Editing CD player (section)

===Digital audio laser-disc prototypes===
In 1974, Lou Ottens, director of the audio division of Philips, started a small group with the aim to develop an analog<ref name="Immink">{{cite journal|url=http://www.exp-math.uni-essen.de/~immink/pdf/cdstory.htm |title=The CD Story |author=Kees A. Schouhamer Immink |journal=Journal of the Audio Engineering Society |volume=46 |pages=458–465 |year=1998 |access-date=21 December 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141104160226/http://www.exp-math.uni-essen.de/~immink/pdf/cdstory.htm |archive-date=4 November 2014 }}</ref> optical audio disc with a diameter of {{cvt|20|cm|in}} and a sound quality superior to that of the vinyl record.<ref>[http://www.laweekly.com/music/why-cds-may-actually-sound-better-than-vinyl-5352162 Why CDs may actually sound better than vinyl],
Chris Kornelis, 27 January 2015</ref> However, due to the unsatisfactory performance of the analog format, two Philips research engineers recommended a digital format in March 1974.<ref name="Immink"/> In 1977, Philips then established a laboratory with the mission of creating a digital audio disc. The diameter of Philips's prototype compact disc was set at {{cvt|11.5|cm|in}}, the diagonal of an audio cassette.<ref name="Immink" /><ref name="peek">{{cite journal |first=Hans B. |last=Peek |title=The Emergence of the Compact Disc |journal=IEEE Communications Magazine |date=January 2010 |pages=10–17 |volume=48 |number=1 |issn=0163-6804 |doi= 10.1109/MCOM.2010.5394021 |s2cid=21402165 }}</ref>

[[Heitaro Nakajima]], who developed an early digital audio recorder within Japan's national public broadcasting organization [[NHK]] in 1970, became general manager of [[Sony]]'s audio department in 1971. His team developed a digital [[PCM adaptor]] audio tape recorder using a [[Betamax]] video recorder in 1973. After this, in 1974 the leap to storing digital audio on an optical disc was easily made.<ref>{{cite magazine | url=https://books.google.com/books?id=kw0EAAAAMBAJ&pg=PA68 | title=Heitaro Nakajima | magazine=Billboard | date=8 January 2000 | access-date=4 November 2014 | author=McClure, Steve | pages=68}}</ref> [[Sony]] first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a {{cvt|30|cm|in}} disc that could play 60 minutes of digital audio (44,100&nbsp;Hz sampling rate and 16-bit resolution) using [[Run-length limited|MFM]] modulation.<ref name="SonyHistorical">{{cite web | url = http://www.aes.org/e-lib/browse.cfm?elib=2912 | title = A Long Play Digital Audio Disc System | date = March 1979 | publisher = AES | access-date = 14 February 2009 }}</ref> In September 1978, the company demonstrated an optical digital audio disc with a 150-minute playing time, 44,056&nbsp;Hz sampling rate, 16-bit linear resolution, and [[Cross-interleaved Reed-Solomon coding|cross-interleaved]] [[error correction]] code—specifications similar to those later settled upon for the standard compact disc format in 1980. Technical details of Sony's digital audio disc were presented during the 62nd [[Audio Engineering Society|AES]] Convention, held on 13–16 March 1979, in [[Brussels]].<ref name="SonyHistorical" /> Sony's AES technical paper was published on 1 March 1979. A week later, on 8 March, Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc"<ref name="BBC6950933">{{cite news | url = http://news.bbc.co.uk/2/hi/technology/6950933.stm | title = How the CD Was Developed | work=BBC News | date = 17 August 2007 | access-date = 17 August 2007 }}</ref> in [[Eindhoven]], [[Netherlands]].<ref name="PhilipsHistorical">{{cite web | url = http://www.philipsmuseumeindhoven.nl/phe/products/e_cd.htm | title = Philips Compact Disc | publisher = Philips | access-date = 14 February 2009 | url-status = dead | archive-url = https://web.archive.org/web/20090319141821/http://www.philipsmuseumeindhoven.nl/phe/products/e_cd.htm | archive-date = 19 March 2009 }}</ref>