Fundamentals and Evolution of MPEG-2 Systems

Paving the MPEG Road

Jan Van der Meer

• Publisher: Wiley
• Year: 2014
• Print ISBN:
  9780470974339
• Edition: 1
• eBook ISBN:
  9781118875940
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

This book describes the fundamentals and details of MPEG-2 Systems technology

Written by an expert in the field, this book examines the MPEG-2 system specification as developed in the early 1990's, as well as its evolution into the fourth edition of the MPEG-2 systems standard, published in 2013. While MPEG-2 systems will continue to evolve further, this book describes the MPEG-2 system functionality as of October 2013. Furthermore, relevant background information is provided. The discussion of MPEG-2 system functionality requires knowledge of various fundamental issues, such as timing, and supported content formats. Therefore also some basic information on video and audio coding is provided, including their evolution. Also other content formats supported in MPEG-2 systems are described, as far as needed to understand MPEG-2 systems.

• Ordered logically working from the basics and background through to the details and fundamentals of MPEG-2 transport streams and program streams
• Explores important issues within the standardization process itself
• Puts the developments on MPEG-2 systems into historic perspective
• Includes support of 3D Video and transport of AVC, SVC and MVC
• Concludes with additional issues such as real-time interface, delivery over IP networks and usage by application standardization bodies
• Predicts a continuing promising future for MPEG-2 transport streams

Part One
Backgrounds of MPEG-2 Systems

1
Introduction

What MPEG is, the efforts that MPEG initially undertook, what MPEG-2 Systems is and how it is used by applications.

MPEG, which stands for the Moving Picture Experts Group, is the name of a group of audiovisual coding experts operating in ISO/IEC, see Note 1.1. The MPEG group is responsible for a series of well-known international standards, used for coding of audio-visual information in a digital compressed format, such as MPEG-2 video, AVC, MP3 audio and AAC. MPEG was established in 1988 and had its first meeting in May 1988 in Ottawa, Canada. The first two standards produced by MPEG were MPEG-1 and MPEG-2, published as ISO/IEC 11172 [1–6] and ISO/IEC 13818 [7–18], respectively.

Typically, each MPEG standard contains specifications for compression of audio, for compression of video and for transport and synchronization of compressed audio and video. These specifications are usually referred to as MPEG audio, MPEG video and MPEG systems, respectively, and documented in different parts of MPEG standards. For the parts contained in the MPEG-1 and MPEG-2 standards, see Note 1.1.

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Note 1.1 The MPEG Committee and Some of Its Standards

MPEG is a Working Group within a Sub-Committee of a Joint Technical Committee on Information Technology of ISO and IEC; more particularly, MPEG is referred to as ISO/IEC/JTC1/SC29/WG11, that is, WG 11 within SC 29 of JTC 1 of ISO and IEC. The ISO is the International Standardization Organization (see www.iso.org/). The IEC is the International Electrotechnical Commission (see http://www.iec.ch/). The first two standards produced by MPEG were MPEG-1 (1992) and MPEG-2 (1994), published as ISO/IEC 11172 and ISO/IEC 13818; each containing several parts:

ISO/IEC 11172-1	MPEG-1 systems	ISO/IEC 13818-1	MPEG-2 systems
ISO/IEC 11172-2	MPEG-1 video	ISO/IEC 13818-2	MPEG-2 video
ISO/IEC 11172-3	MPEG-1 audio	ISO/IEC 13818-3	MPEG-2 audio
ISO/IEC 11172-4	MPEG-1 compliance	ISO/IEC 13818-4	MPEG-2 compliance
ISO/IEC 11172-5	MPEG-1 software simulation	ISO/IEC 13818-5	MPEG-2 software simulation
		Various other 13818 parts, amongst others:
		ISO/IEC 13818-9	MPEG-2 real-time interface for system decoders

Initially, MPEG was part of ISO/IEC JTC1/SC2/WG8, the same working group that was developing the JPEG standard; but in 1990, when the subgroups became too large, both MPEG and JPEG were promoted to Working Group level under SC29: JPEG became WG1, while MPEG became WG11.

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From the start, the objective of MPEG was to develop standards for the compression of digital video and audio. The MPEG-1 work item ‘Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbit/s’ expressed a focus on Compact Disc and its bitrate. However, when it became clear that the developed technology was suitable for usage by many applications at a wide range of bitrates, the objective for MPEG-2 was broadened to ‘Generic coding of moving pictures and associated audio’. As a consequence of this broadening the MPEG-3 work item on HDTV at high bitrates was dropped: MPEG-3 never happened.

The MPEG-1 standard is successfully used in Video CD, in MP3 audio devices and for coding audio in digital TV broadcast.¹ The MPEG-2 standard is almost universally used in digital cable TV, digital satellite TV, terrestrial digital TV broadcast, DVD, Blu-ray™ Disc,² digital camcorders and other families of products.

The focus of this book is on MPEG-2, in particular on MPEG-2 systems. Several of the basic concepts in MPEG-2 systems were developed first for MPEG-1 systems, and therefore MPEG-1 systems also will be addressed to some extent in this book. To understand MPEG-2 systems, some basic knowledge of MPEG video and audio is needed. The audio and video parts of MPEG standards define the format of compressed audio and video streams and how to decode such MPEG audio and video streams back into uncompressed audio and video.

In the audiovisual applications addressed by MPEG-1 and MPEG-2, the MPEG audio and video streams are not transported in parallel, but instead are transported in a single stream that contains both MPEG audio and MPEG video data. Such a stream is called an MPEG-1 or MPEG-2 system stream. The format of system streams as well as the rules and conditions on their construction are specified in the MPEG-1 and MPEG-2 system specifications [2,8].

The MPEG-1 and MPEG-2 systems features include packetization of audio and video streams, their signalling, synchronization of audio and video and requirements for the decoding of audio and video from an MPEG system stream, while ensuring a high quality of service. So as to accurately define synchronization of audio and video, the system specifications include a model of audio and video decoding. MPEG does not specify how to perform audio, video and systems encoding; instead only the format of the MPEG audio, video and system streams at the output of the encoders is specified, thereby leaving to the market how to encode audio, video and systems in a most efficient and cost-effective manner (see Figure 1.1).

Figure 1.1 Scope of MPEG audio, MPEG video and MPEG system specifications

MPEG-2 systems provide an application independent interchange format, optimized for the target applications, so that mapping to practical transport layers can be made conveniently. For example, the MPEG-2 system specification defines for broadcast applications a transport format that is suitable for transport over terrestrial, satellite, cable and IP networks and that can also be used by recording devices. This approach allows producing and managing content independently of the delivery network to the consumer. Thereby MPEG-2 systems became the basis of an infrastructure to produce, store, exchange and transport audiovisual content.

In order to provide a generally useful interchange format, the MPEG-2 system stream format is designed so that all practical transport requirements of target applications are met. Not only MPEG audio and MPEG video streams can be carried, but also other content, such as subtitling and metadata, as well as audio or video formats defined by other standardization bodies. Moreover, when new audio and video formats evolve, MPEG-2 systems can be extended with support for these new formats, provided that a market requirement for such carriage is identified.

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Note 1.2 Some Application Standardization Bodies

1. DVB is an industry-led consortium designing open interoperable standards for the global delivery of digital media services, operating from Europe. ‘DVB’ stands for Digital Video Broadcasting (see www.dvb.org/).
2. ATSC is an international organization developing standards for digital television, operating from the United States. ‘ATSC’ stands for Advanced Television Systems Committee (see www.atsc.org/).
3. ARIB is the Association of Radio Industries and Businesses, operating from Japan. ARIB aims at establishing technical standards for radio systems in the field of telecommunications and broadcasting (see http://www.arib.or.jp/english/).
4. DVD Forum is the international organization that defines formats for DVD (Digital Versatile Disc) products and technologies (see www.dvdforum.org/).
5. BDA is the Blu-ray Disc Association, dedicated to developing and promoting the Blu-ray Disc Format (see www.blu-raydisc.com/).
6. OIPF is the Open IPTV Forum with the objective to enable and to accelerate t...

Table of contents

• Cover
• Title Page
• Copyright
• Foreword
• Preface
• About the Author
• Acknowledgements
• Part One: Backgrounds of MPEG-2 Systems
• Part Two: The MPEG-2 Systems Standard
• Epilogue
• Annexes
• Index
• End User License Agreement