1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T Series H TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 15 (01/2017) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Conversion and coding practices for HDR/ WCG YCbCr 4:2:0 video with PQ transfer characteristics I
2、TU-T H-series Recommendations Supplement 15 ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS H.100H.199 INFRASTRUCTURE OF AUDIOVISUAL SERVICES General H.200H.219 Transmission multiplexing and synchronization H.220H.229 Systems aspects H.23
3、0H.239 Communication procedures H.240H.259 Coding of moving video H.260H.279 Related systems aspects H.280H.299 Systems and terminal equipment for audiovisual services H.300H.349 Directory services architecture for audiovisual and multimedia services H.350H.359 Quality of service architecture for au
4、diovisual and multimedia services H.360H.369 Telepresence H.420H.429 Supplementary services for multimedia H.450H.499 MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, protocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H
5、.510H.519 Mobile multimedia collaboration applications and services H.520H.529 Security for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services H.540H.549 Mobility interworking procedures H.550H.559 Mobile multimedia collaboration
6、inter-working procedures H.560H.569 BROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 Ubiquitous sensor network applications and Internet of Things H.640H.649 IPTV MULTIMEDIA SERVICES AN
7、D APPLICATIONS FOR IPTV General aspects H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV application event handling H.740H.749 IPTV metadata H.750H.759 IPTV multimedia application frameworks H.760H.769 IPTV service discovery up to consumption H.770H.779 Digital Signage H.7
8、80H.789 E-HEALTH MULTIMEDIA SERVICES AND APPLICATIONS Personal health systems H.810H.819 Interoperability compliance testing of personal health systems (HRN, PAN, LAN, TAN and WAN) H.820H.859 Multimedia e-health data exchange services H.860H.869 For further details, please refer to the list of ITU-T
9、 Recommendations. H series Supplement 15 (01/2017) i Supplement 15 to ITU-T H-series Recommendations Conversion and coding practices for HDR/WCG YCbCr 4:2:0 video with PQ transfer characteristics Summary Supplement 15 to the ITU-T H-series of Recommendations provides guidance on the processing of hi
10、gh dynamic range (HDR) and wide colour gamut (WCG) video content. The purpose of this document is to provide a set of publicly referenceable recommended guidelines for the operation of advanced video coding (AVC) or high efficiency video coding (HEVC) video coding systems adapted for compressing HDR
11、/WCG video for consumer distribution applications. This document includes a description of processing steps for converting from 4:4:4 RGB linear light representation video signals into non-constant luminance (NCL) YCbCr video signals that use the perceptual quantizer (PQ) transfer function defined i
12、n SMPTE ST 2084 and Recommendation ITU-R BT.2100. Although the focus of this document is primarily on 4:2:0 YCbCr 10 bit representations, these guidelines may also apply to other representations with higher bit depth or other colour formats, such as 4:4:4 YCbCr 12 bit video. In addition, this docume
13、nt provides some high-level recommendations for compressing these signals using either the AVC or HEVC video coding standards. A description of post-decoding processing steps is also included for converting these NCL YCbCr signals back to a linear light, 4:4:4 RGB representation. This Supplement was
14、 jointly developed by ITU-T Study Group 16 and ISO/IEC JTC1 SC29/WG11 and the ISO title is ISO/IEC TR 23008-14 “Information technology High efficiency coding and media delivery in heterogeneous environments Part 14: Conversion and coding practices for HDR/WCG YCbCr 4:2:0 video with PQ transfer chara
15、cteristics“. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T H Suppl. 15 2017-01-27 16 11.1002/1000/13243 Keywords AVC, HDR, HEVC, video coding, WCG. * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the
16、Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/ 11830-en. ii H series Supplement 15 (01/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (I
17、CTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunicatio
18、n Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of info
19、rmation technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this publication, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency
20、. Compliance with this publication is voluntary. However, the publication may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the publication is achieved when all of these mandatory provisions are met. The words “shall“ or some other obli
21、gatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the publication is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation o
22、f this publication may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the publication development process. As of the date
23、of approval of this publication, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this publication. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB
24、 patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. H series Supplement 15 (01/2017) iii Table of Contents Page 1 Scope 1 2 References 1 3 Definitions 2 4
25、Abbreviations and acronyms 2 5 Conventions 3 5.1 General 3 5.2 Arithmetic operators 3 5.3 Bit-wise operators . 4 5.4 Assignment operators 4 5.5 Relational, logical and other operators 4 5.6 Mathematical functions . 5 5.7 Order of operations . 5 6 Overview 6 7 Pre-encoding process 7 7.1 General 7 7.2
26、 Pre-encoding process stages 8 7.3 Closed loop pre-encoding conversion luma adjustment . 13 8 Encoding process 19 8.1 General 19 8.2 Perceptual luma quantization 19 8.3 Chroma QP offset 21 8.4 Other encoding aspects 23 8.5 HEVC encoding 23 8.6 AVC encoding . 24 9 Decoding process . 25 10 Post-decodi
27、ng processes . 25 10.1 General 25 10.2 Conversion from a fixed-point to a floating-point representation . 25 10.3 Chroma up-sampling . 25 10.4 Colour representation conversion: non-constant luminance YCbCr to RGB . 26 10.5 Conversion from a non-linear to a linear light representation: RGB to RGB 26
28、Appendix I Supplemental enhancement information (SEI) messages 28 I.1 Mastering display colour volume SEI message . 28 I.2 Content light level information SEI message 28 I.3 Ambient viewing environment SEI message 28 iv H series Supplement 15 (01/2017) Introduction High dynamic range (HDR) video is
29、a type of video content in which the sample values span a larger luminance range than conventional standard dynamic range (SDR) video. HDR video can provide an enhanced viewer experience and can more accurately reproduce scenes that include, within the same image, dark areas and bright highlights, s
30、uch as emissive light sources and reflections. Wide colour gamut (WCG) video, on the other hand, is video characterized by a wider spectrum of colours compared to what has been commonly available in conventional video. Recent advances in capture and display technology have enabled consumer distribut
31、ion of HDR and WCG content. However, given the characteristics of such content, special considerations may need to be made, in terms of both processing and compression, compared to conventional content. This Supplement provides a set of recommended guidelines on the processing of consumer distributi
32、on HDR/WCG video. This includes recommendations for converting a video signal, in a linear light RGB representation with ITU-R BT.2020 colour primaries, to a 10-bit, narrow range, PQ encoded (as defined in SMPTE ST 2084 and Recommendation ITU-R BT.2100), 4:2:0, non-constant luminance YCbCr represent
33、ation. These guidelines may also apply to other representations with a higher bit depth or other colour formats, such as 4:4:4 YCbCr 12 bit video. The scope of this document is illustrated in Figure 1. Figure 1 Illustration of the scope of this document The content preparation step, as well as the d
34、isplay adaptation step, are considered to be out of the scope of this document. However, metadata generated during the content preparation step may be passed through the encoder-decoder chain and can significantly affect the display adaptation step. The content preparation step may include filtering
35、 and image enhancement processing such as de-noising, colour correction and sharpening, as well as other processes. Such methods are deliberately not described in this document. The processing steps described in this document are made available for reference only and the document does not contain an
36、y elements of normative nature. It is possible to replace one or more of the processing steps described in this document, for example, in order to reduce computational complexity or to improve fidelity. This documents intention is to provide some guidelines for operating an HDR/WCG video system that
37、 is constrained to code a 10-bit, PQ (as defined in SMPTE ST 2084 and ITU-R BT.2100-0, 4:2:0, non-constant luminance YCbCr signal representation. This configuration is also aligned with the HDR10 media profile defined in DECE, the interface defined in CTA 861-G and the restrictions in Blu-ray2015. T
38、he processing steps in this document are optimized with the intention of providing the best possible result when the same hypothetical reference viewing environment (HRVE) is used before and after the HDR/WCG system. This document does not account for when the viewing environment used after the HDR/
39、WCG system is different from the viewing environment used as the HRVE. In particular, display adaptation, such as the techniques described in the SMPTE ST 2094 standards, is not considered in this document. ITU-R BT.2390-0 contains additional information on viewing environments and examples of param
40、eters that may be appropriate to apply for practical HDR/WCG systems. This document does not provide a description of any preferred HRVE, but acknowledges the fact that in many applications of HDR/WCG video it may be desirable to have a well-defined HRVE description in order to ensure alignment betw
41、een content preparation and content consumption. H series Supplement 15 (01/2017) 1 Supplement 15 to the H-Series of Recommendations Conversion and coding practices for HDR/WCG YCbCr 4:2:0 video with PQ transfer characteristics 1 Scope This Supplement provides guidance on the processing of high dyna
42、mic range (HDR) and wide colour gamut (WCG) video content. The purpose of this document is to provide a set of publicly referenceable recommended guidelines for the operation of AVC or HEVC video coding systems adapted for compressing HDR/WCG video for consumer distribution applications. This docume
43、nt includes a description of processing steps for converting from 4:4:4 RGB linear light representation video signals into non-constant luminance (NCL) YCbCr video signals that use the perceptual quantizer (PQ) transfer function defined in SMPTE ST 2084 and ITU-R BT.2100-0. Although the focus of thi
44、s document is primarily on 4:2:0 YCbCr 10 bit representations, these guidelines may also apply to other representations with higher bit depth or other colour formats, such as 4:4:4 YCbCr 12 bit video. In addition, this document provides some high-level recommendations for compressing these signals u
45、sing either the AVC or HEVC video coding standards. A description of post-decoding processing steps is also included for converting these NCL YCbCr signals back to a linear light, 4:4:4 RGB representation. 2 References ITU-T H.264 Recommendation ITU-T H.264 (in force) | ISO/IEC 14496-10 (in force),
46、Advanced video coding for generic audiovisual services. ITU-T H.265 Recommendation ITU-T H.265 (in force) | ISO/IEC 23008-2 (in force)High Efficiency Video Coding. ITU-R BT.709-6 Recommendation ITU-R BT.709-6 (2015), Parameter values for the HDTV standards for production and international programme
47、exchange. ITU-R BT.1886-0 Recommendation ITU-R BT.1886-0 (2011), Reference electro-optical transfer function for flat panel displays used in HDTV studio production. ITU-R BT.2020-2 Recommendation ITU-R BT.2020-2 (2015), Parameter values for ultra-high definition television systems for production and
48、 international programme exchange. ITU-R BT.2100-0 Recommendation ITU-R BT.2100-0 (2016), Image parameter values for high dynamic range television for use in production and international programme exchange. ITU-R BT.2390-0 Report ITU-R BT.2390-0 (2016), High dynamic range television for production a
49、nd international programme exchange. Baroncini 2016 V. Baroncini, K. Andersson, A. K. Ramasubramonian, and G. J. Sullivan (editors) (2016), Revised Verification Test Report for HDR/WCG Video Coding Using HEVC Main 10 Profile, JCTVC-Y1018. Blu-ray 2015 Blu-ray Disc Association (2015), BD-ROM: Audio Visual Application Format Specifications version 3 CTA 861-G CTA 861-G (2017), A DTV Profile for Uncompressed High Speed Digital Interfaces. DECE DECE (
