Video: IP-based Networks for UHD and HDR Video

If you get given a video signal, would you know what type it was? Life used to be simple, an SD signal would decode in a waveform monitor and you’d see which type it was. Now, with UHD and HDR, this isn’t all the information you need. Arguably this gets easier with IP and is possibly one of the few things that does. This video from AIMS helps to clear up why IP’s the best choice for UHD and HDR.

John Mailhot from Imagine Communications joins Wes Simpson from LearnIPVideo.com to introduce us to the difficulties wrangling with UHD and HDR video. Reflecting on the continued improvement of in-home displays’ ability to show brighter and better pictures as well as the broadcast cameras’ ability to capture much more dynamic range, John’s work at Imagine is focussed on helping broadcasters ensure their infrastructure can enable these high dynamic range experiences. Streaming services have a slightly easier time delivering HDR to end-users as they are in complete control of the distribution chain whereas often in broadcast, particularly with affiliates, there are many points in the chain which need to be HDR/UHD capable.

John starts by looking at how UHD was implemented in the early stages. UHD, being twice the horizontal and twice the vertical resolution of HD is usually seen as 4xHD, but, importantly, John points out that this is true for resolution but, as most HD is 1080i, it also represents a move to 1080p, 3Gbps signals. John’s point is that this is a strain on the infrastructure which was not necessarily tested for initially. Given the UHD signal, initially, was carried by four cables, there is now 4 times the chance of a signal impairment due to cabling.

Square Division Multiplexing (SQD) is the ‘most obvious’ way to carry UHD signals with existing HD infrastructure. The picture is simply cut into four quarters and each quarter is sent down one cable. The benefit here is that it’s easy to see which order the cables need to be connected to the equipment. The downsides included a frame-buffer delay (half a frame) each time the signal was received, difficulties preventing drift of quadrants if they were treated differently by the infrastructure (i.e. there was a non-synced hand-off). One important problem is that there is no way to know an HD feed is from a UHD set or just a lone 3G signal.

2SI, two-sample interleave, was another method of splitting up the signal which was standardised by SMPTE. This worked by taking a pair of samples and sending them down cable 1, then the next pair down cable 2, the pair of samples under the first pair went down cable 3 then the pair under 2 went down 4. This had the happy benefit that each cable held a complete picture, albeit very crudely downsampled. However, for monitoring applications, this is a benefit as you can DA one feed and send this to a monitor. Well, that would have been possible except for the problem that each signal had to maintain 400ns timing with the others which meant DAs often broke the timing budget if they reclocked. It did, however, remove the half-field latency burden which SQD carries. The main confounding factor in this mechanism is that looking at the video from any cable on a monitor isn’t enough to understand which of the four feeds you are looking at. Mis-cabling equipment leads to subtle visual errors which are hard to spot and hard to correct.

Enter the VPID, the Video Payload ID. SD SDI didn’t require this, HD often had it, but for UHD it became essential. SMPTE ST 425-5:2019 is the latest document explaining payload ID for UHD. As it’s version five, you should be aware that older equipment may not parse the information in the correct way a) as a bug and b) due to using an old standard. The VPID carries information such as interlaced/progressive, aspect ratio, transfer characteristics (HLG, SDR etc.), frame rate etc. John talks through some of the common mismatches in interpretation and implementation of VPID.

12G is the obvious baseband solution to the four-wires problem of UHD. Nowadays the cost of a 12G transceiver is only slightly more than 3G ones, therefore 12G is a very reasonable solution for many. It does require careful cabling to ensure the cable is in good condition and not too long. For OB trucks and small projects, 12G can work well. For larger installations, optical connections are needed, one signal per fibre.

The move to IP initially went to SMPTE ST 2022-6, which is a mapping of SDI onto IP. This meant it was still quite restrictive as we were still living within the SDI-described world. 12G was difficult to do. Getting four IP streams correctly aligned, and all switched on time, was also impractical. For UHD, therefore SMPTE ST 2110 is the natural home. 2110 can support 32K, so UHD fits in well. ST 2110-22 allows use of JPEG XS so if the 9-11Gbps bitrate of UHDp50/60 is too much it can be squeezed down to 1.5Gbps with almost no latency. Being carried as a single video flow removes any switch timing problems and as 2110 doesn’t use VPID, there is much more flexibility to fully describe the signal allowing future growth. We don’t know what’s to come, but if it’s different shapes of video rater, new colour spaces or extensions needed for IPMX, these are possible.

John finishes his conversation with Wes mentioning two big benefits of moving to IT-based infrastructure. One is the ability to use the free Wireshark or EBU List tools to analyse video. Whilst there are still good reasons to buy test equipment, the fact that many checks can be done without expensive equipment like waveform monitors is good news. The second big benefit is that whilst these standards were being made, the available network infrastructure has moved from 25 to 100 to 400Gbps links with 800Gbps coming in the next year or two. None of these changes has required any change in the standards, unlike with SDI where improvements in signal required improvements in baseband. Rather, the industry is able to take advantage of this new infrastructure with no effort on our part to develop it or modify the standards.

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Speakers

John Mailhot John Mailhot
Systems Architect, IP Convergence,
Imagine Communications
Wes Simpson Wes Simpson
RIST AG Co-Chair, VSF
President & Founder, LearnIPvideo.com

Video: A Snapshot of NMOS: Just the Facts, Please.

NMOS is the open standard for multiple vendors co-operating on a broadcaster network, particularly ST 2110, to announce new devices and configure them. Acting as both a database but also a way of easily describing settings to be shared between systems. Often new ST 2110 systems are specified to be NMOS IS-04 and IS-05 capable.

NMOS IS-04 is the name of the specification which defines discovery and registration of devices while IS-05 describes the control of said devices. It’s very hard to run a SMPTE ST 2110 system without these or a proprietary protocol which exchanges the same information. It’s not practical to manage any of these tasks at anything more than the smallest scale.

John Mailhot from Imagine Communications delivers a concise summary of these technologies which may be new to you. He explains that an SDP will be generated and John reviews how you would read them. John explains that the stack is open source with the aim of promoting interoperability.

John takes the time needed to look at IS-04 and IS-05 in terms of practically implementing it at the end of this short talk.

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Speaker

John Mailhot John Mailhot
Systems Architect, IP Convergence,
Imagine Communications

Video: Building Television Systems in a Time of Multiple Technology Transitions

Major technology transitions can be hard to keep up with, and when you have a project requiring you decide which one to go with, it can seem unmanageable. This panel put together by SMPTE New York looks gives the view from System Integrators on how to make this work and cover their experience with a wide range of new technologies.

SMPTE ST 2110 is an entire paradigm shift

John Humphrey
John Turner kicked off explaining the reasoning for using SDI over SMPTE ST 2110 in some circumstances. For that project, his client had a fixed space so wouldn’t see the benefits of 2110 in terms of expansion. Their workflow already worked well in SDI and at the time, the costs of 2110 would have been higher. Overall, the project went with SDI, was successful and they are a happy customer. Karl Paulsen agreed that new technology shouldn’t be ‘for the sake of it’ and added that whilst individual products with a new technology may be stable, that’s not certain to be the case when interoperating within a whole system. As such, this puts the implementation time up meaning the incumbent technologies do tend to get chosen when time is at a premium.

Turning to 5G, Karl answered the question “what are the transformational technologies”. For some applications, for instance back of the camera RF in a stadium, 5G is a major leap compared to microwave packs, but early on in a technology’s life, like we are with 5G, it’s a matter of working out where it does and where it doesn’t work well. In time, it will probably adapt to some of those other use cases that it wasn’t suited for initially. John Turner highlighted the elements that ATSC 3.0 transforms in a big way. From an RF perspective, its modulation is much stronger and more flexible, that it’s able to drive new business models.

John Mailhot’s view on transformational challenge is ‘the people’. He puts forward the idea that the technical constraints of router size and max cable length, to name two examples, embedded themselves into the routines, assumptions and architectures that people embody in their work. With SMPTE ST-2110, most of these constraints are removed. This means you are a lot freer to work out the workflows the business wants. The challenge here is to have the imagination and fortitude to forge the right workflow without getting paralysed by choice.

“SMPTE ST 2110 is an entire paradigm shift”, John Humphrey

After responding to the moderator’s question on how much turmoil these transitions are causing, Mark Schubin summarises the situation by saying we need to work out which of the technologies is like a fridge (replacing previous technologies), a microwave (used as well as a conventional oven) and an induction cooker (requires change in cookware, little adoption). John Humphrey adds that ST 2110 is a technology which viewers don’t notice since the visual quality is the same. HDR, is the opposite so they need different approaches.

During the last 45 minutes, the panel took questions from the audience covering how to hire talent, the perspective of younger people on technology, programming specifically made for smartphones, ATSC 3.0 implementation, reliability of home internet, PTP and more.

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Speakers

Mark Schubin Mark Schubin
Consultant & Explainer
John Humphrey John Humphrey
VP, Business Development,
Hitachi Kokusai Electric America Ltd.
Karl Paulsen Karl Paulsen
CTO,
Diversified
John Turner John Turner
Principal Engineer
Turner Engineering Inc.
John Mailhot John Mailhot
Systems Architect for IP Convergence
Imagine Communications

Video: Benefits of IP Systems for Sporting Venues

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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Download the slides
Speakers

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