Editing MPEG-1 Audio Layer II (section)

=== MPEG Audio ===
In the late 1980s, [[International Organization for Standardization|ISO]]'s [[Moving Picture Experts Group]] (MPEG) started an effort to standardize digital audio and video encoding, expected to have a wide range of applications in digital radio and TV broadcasting (later [[Digital audio broadcasting|DAB]], [[Digital Multimedia Broadcasting|DMB]], [[Digital video broadcasting|DVB]]), and use on CD-ROM (later [[Video CD]]).<ref>{{cite web |last=Chiariglione |first=Leonardo |date=October 1989 |title=MPEG Press Release |url=http://mpeg.chiariglione.org/meetings/kurihama89/kurihama_press.htm |archive-url=https://web.archive.org/web/20100805102339/http://mpeg.chiariglione.org/meetings/kurihama89/kurihama_press.htm |archive-date=2010-08-05 |publisher=[[Moving Picture Experts Group]] |location=Kurihama}}.</ref> The MUSICAM audio coding was one of 14 proposals for MPEG-1 Audio standard that were submitted to ISO in 1989.<ref name="aes-musicam" /><ref name="santaclara" />

The MPEG-1 Audio standard was based on the existing MUSICAM and ASPEC audio formats.<ref>Digital Video and Audio Broadcasting Technology: A Practical Engineering Guide (Signals and Communication Technology) {{ISBN|3-540-76357-0}} p. 144: "In the year 1988, the MASCAM method was developed at the Institut für Rundfunktechnik (IRT) in Munich in preparation for the digital audio broadcasting (DAB) system. From MASCAM, the MUSICAM (masking pattern universal subband integrated coding and multiplexing) method was developed in 1989 in cooperation with CCETT, Philips and Matsushita."</ref>
The [[MPEG-1]] Audio standard included the three audio "layers" (encoding techniques) now known as Layer I (MP1), Layer II (MP2) and Layer III (MP3).
All algorithms for MPEG-1 Audio Layer I, II and III were approved in 1991 as the committee draft of ISO-11172<ref name="cd-1991">{{cite web |last=Chiariglione |first=Leonardo |date=November 1991 |title=MPEG Press Release |url=http://mpeg.chiariglione.org/meetings/kurihama91/kurihama_press.htm |url-status=dead |archive-url=https://web.archive.org/web/20110503174827/http://mpeg.chiariglione.org/meetings/kurihama91/kurihama_press.htm |archive-date=2011-05-03 |access-date=2010-07-17 |publisher=[[Moving Picture Experts Group]] |location=Kurihama}}</ref><ref name="neuron2-cd-1991">{{cite web |author=ISO |date=November 1991 |title=CD 11172-3 - Coding of Moving Pictures and Associated Audio for Digital Storage Media at up to About 1.5 MBit/s Part 3 Audio |url=http://neuron2.net/library/mpeg1/MPGAUDIO.DOC |archive-url=https://web.archive.org/web/20100611215029/http://neuron2.net/library/mpeg1/MPGAUDIO.DOC |archive-date=June 11, 2010 |access-date=2010-07-17 |publisher=neuron2.net |format=DOC}}</ref><ref>{{cite conference |last1=Patel |first1=Ketan |last2=Smith |first2=Brian C. |last3=Rowe |first3=Lawrence A. |title=Performance of a Software MPEG Video Decoder |url=http://www.cs.unc.edu/~kmp/publications/mm93/MM93-paper.pdf |conference=ACM Multimedia 1993 Conference}} Article's reference 3 is: 'ISO/IEC JTC/SC29, "Coded Representation of Picture, Audio and Multimedia/Hypermedia Information", ''Committee Draft of Standard ISO/IEC 11172'', December 6, 1991'.</ref> and finalized in 1992<ref name="dis-1992">{{cite web |author=ISO |date=1992-11-06 |title=MPEG Press Release, London, 6 November 1992 |url=http://mpeg.chiariglione.org/meetings/london/london_press.htm |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 |access-date=2010-07-17 |website=Chiariglione.org}}</ref> as part of [[MPEG-1]], the first standard suite by [[MPEG]], which resulted in the international standard '''[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] 11172-3''' (a.k.a. ''MPEG-1 Audio'' or ''MPEG-1 Part 3''), published in 1993.<ref name="11172-3" /> Further work on MPEG audio<ref name="sydney1993">{{cite press release |title=Press Release - Adopted at 22nd WG11 meeting |date=1993-04-02 |publisher=[[International Organization for Standardization]] |url=http://mpeg.chiariglione.org/meetings/sydney93/sydney_press.htm |access-date=2010-07-18 |url-status=dead |archive-url=https://web.archive.org/web/20100806161942/http://mpeg.chiariglione.org/meetings/sydney93/sydney_press.htm |archive-date=2010-08-06}}</ref> was finalized in 1994 as part of the second suite of MPEG standards, [[MPEG-2]], more formally known as international standard '''ISO/IEC 13818-3''' (a.k.a. ''MPEG-2 Part 3'' or [[backward compatible]] ''MPEG-2 Audio'' or ''MPEG-2 Audio BC''<ref name="mpeg-audio-faq-bc">{{cite web |author=ISO |date=October 1998 |title=MPEG Audio FAQ Version 9 - MPEG-1 and MPEG-2 BC |url=http://mpeg.chiariglione.org/faq/mp1-aud/mp1-aud.htm |access-date=2009-10-28 |publisher=ISO}}</ref>), originally published in 1995.<ref name="13818-3" /><ref name="Brandenburg1997">{{cite journal |last1=Brandenburg |first1=Karlheinz |last2=Bosi |first2=Marina |date=February 1997 |title=Overview of MPEG Audio: Current and Future Standards for Low-Bit-Rate Audio Coding |url=http://www.aes.org/e-lib/browse.cfm?elib=7871 |journal=Journal of the Audio Engineering Society |volume=45 |issue=1/2 |pages=4–21 |access-date=30 June 2008}}</ref> MPEG-2 Part 3 (ISO/IEC 13818-3) defined additional bit rates and sample rates for MPEG-1 Audio Layer I, II and III. The new sampling rates are exactly half that of those originally defined for MPEG-1 Audio. MPEG-2 Part 3 also enhanced MPEG-1's audio by allowing the coding of audio programs with more than two channels, up to 5.1 multichannel.<ref name="sydney1993" />

The Layer III ([[MP3]]) component uses a [[lossy compression]] algorithm that was designed to greatly reduce the amount of data required to represent an audio recording and sound like a decent reproduction of the original uncompressed audio for most listeners.