workflow, so even those of us who are not streaming at maximum scale, there are many lessons to be learnt. CBS Sports Digital delivered the Super Bowl using the principles of ‘practice, practice, practice’, keeping the solution as simple as possible and making mitigation of problems primary to solving them.

Taylor Busch tells walks us through their solution explaining how it supported their key principles and highlighting the technology used. Starting with Acquisition, he covers the SDI fibre delivery to a backup facility as well as the AWS Direct Connect links for their Elemental Live encoders. The origin servers were in two different regions and both received data from both sets of encoders.

CBS used ‘Output locking’ which ensures that the TS segments are all aligned even across different encoders which is done by respecting the timecode in the SDI and helps in encoder failover situations. QVBR encoding is a method of encoding up to a quality level rather than simply saying ‘7000 kbps’. QVBR provides a more efficient use a bandwidth since in the situations where a scene doesn’t require a lot of bandwidth, it won’t be sent. This variability, even if you run in capped mode to limit the bandwidth of particularly complex scenes, can look like a failing encoder to some systems, so the fact this is now in ‘VBR’ mode, needs to be understood by all the departments and companies who monitor your feed.

Advertising is famously important for the Super Bowl, so Taylor gives an overview of how they used the CableLabs ESAM protocol and SCTE to receive information about and trigger the adverts. This combined SCTE-104, ESAM and SCTE-35 as we’ll as allowing clients to use VAST for tracking. Extra caching was provided by Fastly’s Media Shield which tests for problems with manifests, origin servers and encoders. This fed a Multi-CDN setup using 4 CDNs which could be switched between. There is a decision point for requests to determine which CDN should answer.

Taylor then looks at the tools, such as Mux’s dashboard, which they used to spot problems in the system; both NOC-style tools and multiviewers. They set up three war rooms which looked at different aspects of the system, connectivity, APIs etc. This allowed them to focus on what should be communicated keeping ‘noise’ down to give people the space they needed to do their work at the same time as providing the information required. Taylor then opens up to questions from the floor.

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Speaker

Taylor Busch
Senior Director Engineering,
CBS Sports Digital

Video: Edge Compute

Posted on 8th April 2020 by Russell Trafford-Jones

Delivering personalised video at scale, live or otherwise, is a tradeoff between speed and complexity. In this lightning talk at Demuxed 2019, Kyle Boutette from Cloudflare explains the benefits of running code on the ‘edge’.

Kyle starts by highlighting the reason to use CDNs; they take the management of a whole fleet of servers off your hands allowing you to concentrate on delivering a video service and deploying the technology to do just that. This works really well and CDNs are the backbone of most of the large sites on the internet. Some companies build their own whilst some use Cloudflare or Amazon CloudFront among the many CDNs out there. Apart from dealing with the admin of the servers, CDNs are careful to provide servers as close to your users as practical which helps in reducing latency.

The problem that Kyle exposes is that any personalisation needs to be done on the player itself or on the server. The former requiring implementing the same features on many platforms, the latter destroying the value of the CDN since it’s based on needing the central server(s) to calculate the new information and send it to the CDN bringing us back to square one.

The solution that Cloudflare has developed allows javascript to run on the the CDN’s computers, referred to as the ‘edge’. This allows much of the logic to be done close to the consumer and gives the highest chance of reusing CDN assets whilst also reducing the latency of the requests compared to talking to the central server infrastructure. Doing this with javascript provides a well-understood environment for web developers. Kyle provides examples to understand how this can be done with relatively simple code.

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Speaker

Kyle Boutette
Systems Engineer,
Cloudflare

Video: Benefits of IP Systems for Sporting Venues

Posted on 7th April 2020 by Russell Trafford-Jones

As you walk around any exhibitions there seems to be a myriad of ‘benefits’ of IP working, many of which don’t resonate for particular use cases. Only the most extraordinary businesses need all of the benefits, so in this talk, Imagine Communication’s John Mailhot discusses how IP helps sports venues.

John sets the scene by separating out the function of OB trucks and the ‘inside production’ facilities which have a whole host of non-TV production to do including driving scoreboards, displays inside the venue, replays and importantly has to deal with over 250 events a year, not all of which will have an OB truck.

We see that the scale that IP can work at is a great benefit as many signals can fit down one fibre and 2022-7 seamless switching can easily provide full redundancy for every fibre and SFP. This is a level of redundancy which is simply not seen in SDI systems. With stadia being very large, necessitating cable runs of over 500m, the fact that IP needs fewer cables overall is a great benefit.

John shows an example of an Arista switch only 7U in height which provides 144x 100G ports meaning it could support over 4000 inputs and 4000 outputs. Such density is unprecedented and for OB trucks can be a dealbreaker. For sports venues, this can also be a big motivator but also allow more flexibility in distributing the solution rather than relying on a massive central interconnect with a 1100×1100 SDI router in a central CTA.

TV is nothing without audio and the benefits to audio in 2110 are non trivial since with the audio being split off from the video, we are no longer limited to dealing with just 16 channels per video and de-embedding from a video frame any time we want to touch it.

Timing is an interesting benefit. I say this because, whilst PTP can end up being quite complex compared to black and burst, it has some big benefits. First off, it can live in the same cables as your data where as black and burst requires a whole separate cable infrastructure. PTP also allows you to timestamp all essences which helps with lip-sync throughout your workflow.

John leads us through some examples of how this works for different areas finishing by summing up the relevant benefits such as scalability, multi-format, space efficient, and timing amongst others.

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