Overview of the High Efficiency Video Coding(HEVC) Standard之一

Overview of the High Efficiency Video Coding  (HEVC) Standard

Gary J. Sullivan, Fellow, IEEE, 
Jens-Rainer Ohm, Member, IEEE, 
Woo-Jin Han, Member, IEEE, and
Thomas Wiegand, Fellow, IEEE


Abstract
High Efficiency Video Coding (HEVC) is currently being prepared as 
the newest video coding standard of the ITU-T Video Coding Experts Group 
and the ISO/IEC Moving Picture Experts Group. 
The main goal of the HEVC standardization effort is to 
enable significantly improved compression performance relative to 
existing standards—in the range of 50% bit-rate reduction for 
equal perceptual video quality. This paper provides 
an overview of the technical features and characteristics
of the HEVC standard.


Index Terms—Advanced video coding (AVC), H.264, High
Efficiency Video Coding (HEVC), Joint Collaborative Team
on Video Coding (JCT-VC), Moving Picture Experts Group
(MPEG), MPEG-4, standards, Video Coding Experts Group
(VCEG), video compression.


摘要
HEVC是ITU-T Video Coding Experts Group和ISO/IEC Moving Picture Experts Group
联合发布的最新的视频编码标准。
HEVC的最主要目标是对当前的视频标准在压缩效率上获得显著的提高
-- 在同等视频质量下减少50%的码率。
本文提供了HEVC的功能和特性的综述。


一、简介
INTRODUCTION
THE High Efficiency Video Coding (HEVC) standard is the most recent joint video 
project of the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving
Picture Experts Group (MPEG) standardization organizations, working together in 
a partnership known as the Joint Collaborative Team on Video Coding (JCT-VC) [1]. 
The first edition of the HEVC standard is expected to be finalized in January 2013, 
resulting in an aligned text that will be published by both ITU-T and ISO/IEC. 
Additional work is planned to extend the standard to support several additional 
application scenarios, including extended-range uses with enhanced precision
and color format support, scalable video coding, and 3-D/stereo/multiview video 
coding. In ISO/IEC, the HEVC standard will become MPEG-H Part 2 (ISO/IEC 23008-2)
and in ITU-T it is likely to become ITU-T Recommendation H.265.
HEVC是ITU-T Video Coding Experts Group (VCEG)和ISO/IEC Moving Picture Experts Group (MPEG)
联合体Joint Collaborative Team on Video Coding (JCT-VC)发布的最新视频编码标准。
第一版本在2013年1月最终敲定，并发布了相应的文档。
剩下的工作主要在标准的扩展功能支持上，包括:
. 更多的颜色格式支持;
. 可伸缩视频编码;
. 3D/stereo/multiview视频编码;
HEVC将会成为MPEG-H的第二部分(ISO/IEC 23008-2),即H.265.

Video coding standards have evolved primarily through the development of the 
well-known ITU-T and ISO/IEC standards. The ITU-T produced H.261 [2] and H.263 [3], 
ISO/IEC produced MPEG-1 [4] and MPEG-4 Visual [5], and the two organizations 
jointly produced the H.262/MPEG-2 Video [6] and H.264/MPEG-4 Advanced Video 
Coding (AVC) [7] standards. The two standards that were jointly produced have had a
particularly strong impact and have found their way into a wide variety of products 
that are increasingly prevalent in our daily lives. Throughout this evolution, 
continued efforts have been made to maximize compression capability and improve other
characteristics such as data loss robustness, while considering the computational 
resources that were practical for use in products at the time of anticipated deployment 
of each standard.
视频编码标准的发展历程上有:
. ITU-T的H.261, H.263;
. ISO/IEC的MPEG-1, MPEG-4 Visual;
. 两者联合体JCT-VC的H.262/MPEG-2 Video, H.264/MPEG-4 AVC;

The major video coding standard directly preceding the HEVC project was 
H.264/MPEG-4 AVC, which was initially developed in the period between 1999 and 2003, 
and then was extended in several important ways from 2003–2009. H.264/MPEG-4 AVC 
has been an enabling technology for digital video in almost every area that was 
not previously covered by H.262/MPEG-2 Video and has substantially displaced the
older standard within its existing application domains. It is widely used for many 
applications, including broadcast of high definition (HD) TV signals over satellite, 
cable, and terrestrial transmission systems, video content acquisition and editing
systems, camcorders, security applications, Internet and mobile network video, 
Blu-ray Discs, and real-time conversational applications such as video chat, 
video conferencing, and telepresence systems.
HEVC的上一代H.264/MPEG-4 AVC在1999-2003年开发,在2003-2009年开发了多个重要扩展。
它现在获得了广泛而重要的应用。


However, an increasing diversity of services, the growing popularity of HD video, 
and the emergence of beyond-HD formats (e.g., 4k×2k or 8k×4k resolution) are 
creating even stronger needs for coding efficiency superior to H.264/MPEG-4 AVC’s 
capabilities. The need is even stronger when higher resolution is accompanied by 
stereo or multiview capture and display. Moreover, the traffic caused by video
applications targeting mobile devices and tablet PCs, as well as the transmission 
needs for video-on-demand services, are imposing severe challenges on today’s networks. 
An increased desire for higher quality and resolutions is also arising in mobile applications.
然而，现在，随着服务种类越来越多，高清视频，超高清视频越来越流行，
对编码效率的强劲需求已超出了H.264/MPEG-4 AVC的能力;
但同时还要兼顾平板等移动设备，VOD服务对网络传输的挑战;


HEVC has been designed to address essentially all existing applications of 
H.264/MPEG-4 AVC and to particularly focus on two key issues: increased video 
resolution and increased use of parallel processing architectures. The syntax of HEVC
is generic and should also be generally suited for other applications that are 
not specifically mentioned above.
HEVC除了兼顾现在H.264/MPEG-4 AVC的所有应用外，还特别关注了两个关键方面:
. 更大的视频分辨率;
. 更好的并行处理架构;


As has been the case for all past ITU-T and ISO/IEC video coding standards, 
in HEVC only the bitstream structure and syntax is standardized, as well as 
constraints on the bitstream and its mapping for the generation of decoded pictures. 
The mapping is given by defining the semantic meaning of syntax elements and 
a decoding process such that every decoder conforming to the standard will produce 
the same output when given a bitstream that conforms to the constraints of the
standard. This limitation of the scope of the standard permits maximal freedom 
to optimize implementations in a manner appropriate to specific applications 
(balancing compression quality, implementation cost, time to market, and other 
considerations). However, it provides no guarantees of end-to-end reproduction 
quality, as it allows even crude encoding techniques to be considered conforming.
和之前的视频编码标准一样，HEVC也只规定了码流的结构和语法，
它们映射的是解码流程生成的解码图像，以保证相同的码流会生成相同的输出图像。


To assist the industry community in learning how to use the standard, the standardization 
effort not only includes the development of a text specification document, but also 
reference software source code as an example of how HEVC video can be encoded and decoded. 
The draft reference software has been used as a research tool for the internal work of 
the committee during the design of the standard, and can also be used as a general 
research tool and as the basis of products. A standard test data suite is also being 
developed for testing conformance to the standard.
为了帮助行业实体快速使用这个标准，发布了文档和相应的参考代码。


This paper is organized as follows. 
本文组织如下:
Section II  highlights some key features of the HEVC coding design. 
Section III explains the high-level syntax and the overall structure of HEVC coded data. 
Section IV  The HEVC coding technology is then described in greater  detail. 
Section V   explains the profile, tier, and level design of HEVC. 
            Since writing an overview of a technology as substantial as HEVC involves a
            significant amount of summarization, the reader is referred to [1] 
            for any omitted details. 
Section VI  The history of the HEVC standardization effort is discussed.