MPEG-4 explained

MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) (ISO/IEC JTC 1/SC29/WG11) under the formal standard ISO/IEC 14496 – Coding of audio-visual objects. Uses of MPEG-4 include compression of audiovisual data for Internet video and CD distribution, voice (telephone, videophone) and broadcast television applications. The MPEG-4 standard was developed by a group led by Touradj Ebrahimi (later the JPEG president) and Fernando Pereira.[1]

Background

MPEG-4 absorbs many of the features of MPEG-1 and MPEG-2 and other related standards, adding new features such as (extended) VRML support for 3D rendering, object-oriented composite files (including audio, video and VRML objects), support for externally specified digital rights management and various types of interactivity. AAC (Advanced Audio Coding) was standardized as an adjunct to MPEG-2 (as Part 1) before MPEG-4 was issued.

MPEG-4 is still an evolving standard and is divided into a number of parts. Companies promoting MPEG-4 compatibility do not always clearly state which "part" level compatibility they are referring to. The key parts to be aware of are MPEG-4 Part 2 (including Advanced Simple Profile, used by codecs such as DivX, Xvid, Nero Digital, RealMedia, 3ivx, H.263 and by QuickTime 6) and MPEG-4 part 10 (MPEG-4 AVC/H.264 or Advanced Video Coding, used by the x264 encoder, Nero Digital AVC, QuickTime 7, Flash Video, and high-definition video media like Blu-ray Disc).

Most of the features included in MPEG-4 are left to individual developers to decide whether or not to implement. This means that there are probably no complete implementations of the entire MPEG-4 set of standards. To deal with this, the standard includes the concept of "profiles" and "levels", allowing a specific set of capabilities to be defined in a manner appropriate for a subset of applications.

Initially, MPEG-4 was aimed primarily at low-bit-rate video communications; however, its scope as a multimedia coding standard was later expanded. MPEG-4 is efficient across a variety of bit rates ranging from a few kilobits per second to tens of megabits per second. MPEG-4 provides the following functions:

Overview

MPEG-4 provides a series of technologies for developers, for various service-providers and for end users:

The MPEG-4 format can perform various functions, among which might be the following:

Profiles and Levels

MPEG-4 provides a large and rich set of tools for encoding.Subsets of the MPEG-4 tool sets have been provided for use in specific applications.These subsets, called 'Profiles', limit the size of the tool set a decoder is required to implement. In order to restrict computational complexity, one or more 'Levels' are set for each Profile. A Profile and Level combination allows:[3]

MPEG-4 Parts

MPEG-4 consists of several standards—termed "parts"—including the following (each part covers a certain aspect of the whole specification):

MPEG-4 parts[4] [5]
PartNumberFirst public release date (first edition)Latest public release date (last edition)Latest amendmentTitleDescription
Part 1 ISO/IEC 14496-119992010[6] 2014[7] SystemsDescribes synchronization and multiplexing of video and audio. For example, the MPEG-4 file format version 1 (obsoleted by version 2 defined in MPEG-4 Part 14). The functionality of a transport protocol stack for transmitting and/or storing content complying with ISO/IEC 14496 is not within the scope of 14496-1 and only the interface to this layer is considered (DMIF). Information about transport of MPEG-4 content is defined e.g. in MPEG-2 Transport Stream, RTP Audio Video Profiles and others.[8] [9] [10]
ISO/IEC 14496-2 19992004[11] 2009VisualA compression format for visual data (video, still textures, synthetic images, etc.). Contains many profiles, including the Advanced Simple Profile (ASP), and the Simple Profile (SP).
Part 3ISO/IEC 14496-3 19992009[12] 2017[13] AudioA set of compression formats for perceptual coding of audio signals, including some variations of Advanced Audio Coding (AAC) as well as other audio/speech coding formats and tools (such as Audio Lossless Coding (ALS), Scalable Lossless Coding (SLS), Structured Audio, Text-To-Speech Interface (TTSI), HVXC, CELP and others)
Part 4ISO/IEC 14496-4 20002004[14] 2016Conformance testingDescribes procedures for testing conformance to other parts of the standard.
Part 5ISO/IEC 14496-5 20002001[15] 2017Reference softwareProvides reference software for demonstrating and clarifying the other parts of the standard.
Part 6ISO/IEC 14496-6 19992000[16] Delivery Multimedia Integration Framework (DMIF)
Part 7ISO/IEC TR 14496-7 20022004[17] Optimized reference software for coding of audio-visual objectsProvides examples of how to make improved implementations (e.g., in relation to Part 5).
Part 8ISO/IEC 14496-8 20042004[18] Carriage of ISO/IEC 14496 contents over IP networksSpecifies a method to carry MPEG-4 content on IP networks. It also includes guidelines to design RTP payload formats, usage rules of SDP to transport ISO/IEC 14496-1-related information, MIME type definitions, analysis on RTP security and multicasting.
Part 9ISO/IEC TR 14496-9 20042009[19] Reference hardware descriptionProvides hardware designs for demonstrating how to implement the other parts of the standard.
Part 10ISO/IEC 14496-10 20032014[20] 2016[21] Advanced Video Coding (AVC)A compression format for video signals which is technically identical to the ITU-T H.264 standard.
Part 11ISO/IEC 14496-11 20052015[22] Scene description and application engineCan be used for rich, interactive content with multiple profiles, including 2D and 3D versions. MPEG-4 Part 11 revised MPEG-4 Part 1 – ISO/IEC 14496-1:2001 and two amendments to MPEG-4 Part 1. It describes a system level description of an application engine (delivery, lifecycle, format and behaviour of downloadable Java byte code applications) and the Binary Format for Scene (BIFS) and the Extensible MPEG-4 Textual (XMT) format – a textual representation of the MPEG-4 multimedia content using XML, etc. (It is also known as BIFS, XMT, MPEG-J.[23] MPEG-J was defined in MPEG-4 Part 21)
Part 12ISO/IEC 14496-12 20042015[24] 2017[25] ISO base media file formatA file format for storing time-based media content. It is a general format forming the basis for a number of other more specific file formats (e.g. 3GP, Motion JPEG 2000, MPEG-4 Part 14). It is technically identical to ISO/IEC 15444-12 (JPEG 2000 image coding system – Part 12).
Part 13ISO/IEC 14496-13 20042004[26] Intellectual Property Management and Protection (IPMP) ExtensionsMPEG-4 Part 13 revised an amendment to MPEG-4 Part 1 – ISO/IEC 14496-1:2001/Amd 3:2004. It specifies common Intellectual Property Management and Protection (IPMP) processing, syntax and semantics for the carriage of IPMP tools in the bit stream, IPMP information carriage, mutual authentication for IPMP tools, a list of registration authorities required for the support of the amended specifications (e.g. CISAC), etc. It was defined due to the lack of interoperability of different protection mechanisms (different DRM systems) for protecting and distributing copyrighted digital content such as music or video.[27] [28] [29] [30] [31]
Part 14ISO/IEC 14496-14 20032003[32] 2010[33] MP4 file formatIt is also known as "MPEG-4 file format version 2". The designated container file format for MPEG-4 content, which is based on Part 12. It revises and completely replaces Clause 13 of ISO/IEC 14496-1 (MPEG-4 Part 1: Systems), in which the MPEG-4 file format was previously specified.
Part 15ISO/IEC 14496-15 20042022[34] 2023[35] Part 15: Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file formatFor storage of Part 10 video. File format is based on Part 12, but also allows storage in other file formats.
Part 16ISO/IEC 14496-16 20042011[36] 2016[37] Animation Framework eXtension (AFX)It specifies MPEG-4 Animation Framework eXtension (AFX) model for representing 3D Graphics content. MPEG-4 is extended with higher-level synthetic objects for specifying geometry, texture, animation and dedicated compression algorithms.
Part 17ISO/IEC 14496-17 20062006[38] Streaming text formatTimed Text subtitle format
Part 18ISO/IEC 14496-18 20042004[39] 2014Font compression and streamingFor Open Font Format defined in Part 22.
Part 19ISO/IEC 14496-19 20042004[40] Synthesized texture streamSynthesized texture streams are used for creation of very low bitrate synthetic video clips.
Part 20ISO/IEC 14496-20 20062008[41] 2010Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)LASeR requirements (compression efficiency, code and memory footprint) are fulfilled by building upon the existing the Scalable Vector Graphics (SVG) format defined by the World Wide Web Consortium.[42]
Part 21ISO/IEC 14496-2120062006[43] MPEG-J Graphics Framework eXtensions (GFX)Describes a lightweight programmatic environment for advanced interactive multimedia applications – a framework that marries a subset of the MPEG standard Java application environment (MPEG-J) with a Java API.[44] [45] (at "FCD" stage in July 2005, FDIS January 2006, published as ISO standard on 2006-11-22).
Part 22ISO/IEC 14496-2220072015[46] 2017Open Font FormatOFFS is based on the OpenType version 1.4 font format specification, and is technically equivalent to that specification.[47] [48] Reached "CD" stage in July 2005, published as ISO standard in 2007
Part 23ISO/IEC 14496-2320082008[49] Symbolic Music Representation (SMR)Reached "FCD" stage in October 2006, published as ISO standard in 2008-01-28
Part 24ISO/IEC TR 14496-24 20082008[50] Audio and systems interactionDescribes the desired joint behavior of MPEG-4 File Format and MPEG-4 Audio.
Part 25ISO/IEC 14496-25 20092011[51] 3D Graphics Compression ModelDefines a model for connecting 3D Graphics Compression tools defined in MPEG-4 standards to graphics primitives defined in any other standard or specification.
Part 26ISO/IEC 14496-26 20102010[52] 2016Audio Conformance
Part 27ISO/IEC 14496-27 20092009[53] 2015[54] 3D Graphics conformance3D Graphics Conformance summarizes the requirements, cross references them to characteristics, and defines how conformance with them can be tested. Guidelines are given on constructing tests to verify decoder conformance.
Part 28 ISO/IEC 14496-2820122012[55] Composite font representation
Part 29ISO/IEC 14496-29 20142015Web video codingText of Part 29 is derived from Part 10 - ISO/IEC 14496-10. Web video coding is a technology that is compatible with the Constrained Baseline Profile of ISO/IEC 14496-10 (the subset that is specified in Annex A for Constrained Baseline is a normative specification, while all remaining parts are informative).
Part 30ISO/IEC 14496-3020142014Timed text and other visual overlays in ISO base media file formatIt describes the carriage of some forms of timed text and subtitle streams in files based on ISO/IEC 14496-12 - W3C Timed Text Markup Language 1.0, W3C WebVTT (Web Video Text Tracks). The documentation of these forms does not preclude other definition of carriage of timed text or subtitles; see, for example, 3GPP Timed Text (3GPP TS 26.245).
Part 31ISO/IEC 14496-31Under development (2018-05)Video Coding for BrowsersVideo Coding for Browsers (VCB) - a video compression technology that is intended for use within World Wide Web browser
Part 32ISO/IEC CD 14496-32Under developmentConformance and reference software
Part 33ISO/IEC FDIS 14496-33Under developmentInternet video coding

Profiles are also defined within the individual "parts", so an implementation of a part is ordinarily not an implementation of an entire part.

MPEG-1, MPEG-2, MPEG-7 and MPEG-21 are other suites of MPEG standards.

Licensing

MPEG-4 contains patented technologies, the use of which requires licensing in countries that acknowledge software algorithm patents. Over two dozen companies claim to have patents covering MPEG-4. MPEG LA[56] licenses patents required for MPEG-4 Part 2 Visual from a wide range of companies (audio is licensed separately) and lists all of its licensors and licensees on the site. New licenses for MPEG-4 System patents are under development[57] and no new licenses are being offered while holders of its old MPEG-4 Systems license are still covered under the terms of that license for the patents listed (MPEG LA – Patent List).

The majority of patents used for the MPEG-4 Visual format are held by three Japanese companies: Mitsubishi Electric (255 patents), Hitachi (206 patents), and Panasonic (200 patents).

See also

External links

Notes and References

  1. Book: Ebrahimi . Touradj . Pereira . Fernando . The MPEG-4 Book . 2002 . . 9780130616210 .
  2. Wiegand . T . Thomas Wiegand . Sullican . G J . Bjontegaard . G . Luthra . A . Overview of the H.264/AVC video coding standard . IEEE Transactions on Circuits and Systems for Video Technology . 2003 . 13 . 7 . 560–576 . 10.1109/TCSVT.2003.815165 .
  3. .
  4. Web site: MPEG standards – Full list of standards developed or under development . MPEG . Chiariglione . 2010-02-09 . dead . https://web.archive.org/web/20100420192552/http://mpeg.chiariglione.org/standards.htm . 2010-04-20 .
  5. Web site: Programme of Work – MPEG-4 (Coding of audio-visual objects) . ISO/IEC JTC 1/SC 29 . 2009-11-09 . 2009-11-10 . dead . https://web.archive.org/web/20131231054907/http://kikaku.itscj.ipsj.or.jp/sc29/29w42911.htm . 2013-12-31 .
  6. Web site: ISO/IEC 14496-1:2010 – Information technology — Coding of audio-visual objects — Part 1: Systems . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235838/https://www.iso.org/standard/55688.html . live .
  7. Web site: ISO/IEC 14496-1:2010/Amd 2:2014 – Support for raw audio-visual data . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235134/https://www.iso.org/standard/62114.html . live .
  8. Web site: Overview of the MPEG-4 Standard . WG11 (MPEG) . March 2002 . 2010-04-11 . 2010-03-27 . https://web.archive.org/web/20100327042022/http://mpeg.chiariglione.org/standards/mpeg-4/mpeg-4.htm . live .
  9. Web site: MPEG-4 Systems Elementary Stream Management (ESM) . July 2001 . 2010-04-11 . 2010-04-01 . https://web.archive.org/web/20100401091408/http://mpeg.chiariglione.org/faq/mp4-sys/sys-faq-esm.htm . live .
  10. Web site: MPEG Systems (1-2-4-7) FAQ, Version 17.0 . July 2001 . 2010-04-11 . 2020-10-27 . https://web.archive.org/web/20201027160601/http://mpeg.chiariglione.org/faq/mp4-sys/mp4-sys.htm . live .
  11. Web site: ISO/IEC 14496-2:2004 – Information technology — Coding of audio-visual objects — Part 2: Visual . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235141/https://www.iso.org/standard/39259.html . live .
  12. Web site: ISO/IEC 14496-3:2009 – Information technology — Coding of audio-visual objects — Part 3: Audio . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234701/https://www.iso.org/standard/53943.html . live .
  13. Web site: ISO/IEC 14496-3:2009/Amd 6:2017, Profiles, levels and downmixing method for 22.2 channel programs . ISO . 2017 . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234725/https://www.iso.org/standard/70436.html . live .
  14. Web site: ISO/IEC 14496-4:2004 – Information technology — Coding of audio-visual objects — Part 4: Conformance testing . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235126/https://www.iso.org/standard/36084.html . live .
  15. Web site: ISO/IEC 14496-5:2001 – Information technology — Coding of audio-visual objects — Part 5: Reference software . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235446/https://www.iso.org/standard/36086.html . live .
  16. Web site: ISO/IEC 14496-6:2000 – Information technology — Coding of audio-visual objects — Part 6: Delivery Multimedia Integration Framework (DMIF) . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000234/https://www.iso.org/standard/34418.html . live .
  17. Web site: ISO/IEC TR 14496-7:2004 – Information technology — Coding of audio-visual objects — Part 7: Optimized reference software for coding of audio-visual objects . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000423/https://www.iso.org/standard/40728.html . live .
  18. Web site: ISO/IEC 14496-8:2004 – Information technology — Coding of audio-visual objects — Part 8: Carriage of ISO/IEC 14496 contents over IP networks . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234045/https://www.iso.org/standard/36066.html . live .
  19. Web site: ISO/IEC TR 14496-9:2009 – Information technology — Coding of audio-visual objects — Part 9: Reference hardware description . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235300/https://www.iso.org/standard/52073.html . live .
  20. Web site: ISO/IEC 14496-10:2014 – Information technology — Coding of audio-visual objects — Part 10: Advanced Video Coding . ISO . 2017-08-30.
  21. Web site: ISO/IEC 14496-10:2014/Amd 3:2016 – Constrained Additional supplemental enhancement information . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234716/https://www.iso.org/standard/69728.html . live .
  22. Web site: ISO/IEC 14496-11:2015 – Information technology — Coding of audio-visual objects — Part 11: Scene description and application engine . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235720/https://www.iso.org/standard/63548.html . live .
  23. Web site: MPEG-J White Paper . July 2005 . 2010-04-11 . 2011-11-23 . https://web.archive.org/web/20111123040838/http://mpeg.chiariglione.org/technologies/mpeg-4/mp04-j/ . live .
  24. Web site: ISO/IEC 14496-12:2015 – Information technology — Coding of audio-visual objects — Part 12: ISO base media file format . ISO . 2014-01-19 . 2023-01-27 . https://web.archive.org/web/20230127141004/https://www.iso.org/standard/68960.html . live .
  25. Web site: ISO/IEC 14496-12:2015/Amd 1:2017 – DRC Extensions . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000415/https://www.iso.org/standard/70430.html . live .
  26. Web site: ISO/IEC 14496-13:2004 – Information technology — Coding of audio-visual objects — Part 13: Intellectual Property Management and Protection (IPMP) extensions . ISO . 2017-08-30.
  27. Web site: MPEG-4 IPMPX white paper . July 2005 . MPEG . 2010-08-01 . 2011-11-23 . https://web.archive.org/web/20111123040258/http://mpeg.chiariglione.org/technologies/mpeg-4/mp04-ipx/ . live .
  28. Web site: MPEG Intellectual Property Management and Protection . April 2009 . MPEG . 2010-08-01 . 2011-11-23 . https://web.archive.org/web/20111123041715/http://mpeg.chiariglione.org/technologies/general/mp-drm/ . live .
  29. Web site: MPEG Registration Authority – IPMP . MPEG RA International Agency (CISAC) . 2010-08-01 . dead . https://web.archive.org/web/20070616033830/http://www.mpegra.org/aspx/Login.aspx?Type=IPMP . 2007-06-16 .
  30. Web site: MPEG RA – FAQ IPMP . MPEG RA International Agency (CISAC) . 2010-08-01 .
  31. Web site: Intellectual Property Management and Protection Registration Authority . . 2004-12-05 . 2010-08-01 . https://web.archive.org/web/20041205233806/http://www.ipmp-ra.org/ipmp/ipmpweb.nsf/home1 . 2004-12-05.
  32. Web site: ISO/IEC 14496-14:2003 – Information technology — Coding of audio-visual objects — Part 14: MP4 file format . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000353/https://www.iso.org/standard/38538.html . live .
  33. Web site: ISO/IEC 14496-14:2003/Amd 1:2010 – Handling of MPEG-4 audio enhancement layers . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235829/https://www.iso.org/standard/53749.html . live .
  34. Web site: ISO/IEC 14496-15:2022 – Information technology — Coding of audio-visual objects — Part 15: Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format . ISO . 2023-12-07 . 2023-12-07 . https://web.archive.org/web/20231207182412/https://www.iso.org/standard/83336.html . live .
  35. Web site: ISO/IEC 14496-15:2022/Amd 1:2023 - Information technology — Coding of audio-visual objects — Part 15: Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format — Amendment 1: Support for LCEVC . 2023-12-07 . ISO . en . 2023-12-07 . https://web.archive.org/web/20231207182411/https://www.iso.org/standard/83337.html . live .
  36. Web site: ISO/IEC 14496-16:2011 – Information technology — Coding of audio-visual objects — Part 16: Animation Framework eXtension (AFX) . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235735/https://www.iso.org/standard/57367.html . live .
  37. Web site: ISO/IEC 14496-16:2011/Amd 3:2016 – Printing material and 3D graphics coding for browsers . 2017-08-30.
  38. Web site: ISO/IEC 14496-17:2006 – Information technology — Coding of audio-visual objects — Part 17: Streaming text format . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234409/https://www.iso.org/standard/39478.html . live .
  39. Web site: ISO/IEC 14496-18:2004 – Information technology — Coding of audio-visual objects — Part 18: Font compression and streaming . ISO . 2017-08-30.
  40. Web site: ISO/IEC 14496-19:2004 – Information technology – Coding of audio-visual objects — Part 19: Synthesized texture stream . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234100/https://www.iso.org/standard/40152.html . live .
  41. Web site: ISO/IEC 14496-20:2008 – Information technology — Coding of audio-visual objects — Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830235853/https://www.iso.org/standard/52454.html . live .
  42. Web site: MPEG-4 LASeR white paper . July 2005 . 2010-04-11 . 2011-11-23 . https://web.archive.org/web/20111123041421/http://mpeg.chiariglione.org/technologies/mpeg-4/mp04-lsr/ . live .
  43. Web site: ISO/IEC 14496-21:2006 – Information technology — Coding of audio-visual objects — Part 21: MPEG-J Graphics Framework eXtensions (GFX) . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000400/https://www.iso.org/standard/41733.html . live .
  44. Web site: MPEG-4 Systems MPEG-J . July 2001 . 2010-04-11 . 2010-02-23 . https://web.archive.org/web/20100223074833/http://mpeg.chiariglione.org/faq/mp4-sys/sys-faq-mpegj.htm . live .
  45. Web site: MPEG-J GFX white paper . July 2005 . 2010-04-11 . 2011-11-23 . https://web.archive.org/web/20111123035146/http://mpeg.chiariglione.org/technologies/mpeg-4/mpj-gfx/ . live .
  46. Web site: ISO/IEC 14496-22:2009 – Information technology — Coding of audio-visual objects — Part 22: Open Font Format . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830233903/https://www.iso.org/standard/66391.html . live .
  47. Web site: ISO/IEC 14496-22 "Open Font Format" . ISO/IEC JTC 1/SC 29/WG 11 . Chiariglione . July 2008 . 2010-02-09 . 2011-11-23 . https://web.archive.org/web/20111123041723/http://mpeg.chiariglione.org/technologies/mpeg-4/mp04-off/ . live .
  48. Web site: ISO/IEC 14496-22 Information technology — Coding of audio-visual objects — Part 22: Open Font Format . first . Zip . 2007-03-15 . 2010-01-28 . 2019-12-18 . https://web.archive.org/web/20191218185248/https://standards.iso.org/ittf/PubliclyAvailableStandards/c043466_ISO_IEC_14496-22_2007(E).zip . live .
  49. Web site: ISO/IEC 14496-23:2008 – Information technology — Coding of audio-visual objects — Part 23: Symbolic Music Representation . ISO . 2017-08-30.
  50. Web site: ISO/IEC TR 14496-24:2008 – Information technology — Coding of audio-visual objects — Part 24: Audio and systems interaction . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000530/https://www.iso.org/standard/46461.html . live .
  51. Web site: ISO/IEC 14496-25:2011 – Information technology — Coding of audio-visual objects — Part 25: 3D Graphics Compression Model . ISO . 2017-08-30 . 2017-08-30 . https://web.archive.org/web/20170830234052/https://www.iso.org/standard/57755.html . live .
  52. Web site: ISO/IEC 14496-26:2010 – Information technology — Coding of audio-visual objects — Part 26: Audio conformance . ISO . 2017-08-30 . 2017-08-31 . https://web.archive.org/web/20170831000006/https://www.iso.org/standard/53750.html . live .
  53. Web site: ISO/IEC 14496-27:2009 – Information technology — Coding of audio-visual objects — Part 27: 3D Graphics conformance . ISO . 2017-08-30.
  54. Web site: ISO/IEC 14496-27:2009/Amd 6:2015 – Pattern-based 3D mesh coding conformance . ISO . 2017-08-30.
  55. Web site: ISO/IEC CD 14496-28 – Information technology — Coding of audio-visual objects — Part 28: Composite font representation . ISO . 2017-08-30.
  56. Web site: MPEG Licensing Authority – MPEG-4 Visual: Introduction . 2011-01-07 . https://web.archive.org/web/20180626135353/http://www.mpegla.com/main/programs/M4V/Pages/Intro.aspx . 2018-06-26 . dead.
  57. Web site: MPEG Licensing Authority – MPEG-4 Systems: Introduction . 2011-01-07 . https://web.archive.org/web/20110122184315/http://www.mpegla.com/main/programs/M4S/Pages/Intro.aspx . 2011-01-22 . dead.

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