GB/T 17975.2-2000 in English

《GB/T 17975.2-2000信息技术 运动图像及其伴音信号的通用编码 第2部分:视频》由TC28（全国信息技术标准化技术委员会）归口，TC28SC29（全国信息技术标准化技术委员会多媒体分会）执行，主管部门为国家标准化管理委员会。
本标准规定了数字存储媒体和数字视频通信用的图像信息的编码表示，并且规定了解码过程。这种表示支持恒定码率传输、可变码率传输、随机存娶信道跳换、可分级解码、比特流编辑、以及诸如快速正放、快速倒放、慢放、暂停和镜像等特殊功能。本标准与GB/T 17191.2前向兼容、并与EDTV、HDTV、SDTV格式上兼容或下兼容。本标准主要应用于数字存贮媒体、视频广播与通信。存贮媒体可以与解码器直接联接，或是通过诸如总线、LAN或电信链路等通信设施与解码器联接。

1 Scope

This standard specifies the coded representation of picture information for digital storage media and digital video communication and specifies the decoding process. The representation supports constant bitrate transmission, variable bitrate transmission, random access, channel hopping, scalable decoding, bitstream editing, as well as special functions such as fast forward playback, fast reverse playback, slow motion, pause and still pictures. This standard is forward compatible with GB/T 17191.2 and upward or downward compatible with EDTV, HDTV, SDTV formats.
This standard is primarily applicable to digital storage media, video broadcast and communication. The storage media may be directly connected to the decoder, or via communications means such as busses, LANs, or telecommunications links.

2 Normative References

The following standards contain provisions which, through reference, constitute provisions of this standard. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
GB/T 14857-1993 The Specifications of Encoding Parameters of Digital Television for Studio (eqv CCIR 601-3)
GB/T 17191.1-1997 Information Technology-Coding of Moving Pictures and Associated Audio for Digital Storage Media at up to about 1.5Mbit/s-Part 1: Systems (idt ISO/IEC 111 72-1: 1993)
GB/T 17191.2-1997 Information Technology-Coding of Moving Pictures and Associated Audio for Digital Storage Media at up to about 1.5Mbit/s-Part 2: Video (idt ISO/IEC 11172 2: 1993)
GB/T 17191.3-1997 Information Technology-Coding of Moving Pictures and Associated Audio for Digital Storage Media at up to about 1.5Mbit/s-Part 3: Audio (idt ISO/TEC 11172-3: 1993)
GB/T 17576-1998 Compact Disc Digital Audio System (idt IEC 908-1987)
GB/T 17975.1-2000 Information Technology-Generic Coding of Moving Pictures and Associated Audio Information - Part 1: Systems (idt ISO/IEC: 13818-1: 1996)
IEC 461-1986 Time and Control Code for Video Tape Recorders
ITU-T T.81(JPEG) ISO/IEC 10918-1 Information Technology-Digital Compression and Coding of Continuous-tone Still Images: Requirements and Guidelines
ITU-T H.261 Video Codec for Audiovisual Services at p×64 kbit/s
ITU-T Recommendation H.320 (1997) Narrow-band Visual Telephone Systems and Terminal Equipment,
ITU-R Recommendation BR.648 Digital Recording of Audio Signals
ITU-R Recommendation 955-2 Satellite Sound Broadcasting to Vehicular, Portable and Fixed Receivers in the Range 500 - 3000Mhz
IEEE 1180-1990 Standard Specifications for the Implementation of 8×8 Inverse Discrete Cosine Transform

3 Definitions

For the purposes of this standard, the following definitions apply.
3.1 AC coefficient
Any DCT coefficient for which the frequency in one or both dimensions is non-zero.
3.2 B-field picture
A field structure B-Picture.
3.3 B-frame picture
A frame structure B-Picture.
3.4 Big picture
A coded picture that would cause VBV buffer underflow as defined in C7. Big pictures can only occur in sequences where low_delay is equal to 1. "Skipped picture" is a term that is sometimes used to describe the same concept.
3.5 B-picture; bidirectionally predictive-coded picture
A picture that is coded using motion compensated prediction from past and/or future reference fields or frames.
3.6 Backward compatibility
A newer coding standard is backward compatible with an older coding standard if decoders designed to operate with the older coding standard are able to continue to operate by decoding all or part of a bitstream produced according to the newer coding standard.
3.7 Backward motion vector

Foreword III
ITU Foreword V
I Introduction VI
I.1 Purpose VI
I.2 Application VI
I.3 Profiles and Levels VI
I.4 The Scalable and the Non-scalable Syntax VII
1 Scope
2 Normative References
3 Definitions
4 Abbreviations and Symbols
4.1 Arithmetic Operators
4.2 Logical Operators
4.3 Relational Operators
4.4 Bitwise Operators
4.5 Assignment
4.6 Mnemonics
4.7 Constants
5 Conventions
5.1 Method of Describing Bitstream Syntax
5.2 Definition of Functions
5.3 Reserved, Forbidden and Marker_bit
5.4 Arithmetic Precision
6 Video Bitstream Syntax and Semantics
6.1 Structure of Coded Video Data
6.2 Video Bitstream Syntax
6.3 Video Bitstream Semantics
7 The Video Decoding Process
7.1 Higher Syntactic Structures
7.2 Variable Length Decoding
7.3 Inverse Scan
7.4 Dequantisation
7.5 Inverse DCT
7.6 Motion Compensation
7.7 Spatial Scalability
7.8 SNR Scalability
7.9 Temporal Scalability
7.10 Data Partitioning
7.11 Hybrid Scalability
7.12 Output of the Decoding Process
8 Profiles and Levels
8.1 GB/T 17191.2 Compatibility
8.2 Relationship between Defined Profiles
8.3 Relationship between Defined Profiles
8.4 Scalable Layers
8.5 Parameter Values for Defined Profiles, Levels and Layers
8.6 Compatibility Requirements for Decoder
Appendix A (Normative) Discrete Cosine Transform
Appendix B (Normative) Variable Length Code Tables
B.1 Macroblock Addressing
B.2 Macroblock Type
B.3 Macroblock Pattern
B.4 Motion Vectors
B.5 DCT Coefficients
Appendix C (Normative) Video Buffering Verifier
Appendix D (Informative) Features Supported by the Algorithm
D.1 Overview
D.2 Video Formats
D.3 Picture Quality
D.4 Data Rate Control
D.5 Low Delay Mode
D.6 Random Access/Channel Hopping
D.7 Severability
D.8 Compatibility
D.9 Differences between this Standard and GB/T 17191.2
D.10 Complexity
D.11 Editing Encoded Bitstreams
D.12 Trick Modes
D.13 Error Resilience
D.14 Concatenated Sequences
Appendix E (Informative) Profile and Level Restrictions
E.1 Syntax Element Restrictions in Profiles
E.2 Permissible Layer Combinations