Editing MPEG-1 (section)

==History==
The predecessor of MPEG-1 for video coding was the [[H.261]] standard produced by the [[CCITT]] (now known as the [[ITU-T]]). The basic architecture established in H.261 was the [[motion compensation|motion-compensated]] [[Discrete cosine transform|DCT]] hybrid video coding structure.<ref name="Lea">{{cite book |last1=Lea |first1=William |title=Video on demand: Research Paper 94/68 |date=1994 |publisher=[[House of Commons Library]] |url=https://researchbriefings.parliament.uk/ResearchBriefing/Summary/RP94-68 |access-date=20 September 2019 |archive-url=https://web.archive.org/web/20190920082623/https://researchbriefings.parliament.uk/ResearchBriefing/Summary/RP94-68 |archive-date=20 September 2019 |url-status=dead }}</ref><ref name="ITU">{{cite web |title=History of Video Compression |url=https://www.itu.int/wftp3/av-arch/jvt-site/2002_07_Klagenfurt/JVT-D068.doc |website=[[ITU-T]] |publisher=Joint Video Team (JVT) of ISO/IEC MPEG & ITU-T VCEG (ISO/IEC JTC1/SC29/WG11 and ITU-T SG16 Q.6) |date=July 2002 |pages=11, 24–9, 33, 40–1, 53–6 |access-date=3 November 2019 |archive-date=8 March 2021 |archive-url=https://web.archive.org/web/20210308172051/https://www.itu.int/wftp3/av-arch/jvt-site/2002_07_Klagenfurt/JVT-D068.doc |url-status=live }}</ref> It uses [[macroblocks]] of size 16×16 with block-based [[motion estimation]] in the encoder and [[motion compensation]] using encoder-selected [[motion vector]]s in the decoder, with residual difference coding using a [[discrete cosine transform]] (DCT) of size 8×8, scalar [[quantization (signal processing)|quantization]], and variable-length codes (like [[Huffman code]]s) for [[entropy coding]].<ref name="Ghanbari">{{cite book |last1=Ghanbari |first1=Mohammed |title=Standard Codecs: Image Compression to Advanced Video Coding |date=2003 |publisher=[[Institution of Engineering and Technology]] |isbn=9780852967102 |pages=1–2 |url=https://books.google.com/books?id=7XuU8T3ooOAC&pg=PA1}}</ref> H.261 was the first practical video coding standard, and all of its described design elements were also used in MPEG-1.<ref name="history">{{cite web |title=The History of Video File Formats Infographic |url=http://www.real.com/resources/digital-video-file-formats/ |website=[[RealNetworks]] |access-date=5 August 2019 |date=22 April 2012 |archive-date=29 June 2018 |archive-url=https://web.archive.org/web/20180629022057/http://www.real.com/resources/digital-video-file-formats/ |url-status=live }}</ref>

Modeled on the successful collaborative approach and the compression technologies developed by the [[Joint Photographic Experts Group]] and [[CCITT]]'s Experts Group on Telephony (creators of the [[JPEG]] image compression standard and the H.261 standard for [[video conferencing]] respectively), the [[Moving Picture Experts Group]] (MPEG) working group was established in January 1988,<!--http://mpeg.chiariglione.org/about_mpeg.htm--> by the initiative of [[Hiroshi Yasuda]] ([[Nippon Telegraph and Telephone]]) and [[Leonardo Chiariglione]] ([[CSELT]]).<ref>{{citation |url=http://users.ipfw.edu/reddpv01/mp3Genesis.pdf |title=Genesis of the MP3 Audio Coding Standard |author=Hans Geog Musmann |access-date=2011-07-26 |url-status=dead |archive-url=https://web.archive.org/web/20120117173334/http://users.ipfw.edu/reddpv01/mp3Genesis.pdf |archive-date=2012-01-17 }}</ref> MPEG was formed to address the need for [[Technical standard|standard]] video and audio formats, and to build on H.261 to get better quality through the use of somewhat more complex encoding methods (e.g., supporting higher precision for motion vectors).<ref name=Didier_MPEG>{{Citation |first=Didier |last=Le Gall |title=MPEG: a video compression standard for multimedia applications |date=April 1991 |publisher=[[Communications of the ACM]] |url=http://www.cis.temple.edu/~vasilis/Courses/CIS750/Papers/mpeg_6.pdf |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20170127093505/https://cis.temple.edu/~vasilis/Courses/CIS750/Papers/mpeg_6.pdf |archive-date=2017-01-27 }}</ref><ref name=bmrc_mpeg2_faq-deadlink>{{Citation|first=Chad |last=Fogg |title=MPEG-2 FAQ |date=April 2, 1996 |publisher=[[University of California, Berkeley]] |url=http://bmrc.berkeley.edu/research/mpeg/faq/mpeg2-v38/faq_v38.html |archive-url=https://web.archive.org/web/20000829033706/http://bmrc.berkeley.edu/research/mpeg/faq/mpeg2-v38/faq_v38.html |url-status=dead |archive-date=August 29, 2000 |access-date=2008-04-09 }}</ref><ref name=bmrc_mpeg2_faq>{{Citation |first=Chad |last=Fogg |title=MPEG-2 FAQ (archived website) |date=April 2, 1996 |publisher=[[University of California, Berkeley]] |url=http://bmrc.berkeley.edu/research/mpeg/faq/mpeg2-v38/faq_v38.html  |access-date = 2016-11-11 |archive-url=https://web.archive.org/web/20080616113041/http://bmrc.berkeley.edu/research/mpeg/faq/mpeg2-v38/faq_v38.html |archive-date=2008-06-16}}</ref>

Development of the MPEG-1 standard began in May 1988. Fourteen video and fourteen audio codec proposals were submitted by individual companies and institutions for evaluation. The codecs were extensively tested for [[Computational complexity theory|computational complexity]] and [[Subjectivity|subjective]] (human perceived) quality, at data rates of 1.5&nbsp;Mbit/s. This specific bitrate was chosen for transmission over [[Digital Signal 1|T-1]]/[[E-carrier|E-1]] lines and as the approximate data rate of [[Red Book (audio CD standard)|audio CDs]].<ref name=opensource>{{Citation |first=Leonardo |last=Chiariglione |title=Open source in MPEG |date=March 2001 |publisher=[[Linux Journal]] |url=http://leonardo.chiariglione.org/publications/linux/linux00.htm |archive-url=https://web.archive.org/web/20110725162125/http://leonardo.chiariglione.org/publications/linux/linux00.htm |url-status=dead |archive-date=2011-07-25 |access-date=2008-04-09}}</ref> The codecs that excelled in this testing were utilized as the basis for the standard and refined further, with additional features and other improvements being incorporated in the process.<ref name=santa_clara90>{{Citation|first1=Leonardo |last1=Chiariglione |first2=Didier |last2=Le Gall |first3=Hans-Georg |last3=Musmann |first4=Allen |last4=Simon |title=Press Release – Status report of ISO MPEG |date=September 1990 |publisher=[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] |url=http://mpeg.chiariglione.org/meetings/santa_clara90/santa_clara_press.htm |archive-url=https://web.archive.org/web/20100214044029/http://mpeg.chiariglione.org/meetings/santa_clara90/santa_clara_press.htm |url-status=dead |archive-date=2010-02-14 |access-date=2008-04-09 }}</ref>

After 20 meetings of the full group in various cities around the world, and 4½ years of development and testing, the final standard (for parts 1–3) was approved in early November 1992 and published a few months later.<ref name=mpeg_meetings>{{Citation|title=Meetings |publisher=[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] |url=http://mpeg.chiariglione.org/meetings.htm |archive-url=https://web.archive.org/web/20100210155305/http://mpeg.chiariglione.org/meetings.htm |url-status=dead |archive-date=2010-02-10 |access-date=2008-04-09 }}</ref> The reported completion date of the MPEG-1 standard varies greatly: a largely complete draft standard was produced in September 1990, and from that point on, only minor changes were introduced.<ref name=Didier_MPEG/> The draft standard was publicly available for purchase.<ref name="mpeg_faq_draft">{{cite web|url=http://bmrc.berkeley.edu/research/mpeg/software/Old/mpegfa31.txt |title=The MPEG-FAQ, Version 3.1 |access-date=2008-10-12 |url-status=dead |archive-url=https://web.archive.org/web/20090723213246/http://bmrc.berkeley.edu/research/mpeg/software/Old/mpegfa31.txt |archive-date=2009-07-23 |quote=Q. Well, then how do I get the documents, like the MPEG I draft? A. MPEG is a draft ISO standard. {{sic|It's}} exact name is ISO CD 11172. [...] You may order it from your national standards body (e.g. ANSI in the USA) or buy it from companies like OMNICOM [...]}}</ref> The standard was finished with the 6 November 1992 meeting.<ref>{{cite press release|url=http://mpeg.chiariglione.org/meetings/london/london_press.htm|title=MPEG Press Release|date=6 November 1992|publisher=ISO/IEC JTC1/SC29/WG11|access-date=7 May 2018|url-status=dead|archive-url=https://web.archive.org/web/20100812034709/http://mpeg.chiariglione.org/meetings/london/london_press.htm|archive-date=12 August 2010}}</ref> The Berkeley Plateau Multimedia Research Group developed an MPEG-1 decoder in November 1992.<ref>{{cite web |url=http://bmrc.berkeley.edu/research/publications/1992/101/101.html |title=Abstract Page #101 |access-date=2008-07-13 |url-status=dead |archive-url=https://web.archive.org/web/20081006133233/http://bmrc.berkeley.edu/research/publications/1992/101/101.html |archive-date=2008-10-06 }} {{cite web |url=http://bmrc.berkeley.edu/frame/research/mpeg/ |title=BMRC |access-date=2008-07-13 |url-status=dead |archive-url=https://web.archive.org/web/20080612140755/http://bmrc.berkeley.edu/frame/research/mpeg |archive-date=2008-06-12 }} A Continuous Media Player, Lawrence A. Rowe and Brian C. Smith, Proc. 3rd Int. Workshop on Network and OS Support for Digital Audio and Video, San Diego CA (November 1992){{dead link |date=November 2016}}</ref> In July 1990, before the first draft of the MPEG-1 standard had even been written, work began on a second standard, [[MPEG-2]],<ref name=mpeg_achievements>{{Citation |title=Achievements |publisher=[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] |url=http://mpeg.chiariglione.org/achievements.htm |archive-url=https://web.archive.org/web/20080708183405/http://mpeg.chiariglione.org/achievements.htm |url-status=dead |archive-date=2008-07-08 |access-date=2008-04-03}}</ref> intended to extend MPEG-1 technology to provide full broadcast-quality video (as per [[CCIR 601]]) at high bitrates (3–15&nbsp; Mbit/s) and support for [[interlaced]] video.<ref name=london92>{{Citation|first=Leonardo |last=Chiariglione |title=MPEG Press Release, London, 6 November 1992 |date=November 6, 1992 |publisher=[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] |url=http://mpeg.chiariglione.org/meetings/london/london_press.htm |archive-url=https://web.archive.org/web/20100812034709/http://mpeg.chiariglione.org/meetings/london/london_press.htm |url-status=dead |archive-date=12 August 2010 |access-date=2008-04-09 }}</ref> Due in part to the similarity between the two codecs, the MPEG-2 standard includes full backwards compatibility with MPEG-1 video, so any MPEG-2 decoder can play MPEG-1 videos.<ref name=sydney93>{{Citation|first=Greg |last=Wallace |title=Press Release |date=April 2, 1993 |publisher=[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] |url=http://mpeg.chiariglione.org/meetings/sydney93/sydney_press.htm |archive-url=https://web.archive.org/web/20100806161942/http://mpeg.chiariglione.org/meetings/sydney93/sydney_press.htm |url-status=dead |archive-date=August 6, 2010 |access-date=2008-04-09 }}</ref>

Notably, the MPEG-1 standard very strictly defines the [[bitstream]], and decoder function, but does not define how MPEG-1 encoding is to be performed, although a reference implementation is provided in ISO/IEC-11172-5.<ref name=mpeg_faqs1/> This means that MPEG-1 [[Data compression|coding efficiency]] can drastically vary depending on the encoder used, and generally means that newer encoders perform significantly better than their predecessors.<ref name=mpeg_faqs2/> The first three parts (Systems, Video and Audio) of ISO/IEC 11172 were published in August 1993.<ref>{{cite web|url=http://mpeg.chiariglione.org/meetings/paris94/paris_press.htm|title=INTERNATIONAL ORGANISATION FOR STANDARDISATION ORGANISATION INTERNATIONALE DE NORMALISATION ISO|date=26 July 2010|access-date=7 May 2018|url-status=dead|archive-url=https://web.archive.org/web/20100726103705/http://mpeg.chiariglione.org/meetings/paris94/paris_press.htm|archive-date=26 July 2010}}</ref>

{| class="wikitable sortable"
|+MPEG-1 Parts<ref name="mpeg-standards"/><ref name="jtc1-sc29_mpeg1">{{cite web|url=http://kikaku.itscj.ipsj.or.jp/sc29/29w42911.htm#MPEG-1 |title=MPEG-1 (Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s) |author=ISO/IEC JTC 1/SC 29 |date=2010-07-17 |access-date=2010-07-18 |url-status=dead |archive-url=https://web.archive.org/web/20131231054907/http://kikaku.itscj.ipsj.or.jp/sc29/29w42911.htm |archive-date=2013-12-31 }}</ref>
|-
! Part
! Number
! First public<br />release date<br />(first edition)
! latest<br />correction
! Title
! Description
|-
| Part 1 
| [https://www.iso.org/standard/19180.html ISO/IEC 11172-1] {{Webarchive|url=https://web.archive.org/web/20170830194543/https://www.iso.org/standard/19180.html |date=2017-08-30 }} 
| 1993
| 1999<ref>{{cite web |url=https://www.iso.org/standard/19180.html |title=ISO/IEC 11172-1:1993 – Information technology – Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – Part 1: Systems |author=ISO |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20170830194543/https://www.iso.org/standard/19180.html |archive-date=2017-08-30 }}</ref>
| Systems 
| 
|-
| Part 2
| [https://www.iso.org/standard/22411.html ISO/IEC 11172-2] {{Webarchive|url=https://web.archive.org/web/20170830194202/https://www.iso.org/standard/22411.html |date=2017-08-30 }} 
| 1993
| 2006<ref>{{cite web |url=https://www.iso.org/standard/22411.html |title=ISO/IEC 11172-2:1993 – Information technology – Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – Part 2: Video |author=ISO |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20170830194202/https://www.iso.org/standard/22411.html |archive-date=2017-08-30 }}</ref>
| Video
| 
|-
| Part 3
| [https://www.iso.org/standard/22412.html ISO/IEC 11172-3] {{Webarchive|url=https://web.archive.org/web/20170515194520/https://www.iso.org/standard/22412.html |date=2017-05-15 }} 
| 1993
| 1996<ref>{{cite web |url=https://www.iso.org/standard/22412.html |title=ISO/IEC 11172-3:1993 – Information technology – Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – Part 3: Audio |author=ISO |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20170515194520/https://www.iso.org/standard/22412.html |archive-date=2017-05-15 }}</ref>
| Audio
| 
|-
| Part 4
| [https://www.iso.org/standard/22691.html ISO/IEC 11172-4] {{Webarchive|url=https://web.archive.org/web/20170830191730/https://www.iso.org/standard/22691.html |date=2017-08-30 }} 
| 1995
| 2007<ref>{{cite web |url=https://www.iso.org/standard/22691.html |title=ISO/IEC 11172-4:1995 – Information technology – Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – Part 4: Compliance testing |author=ISO |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20170830191730/https://www.iso.org/standard/22691.html |archive-date=2017-08-30 }}</ref>
| Compliance testing
| 
|-
| Part 5
| [https://www.iso.org/standard/25029.html ISO/IEC TR 11172-5] {{Webarchive|url=https://web.archive.org/web/20170830193748/https://www.iso.org/standard/25029.html |date=2017-08-30 }} 
| 1998
| 2007<ref>{{cite web |url=https://www.iso.org/standard/25029.html |title=ISO/IEC TR 11172-5:1998 – Information technology – Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – Part 5: Software simulation |author=ISO |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20170830193748/https://www.iso.org/standard/25029.html |archive-date=2017-08-30 }}</ref>
| Software simulation
| 
|}