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
H.266
TELECOMMUNICATION
STANDARDIZATION SECTOR
OF ITU
(04/2022)
SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS
Infrastructure of audiovisual services – Coding of moving
video
Versatile video coding
Recommendation ITU-T H.266
ITU-T H-SERIES RECOMMENDATIONS
AUDIOVISUAL AND MULTIMEDIA SYSTEMS
CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS
H.100–H.199
INFRASTRUCTURE OF AUDIOVISUAL SERVICES
General
H.200–H.219
Transmission multiplexing and synchronization
H.220–H.229
Systems aspects
H.230–H.239
Communication procedures
H.240–H.259
Coding of moving video
H.260–H.279
Related systems aspects
H.280–H.299
Systems and terminal equipment for audiovisual services
H.300–H.349
Directory services architecture for audiovisual and multimedia services
H.350–H.359
Quality of service architecture for audiovisual and multimedia services
H.360–H.369
Telepresence, immersive environments, virtual and extended reality
H.420–H.439
Supplementary services for multimedia
H.450–H.499
MOBILITY AND COLLABORATION PROCEDURES
Overview of Mobility and Collaboration, definitions, protocols and procedures
H.500–H.509
Mobility for H-Series multimedia systems and services
H.510–H.519
Mobile multimedia collaboration applications and services
H.520–H.529
Security for mobile multimedia systems and services
H.530–H.539
Security for mobile multimedia collaboration applications and services
H.540–H.549
VEHICULAR GATEWAYS AND INTELLIGENT TRANSPORTATION SYSTEMS (ITS)
Architecture for vehicular gateways
H.550–H.559
Vehicular gateway interfaces
H.560–H.569
BROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES
Broadband multimedia services over VDSL
H.610–H.619
Advanced multimedia services and applications
H.620–H.629
Content delivery and ubiquitous sensor network applications
H.640–H.649
IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV
General aspects
H.700–H.719
IPTV terminal devices
H.720–H.729
IPTV middleware
H.730–H.739
IPTV application event handling
H.740–H.749
IPTV metadata
H.750–H.759
IPTV multimedia application frameworks
H.760–H.769
IPTV service discovery up to consumption
H.770–H.779
Digital Signage
H.780–H.789
E-HEALTH MULTIMEDIA SYSTEMS, SERVICES AND APPLICATIONS
Personal health systems
H.810–H.819
Interoperability compliance testing of personal health systems (HRN, PAN, LAN, TAN and
WAN)
H.820–H.859
Multimedia e-health data exchange services
H.860–H.869
Safe listening
H.870–H.879
For further details, please refer to the list of ITU-T Recommendations.
Rec. ITU-T H.266 (04/2022) i
Recommendation ITU-T H.266
Versatile video coding
Summary
Recommendation ITU-T H.266 specifies a video coding technology known as Versatile Video Coding and it has been
designed with two primary goals. The first of these is to specify a video coding technology with a compression capability
that is substantially beyond that of the prior generations of such standards, and the second is for this technology to be
highly versatile for effective use in a broadened range of applications than that addressed by prior standards. Some key
application areas for the use of this standard particularly include ultra-high-definition video (e.g., with 3840×2160 or
7620×4320 picture resolution and bit depth of 10 bits as specified in Rec. ITU-R BT.2100), video with a high dynamic
range and wide colour gamut (e.g., with the perceptual quantization or hybrid log-gamma transfer characteristics specified
in Rec. ITU-R BT.2100), and video for immersive media applications such as 360° omnidirectional video projected using
a common projection format such as the equirectangular or cubemap projection formats, in addition to the applications that
have commonly been addressed by prior video coding standards.
This Recommendation was developed collaboratively with ISO/IEC JTC 1/SC 29, and corresponds with ISO/IEC 23090-3
as technically aligned twin text.
History
Edition
Recommendation
Approval
Study Group
Unique ID
*
1.0
ITU-T H.266
2020-08-29
16
11.1002/1000/14336
2.0
ITU-T H.266 (V2)
2022-04-29
16
11.1002/1000/14948
*
To access the Recommendation, type the URL http://handle.itu.int/ in the address field of your web browser, followed by
the Recommendation's unique ID. For example, http://handle.itu.int/11.1002/1000/11830-en.
ii Rec. ITU-T H.266 (04/2022)
FOREWORD
The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of
telecommunications, information and communication technologies (ICTs). 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 Telecommunication 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 information technology which fall within ITU-T's purview, the necessary standards are
prepared on a collaborative basis with ISO and IEC.
NOTE
In this Recommendation, the expression "Administration" is used for conciseness to indicate both a
telecommunication administration and a recognized operating agency.
Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain
mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the
Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other
obligatory 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 Recommendation is required of any party.
INTELLECTUAL PROPERTY RIGHTS
ITU draws attention to the possibility that the practice or implementation of this Recommendation 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
Recommendation development process.
As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected
by patents/software copyrights, which may be required to implement this Recommendation. However,
implementers are cautioned that this may not represent the latest information and are therefore strongly urged
to consult the appropriate ITU-T databases available via the ITU-T website at http://www.itu.int/ITU-T/ipr/.
© ITU 2022
All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior
written permission of ITU.
Rec. ITU-T H.266 (04/2022) iii
CONTENTS
Page
Introduction ........................................................................................................................................................ 1
Purpose .................................................................................................................................................... 1
Profiles, tiers, and levels ........................................................................................................................... 1
Encoding process, decoding process, and use of VUI parameters and SEI messages ................................. 1
Versions of this Recommendation | International Standard ....................................................................... 2
Overview of the design characteristics ...................................................................................................... 2
How to read this document ....................................................................................................................... 2
1 Scope ....................................................................................................................................................... 2
2 Normative references ............................................................................................................................... 3
2.1 Identical Recommendations | International Standards .................................................................... 3
2.2 Paired Recommendations | International Standards equivalent in technical content ........................ 3
2.3 Additional references .................................................................................................................... 3
3 Definitions ............................................................................................................................................... 3
4 Abbreviations ......................................................................................................................................... 11
5 Conventions ........................................................................................................................................... 13
5.1 General........................................................................................................................................ 13
5.2 Arithmetic operators .................................................................................................................... 14
5.3 Logical operators ......................................................................................................................... 14
5.4 Relational operators ..................................................................................................................... 14
5.5 Bit-wise operators ....................................................................................................................... 14
5.6 Assignment operators .................................................................................................................. 15
5.7 Range notation ............................................................................................................................ 15
5.8 Mathematical functions ............................................................................................................... 15
5.9 Order of operation precedence ..................................................................................................... 16
5.10 Variables, syntax elements and tables .......................................................................................... 16
5.11 Text description of logical operations .......................................................................................... 17
5.12 Processes ..................................................................................................................................... 18
6 Bitstream and picture formats, partitionings, scanning processes and neighbouring relationships ........... 19
6.1 Bitstream formats ........................................................................................................................ 19
6.2 Source, decoded and output picture formats ................................................................................. 19
6.3 Partitioning of pictures, subpictures, slices, tiles, and CTUs ........................................................ 21
6.3.1 Partitioning of pictures into subpictures, slices, and tiles ............................................ 21
6.3.2 Block, quadtree and multi-type tree structures ............................................................ 23
6.3.3 Spatial or component-wise partitionings ..................................................................... 24
6.4 Availability processes .................................................................................................................. 25
6.4.1 Allowed quad split process ........................................................................................ 25
6.4.2 Allowed binary split process ...................................................................................... 25
6.4.3 Allowed ternary split process ..................................................................................... 27
6.4.4 Derivation process for neighbouring block availability............................................... 28
6.5 Scanning processes ...................................................................................................................... 28
6.5.1 CTB raster scanning, tile scanning, and subpicture scanning processes ...................... 28
6.5.2 Up-right diagonal scan order array initialization process ............................................ 32
6.5.3 Horizontal and vertical traverse scan order array initialization process ....................... 33
7 Syntax and semantics ............................................................................................................................. 33
7.1 Method of specifying syntax in tabular form................................................................................ 33
7.2 Specification of syntax functions and descriptors ......................................................................... 34
7.3 Syntax in tabular form ................................................................................................................. 36
7.3.1 NAL unit syntax ........................................................................................................ 36
7.3.2 Raw byte sequence payloads, trailing bits and byte alignment syntax ......................... 36
7.3.3 Profile, tier, and level syntax ...................................................................................... 56
7.3.4 DPB parameters syntax .............................................................................................. 59
7.3.5 Timing and HRD parameters syntax .......................................................................... 59
7.3.6 Supplemental enhancement information message syntax ............................................ 60
7.3.7 Slice header syntax .................................................................................................... 60
