The Ultra HD Forum has published version 2.6 of its guidelines, including updates on colour accuracy, NGA production tools and workflows, ATSC 3.0, and the use of video over IP for UHD production.
The Ultra HD Forum Guidelines aim to provide recommendations and procedures that promote uniformity of product, interchangeability and “ultimately the long-term reliability of audio/video service transmission”.
The latest guidelines cover a number of developments including a section on best practices for OTT deployment for UHD . The Forum has provided information on DASH-HLS and Adaptive Bitrate Streaming (ABR).
It has also updated information on the release of AVS3 video encoding, including an overview of the coding framework and references to the evolving standard.
Version 2.6 has expanded the section describing the use of video over IP for UHD production to include technologies such as ST 2022, NDI, Zixi, and SRT.
NBCUniversal has contributed a detailed description of their production workflow for producing live events using a single-stream workflow to output an HD/SDR program and a UHD/HDR programme. They broadcaster describes its approach using HLG as a production format, including reference 3D LUTs, to go between HDR and SDR, SDR to HDR, and HLG to PQ.
The updated guidelines also look at NGA real-world deployments, including AC-4 use during Euro 2020 Football (TVP, Polish TV), French Open Tennis (France TV over DVB-T2), as well as MPEG-H, at the Eurovision Song Contests in 2018 (RTP, Portugal) and 2019 (EBU).
The document also includes a detailed discussion of the challenge of converting HD SDR with Rec 709 colour to HDR with Wide Colour (Rec 2020). There are methods of measuring colour accuracy with examples of problems that can happen when using LUTs that are not correct or precise enough, said the Forum. Discussion of the interoperability between PQ and HLG video and the use of defined reference points for peak white as defined in ITU Rec BT. 2100 and an explanation of ICtCp and the use of ΔE-ITP colour error metrics are included.
The full version of UHD Forum Guidelines V2.6 is available here.