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[[File:Opus quality comparison colorblind compatible.svg|thumb|Comparison of coding efficiency between popular audio formats]]
An '''audio coding format'''<ref>The term "audio coding" can be seen in e.g. the name [[Advanced Audio Coding]], and is analogous to the term [[video coding format|video coding]]</ref> (or sometimes '''audio compression format''') is a [[Content format|content representation format]] for storage or transmission of [[digital audio]] (such as in [[digital television]], [[digital radio]] and in audio and video files). Examples of audio coding formats include [[MP3]], [[Advanced Audio Coding|AAC]], [[Vorbis]], [[FLAC]], and [[Opus (audio format)|Opus]]. A specific software or hardware implementation capable of [[Data_compression#Audio|audio compression]] and decompression to/from a specific audio coding format is called an [[audio codec]]; an example of an audio codec is [[LAME]], which is one of several different codecs which implements encoding and decoding audio in the [[MP3]] audio coding format in software.
Some audio coding formats are documented by a detailed [[technical specification]] document known as an '''audio coding specification'''. Some such specifications are written and approved by [[standardization organization]]s as [[technical standard]]s, and are thus known as an '''audio coding standard'''. The term "standard" is also sometimes used for [[de facto standard|''de facto'' standards]] as well as formal standards.
Audio content encoded in a particular audio coding format is normally encapsulated within a [[container format (digital)|container format]]. As such, the user normally doesn't have a raw [[Advanced Audio Coding|AAC]] file, but instead has a .m4a [[audio file format|audio file]], which is a [[MPEG-4 Part 14]] container containing AAC-encoded audio. The container also contains [[metadata]] such as title and other tags, and perhaps an index for fast seeking.<ref>{{Cite web | url=http://superuser.com/questions/357686/where-is-synchronization-information-stored-in-container-formats | title=Video - Where is synchronization information stored in container formats?}}</ref> A notable exception is [[MP3]] files, which are raw audio coding without a container format. De facto standards for adding metadata tags such as title and artist to MP3s, such as [[ID3]], are [[Hack (computer science)#In computer science|hack]]s which work by appending the tags to the MP3, and then relying on the MP3 player to recognize the chunk as malformed audio coding and therefore skip it. In video files with audio, the encoded audio content is bundled with video (in a [[video coding format]]) inside a [[multimedia container format]].
An audio coding format does not dictate all [[algorithm]]s used by a [[codec]] implementing the format. An important part of how lossy audio compression works is by removing data in ways humans can't hear, according to a [[psychoacoustic model]]; the implementer of an encoder has some freedom of choice in which data to remove (according to their psychoacoustic model).
==Lossless, lossy, and uncompressed audio coding formats==
A [[lossless compression|lossless]] audio coding format reduces the total data needed to represent a sound but can be de-coded to its original, uncompressed form. A [[lossy compression|lossy]] audio coding format additionally reduces the [[audio bit depth|bit resolution]] of the sound on top of compression, which results in far less data at the cost of irretrievably lost information.
Consumer audio is most often compressed using lossy audio codecs as the smaller size is far more convenient for distribution. The most widely used audio coding formats are [[MP3]] and [[Advanced Audio Coding]] (AAC), both of which are lossy formats based on [[modified discrete cosine transform]] (MDCT) and [[perceptual coding]] algorithms.
Lossless audio coding formats such as [[FLAC]] and [[Apple Lossless]] are sometimes available, though at the cost of larger files.
[[Uncompressed audio]] formats, such as [[pulse-code modulation]] (PCM, or .wav), are also sometimes used. PCM was the standard format for [[Compact Disc Digital Audio]] (CDDA), before lossy compression eventually became the standard after the introduction of MP3.
==History==
[[File:Placa-audioPC-925.jpg|right|thumb|Solidyne 922: The world's first commercial audio bit compression [[sound card]] for PC, 1990]]
In 1950, [[Bell Labs]] filed the patent on [[differential pulse-code modulation]] (DPCM).<ref name="DPCM">{{US patent reference|inventor=C. Chapin Cutler|title=Differential Quantization of Communication Signals|number=2605361|A-Datum=1950-06-29|issue-date=1952-07-29}}</ref> [[Adaptive DPCM]] (ADPCM) was introduced by P. Cummiskey, [[Nikil Jayant|Nikil S. Jayant]] and [[James L. Flanagan]] at [[Bell Labs]] in 1973.<ref>P. Cummiskey, Nikil S. Jayant, and J. L. Flanagan, "Adaptive quantization in differential PCM coding of speech", ''Bell Syst. Tech. J.'', vol. 52, pp. 1105—1118, Sept. 1973</ref><ref>{{cite journal |last1=Cummiskey |first1=P. |last2=Jayant |first2=Nikil S. |last3=Flanagan |first3=J. L. |title=Adaptive quantization in differential PCM coding of speech |journal=The Bell System Technical Journal |date=1973 |volume=52 |issue=7 |pages=1105–1118 |doi=10.1002/j.1538-7305.1973.tb02007.x |issn=0005-8580}}</ref>
[[Perceptual coding]] was first used for [[speech coding]] compression, with [[linear predictive coding]] (LPC).<ref name="Schroeder2014">{{cite book |last1=Schroeder |first=Manfred R. |title=Acoustics, Information, and Communication: Memorial Volume in Honor of Manfred R. Schroeder |date=2014 |publisher=Springer |isbn=9783319056609 |chapter=Bell Laboratories |page=388 |chapter-url=https://books.google.com/books?id=d9IkBAAAQBAJ&pg=PA388}}</ref> Initial concepts for LPC date back to the work of [[Fumitada Itakura]] ([[Nagoya University]]) and Shuzo Saito ([[Nippon Telegraph and Telephone]]) in 1966.<ref>{{cite journal |last1=Gray |first1=Robert M. |title=A History of Realtime Digital Speech on Packet Networks: Part II of Linear Predictive Coding and the Internet Protocol |journal=Found. Trends Signal Process. |date=2010 |volume=3 |issue=4 |pages=203–303 |doi=10.1561/2000000036 |url=https://ee.stanford.edu/~gray/lpcip.pdf |issn=1932-8346|doi-access=free }}</ref> During the 1970s, [[Bishnu S. Atal]] and [[Manfred R. Schroeder]] at [[Bell Labs]] developed a form of LPC called [[adaptive predictive coding]] (APC), a perceptual coding algorithm that exploited the masking properties of the human ear, followed in the early 1980s with the [[code-excited linear prediction]] (CELP) algorithm which achieved a significant compression ratio for its time.<ref name="Schroeder2014"/> Perceptual coding is used by modern audio compression formats such as [[MP3]]<ref name="Schroeder2014"/> and [[Advanced Audio Codec|AAC]].
[[Discrete cosine transform]] (DCT), developed by [[N. Ahmed|Nasir Ahmed]], T. Natarajan and [[K. R. Rao]] in 1974,<ref name="DCT">{{cite journal |author1=Nasir Ahmed |author1-link=N. Ahmed |author2=T. Natarajan |author3=Kamisetty Ramamohan Rao |journal=IEEE Transactions on Computers|title=Discrete Cosine Transform|volume=C-23|issue=1|pages=90–93|date=January 1974 |doi=10.1109/T-C.1974.223784 |url=https://www.ic.tu-berlin.de/fileadmin/fg121/Source-Coding_WS12/selected-readings/Ahmed_et_al.__1974.pdf}}</ref> provided the basis for the [[modified discrete cosine transform]] (MDCT) used by modern audio compression formats such as MP3<ref name="Guckert">{{cite web |last1=Guckert |first1=John |title=The Use of FFT and MDCT in MP3 Audio Compression |url=http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf |website=[[University of Utah]] |date=Spring 2012 |access-date=14 July 2019}}</ref> and AAC. MDCT was proposed by J. P. Princen, A. W. Johnson and A. B. Bradley in 1987,<ref>J. P. Princen, A. W. Johnson und A. B. Bradley: ''Subband/transform coding using filter bank designs based on time ___domain aliasing cancellation'', IEEE Proc. Intl. Conference on Acoustics, Speech, and Signal Processing (ICASSP), 2161–2164, 1987.</ref> following earlier work by Princen and Bradley in 1986.<ref>John P. Princen, Alan B. Bradley: ''Analysis/synthesis filter bank design based on time ___domain aliasing cancellation'', IEEE Trans. Acoust. Speech Signal Processing, ''ASSP-34'' (5), 1153–1161, 1986.</ref> The MDCT is used by modern audio compression formats such as [[Dolby Digital]],<ref name="Luo">{{cite book |last1=Luo |first1=Fa-Long |title=Mobile Multimedia Broadcasting Standards: Technology and Practice |date=2008 |publisher=[[Springer Science & Business Media]] |isbn=9780387782638 |page=590 |url=https://books.google.com/?id=l6PovWat8SMC&pg=PA590}}</ref><ref>{{cite journal |last1=Britanak |first1=V. |title=On Properties, Relations, and Simplified Implementation of Filter Banks in the Dolby Digital (Plus) AC-3 Audio Coding Standards |journal=IEEE Transactions on Audio, Speech, and Language Processing |date=2011 |volume=19 |issue=5 |pages=1231–1241 |doi=10.1109/TASL.2010.2087755}}</ref> [[MP3]],<ref name="Guckert">{{cite web |last1=Guckert |first1=John |title=The Use of FFT and MDCT in MP3 Audio Compression |url=http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf |website=[[University of Utah]] |date=Spring 2012 |access-date=14 July 2019}}</ref> and [[Advanced Audio Coding]] (AAC).<ref name=brandenburg>{{cite web|url=http://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|title=MP3 and AAC Explained|last=Brandenburg|first=Karlheinz|year=1999|url-status=live|archive-url=https://web.archive.org/web/20170213191747/https://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|archive-date=2017-02-13}}</ref>
==List of lossy formats==
===General===
{| class="wikitable sortable"
|-
! Basic compression algorithm
! Audio coding standard
! Abbreviation
! Introduction
! Market share {{small|(2019)}}<ref name="Bitmovin">{{cite web |url=https://cdn2.hubspot.net/hubfs/3411032/Bitmovin%20Magazine/Video%20Developer%20Report%202019/bitmovin-video-developer-report-2019.pdf |title=Video Developer Report 2019 |website=[[Bitmovin]] |year=2019 |access-date=5 November 2019}}</ref>
! {{Abbr|Ref|Reference(s)}}
|-
| rowspan="9" | [[Modified discrete cosine transform]] (MDCT)
| [[Dolby Digital]] (AC-3)
| AC3
| 1991
| 58%
| <ref name="Luo">{{cite book |last1=Luo |first1=Fa-Long |title=Mobile Multimedia Broadcasting Standards: Technology and Practice |date=2008 |publisher=[[Springer Science & Business Media]] |isbn=9780387782638 |page=590 |url=https://books.google.com/?id=l6PovWat8SMC&pg=PA590}}</ref><ref name="Britanak2011">{{cite journal |last1=Britanak |first1=V. |title=On Properties, Relations, and Simplified Implementation of Filter Banks in the Dolby Digital (Plus) AC-3 Audio Coding Standards |journal=IEEE Transactions on Audio, Speech, and Language Processing |date=2011 |volume=19 |issue=5 |pages=1231–1241 |doi=10.1109/TASL.2010.2087755}}</ref>
|-
| [[Adaptive Transform Acoustic Coding]]
| ATRAC
| 1992
| {{unk}}
| <ref name="Luo"/>
|-
| [[MPEG Layer III]]
| MP3
| 1993
| 49%
| <ref name="Guckert">{{cite web |last1=Guckert |first1=John |title=The Use of FFT and MDCT in MP3 Audio Compression |url=http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf |website=[[University of Utah]] |date=Spring 2012 |access-date=14 July 2019}}</ref><ref name="Stankovic">{{cite journal |last1=Stanković |first1=Radomir S. |last2=Astola |first2=Jaakko T. |title=Reminiscences of the Early Work in DCT: Interview with K.R. Rao |journal=Reprints from the Early Days of Information Sciences |date=2012 |volume=60 |url=http://ticsp.cs.tut.fi/reports/ticsp-report-60-reprint-rao-corrected.pdf |access-date=13 October 2019}}</ref>
|-
| [[Advanced Audio Coding]] ([[MPEG-2]] / [[MPEG-4]])
| AAC
| 1997
| 88%
| <ref name=brandenburg>{{cite web|url=http://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|title=MP3 and AAC Explained|last=Brandenburg|first=Karlheinz|year=1999|url-status=live|archive-url=https://web.archive.org/web/20170213191747/https://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|archive-date=2017-02-13}}</ref><ref name="Luo"/>
|-
| [[Windows Media Audio]]
| WMA
| 1999
| {{unk}}
| <ref name="Luo"/>
|-
| [[Ogg]] [[Vorbis]]
| Ogg
| 2000
| 7%
| <ref name="vorbis-mdct">{{cite web |author=Xiph.Org Foundation |publisher=Xiph.Org Foundation |url=http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-50001.1.2 |title=Vorbis I specification - 1.1.2 Classification |date=2009-06-02 |access-date=2009-09-22}}</ref><ref name="Luo"/>
|-
| [[Constrained Energy Lapped Transform]]
| CELT
| 2011
| {{n/a}}
| <ref name="presentation">[http://people.xiph.org/~greg/video/linux_conf_au_CELT_2.ogv Presentation of the CELT codec] by Timothy B. Terriberry (65 minutes of video, see also [http://www.celt-codec.org/presentations/misc/lca-celt.pdf presentation slides] in PDF)</ref>
|-
| [[Opus (codec)|Opus]]
| Opus
| 2012
| 8%
| <ref>{{cite conference|last1=Valin|first1=Jean-Marc|last2=Maxwell|first2=Gregory|last3=Terriberry|first3=Timothy B.|last4=Vos|first4=Koen|date=October 2013|title=High-Quality, Low-Delay Music Coding in the Opus Codec|conference=135th AES Convention|publisher=[[Audio Engineering Society]]|arxiv=1602.04845}}</ref>
|-
| [[LDAC (codec)|LDAC]]
| LDAC
| 2015
| {{unk}}
| <ref name="Darko 2017">{{cite web | last=Darko | first=John H. | title=The inconvenient truth about Bluetooth audio | website=DAR__KO | date=2017-03-29 | url=http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/ | access-date=2018-01-13 | archive-url=https://web.archive.org/web/20180114020200/http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/ | archive-date=2018-01-14 | url-status=dead }}</ref><ref name="AVHub 2015">{{cite web|url=http://www.avhub.com.au/news/sound-image/what-is-sony-ldac-and-how-does-it-do-it-408285|title=What is Sony LDAC, and how does it do it?|last=Ford|first=Jez|date=2015-08-24|website=AVHub|access-date=2018-01-13}}</ref>
|-
| rowspan="3" | [[Adaptive differential pulse-code modulation]] (ADPCM)
| [[AptX|aptX / aptX-HD]]
| aptX
| 1989
| {{unk}}
| <ref name="AVHub 2016">{{cite web|url=http://www.avhub.com.au/news/sound-image/aptx-hd---lossless-or-lossy-442124|title=aptX HD - lossless or lossy?|last=Ford|first=Jez|date=2016-11-22|website=AVHub|access-date=2018-01-13}}</ref>
|-
| [[DTS (sound system)#DTS audio codec|Digital Theater Systems]]
| DTS
| 1990
| 14%
| <ref>{{cite web |title=Digital Theater Systems Audio Formats |url=https://www.loc.gov/preservation/digital/formats/fdd/fdd000232.shtml |website=[[Library of Congress]] |access-date=10 November 2019 |date=27 December 2011}}</ref><ref>{{cite book |last1=Spanias |first1=Andreas |last2=Painter |first2=Ted |last3=Atti |first3=Venkatraman |title=Audio Signal Processing and Coding |date=2006 |publisher=[[John Wiley & Sons]] |isbn=9780470041963 |page=338 |url=https://books.google.com/?id=a1RULRErhOYC&pg=PA338}}</ref>
|-
| [[Master Quality Authenticated]]
| MQA
| 2014
| {{unk}}
|
|-
| rowspan="2" | [[Sub-band coding]] (SBC)
| [[MPEG-1 Audio Layer II]]
| MP2
| 1993
| rowspan="2" {{unk}}
| rowspan="2" |
|-
| [[Musepack]]
| MPC
| 1997
|}
===Speech===
{{further|Speech coding}}
* [[Linear predictive coding]] (LPC)
** [[Adaptive predictive coding]] (APC)
** [[Code-excited linear prediction]] (CELP)
** [[Algebraic code-excited linear prediction]] (ACELP)
** [[Relaxed code-excited linear prediction]] (RCELP)
** [[Low-delay CELP]] (LD-CELP)
** [[Adaptive Multi-Rate audio codec|Adaptive Multi-Rate]] (used in [[GSM]] and [[3GPP]])
** [[Codec2]] (noted for its lack of patent restrictions)
** [[Speex]] (noted for its lack of patent restrictions)
* [[Modified discrete cosine transform]] (MDCT)
** [[AAC-LD]]
** [[Constrained Energy Lapped Transform]] (CELT)
** [[Opus (codec)|Opus]] (mostly for real-time applications)
== List of lossless formats ==
* [[Apple Lossless]] (ALAC – Apple Lossless Audio Codec)
* [[Adaptive Transform Acoustic Coding]] (ATRAC)
* [[Audio Lossless Coding]] (also known as MPEG-4 ALS)
* [[Super Audio CD#DST|Direct Stream Transfer]] (DST)
* [[Dolby TrueHD]]
* [[DTS-HD Master Audio]]
* [[Free Lossless Audio Codec]] (FLAC)
* [[Discrete cosine transform|Lossless discrete cosine transform]] (LDCT)
* [[Meridian Lossless Packing]] (MLP)
* [[Monkey's Audio]] (Monkey's Audio APE)
* [[MPEG-4 SLS]] (also known as HD-AAC)
* [[OptimFROG]]
* [[Original Sound Quality]] (OSQ)
* [[RealPlayer]] (RealAudio Lossless)
* [[Shorten (file format)|Shorten]] (SHN)
* [[TTA (codec)|TTA]] (True Audio Lossless)
* [[WavPack]] (WavPack lossless)
* [[Windows Media Audio 9 Lossless|WMA Lossless]] (Windows Media Lossless)
==See also==
* [[Comparison of audio coding formats]]
* [[Data compression#Audio]]
* [[Audio file format]]
* [[List of audio compression formats]]
==References==
<references/>
[[Category:Audio file formats| ]]' |
New page wikitext, after the edit (new_wikitext) | 'DJ GALAXY UG
==Lossless, lossy, and uncompressed audio coding formats==
A [[lossless compression|lossless]] audio coding format reduces the total data needed to represent a sound but can be de-coded to its original, uncompressed form. A [[lossy compression|lossy]] audio coding format additionally reduces the [[audio bit depth|bit resolution]] of the sound on top of compression, which results in far less data at the cost of irretrievably lost information.
Consumer audio is most often compressed using lossy audio codecs as the smaller size is far more convenient for distribution. The most widely used audio coding formats are [[MP3]] and [[Advanced Audio Coding]] (AAC), both of which are lossy formats based on [[modified discrete cosine transform]] (MDCT) and [[perceptual coding]] algorithms.
Lossless audio coding formats such as [[FLAC]] and [[Apple Lossless]] are sometimes available, though at the cost of larger files.
[[Uncompressed audio]] formats, such as [[pulse-code modulation]] (PCM, or .wav), are also sometimes used. PCM was the standard format for [[Compact Disc Digital Audio]] (CDDA), before lossy compression eventually became the standard after the introduction of MP3.
==History==
[[File:Placa-audioPC-925.jpg|right|thumb|Solidyne 922: The world's first commercial audio bit compression [[sound card]] for PC, 1990]]
In 1950, [[Bell Labs]] filed the patent on [[differential pulse-code modulation]] (DPCM).<ref name="DPCM">{{US patent reference|inventor=C. Chapin Cutler|title=Differential Quantization of Communication Signals|number=2605361|A-Datum=1950-06-29|issue-date=1952-07-29}}</ref> [[Adaptive DPCM]] (ADPCM) was introduced by P. Cummiskey, [[Nikil Jayant|Nikil S. Jayant]] and [[James L. Flanagan]] at [[Bell Labs]] in 1973.<ref>P. Cummiskey, Nikil S. Jayant, and J. L. Flanagan, "Adaptive quantization in differential PCM coding of speech", ''Bell Syst. Tech. J.'', vol. 52, pp. 1105—1118, Sept. 1973</ref><ref>{{cite journal |last1=Cummiskey |first1=P. |last2=Jayant |first2=Nikil S. |last3=Flanagan |first3=J. L. |title=Adaptive quantization in differential PCM coding of speech |journal=The Bell System Technical Journal |date=1973 |volume=52 |issue=7 |pages=1105–1118 |doi=10.1002/j.1538-7305.1973.tb02007.x |issn=0005-8580}}</ref>
[[Perceptual coding]] was first used for [[speech coding]] compression, with [[linear predictive coding]] (LPC).<ref name="Schroeder2014">{{cite book |last1=Schroeder |first=Manfred R. |title=Acoustics, Information, and Communication: Memorial Volume in Honor of Manfred R. Schroeder |date=2014 |publisher=Springer |isbn=9783319056609 |chapter=Bell Laboratories |page=388 |chapter-url=https://books.google.com/books?id=d9IkBAAAQBAJ&pg=PA388}}</ref> Initial concepts for LPC date back to the work of [[Fumitada Itakura]] ([[Nagoya University]]) and Shuzo Saito ([[Nippon Telegraph and Telephone]]) in 1966.<ref>{{cite journal |last1=Gray |first1=Robert M. |title=A History of Realtime Digital Speech on Packet Networks: Part II of Linear Predictive Coding and the Internet Protocol |journal=Found. Trends Signal Process. |date=2010 |volume=3 |issue=4 |pages=203–303 |doi=10.1561/2000000036 |url=https://ee.stanford.edu/~gray/lpcip.pdf |issn=1932-8346|doi-access=free }}</ref> During the 1970s, [[Bishnu S. Atal]] and [[Manfred R. Schroeder]] at [[Bell Labs]] developed a form of LPC called [[adaptive predictive coding]] (APC), a perceptual coding algorithm that exploited the masking properties of the human ear, followed in the early 1980s with the [[code-excited linear prediction]] (CELP) algorithm which achieved a significant compression ratio for its time.<ref name="Schroeder2014"/> Perceptual coding is used by modern audio compression formats such as [[MP3]]<ref name="Schroeder2014"/> and [[Advanced Audio Codec|AAC]].
[[Discrete cosine transform]] (DCT), developed by [[N. Ahmed|Nasir Ahmed]], T. Natarajan and [[K. R. Rao]] in 1974,<ref name="DCT">{{cite journal |author1=Nasir Ahmed |author1-link=N. Ahmed |author2=T. Natarajan |author3=Kamisetty Ramamohan Rao |journal=IEEE Transactions on Computers|title=Discrete Cosine Transform|volume=C-23|issue=1|pages=90–93|date=January 1974 |doi=10.1109/T-C.1974.223784 |url=https://www.ic.tu-berlin.de/fileadmin/fg121/Source-Coding_WS12/selected-readings/Ahmed_et_al.__1974.pdf}}</ref> provided the basis for the [[modified discrete cosine transform]] (MDCT) used by modern audio compression formats such as MP3<ref name="Guckert">{{cite web |last1=Guckert |first1=John |title=The Use of FFT and MDCT in MP3 Audio Compression |url=http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf |website=[[University of Utah]] |date=Spring 2012 |access-date=14 July 2019}}</ref> and AAC. MDCT was proposed by J. P. Princen, A. W. Johnson and A. B. Bradley in 1987,<ref>J. P. Princen, A. W. Johnson und A. B. Bradley: ''Subband/transform coding using filter bank designs based on time ___domain aliasing cancellation'', IEEE Proc. Intl. Conference on Acoustics, Speech, and Signal Processing (ICASSP), 2161–2164, 1987.</ref> following earlier work by Princen and Bradley in 1986.<ref>John P. Princen, Alan B. Bradley: ''Analysis/synthesis filter bank design based on time ___domain aliasing cancellation'', IEEE Trans. Acoust. Speech Signal Processing, ''ASSP-34'' (5), 1153–1161, 1986.</ref> The MDCT is used by modern audio compression formats such as [[Dolby Digital]],<ref name="Luo">{{cite book |last1=Luo |first1=Fa-Long |title=Mobile Multimedia Broadcasting Standards: Technology and Practice |date=2008 |publisher=[[Springer Science & Business Media]] |isbn=9780387782638 |page=590 |url=https://books.google.com/?id=l6PovWat8SMC&pg=PA590}}</ref><ref>{{cite journal |last1=Britanak |first1=V. |title=On Properties, Relations, and Simplified Implementation of Filter Banks in the Dolby Digital (Plus) AC-3 Audio Coding Standards |journal=IEEE Transactions on Audio, Speech, and Language Processing |date=2011 |volume=19 |issue=5 |pages=1231–1241 |doi=10.1109/TASL.2010.2087755}}</ref> [[MP3]],<ref name="Guckert">{{cite web |last1=Guckert |first1=John |title=The Use of FFT and MDCT in MP3 Audio Compression |url=http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf |website=[[University of Utah]] |date=Spring 2012 |access-date=14 July 2019}}</ref> and [[Advanced Audio Coding]] (AAC).<ref name=brandenburg>{{cite web|url=http://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|title=MP3 and AAC Explained|last=Brandenburg|first=Karlheinz|year=1999|url-status=live|archive-url=https://web.archive.org/web/20170213191747/https://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|archive-date=2017-02-13}}</ref>
==List of lossy formats==
===General===
{| class="wikitable sortable"
|-
! Basic compression algorithm
! Audio coding standard
! Abbreviation
! Introduction
! Market share {{small|(2019)}}<ref name="Bitmovin">{{cite web |url=https://cdn2.hubspot.net/hubfs/3411032/Bitmovin%20Magazine/Video%20Developer%20Report%202019/bitmovin-video-developer-report-2019.pdf |title=Video Developer Report 2019 |website=[[Bitmovin]] |year=2019 |access-date=5 November 2019}}</ref>
! {{Abbr|Ref|Reference(s)}}
|-
| rowspan="9" | [[Modified discrete cosine transform]] (MDCT)
| [[Dolby Digital]] (AC-3)
| AC3
| 1991
| 58%
| <ref name="Luo">{{cite book |last1=Luo |first1=Fa-Long |title=Mobile Multimedia Broadcasting Standards: Technology and Practice |date=2008 |publisher=[[Springer Science & Business Media]] |isbn=9780387782638 |page=590 |url=https://books.google.com/?id=l6PovWat8SMC&pg=PA590}}</ref><ref name="Britanak2011">{{cite journal |last1=Britanak |first1=V. |title=On Properties, Relations, and Simplified Implementation of Filter Banks in the Dolby Digital (Plus) AC-3 Audio Coding Standards |journal=IEEE Transactions on Audio, Speech, and Language Processing |date=2011 |volume=19 |issue=5 |pages=1231–1241 |doi=10.1109/TASL.2010.2087755}}</ref>
|-
| [[Adaptive Transform Acoustic Coding]]
| ATRAC
| 1992
| {{unk}}
| <ref name="Luo"/>
|-
| [[MPEG Layer III]]
| MP3
| 1993
| 49%
| <ref name="Guckert">{{cite web |last1=Guckert |first1=John |title=The Use of FFT and MDCT in MP3 Audio Compression |url=http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf |website=[[University of Utah]] |date=Spring 2012 |access-date=14 July 2019}}</ref><ref name="Stankovic">{{cite journal |last1=Stanković |first1=Radomir S. |last2=Astola |first2=Jaakko T. |title=Reminiscences of the Early Work in DCT: Interview with K.R. Rao |journal=Reprints from the Early Days of Information Sciences |date=2012 |volume=60 |url=http://ticsp.cs.tut.fi/reports/ticsp-report-60-reprint-rao-corrected.pdf |access-date=13 October 2019}}</ref>
|-
| [[Advanced Audio Coding]] ([[MPEG-2]] / [[MPEG-4]])
| AAC
| 1997
| 88%
| <ref name=brandenburg>{{cite web|url=http://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|title=MP3 and AAC Explained|last=Brandenburg|first=Karlheinz|year=1999|url-status=live|archive-url=https://web.archive.org/web/20170213191747/https://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf|archive-date=2017-02-13}}</ref><ref name="Luo"/>
|-
| [[Windows Media Audio]]
| WMA
| 1999
| {{unk}}
| <ref name="Luo"/>
|-
| [[Ogg]] [[Vorbis]]
| Ogg
| 2000
| 7%
| <ref name="vorbis-mdct">{{cite web |author=Xiph.Org Foundation |publisher=Xiph.Org Foundation |url=http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-50001.1.2 |title=Vorbis I specification - 1.1.2 Classification |date=2009-06-02 |access-date=2009-09-22}}</ref><ref name="Luo"/>
|-
| [[Constrained Energy Lapped Transform]]
| CELT
| 2011
| {{n/a}}
| <ref name="presentation">[http://people.xiph.org/~greg/video/linux_conf_au_CELT_2.ogv Presentation of the CELT codec] by Timothy B. Terriberry (65 minutes of video, see also [http://www.celt-codec.org/presentations/misc/lca-celt.pdf presentation slides] in PDF)</ref>
|-
| [[Opus (codec)|Opus]]
| Opus
| 2012
| 8%
| <ref>{{cite conference|last1=Valin|first1=Jean-Marc|last2=Maxwell|first2=Gregory|last3=Terriberry|first3=Timothy B.|last4=Vos|first4=Koen|date=October 2013|title=High-Quality, Low-Delay Music Coding in the Opus Codec|conference=135th AES Convention|publisher=[[Audio Engineering Society]]|arxiv=1602.04845}}</ref>
|-
| [[LDAC (codec)|LDAC]]
| LDAC
| 2015
| {{unk}}
| <ref name="Darko 2017">{{cite web | last=Darko | first=John H. | title=The inconvenient truth about Bluetooth audio | website=DAR__KO | date=2017-03-29 | url=http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/ | access-date=2018-01-13 | archive-url=https://web.archive.org/web/20180114020200/http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/ | archive-date=2018-01-14 | url-status=dead }}</ref><ref name="AVHub 2015">{{cite web|url=http://www.avhub.com.au/news/sound-image/what-is-sony-ldac-and-how-does-it-do-it-408285|title=What is Sony LDAC, and how does it do it?|last=Ford|first=Jez|date=2015-08-24|website=AVHub|access-date=2018-01-13}}</ref>
|-
| rowspan="3" | [[Adaptive differential pulse-code modulation]] (ADPCM)
| [[AptX|aptX / aptX-HD]]
| aptX
| 1989
| {{unk}}
| <ref name="AVHub 2016">{{cite web|url=http://www.avhub.com.au/news/sound-image/aptx-hd---lossless-or-lossy-442124|title=aptX HD - lossless or lossy?|last=Ford|first=Jez|date=2016-11-22|website=AVHub|access-date=2018-01-13}}</ref>
|-
| [[DTS (sound system)#DTS audio codec|Digital Theater Systems]]
| DTS
| 1990
| 14%
| <ref>{{cite web |title=Digital Theater Systems Audio Formats |url=https://www.loc.gov/preservation/digital/formats/fdd/fdd000232.shtml |website=[[Library of Congress]] |access-date=10 November 2019 |date=27 December 2011}}</ref><ref>{{cite book |last1=Spanias |first1=Andreas |last2=Painter |first2=Ted |last3=Atti |first3=Venkatraman |title=Audio Signal Processing and Coding |date=2006 |publisher=[[John Wiley & Sons]] |isbn=9780470041963 |page=338 |url=https://books.google.com/?id=a1RULRErhOYC&pg=PA338}}</ref>
|-
| [[Master Quality Authenticated]]
| MQA
| 2014
| {{unk}}
|
|-
| rowspan="2" | [[Sub-band coding]] (SBC)
| [[MPEG-1 Audio Layer II]]
| MP2
| 1993
| rowspan="2" {{unk}}
| rowspan="2" |
|-
| [[Musepack]]
| MPC
| 1997
|}
===Speech===
{{further|Speech coding}}
* [[Linear predictive coding]] (LPC)
** [[Adaptive predictive coding]] (APC)
** [[Code-excited linear prediction]] (CELP)
** [[Algebraic code-excited linear prediction]] (ACELP)
** [[Relaxed code-excited linear prediction]] (RCELP)
** [[Low-delay CELP]] (LD-CELP)
** [[Adaptive Multi-Rate audio codec|Adaptive Multi-Rate]] (used in [[GSM]] and [[3GPP]])
** [[Codec2]] (noted for its lack of patent restrictions)
** [[Speex]] (noted for its lack of patent restrictions)
* [[Modified discrete cosine transform]] (MDCT)
** [[AAC-LD]]
** [[Constrained Energy Lapped Transform]] (CELT)
** [[Opus (codec)|Opus]] (mostly for real-time applications)
== List of lossless formats ==
* [[Apple Lossless]] (ALAC – Apple Lossless Audio Codec)
* [[Adaptive Transform Acoustic Coding]] (ATRAC)
* [[Audio Lossless Coding]] (also known as MPEG-4 ALS)
* [[Super Audio CD#DST|Direct Stream Transfer]] (DST)
* [[Dolby TrueHD]]
* [[DTS-HD Master Audio]]
* [[Free Lossless Audio Codec]] (FLAC)
* [[Discrete cosine transform|Lossless discrete cosine transform]] (LDCT)
* [[Meridian Lossless Packing]] (MLP)
* [[Monkey's Audio]] (Monkey's Audio APE)
* [[MPEG-4 SLS]] (also known as HD-AAC)
* [[OptimFROG]]
* [[Original Sound Quality]] (OSQ)
* [[RealPlayer]] (RealAudio Lossless)
* [[Shorten (file format)|Shorten]] (SHN)
* [[TTA (codec)|TTA]] (True Audio Lossless)
* [[WavPack]] (WavPack lossless)
* [[Windows Media Audio 9 Lossless|WMA Lossless]] (Windows Media Lossless)
==See also==
* [[Comparison of audio coding formats]]
* [[Data compression#Audio]]
* [[Audio file format]]
* [[List of audio compression formats]]
==References==
<references/>
[[Category:Audio file formats| ]]' |
Unified diff of changes made by edit (edit_diff) | '@@ -1,11 +1,3 @@
-{{short description|Digitally coded format for audio signals}}
-[[File:Opus quality comparison colorblind compatible.svg|thumb|Comparison of coding efficiency between popular audio formats]]
-An '''audio coding format'''<ref>The term "audio coding" can be seen in e.g. the name [[Advanced Audio Coding]], and is analogous to the term [[video coding format|video coding]]</ref> (or sometimes '''audio compression format''') is a [[Content format|content representation format]] for storage or transmission of [[digital audio]] (such as in [[digital television]], [[digital radio]] and in audio and video files). Examples of audio coding formats include [[MP3]], [[Advanced Audio Coding|AAC]], [[Vorbis]], [[FLAC]], and [[Opus (audio format)|Opus]]. A specific software or hardware implementation capable of [[Data_compression#Audio|audio compression]] and decompression to/from a specific audio coding format is called an [[audio codec]]; an example of an audio codec is [[LAME]], which is one of several different codecs which implements encoding and decoding audio in the [[MP3]] audio coding format in software.
-
-Some audio coding formats are documented by a detailed [[technical specification]] document known as an '''audio coding specification'''. Some such specifications are written and approved by [[standardization organization]]s as [[technical standard]]s, and are thus known as an '''audio coding standard'''. The term "standard" is also sometimes used for [[de facto standard|''de facto'' standards]] as well as formal standards.
-
-Audio content encoded in a particular audio coding format is normally encapsulated within a [[container format (digital)|container format]]. As such, the user normally doesn't have a raw [[Advanced Audio Coding|AAC]] file, but instead has a .m4a [[audio file format|audio file]], which is a [[MPEG-4 Part 14]] container containing AAC-encoded audio. The container also contains [[metadata]] such as title and other tags, and perhaps an index for fast seeking.<ref>{{Cite web | url=http://superuser.com/questions/357686/where-is-synchronization-information-stored-in-container-formats | title=Video - Where is synchronization information stored in container formats?}}</ref> A notable exception is [[MP3]] files, which are raw audio coding without a container format. De facto standards for adding metadata tags such as title and artist to MP3s, such as [[ID3]], are [[Hack (computer science)#In computer science|hack]]s which work by appending the tags to the MP3, and then relying on the MP3 player to recognize the chunk as malformed audio coding and therefore skip it. In video files with audio, the encoded audio content is bundled with video (in a [[video coding format]]) inside a [[multimedia container format]].
-
-An audio coding format does not dictate all [[algorithm]]s used by a [[codec]] implementing the format. An important part of how lossy audio compression works is by removing data in ways humans can't hear, according to a [[psychoacoustic model]]; the implementer of an encoder has some freedom of choice in which data to remove (according to their psychoacoustic model).
+DJ GALAXY UG
==Lossless, lossy, and uncompressed audio coding formats==
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21 => 'http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/',
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24 => 'https://books.google.com/?id=a1RULRErhOYC&pg=PA338',
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26 => 'https://books.google.com/books?id=d9IkBAAAQBAJ&pg=PA388',
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Parsed HTML source of the new revision (new_html) | '<div class="mw-parser-output"><p>DJ GALAXY UG
</p>
<div id="toc" class="toc" role="navigation" aria-labelledby="mw-toc-heading"><input type="checkbox" role="button" id="toctogglecheckbox" class="toctogglecheckbox" style="display:none" /><div class="toctitle" lang="en" dir="ltr"><h2 id="mw-toc-heading">Contents</h2><span class="toctogglespan"><label class="toctogglelabel" for="toctogglecheckbox"></label></span></div>
<ul>
<li class="toclevel-1 tocsection-1"><a href="#Lossless,_lossy,_and_uncompressed_audio_coding_formats"><span class="tocnumber">1</span> <span class="toctext">Lossless, lossy, and uncompressed audio coding formats</span></a></li>
<li class="toclevel-1 tocsection-2"><a href="#History"><span class="tocnumber">2</span> <span class="toctext">History</span></a></li>
<li class="toclevel-1 tocsection-3"><a href="#List_of_lossy_formats"><span class="tocnumber">3</span> <span class="toctext">List of lossy formats</span></a>
<ul>
<li class="toclevel-2 tocsection-4"><a href="#General"><span class="tocnumber">3.1</span> <span class="toctext">General</span></a></li>
<li class="toclevel-2 tocsection-5"><a href="#Speech"><span class="tocnumber">3.2</span> <span class="toctext">Speech</span></a></li>
</ul>
</li>
<li class="toclevel-1 tocsection-6"><a href="#List_of_lossless_formats"><span class="tocnumber">4</span> <span class="toctext">List of lossless formats</span></a></li>
<li class="toclevel-1 tocsection-7"><a href="#See_also"><span class="tocnumber">5</span> <span class="toctext">See also</span></a></li>
<li class="toclevel-1 tocsection-8"><a href="#References"><span class="tocnumber">6</span> <span class="toctext">References</span></a></li>
</ul>
</div>
<h2><span id="Lossless.2C_lossy.2C_and_uncompressed_audio_coding_formats"></span><span class="mw-headline" id="Lossless,_lossy,_and_uncompressed_audio_coding_formats">Lossless, lossy, and uncompressed audio coding formats</span></h2>
<p>A <a href="/wiki/Lossless_compression" title="Lossless compression">lossless</a> audio coding format reduces the total data needed to represent a sound but can be de-coded to its original, uncompressed form. A <a href="/wiki/Lossy_compression" title="Lossy compression">lossy</a> audio coding format additionally reduces the <a href="/wiki/Audio_bit_depth" title="Audio bit depth">bit resolution</a> of the sound on top of compression, which results in far less data at the cost of irretrievably lost information.
</p><p>Consumer audio is most often compressed using lossy audio codecs as the smaller size is far more convenient for distribution. The most widely used audio coding formats are <a href="/wiki/MP3" title="MP3">MP3</a> and <a href="/wiki/Advanced_Audio_Coding" title="Advanced Audio Coding">Advanced Audio Coding</a> (AAC), both of which are lossy formats based on <a href="/wiki/Modified_discrete_cosine_transform" title="Modified discrete cosine transform">modified discrete cosine transform</a> (MDCT) and <a href="/wiki/Perceptual_coding" class="mw-redirect" title="Perceptual coding">perceptual coding</a> algorithms.
</p><p>Lossless audio coding formats such as <a href="/wiki/FLAC" title="FLAC">FLAC</a> and <a href="/wiki/Apple_Lossless" title="Apple Lossless">Apple Lossless</a> are sometimes available, though at the cost of larger files.
</p><p><a href="/wiki/Uncompressed_audio" class="mw-redirect" title="Uncompressed audio">Uncompressed audio</a> formats, such as <a href="/wiki/Pulse-code_modulation" title="Pulse-code modulation">pulse-code modulation</a> (PCM, or .wav), are also sometimes used. PCM was the standard format for <a href="/wiki/Compact_Disc_Digital_Audio" title="Compact Disc Digital Audio">Compact Disc Digital Audio</a> (CDDA), before lossy compression eventually became the standard after the introduction of MP3.
</p>
<h2><span class="mw-headline" id="History">History</span></h2>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="/wiki/File:Placa-audioPC-925.jpg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/1/19/Placa-audioPC-925.jpg/220px-Placa-audioPC-925.jpg" decoding="async" width="220" height="165" class="thumbimage" data-file-width="591" data-file-height="444" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:Placa-audioPC-925.jpg" class="internal" title="Enlarge"></a></div>Solidyne 922: The world's first commercial audio bit compression <a href="/wiki/Sound_card" title="Sound card">sound card</a> for PC, 1990</div></div></div>
<p>In 1950, <a href="/wiki/Bell_Labs" title="Bell Labs">Bell Labs</a> filed the patent on <a href="/wiki/Differential_pulse-code_modulation" title="Differential pulse-code modulation">differential pulse-code modulation</a> (DPCM).<sup id="cite_ref-DPCM_1-0" class="reference"><a href="#cite_note-DPCM-1">[1]</a></sup> <a href="/wiki/Adaptive_DPCM" class="mw-redirect" title="Adaptive DPCM">Adaptive DPCM</a> (ADPCM) was introduced by P. Cummiskey, <a href="/wiki/Nikil_Jayant" title="Nikil Jayant">Nikil S. Jayant</a> and <a href="/wiki/James_L._Flanagan" title="James L. Flanagan">James L. Flanagan</a> at <a href="/wiki/Bell_Labs" title="Bell Labs">Bell Labs</a> in 1973.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2">[2]</a></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3">[3]</a></sup>
</p><p><a href="/wiki/Perceptual_coding" class="mw-redirect" title="Perceptual coding">Perceptual coding</a> was first used for <a href="/wiki/Speech_coding" title="Speech coding">speech coding</a> compression, with <a href="/wiki/Linear_predictive_coding" title="Linear predictive coding">linear predictive coding</a> (LPC).<sup id="cite_ref-Schroeder2014_4-0" class="reference"><a href="#cite_note-Schroeder2014-4">[4]</a></sup> Initial concepts for LPC date back to the work of <a href="/wiki/Fumitada_Itakura" title="Fumitada Itakura">Fumitada Itakura</a> (<a href="/wiki/Nagoya_University" title="Nagoya University">Nagoya University</a>) and Shuzo Saito (<a href="/wiki/Nippon_Telegraph_and_Telephone" title="Nippon Telegraph and Telephone">Nippon Telegraph and Telephone</a>) in 1966.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5">[5]</a></sup> During the 1970s, <a href="/wiki/Bishnu_S._Atal" title="Bishnu S. Atal">Bishnu S. Atal</a> and <a href="/wiki/Manfred_R._Schroeder" title="Manfred R. Schroeder">Manfred R. Schroeder</a> at <a href="/wiki/Bell_Labs" title="Bell Labs">Bell Labs</a> developed a form of LPC called <a href="/wiki/Adaptive_predictive_coding" title="Adaptive predictive coding">adaptive predictive coding</a> (APC), a perceptual coding algorithm that exploited the masking properties of the human ear, followed in the early 1980s with the <a href="/wiki/Code-excited_linear_prediction" title="Code-excited linear prediction">code-excited linear prediction</a> (CELP) algorithm which achieved a significant compression ratio for its time.<sup id="cite_ref-Schroeder2014_4-1" class="reference"><a href="#cite_note-Schroeder2014-4">[4]</a></sup> Perceptual coding is used by modern audio compression formats such as <a href="/wiki/MP3" title="MP3">MP3</a><sup id="cite_ref-Schroeder2014_4-2" class="reference"><a href="#cite_note-Schroeder2014-4">[4]</a></sup> and <a href="/wiki/Advanced_Audio_Codec" class="mw-redirect" title="Advanced Audio Codec">AAC</a>.
</p><p><a href="/wiki/Discrete_cosine_transform" title="Discrete cosine transform">Discrete cosine transform</a> (DCT), developed by <a href="/wiki/N._Ahmed" class="mw-redirect" title="N. Ahmed">Nasir Ahmed</a>, T. Natarajan and <a href="/wiki/K._R._Rao" title="K. R. Rao">K. R. Rao</a> in 1974,<sup id="cite_ref-DCT_6-0" class="reference"><a href="#cite_note-DCT-6">[6]</a></sup> provided the basis for the <a href="/wiki/Modified_discrete_cosine_transform" title="Modified discrete cosine transform">modified discrete cosine transform</a> (MDCT) used by modern audio compression formats such as MP3<sup id="cite_ref-Guckert_7-0" class="reference"><a href="#cite_note-Guckert-7">[7]</a></sup> and AAC. MDCT was proposed by J. P. Princen, A. W. Johnson and A. B. Bradley in 1987,<sup id="cite_ref-8" class="reference"><a href="#cite_note-8">[8]</a></sup> following earlier work by Princen and Bradley in 1986.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9">[9]</a></sup> The MDCT is used by modern audio compression formats such as <a href="/wiki/Dolby_Digital" title="Dolby Digital">Dolby Digital</a>,<sup id="cite_ref-Luo_10-0" class="reference"><a href="#cite_note-Luo-10">[10]</a></sup><sup id="cite_ref-11" class="reference"><a href="#cite_note-11">[11]</a></sup> <a href="/wiki/MP3" title="MP3">MP3</a>,<sup id="cite_ref-Guckert_7-1" class="reference"><a href="#cite_note-Guckert-7">[7]</a></sup> and <a href="/wiki/Advanced_Audio_Coding" title="Advanced Audio Coding">Advanced Audio Coding</a> (AAC).<sup id="cite_ref-brandenburg_12-0" class="reference"><a href="#cite_note-brandenburg-12">[12]</a></sup>
</p>
<h2><span class="mw-headline" id="List_of_lossy_formats">List of lossy formats</span></h2>
<h3><span class="mw-headline" id="General">General</span></h3>
<table class="wikitable sortable">
<tbody><tr>
<th>Basic compression algorithm
</th>
<th>Audio coding standard
</th>
<th>Abbreviation
</th>
<th>Introduction
</th>
<th>Market share <span style="font-size:85%;">(2019)</span><sup id="cite_ref-Bitmovin_13-0" class="reference"><a href="#cite_note-Bitmovin-13">[13]</a></sup>
</th>
<th><abbr title="Reference(s)">Ref</abbr>
</th></tr>
<tr>
<td rowspan="9"><a href="/wiki/Modified_discrete_cosine_transform" title="Modified discrete cosine transform">Modified discrete cosine transform</a> (MDCT)
</td>
<td><a href="/wiki/Dolby_Digital" title="Dolby Digital">Dolby Digital</a> (AC-3)
</td>
<td>AC3
</td>
<td>1991
</td>
<td>58%
</td>
<td><sup id="cite_ref-Luo_10-1" class="reference"><a href="#cite_note-Luo-10">[10]</a></sup><sup id="cite_ref-Britanak2011_14-0" class="reference"><a href="#cite_note-Britanak2011-14">[14]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Adaptive_Transform_Acoustic_Coding" title="Adaptive Transform Acoustic Coding">Adaptive Transform Acoustic Coding</a>
</td>
<td>ATRAC
</td>
<td>1992
</td>
<td style="background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;" class="unknown table-unknown">Un­known
</td>
<td><sup id="cite_ref-Luo_10-2" class="reference"><a href="#cite_note-Luo-10">[10]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/MPEG_Layer_III" class="mw-redirect" title="MPEG Layer III">MPEG Layer III</a>
</td>
<td>MP3
</td>
<td>1993
</td>
<td>49%
</td>
<td><sup id="cite_ref-Guckert_7-2" class="reference"><a href="#cite_note-Guckert-7">[7]</a></sup><sup id="cite_ref-Stankovic_15-0" class="reference"><a href="#cite_note-Stankovic-15">[15]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Advanced_Audio_Coding" title="Advanced Audio Coding">Advanced Audio Coding</a> (<a href="/wiki/MPEG-2" title="MPEG-2">MPEG-2</a> / <a href="/wiki/MPEG-4" title="MPEG-4">MPEG-4</a>)
</td>
<td>AAC
</td>
<td>1997
</td>
<td>88%
</td>
<td><sup id="cite_ref-brandenburg_12-1" class="reference"><a href="#cite_note-brandenburg-12">[12]</a></sup><sup id="cite_ref-Luo_10-3" class="reference"><a href="#cite_note-Luo-10">[10]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Windows_Media_Audio" title="Windows Media Audio">Windows Media Audio</a>
</td>
<td>WMA
</td>
<td>1999
</td>
<td style="background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;" class="unknown table-unknown">Un­known
</td>
<td><sup id="cite_ref-Luo_10-4" class="reference"><a href="#cite_note-Luo-10">[10]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Ogg" title="Ogg">Ogg</a> <a href="/wiki/Vorbis" title="Vorbis">Vorbis</a>
</td>
<td>Ogg
</td>
<td>2000
</td>
<td>7%
</td>
<td><sup id="cite_ref-vorbis-mdct_16-0" class="reference"><a href="#cite_note-vorbis-mdct-16">[16]</a></sup><sup id="cite_ref-Luo_10-5" class="reference"><a href="#cite_note-Luo-10">[10]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Constrained_Energy_Lapped_Transform" class="mw-redirect" title="Constrained Energy Lapped Transform">Constrained Energy Lapped Transform</a>
</td>
<td>CELT
</td>
<td>2011
</td>
<td data-sort-value="" style="background: #ececec; color: #2C2C2C; vertical-align: middle; text-align: center;" class="table-na">N/A
</td>
<td><sup id="cite_ref-presentation_17-0" class="reference"><a href="#cite_note-presentation-17">[17]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Opus_(codec)" class="mw-redirect" title="Opus (codec)">Opus</a>
</td>
<td>Opus
</td>
<td>2012
</td>
<td>8%
</td>
<td><sup id="cite_ref-18" class="reference"><a href="#cite_note-18">[18]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/LDAC_(codec)" title="LDAC (codec)">LDAC</a>
</td>
<td>LDAC
</td>
<td>2015
</td>
<td style="background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;" class="unknown table-unknown">Un­known
</td>
<td><sup id="cite_ref-Darko_2017_19-0" class="reference"><a href="#cite_note-Darko_2017-19">[19]</a></sup><sup id="cite_ref-AVHub_2015_20-0" class="reference"><a href="#cite_note-AVHub_2015-20">[20]</a></sup>
</td></tr>
<tr>
<td rowspan="3"><a href="/wiki/Adaptive_differential_pulse-code_modulation" title="Adaptive differential pulse-code modulation">Adaptive differential pulse-code modulation</a> (ADPCM)
</td>
<td><a href="/wiki/AptX" title="AptX">aptX / aptX-HD</a>
</td>
<td>aptX
</td>
<td>1989
</td>
<td style="background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;" class="unknown table-unknown">Un­known
</td>
<td><sup id="cite_ref-AVHub_2016_21-0" class="reference"><a href="#cite_note-AVHub_2016-21">[21]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/DTS_(sound_system)#DTS_audio_codec" title="DTS (sound system)">Digital Theater Systems</a>
</td>
<td>DTS
</td>
<td>1990
</td>
<td>14%
</td>
<td><sup id="cite_ref-22" class="reference"><a href="#cite_note-22">[22]</a></sup><sup id="cite_ref-23" class="reference"><a href="#cite_note-23">[23]</a></sup>
</td></tr>
<tr>
<td><a href="/wiki/Master_Quality_Authenticated" title="Master Quality Authenticated">Master Quality Authenticated</a>
</td>
<td>MQA
</td>
<td>2014
</td>
<td style="background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;" class="unknown table-unknown">Un­known
</td>
<td>
</td></tr>
<tr>
<td rowspan="2"><a href="/wiki/Sub-band_coding" title="Sub-band coding">Sub-band coding</a> (SBC)
</td>
<td><a href="/wiki/MPEG-1_Audio_Layer_II" title="MPEG-1 Audio Layer II">MPEG-1 Audio Layer II</a>
</td>
<td>MP2
</td>
<td>1993
</td>
<td rowspan="2" style="background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;" class="unknown table-unknown">Un­known
</td>
<td rowspan="2">
</td></tr>
<tr>
<td><a href="/wiki/Musepack" title="Musepack">Musepack</a>
</td>
<td>MPC
</td>
<td>1997
</td></tr></tbody></table>
<h3><span class="mw-headline" id="Speech">Speech</span></h3>
<style data-mw-deduplicate="TemplateStyles:r1033289096">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}</style><div role="note" class="hatnote navigation-not-searchable">Further information: <a href="/wiki/Speech_coding" title="Speech coding">Speech coding</a></div>
<ul><li><a href="/wiki/Linear_predictive_coding" title="Linear predictive coding">Linear predictive coding</a> (LPC)
<ul><li><a href="/wiki/Adaptive_predictive_coding" title="Adaptive predictive coding">Adaptive predictive coding</a> (APC)</li>
<li><a href="/wiki/Code-excited_linear_prediction" title="Code-excited linear prediction">Code-excited linear prediction</a> (CELP)</li>
<li><a href="/wiki/Algebraic_code-excited_linear_prediction" title="Algebraic code-excited linear prediction">Algebraic code-excited linear prediction</a> (ACELP)</li>
<li><a href="/wiki/Relaxed_code-excited_linear_prediction" title="Relaxed code-excited linear prediction">Relaxed code-excited linear prediction</a> (RCELP)</li>
<li><a href="/wiki/Low-delay_CELP" class="mw-redirect" title="Low-delay CELP">Low-delay CELP</a> (LD-CELP)</li>
<li><a href="/wiki/Adaptive_Multi-Rate_audio_codec" title="Adaptive Multi-Rate audio codec">Adaptive Multi-Rate</a> (used in <a href="/wiki/GSM" title="GSM">GSM</a> and <a href="/wiki/3GPP" title="3GPP">3GPP</a>)</li>
<li><a href="/wiki/Codec2" class="mw-redirect" title="Codec2">Codec2</a> (noted for its lack of patent restrictions)</li>
<li><a href="/wiki/Speex" title="Speex">Speex</a> (noted for its lack of patent restrictions)</li></ul></li>
<li><a href="/wiki/Modified_discrete_cosine_transform" title="Modified discrete cosine transform">Modified discrete cosine transform</a> (MDCT)
<ul><li><a href="/wiki/AAC-LD" title="AAC-LD">AAC-LD</a></li>
<li><a href="/wiki/Constrained_Energy_Lapped_Transform" class="mw-redirect" title="Constrained Energy Lapped Transform">Constrained Energy Lapped Transform</a> (CELT)</li>
<li><a href="/wiki/Opus_(codec)" class="mw-redirect" title="Opus (codec)">Opus</a> (mostly for real-time applications)</li></ul></li></ul>
<h2><span class="mw-headline" id="List_of_lossless_formats">List of lossless formats</span></h2>
<ul><li><a href="/wiki/Apple_Lossless" title="Apple Lossless">Apple Lossless</a> (ALAC – Apple Lossless Audio Codec)</li>
<li><a href="/wiki/Adaptive_Transform_Acoustic_Coding" title="Adaptive Transform Acoustic Coding">Adaptive Transform Acoustic Coding</a> (ATRAC)</li>
<li><a href="/wiki/Audio_Lossless_Coding" title="Audio Lossless Coding">Audio Lossless Coding</a> (also known as MPEG-4 ALS)</li>
<li><a href="/wiki/Super_Audio_CD#DST" title="Super Audio CD">Direct Stream Transfer</a> (DST)</li>
<li><a href="/wiki/Dolby_TrueHD" title="Dolby TrueHD">Dolby TrueHD</a></li>
<li><a href="/wiki/DTS-HD_Master_Audio" title="DTS-HD Master Audio">DTS-HD Master Audio</a></li>
<li><a href="/wiki/Free_Lossless_Audio_Codec" class="mw-redirect" title="Free Lossless Audio Codec">Free Lossless Audio Codec</a> (FLAC)</li>
<li><a href="/wiki/Discrete_cosine_transform" title="Discrete cosine transform">Lossless discrete cosine transform</a> (LDCT)</li>
<li><a href="/wiki/Meridian_Lossless_Packing" title="Meridian Lossless Packing">Meridian Lossless Packing</a> (MLP)</li>
<li><a href="/wiki/Monkey%27s_Audio" title="Monkey's Audio">Monkey's Audio</a> (Monkey's Audio APE)</li>
<li><a href="/wiki/MPEG-4_SLS" title="MPEG-4 SLS">MPEG-4 SLS</a> (also known as HD-AAC)</li>
<li><a href="/wiki/OptimFROG" title="OptimFROG">OptimFROG</a></li>
<li><a href="/wiki/Original_Sound_Quality" title="Original Sound Quality">Original Sound Quality</a> (OSQ)</li>
<li><a href="/wiki/RealPlayer" title="RealPlayer">RealPlayer</a> (RealAudio Lossless)</li>
<li><a href="/wiki/Shorten_(file_format)" title="Shorten (file format)">Shorten</a> (SHN)</li>
<li><a href="/wiki/TTA_(codec)" title="TTA (codec)">TTA</a> (True Audio Lossless)</li>
<li><a href="/wiki/WavPack" title="WavPack">WavPack</a> (WavPack lossless)</li>
<li><a href="/wiki/Windows_Media_Audio_9_Lossless" class="mw-redirect" title="Windows Media Audio 9 Lossless">WMA Lossless</a> (Windows Media Lossless)</li></ul>
<h2><span class="mw-headline" id="See_also">See also</span></h2>
<ul><li><a href="/wiki/Comparison_of_audio_coding_formats" title="Comparison of audio coding formats">Comparison of audio coding formats</a></li>
<li><a href="/wiki/Data_compression#Audio" title="Data compression">Data compression#Audio</a></li>
<li><a href="/wiki/Audio_file_format" title="Audio file format">Audio file format</a></li>
<li><a href="/wiki/List_of_audio_compression_formats" class="mw-redirect" title="List of audio compression formats">List of audio compression formats</a></li></ul>
<h2><span class="mw-headline" id="References">References</span></h2>
<div class="mw-references-wrap mw-references-columns"><ol class="references">
<li id="cite_note-DPCM-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-DPCM_1-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1041539562">.mw-parser-output .citation{word-wrap:break-word}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}</style><span class="citation patent" id="harv"><a rel="nofollow" class="external text" href="https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US2605361">US patent 2605361</a>, C. Chapin Cutler, "Differential Quantization of Communication Signals", issued 1952-07-29</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Apatent&rft.number=2605361&rft.cc=US&rft.title=Differential+Quantization+of+Communication+Signals&rft.inventor=C.+Chapin+Cutler&rft.date=1952-07-29"><span style="display: none;"> </span></span></span>
</li>
<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text">P. Cummiskey, Nikil S. Jayant, and J. L. Flanagan, "Adaptive quantization in differential PCM coding of speech", <i>Bell Syst. Tech. J.</i>, vol. 52, pp. 1105—1118, Sept. 1973</span>
</li>
<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r999302996">.mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .id-lock-free a,.mw-parser-output .citation .cs1-lock-free a{background:linear-gradient(transparent,transparent),url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited a,.mw-parser-output .id-lock-registration a,.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:linear-gradient(transparent,transparent),url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription a,.mw-parser-output .citation .cs1-lock-subscription a{background:linear-gradient(transparent,transparent),url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:linear-gradient(transparent,transparent),url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}</style><cite id="CITEREFCummiskeyJayantFlanagan1973" class="citation journal cs1">Cummiskey, P.; Jayant, Nikil S.; Flanagan, J. L. (1973). "Adaptive quantization in differential PCM coding of speech". <i>The Bell System Technical Journal</i>. <b>52</b> (7): 1105–1118. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fj.1538-7305.1973.tb02007.x">10.1002/j.1538-7305.1973.tb02007.x</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="//www.worldcat.org/issn/0005-8580">0005-8580</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Bell+System+Technical+Journal&rft.atitle=Adaptive+quantization+in+differential+PCM+coding+of+speech&rft.volume=52&rft.issue=7&rft.pages=1105-1118&rft.date=1973&rft_id=info%3Adoi%2F10.1002%2Fj.1538-7305.1973.tb02007.x&rft.issn=0005-8580&rft.aulast=Cummiskey&rft.aufirst=P.&rft.au=Jayant%2C+Nikil+S.&rft.au=Flanagan%2C+J.+L.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-Schroeder2014-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-Schroeder2014_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Schroeder2014_4-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Schroeder2014_4-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFSchroeder2014" class="citation book cs1">Schroeder, Manfred R. (2014). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=d9IkBAAAQBAJ&pg=PA388">"Bell Laboratories"</a>. <i>Acoustics, Information, and Communication: Memorial Volume in Honor of Manfred R. Schroeder</i>. Springer. p. 388. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9783319056609" title="Special:BookSources/9783319056609"><bdi>9783319056609</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Bell+Laboratories&rft.btitle=Acoustics%2C+Information%2C+and+Communication%3A+Memorial+Volume+in+Honor+of+Manfred+R.+Schroeder&rft.pages=388&rft.pub=Springer&rft.date=2014&rft.isbn=9783319056609&rft.aulast=Schroeder&rft.aufirst=Manfred+R.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3Dd9IkBAAAQBAJ%26pg%3DPA388&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFGray2010" class="citation journal cs1">Gray, Robert M. (2010). <a rel="nofollow" class="external text" href="https://ee.stanford.edu/~gray/lpcip.pdf">"A History of Realtime Digital Speech on Packet Networks: Part II of Linear Predictive Coding and the Internet Protocol"</a> <span class="cs1-format">(PDF)</span>. <i>Found. Trends Signal Process</i>. <b>3</b> (4): 203–303. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="cs1-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1561%2F2000000036">10.1561/2000000036</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="//www.worldcat.org/issn/1932-8346">1932-8346</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Found.+Trends+Signal+Process.&rft.atitle=A+History+of+Realtime+Digital+Speech+on+Packet+Networks%3A+Part+II+of+Linear+Predictive+Coding+and+the+Internet+Protocol&rft.volume=3&rft.issue=4&rft.pages=203-303&rft.date=2010&rft_id=info%3Adoi%2F10.1561%2F2000000036&rft.issn=1932-8346&rft.aulast=Gray&rft.aufirst=Robert+M.&rft_id=https%3A%2F%2Fee.stanford.edu%2F~gray%2Flpcip.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-DCT-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-DCT_6-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFNasir_AhmedT._NatarajanKamisetty_Ramamohan_Rao1974" class="citation journal cs1"><a href="/wiki/N._Ahmed" class="mw-redirect" title="N. Ahmed">Nasir Ahmed</a>; T. Natarajan; Kamisetty Ramamohan Rao (January 1974). <a rel="nofollow" class="external text" href="https://www.ic.tu-berlin.de/fileadmin/fg121/Source-Coding_WS12/selected-readings/Ahmed_et_al.__1974.pdf">"Discrete Cosine Transform"</a> <span class="cs1-format">(PDF)</span>. <i>IEEE Transactions on Computers</i>. <b>C-23</b> (1): 90–93. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FT-C.1974.223784">10.1109/T-C.1974.223784</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Transactions+on+Computers&rft.atitle=Discrete+Cosine+Transform&rft.volume=C-23&rft.issue=1&rft.pages=90-93&rft.date=1974-01&rft_id=info%3Adoi%2F10.1109%2FT-C.1974.223784&rft.au=Nasir+Ahmed&rft.au=T.+Natarajan&rft.au=Kamisetty+Ramamohan+Rao&rft_id=https%3A%2F%2Fwww.ic.tu-berlin.de%2Ffileadmin%2Ffg121%2FSource-Coding_WS12%2Fselected-readings%2FAhmed_et_al.__1974.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-Guckert-7"><span class="mw-cite-backlink">^ <a href="#cite_ref-Guckert_7-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Guckert_7-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Guckert_7-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFGuckert2012" class="citation web cs1">Guckert, John (Spring 2012). <a rel="nofollow" class="external text" href="http://www.math.utah.edu/~gustafso/s2012/2270/web-projects/Guckert-audio-compression-svd-mdct-MP3.pdf">"The Use of FFT and MDCT in MP3 Audio Compression"</a> <span class="cs1-format">(PDF)</span>. <i><a href="/wiki/University_of_Utah" title="University of Utah">University of Utah</a></i><span class="reference-accessdate">. Retrieved <span class="nowrap">14 July</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=University+of+Utah&rft.atitle=The+Use+of+FFT+and+MDCT+in+MP3+Audio+Compression&rft.ssn=spring&rft.date=2012&rft.aulast=Guckert&rft.aufirst=John&rft_id=http%3A%2F%2Fwww.math.utah.edu%2F~gustafso%2Fs2012%2F2270%2Fweb-projects%2FGuckert-audio-compression-svd-mdct-MP3.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text">J. P. Princen, A. W. Johnson und A. B. Bradley: <i>Subband/transform coding using filter bank designs based on time ___domain aliasing cancellation</i>, IEEE Proc. Intl. Conference on Acoustics, Speech, and Signal Processing (ICASSP), 2161–2164, 1987.</span>
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<li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text">John P. Princen, Alan B. Bradley: <i>Analysis/synthesis filter bank design based on time ___domain aliasing cancellation</i>, IEEE Trans. Acoust. Speech Signal Processing, <i>ASSP-34</i> (5), 1153–1161, 1986.</span>
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<li id="cite_note-Luo-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-Luo_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Luo_10-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Luo_10-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Luo_10-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Luo_10-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-Luo_10-5"><sup><i><b>f</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFLuo2008" class="citation book cs1">Luo, Fa-Long (2008). <a rel="nofollow" class="external text" href="https://books.google.com/?id=l6PovWat8SMC&pg=PA590"><i>Mobile Multimedia Broadcasting Standards: Technology and Practice</i></a>. <a href="/wiki/Springer_Science_%26_Business_Media" class="mw-redirect" title="Springer Science & Business Media">Springer Science & Business Media</a>. p. 590. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780387782638" title="Special:BookSources/9780387782638"><bdi>9780387782638</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Mobile+Multimedia+Broadcasting+Standards%3A+Technology+and+Practice&rft.pages=590&rft.pub=Springer+Science+%26+Business+Media&rft.date=2008&rft.isbn=9780387782638&rft.aulast=Luo&rft.aufirst=Fa-Long&rft_id=https%3A%2F%2Fbooks.google.com%2F%3Fid%3Dl6PovWat8SMC%26pg%3DPA590&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFBritanak2011" class="citation journal cs1">Britanak, V. (2011). "On Properties, Relations, and Simplified Implementation of Filter Banks in the Dolby Digital (Plus) AC-3 Audio Coding Standards". <i>IEEE Transactions on Audio, Speech, and Language Processing</i>. <b>19</b> (5): 1231–1241. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FTASL.2010.2087755">10.1109/TASL.2010.2087755</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Transactions+on+Audio%2C+Speech%2C+and+Language+Processing&rft.atitle=On+Properties%2C+Relations%2C+and+Simplified+Implementation+of+Filter+Banks+in+the+Dolby+Digital+%28Plus%29+AC-3+Audio+Coding+Standards&rft.volume=19&rft.issue=5&rft.pages=1231-1241&rft.date=2011&rft_id=info%3Adoi%2F10.1109%2FTASL.2010.2087755&rft.aulast=Britanak&rft.aufirst=V.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-brandenburg-12"><span class="mw-cite-backlink">^ <a href="#cite_ref-brandenburg_12-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-brandenburg_12-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFBrandenburg1999" class="citation web cs1">Brandenburg, Karlheinz (1999). <a rel="nofollow" class="external text" href="http://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf">"MP3 and AAC Explained"</a> <span class="cs1-format">(PDF)</span>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170213191747/https://graphics.ethz.ch/teaching/mmcom12/slides/mp3_and_aac_brandenburg.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 2017-02-13.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=MP3+and+AAC+Explained&rft.date=1999&rft.aulast=Brandenburg&rft.aufirst=Karlheinz&rft_id=http%3A%2F%2Fgraphics.ethz.ch%2Fteaching%2Fmmcom12%2Fslides%2Fmp3_and_aac_brandenburg.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-Bitmovin-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-Bitmovin_13-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://cdn2.hubspot.net/hubfs/3411032/Bitmovin%20Magazine/Video%20Developer%20Report%202019/bitmovin-video-developer-report-2019.pdf">"Video Developer Report 2019"</a> <span class="cs1-format">(PDF)</span>. <i><a href="/wiki/Bitmovin" title="Bitmovin">Bitmovin</a></i>. 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">5 November</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Bitmovin&rft.atitle=Video+Developer+Report+2019&rft.date=2019&rft_id=https%3A%2F%2Fcdn2.hubspot.net%2Fhubfs%2F3411032%2FBitmovin%2520Magazine%2FVideo%2520Developer%2520Report%25202019%2Fbitmovin-video-developer-report-2019.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-Britanak2011-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-Britanak2011_14-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFBritanak2011" class="citation journal cs1">Britanak, V. (2011). "On Properties, Relations, and Simplified Implementation of Filter Banks in the Dolby Digital (Plus) AC-3 Audio Coding Standards". <i>IEEE Transactions on Audio, Speech, and Language Processing</i>. <b>19</b> (5): 1231–1241. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FTASL.2010.2087755">10.1109/TASL.2010.2087755</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Transactions+on+Audio%2C+Speech%2C+and+Language+Processing&rft.atitle=On+Properties%2C+Relations%2C+and+Simplified+Implementation+of+Filter+Banks+in+the+Dolby+Digital+%28Plus%29+AC-3+Audio+Coding+Standards&rft.volume=19&rft.issue=5&rft.pages=1231-1241&rft.date=2011&rft_id=info%3Adoi%2F10.1109%2FTASL.2010.2087755&rft.aulast=Britanak&rft.aufirst=V.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-Stankovic-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-Stankovic_15-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFStankovićAstola2012" class="citation journal cs1">Stanković, Radomir S.; Astola, Jaakko T. (2012). <a rel="nofollow" class="external text" href="http://ticsp.cs.tut.fi/reports/ticsp-report-60-reprint-rao-corrected.pdf">"Reminiscences of the Early Work in DCT: Interview with K.R. Rao"</a> <span class="cs1-format">(PDF)</span>. <i>Reprints from the Early Days of Information Sciences</i>. <b>60</b><span class="reference-accessdate">. Retrieved <span class="nowrap">13 October</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Reprints+from+the+Early+Days+of+Information+Sciences&rft.atitle=Reminiscences+of+the+Early+Work+in+DCT%3A+Interview+with+K.R.+Rao&rft.volume=60&rft.date=2012&rft.aulast=Stankovi%C4%87&rft.aufirst=Radomir+S.&rft.au=Astola%2C+Jaakko+T.&rft_id=http%3A%2F%2Fticsp.cs.tut.fi%2Freports%2Fticsp-report-60-reprint-rao-corrected.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-vorbis-mdct-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-vorbis-mdct_16-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFXiph.Org_Foundation2009" class="citation web cs1">Xiph.Org Foundation (2009-06-02). <a rel="nofollow" class="external text" href="http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-50001.1.2">"Vorbis I specification - 1.1.2 Classification"</a>. Xiph.Org Foundation<span class="reference-accessdate">. Retrieved <span class="nowrap">2009-09-22</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Vorbis+I+specification+-+1.1.2+Classification&rft.pub=Xiph.Org+Foundation&rft.date=2009-06-02&rft.au=Xiph.Org+Foundation&rft_id=http%3A%2F%2Fwww.xiph.org%2Fvorbis%2Fdoc%2FVorbis_I_spec.html%23x1-50001.1.2&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-presentation-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-presentation_17-0">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://people.xiph.org/~greg/video/linux_conf_au_CELT_2.ogv">Presentation of the CELT codec</a> by Timothy B. Terriberry (65 minutes of video, see also <a rel="nofollow" class="external text" href="http://www.celt-codec.org/presentations/misc/lca-celt.pdf">presentation slides</a> in PDF)</span>
</li>
<li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFValinMaxwellTerriberryVos2013" class="citation conference cs1">Valin, Jean-Marc; Maxwell, Gregory; Terriberry, Timothy B.; Vos, Koen (October 2013). <i>High-Quality, Low-Delay Music Coding in the Opus Codec</i>. 135th AES Convention. <a href="/wiki/Audio_Engineering_Society" title="Audio Engineering Society">Audio Engineering Society</a>. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="cs1-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="//arxiv.org/abs/1602.04845">1602.04845</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.btitle=High-Quality%2C+Low-Delay+Music+Coding+in+the+Opus+Codec&rft.pub=Audio+Engineering+Society&rft.date=2013-10&rft_id=info%3Aarxiv%2F1602.04845&rft.aulast=Valin&rft.aufirst=Jean-Marc&rft.au=Maxwell%2C+Gregory&rft.au=Terriberry%2C+Timothy+B.&rft.au=Vos%2C+Koen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-Darko_2017-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-Darko_2017_19-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFDarko2017" class="citation web cs1">Darko, John H. (2017-03-29). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20180114020200/http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/">"The inconvenient truth about Bluetooth audio"</a>. <i>DAR__KO</i>. Archived from <a rel="nofollow" class="external text" href="http://www.digitalaudioreview.net/2017/03/the-inconvenient-truth-about-bluetooth-audio/">the original</a> on 2018-01-14<span class="reference-accessdate">. Retrieved <span class="nowrap">2018-01-13</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=DAR__KO&rft.atitle=The+inconvenient+truth+about+Bluetooth+audio&rft.date=2017-03-29&rft.aulast=Darko&rft.aufirst=John+H.&rft_id=http%3A%2F%2Fwww.digitalaudioreview.net%2F2017%2F03%2Fthe-inconvenient-truth-about-bluetooth-audio%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-AVHub_2015-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-AVHub_2015_20-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFFord2015" class="citation web cs1">Ford, Jez (2015-08-24). <a rel="nofollow" class="external text" href="http://www.avhub.com.au/news/sound-image/what-is-sony-ldac-and-how-does-it-do-it-408285">"What is Sony LDAC, and how does it do it?"</a>. <i>AVHub</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2018-01-13</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=AVHub&rft.atitle=What+is+Sony+LDAC%2C+and+how+does+it+do+it%3F&rft.date=2015-08-24&rft.aulast=Ford&rft.aufirst=Jez&rft_id=http%3A%2F%2Fwww.avhub.com.au%2Fnews%2Fsound-image%2Fwhat-is-sony-ldac-and-how-does-it-do-it-408285&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-AVHub_2016-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-AVHub_2016_21-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFFord2016" class="citation web cs1">Ford, Jez (2016-11-22). <a rel="nofollow" class="external text" href="http://www.avhub.com.au/news/sound-image/aptx-hd---lossless-or-lossy-442124">"aptX HD - lossless or lossy?"</a>. <i>AVHub</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2018-01-13</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=AVHub&rft.atitle=aptX+HD+-+lossless+or+lossy%3F&rft.date=2016-11-22&rft.aulast=Ford&rft.aufirst=Jez&rft_id=http%3A%2F%2Fwww.avhub.com.au%2Fnews%2Fsound-image%2Faptx-hd---lossless-or-lossy-442124&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.loc.gov/preservation/digital/formats/fdd/fdd000232.shtml">"Digital Theater Systems Audio Formats"</a>. <i><a href="/wiki/Library_of_Congress" title="Library of Congress">Library of Congress</a></i>. 27 December 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">10 November</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Library+of+Congress&rft.atitle=Digital+Theater+Systems+Audio+Formats&rft.date=2011-12-27&rft_id=https%3A%2F%2Fwww.loc.gov%2Fpreservation%2Fdigital%2Fformats%2Ffdd%2Ffdd000232.shtml&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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<li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r999302996"/><cite id="CITEREFSpaniasPainterAtti2006" class="citation book cs1">Spanias, Andreas; Painter, Ted; Atti, Venkatraman (2006). <a rel="nofollow" class="external text" href="https://books.google.com/?id=a1RULRErhOYC&pg=PA338"><i>Audio Signal Processing and Coding</i></a>. <a href="/wiki/John_Wiley_%26_Sons" class="mw-redirect" title="John Wiley & Sons">John Wiley & Sons</a>. p. 338. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780470041963" title="Special:BookSources/9780470041963"><bdi>9780470041963</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Audio+Signal+Processing+and+Coding&rft.pages=338&rft.pub=John+Wiley+%26+Sons&rft.date=2006&rft.isbn=9780470041963&rft.aulast=Spanias&rft.aufirst=Andreas&rft.au=Painter%2C+Ted&rft.au=Atti%2C+Venkatraman&rft_id=https%3A%2F%2Fbooks.google.com%2F%3Fid%3Da1RULRErhOYC%26pg%3DPA338&rfr_id=info%3Asid%2Fen.wikipedia.org%3AAudio+coding+format" class="Z3988"></span></span>
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</ol></div>
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Unix timestamp of change (timestamp) | 1633172592 |
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