FA Cup Final 2019: BBC Sport to use single production workflow for both SDR broadcast and UHD HDR stream By Will Strauss, Editor Friday, May 17, 2019 - 09:43
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This weekend's FA Cup Final at Wembley between Manchester City and Watford is going to be a one-sided affair, if the bookies are to be believed. And if they're right (Watford are currently 14/1 to lift the trophy), the result of the match won't be the only thing that can only go one way on Saturday.
BBC Sport's coverage of the showpiece final will, for the first time, be produced for both HD standard dynamic range (SDR) broadcast on BBC1 and in UHD with high dynamic range (HDR) as a BBC iPlayer trial using a single production workflow.
Until recently, all of the BBC's live UHD trials including Wimbledon 2018 and the 2018 World Cup in Russia have required a separate, experimental production process that has seen a UHD with HDR production run parallel to the HD with SDR production.
But for the Cup Final, the UHD coverage with HDR will be the master feed from which both the BBC's UHD online test stream and its HD broadcast will be derived. A UHD SDR feed will also be provided for BT Sport.
Devising this single workflow and testing it has been led by BBC R&D working closely with OB firm Arena Television.
Part of what we are trying to do is make this an effective business as usual' process within the BBC for distribution and for production. And having a dual workflow is not sustainable.
Andrew Cotton (pictured below, second right), a principal technologist within BBC R&D's Broadcast & Connected Systems section, believes that HDR to SDR conversion has improved sufficiently well in the last year to allow the BBC to confidently make the programme in UHD-HDR and still provide a great SDR signal to feed the main BBC1 transmission chain.
This will make a huge difference, he says, making it both cheaper and less complicated.
We've got to protect the HD SDR viewers because there are the most eyeballs in front of those screens, he told SVG Europe on the eve of the Cup Final.
High Dynamic Range discussion: (L/R) Will Strauss, SVG Europe; Shane Warden, ATP Media; Andrew Cotton, BBC R&D; and Andy Beale, BT Sport
But clearly we want to deliver a great UHD HDR experience for those watching that signal as well. Most UHD cameras have both an HDR and an SDR output and those two outputs have been effectively been passed through parallel production workflows. It has worked but it's an extremely complicated and costly workflow because you need twice as much equipment and timing up the different signals is more complicated. It's a complete nightmare.
For this to take off at scale we need to have a single production workflow and we need to be able to generate an HD-SDR output from a primary UHD-HDR signal. We now feel that we've reached that stage.
Phil Layton, the head of broadcast and connected systems at BBC R&D, is of the opinion that the previously used dual workflow was not sustainable.
Unless we can simplify the UHD production workflow, then it is very difficult for us to justify these trials, he says.
Part of what we are trying to do is make this an effective business as usual' process within the BBC for distribution and for production. And having a dual workflow is not sustainable. We were having to fund both productions through different means.
Royal approval
Down-conversion work completed for coverage of the Royal Wedding in 2018, which saw UHD-HDR signals down-converted to UHD-SDR for the benefit of Sky News, helped to inform the workflow and proved that the single workflow would be possible, acknowledges Cotton.
For the Cup Final, most of the cameras will be Grass Valley LDX-86Ns running in HDR mode with additional LDX-C86N compact HDR cameras on Steadicam rigs and one housed in a Shotover F1 gyro stabilised system on a helicopter.
HDR up-mapping for non-HDR sources and mixer feed down-mapping will be handled by Grass Valley UHD-3901 processing cards and AJA FS4-HDR units. Phabrix QXs will be used to monitor and analyse the signals.
All of the equipment will be housed in two of Arena's IP-based OB units - one dedicated to creating the match feed, the other being utilised for the BBC's domestic output.
More efficient and elegant: Daf Rees in the audio area of Arena's new OBZ
Daf Rees, Arena Television's deputy director of operations (pictured, right), reveals that this single HDR to SDR production workflow has been in the works for a while.
Our minds have been focused on developing and delivering a single HDR/SDR workflow since late 2015, alongside the development work for our IP OB fleet, he says.
In the same way as we saw quad SDI as an unsatisfactory way of delivering UHD, we recognised that a parallel HDR/SDR workflow was a similarly unsatisfactory, and in many cases, unrealistic way of delivering an HDR master with SDR deliverables.
His company started testing different options back in 2016, initially with single cameras across sport and entertainment events, evaluating HDR camera and monitor performance.
Step by step we introduced various up-map and down-map processes to evaluate their effect on the picture in the real world. It's been vitally important to us to create a format-agnostic platform for our clients so developed a very good rapport with R&D teams at several key vendors to improve the results iteration by iteration.
Mixing camera formats
Being format agnostic is a crucial part of this workflow, as Cotton explains.
For football coverage, it is simply not possible today [to have everything in one format] because we rely on a number of specialist cameras that can only operate in SDR BT.709 such as the super slo-mo camera, the roving cameras and the cameras behind the goals. We need to
