Benjamin Schwarz, Communications Working Group chair, discusses how the Ultra HD Forums activities reflect growing maturity in the run-up to IBC 2022 By Contributor
Published: September 1, 2022
Benjamin Schwarz, Communications Working Group chair, discusses how the Ultra HD Forum's activities reflect growing maturity in the run-up to IBC 2022
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After being established in 2015 to accelerate Ultra HD deployment, the Ultra HD Forum has been showing its work in the form of demos at IBC since 2017. Our 2022 demos will show how far the industry has come.
The Ultra HD Forum brings together market leaders from every part of the industry. Broadcasters, service providers, consumer electronics, and technology vendors collaborate on solving real-world challenges in deploying advanced media. The Forum's Guidelines describe this as a uniform set of characteristics for Ultra HD content and consistent methods for creating and delivering Ultra HD content.
The Guidelines create consistency across the industry to ensure interoperability and a high-quality experience for consumers and present solutions for delivering Ultra HD content from the studio producer or the live event to the consumer via a linear (real-time) service. The Guidelines further recommend profiles and practices across each of the elements in a distribution chain to maximise end-to-end interoperability. Guidelines are available at no cost from: https://ultrahdforum.org/guidelines
The most recent version of the Guidelines published in May 2022 reflects where the industry is and includes various essential updates listed below.
Now that HDR is stable and works for on-demand platforms, the Forum concentrates on HDR workflows for real-world linear and live deployments. After early trials with dedicated HDR workflows, operators now set up single stream production workflows to manage costs (as described below). As an example, the Guideline's Colour Accuracy section now includes new plots showing the effects of incorrect look-up tables (LUT) when converting images between HDR (Rec. 2100) images and SDR (Rec. 709), as well as between PQ10 and HLG10. The objective measurement of perceptible color differences between an original image and a converted image uses just-noticeable difference (JND) scaled metrics such as EITP, TPITP, IITP, and HITP for tracking colour volume, Chroma, Intensity, and hue-shifts
EITP Colour Difference (Source vs. Output)
Figure 2. Intensity Tracking (Source vs. Output)
NextGen Audio (NGA) for live and linear content has moved from experimental to operational since the last IBC. In this spirit, annex K is newly added to the Guidelines to present next-generation audio (NGA) production tools and workflows. Real-world case studies of NGA production deployments provide examples of available tools and workflows in actual use. Sections detail the use of AC-4 and MPEG-H audio codecs. Aspects covered include static metadata over SDI infrastructure, dynamic metadata for live events, dynamic metadata in SMPTE ST-2110 environments, real-time and file-based workflows, interoperability between SDI and IP transport, coexistence with existing 2.0, and 5.1 channel audio, and extensibility considerations.
Figure 3. AC-4 dynamic metadata live event, example workflow
Figure 4. Setup of the UHD FTV Channel using MPEG-H Audio during the French Open tennis tournament
The NBC Universal Single Stream HDR/SDR Workflow, Annex J of the Guidelines, has updated information on the conversion LUTs as well as an update to colour error metrics ( E-ITP).
To go even further than the work described above, our recently formed Broadcast Sub-Group has been addressing live HDR production that involves the simultaneous creation of SDR and HDR versions of the content for distribution to modern HDR and legacy SDR displays. During this process, the SDR and HDR versions are sometimes viewed side by side.
While HDR content is typically created with a diffuse white level of 203 cd/m2, SDR content has historically been created for viewing on displays with a reference nominal peak luminance level of 100 cd/m2. Adaptation of the Human Visual System to the brighter HDR signal requires the SDR signal to be correctly compensated and rendered at the higher nominal peak level of 203 cd/m2 for it to be perceived as intended.
The Broadcast Sub-Group has been developing the appropriate compensation methods for these and related use cases. Also, several broadcasters have begun creating SDR content for viewing on displays with a peak luminance level of 203 cd/m2. The Broadcast Sub-Group has developed signaling methods to inform consumer displays as to whether the SDR content was mastered to target displays with a nominal peak of 100 or 203 cd/m2. Compensation LUTs are proposed for rendering these two types of SDR on displays configured for different peak brightness levels and for viewing in different ambient brightness environments.
The Communications Working Group has continued to conduct periodic surveys of Ultra HD service deployments. The detailed data is collected in a searchable format on the Forum's UHD Service Tracker webpage at https://ultrahdforum.org/uhd-service-tracker/. Details available include the number of subscribers, audio and video formats, HDR formats, etc. The data shows (based on a very conservative projection) that by EOY 2022, there will be almost 240 Ultra HD B2C services deployed globally, compared to 208 services two years prior. Lockdowns have impacted the growth of services, so we remain confident that there is still a lot of potential in the market. Total Ultra HD subscriptions moved from 450 million to 500 million over the last two years. Related and emerging industry developments are being communicated on the Forum's blog at https://ul
