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This chapter is from the book

This chapter is from the book

1.4 MPEG-4 Standard Organization

The MPEG-4 requirements [N4319] have been addressed by a standard organized in several Parts, each one with multiple editions, amendments, and corrigenda. Amendments to each Part of the standard were also called Versions (the first edition itself is Version 1).10 The list of documents issued as of July 2001 for the various Parts of the MPEG-4 standard is as follows:

  • Part 1: Systems. This Part specifies scene description, multiplexing, synchronization, buffer management, and management and protection of intellectual property [MPEG4-1].

    Version 1: First edition (14496-1:1999)

    Version 2 (first amendment to first edition): Systems extensions (MPEG-4 file format, BIFS nodes)

    Corrigendum 1 to first edition

    Second edition of Part 1, including the 1999 edition, Amendment 1, and Corrigendum 1 (14496-1:2001)

    Amendment 1 to second edition: Extended BIFS (Flextime)

    Amendment 2 to second edition: Textual format (XMT)

    Amendment 3 to second edition: Intellectual Property Management and Protection (IPMP) extension

    Amendment 4 to second edition: Multiuser worlds and animation framework (AFX)

    Amendment 5 to second edition: MP4 extensions (common with WG1/JPEG)

    Amendment 6 to second edition: MP4 extensions

    Corrigendum 1 to second edition

    Corrigendum 2 to second edition

  • Part 2: Visual. This Part specifies the coded representation of natural and synthetic visual objects [MPEG4-2].

    Version 1: First edition (14496-2:1999)

    Version 2 (first amendment to first edition): Visual extensions

    Version 3 (second amendment to first edition): 3D mesh profiles (withdrawn)

    Corrigendum 1 to first edition

    Corrigendum 2 to first edition

    Second edition of Part 2, including the first edition, Amendment 1, and Corrigenda 1 and 2 (14496-2:2001)

    Amendment 1 to second edition: Studio profiles

    Amendment 2 to second edition: Streaming video profiles

    Amendment 3 to second edition: New levels and tools

  • Part 3: Audio. This Part specifies the coded representation of natural and synthetic audio objects [MPEG4-3].

    Version 1: First edition (14496-3:1999)

    Version 2 (first amendment to first edition): Audio extensions

    Corrigendum 1 to first edition

    Second edition of Part 3, including the first edition, Amendment 1, and Corrigendum 1 (14496-3:2001)

    Corrigendum 1 to second edition

  • Part 4: Conformance Testing. This Part defines conformance conditions for bitstreams and devices; it is used to test MPEG-4 implementations [MPEG4-4].

    Version 1: First edition (14496-4:2000)

    Version 2 (first amendment to first edition): Extensions to conformance testing

    Corrigendum 1 to first edition

    Second edition of Part 4, including the first edition, Amendment 1, and Corrigendum 1 (14496-4:2001)

    Amendment 1 to second edition: Conformance extensions for studio and streaming video profiles and for Flextime

    Corrigendum 1 to second edition

  • Part 5: Reference Software. This Part includes software corresponding to most Parts of MPEG-4 (normative and non-normative tools); this means the VMs mentioned in Section 1.3.3.1. This software can be used for implementing compliant products as ISO waives the copyright of the code11 [MPEG4-5].

    Version 1: First edition (14496-5:1999)

    Version 2 (first amendment to first edition): Reference software extensions

    Corrigendum 1

    Second edition of Part 5, including the first edition, Amendment 1, and Corrigendum 1 (14496-5:2001)

    Amendment 1 to second edition: Reference software extensions for studio and streaming video profiles and for Flextime

  • Part 6: Delivery Multimedia Integration Framework (DMIF). Part 6 defines a session protocol for the management of multimedia streaming over generic delivery technologies [MPEG4-6].

    Version 1: First edition (14496-6:1999)

    Version 2 (Amendment 1 to first edition): DMIF extensions

    Corrigendum 1

    Second edition of Part 6, including the first edition, Amendment 1, and Corrigendum 1 (14496-6:2000)

  • Part 7: Optimized Visual Reference Software. This Part includes optimized software for visual tools such as fast motion estimation, fast global motion estimation, and fast and robust sprite generation [N4554]; the optimized software is called Optimization Model (OM). Unlike the other MPEG-4 standard Parts, this Part is a TR and not a standard specification.

    Version 1: First edition (14496-7:2001)

  • Part 8: Carriage of MPEG-4 Contents over IP Networks. This Part specifies the mapping of MPEG-4 content into several IP-based protocols [N4427]; it is well known as 4on IP.

    Version 1: First edition (14496-8:2002)

  • Part 9: Reference Hardware Description. Part 9 will include portable synthesizable/simulatable very high-speed integrated circuit hardware description language (VHDL) descriptions of MPEG-4 tools [N4218].

    Version 1: First edition (14496-9:2003)

  • Part 10: Advanced Video Coding (AVC). This Part will specify video syntax and coding tools12 in the context of a joint project with ITU-T SG16 [N4400], known as Joint Video Team (JVT); this activity used as a starting point the available version of the H.26L video coding specification to address the identified requirements [N4466, N4508].

    Version 1: First edition (14496-10:2003)

Although most parts are IS, Parts 7 and 9 are TRs with informative value. Parts 1 to 3 as well as Parts 6, 8, and 10 specify the core MPEG-4 technology, whereas Parts 4, 5, 7, and 9 are supporting Parts. Parts 1, 2, 3, and 10 are delivery-independent, leaving to Parts 6 and 8 the task of dealing with the idiosyncrasies of the delivery layer.

The major reason to develop the MPEG-4 standard in several rather independent Parts (besides avoiding a single document with several thousand pages) is to allow the various pieces of technology to be useful as stand-alones and thus as much used as possible, even if in conjunction with proprietary technologies. This has been the case, for example, for MPEG-2 Video, which today is being used together with MPEG-2 Systems but not with MPEG-2 Audio in the context of the U.S. digital TV system. This means that within the context of a certain standardization effort (e.g., MPEG-4), whenever a new technological area is addressed that is different from the areas already addressed (e.g., MPEG-4 on IP), an additional Part of the standard is created to allow stand-alone use and a clearer organization of the tools specified by the standard as a whole. However, although the various Parts may be used independently, they were developed to give optimal results when they are used together.

During the MPEG-4 development process, it was decided to issue successive versions of the several MPEG-4 Parts whenever new tools needed to be added to that Part of the standard. In this context, versions would serve to specify new tools, either offering new functionalities or bringing a significant improvement in terms of functionalities already supported. Formally speaking, the various versions (except the first) of a certain MPEG-4 Part correspond to amendments to that Part of the standard. So, whereas the IS for Systems (issued in 1999) is called Version 1, MPEG-4 Systems Version 2 corresponds to the first MPEG-4 Systems amendment, Version 3 to the Amendment 2 to Systems, and so on. It is important to note that new versions of a Part do not substitute or redefine tools specified in previous versions but simply add more tools. At each stage of specification, a certain Part of the MPEG-4 standard is the set of all the tools specified in all versions for that Part. In that sense, it is common to say that versions are backward-compatible, meaning that Version N may only add new tools and profiles to Version N-1 and not remove or redefine any tool or profile. This implies that existing terminals will always remain compliant, as profiles will not be changed in retrospect. The same reasoning applies to the amendments to the second and further editions of the various Parts of the standard.

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