ST 2110

Video: Efficient Carriage of Sub-Rasters With ST 2110-20

Posted on by Russell Trafford-Jones

One of the main promises of IP video is flexibility and what better way to demonstrate that than stepping off the well-worn path of broadcast resolutions? 1920×1080 is much loved nowadays, but not everything needs to be put into an HD-sized frame. SMPTE ST-2110 allows video of all shapes and sizes, so let’s not be afraid to use the control given to us.

Paul Briscoe, talking on behalf of Evertz, takes the podium to explain the idea. Using logo insertion as an expample, he shows that if you want to put a small BUG/DOG/graphic on screen with a key, then real there’s not a lot of data that needs to be transferred. Typically a graphic needs a key and a fill. Whilst the key is typically luma-only, the fill needs to be full colour.

In the world of SDI, sending your key and fill around would need two whole HD signals and up to 6Gbps of data. When your graphic is only a small logo, these SDI signals are mainly redundant data. Using ST 2110-20, however, in the IP domain we can be much more efficient. 2110 allows resolutions up to 32,000 pixels square so we should be able to send just the information which is necessary.

Paul introduces the idea of a “pixel group” (pgroup) which is the minimal group of video data samples that make up an integer number of pixels and also align to an octet boundary. Along with defining a size, we also get to define an X,Y position. Paul explains how using pgroups helps, and hinders, sending video this way and then delves in to how timing would work. To finish off, Paul examines edge cases and talks about other examples such as stock tickers, not to mention the possibility of motion as we get to define the X, Y position.

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This wall chart gives more info on pgroups and other low-level ST 2110-20 constructs.
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Speakers

Paul Briscoe Paul Briscoe
Principal Consultant,
Televisionary Consulting

Video: Introduction To AES67 & SMPTE ST 2110

Posted on by Russell Trafford-Jones

While standardisation of video and audio over IP is welcome, this does leave us with a plethora of standards numbers to keep track of along with interoperability edge cases to keep track of. Audio-over-IP standard AES67 is part of the SMPTE ST-2110 standards suite and was born largely from RAVENNA which is still in use in it’s own right. It’s with this backdrop that Andreas Hildebrand from ALC NetworX who have been developing RAVENNA for 10 years now, takes the mic to explain how this all fits together. Whilst there are many technologies at play, this webinar focusses on AES67 and 2110.

Andreas explains how AES67 started out of a plan to unite the many proprietary audio-over-IP formats. For instance, synchronisation – like ST 2110 as we’ll see later – was based on PTP. Andreas gives an overview of this synchronisation and then we shows how they looked at each of the OSI layers and defined a technology that could service everyone. RTP, the Real-time Transport Protocol has been in use for a long time for transport of video and audio so made a perfect option for the transport layer. Andreas highlights the important timing information in the headers and how it can be delivered by unicast or IGMP multicast.

As for the audio, standard PCM is the audio of choice here. Andreas details the different format options available such as 24-bit with 8 channels and 48 samples per packet. By varying the format permutations, we can increase the sample rate to 96kHz or modify the number of audio tracks. To signal all of this format information, Session Description Protocol messages are sent which are small text files outlining the format of the upcoming audio. These are defined in RFC 4566. For a deeper introduction to IP basics and these topics, have a look at Ed Calverley’s talk.

The second half of the video is an introduction to ST-2110. A deeper dive can be found elsewhere on the site from Wes Simpson.
Andreas starts from the basis of ST 2022-6 showing how that was an SDI-based format where all the audio, video and metadata were combined together. ST 2110 brings the splitting of media, known as ‘essences’, which allows them to follow separate workflows without requiring lots of de-embedding and embedding processes.

Like most modern standards, ATSC 3.0 is another example, SMPTE ST 2110 is a suite of many standards documents. Andreas takes the time to explain each one and the ones currently being worked on. The first standard is ST 2110-10 which defines the use of PTP for timing and synchronisation. This uses SMPTE ST 2059 to relate PTP time to the phase of media essences.

2110-20 is up next and is the main standard that defines use of uncompressed video with headline features such as being raster/resolution agnostic, colour sampling and more. 2110-21 defines traffic shaping. Andreas takes time to explain why traffic shaping is necessary and what Narrow, Narrow-Linear, Wide mean in terms of packet timing. Finishing the video theme, 2110-22 defines the carriage of mezzanine-compressed video. Intended for compression like TICO and JPEG XS which have light, fast compression, this is the first time that compressed media has entered the 2110 suite.

2110-30 marks the beginning of the audio standards describing how AES67 can be used. As Andreas demonstrates, AES67 has some modes which are not compatible, so he spends time explaining the constraints and how to implement this. For more detail on this topic, check out his previous talk on the matter. 2110-31 introduces AES3 audio which, like in SDI, provides both the ability to have PCM audio, but also non-PCM audio like Dolby E and D.

Finishing up the talk, we hear about 2110-40 which governs transport of ancillary metadata and a look to the standards still being written, 2110-23 Single Video essence over multiple 2110-20 streams, 2110-24 for transport of SD signals and 2110-41 Transport of extensible, dynamic metadata.

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Speaker

Andreas Hildebrand Andreas Hildebrand
Senior Product Manager,
ALC NetworX Gmbh.

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

Posted on 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 Andreas Hildebrand
Senior Product Manager,
ALC NetworX GmbH

Video: Benefits of IP Systems for Sporting Venues

Posted on 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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Speakers

John Mailhot John Mailhot
CTO, Networking & Infrastructure,
Imagine Communications