Editing Dolby Digital (section)

== Versions ==
Dolby Digital<ref>{{cite web |url=http://www.dolby.com/us/en/technologies/dolby-digital.html |title=Dolby – Dolby Digital Details |publisher=[[Dolby Laboratories]]}}</ref> has similar technologies, included in Dolby Digital EX,<ref>{{cite web |url=http://www.dolby.com/consumer/technology/dolby_ex.html |title=Dolby – What is Dolby Digital EX? |publisher=[[Dolby Laboratories]] |access-date=2009-08-29 |archive-date=2009-02-27 |archive-url=https://web.archive.org/web/20090227084055/http://www.dolby.com/consumer/technology/dolby_ex.html |url-status=dead }}</ref> Dolby Digital Live,<ref>{{cite web |url=http://www.dolby.com/consumer/technology/dolby_live.html |title=Dolby – What is Dolby Digital Live? |publisher=[[Dolby Laboratories]] |access-date=2006-03-20 |archive-date=2009-02-10 |archive-url=https://web.archive.org/web/20090210092357/http://www.dolby.com/consumer/technology/dolby_live.html |url-status=dead }}</ref> Dolby Digital Plus,<ref>{{cite web |url=http://www.dolby.com/us/en/technologies/dolby-digital-plus.html.html |title=Dolby – Dolby Digital Plus Details |publisher=[[Dolby Laboratories]] }}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Dolby Digital Surround EX,<ref>{{cite web |url=http://www.dolby.com/us/en/consumer/technology/movie/dolby-surround-7-1.html |title=Dolby – What is Dolby Digital Surround EX? |publisher=[[Dolby Laboratories]] |access-date=2015-05-25 |archive-date=2014-06-14 |archive-url=https://web.archive.org/web/20140614040932/http://www.dolby.com/us/en/consumer/technology/movie/dolby-surround-7-1.html |url-status=dead }}</ref> Dolby Digital Recording,<ref>{{cite web |url=http://www.dolby.com/consumer/understand/creation/dolby-digital-recording.html |title=Dolby – What is Dolby Digital Recording? |publisher=[[Dolby Laboratories]] |access-date=2009-12-12 |archive-date=2011-10-10 |archive-url=https://web.archive.org/web/20111010062942/http://www.dolby.com/consumer/understand/creation/dolby-digital-recording.html |url-status=dead }}</ref> Dolby Digital Cinema,<ref>{{cite web |url=http://www.dolby.com/consumer/technology/dolby-digital-cinema-details.html |title=Dolby – Dolby Digital Cinema Details |publisher=[[Dolby Laboratories]] |access-date=2009-08-29 |archive-date=2012-03-09 |archive-url=https://web.archive.org/web/20120309010006/http://www.dolby.com/consumer/technology/dolby-digital-cinema-details.html |url-status=dead }}</ref> Dolby Digital Stereo Creator<ref>{{cite web |url=http://www.dolby.com/consumer/technology/dolby-digital-stereo-creator-details.html |title=Dolby – Dolby Digital Stereo Creator Details |publisher=[[Dolby Laboratories]] |access-date=2009-08-29 |archive-date=2012-03-09 |archive-url=https://web.archive.org/web/20120309010003/http://www.dolby.com/consumer/technology/dolby-digital-stereo-creator-details.html |url-status=dead }}</ref> and Dolby Digital 5.1 Creator.<ref>{{cite web |url=http://www.dolby.com/consumer/technology/dolby_creator.html |title=Dolby – What is Dolby Digital 5.1 Creator? |publisher=[[Dolby Laboratories]] |access-date=2009-08-29 |archive-date=2012-03-09 |archive-url=https://web.archive.org/web/20120309005951/http://www.dolby.com/consumer/technology/dolby_creator.html |url-status=dead }}</ref>

===Dolby AC-3===
{{Infobox file format
|name = Dolby AC-3
|extension = .ac3
|mime = audio/ac3
|uniform type = public.ac3-audio<ref>{{cite web |url=https://developer.apple.com/documentation/avfoundation/avfiletypeac3 |title=AVFileTypeAC3 |work=Apple Developer Documentation |publisher=[[Apple Inc]]}}</ref>
}}
[[File:Dolbytrailerdvd07.png|thumb|right|The former Dolby Digital logo, entitled "Aurora", that was sometimes shown at the start of broadcasts, feature films, and video games]]
[[File:Dolby Digital old logo.svg|thumb|The old Dolby Digital logo]]

'''Dolby AC-3''' (a [[backronym]] for Audio Codec 3, Advanced Codec 3, or Acoustic Coder 3), also known as '''[[ATSC]] A/52''' (name of the standard)<ref>{{cite web |url=http://www.atsc.org/cms/index.php/standards/published-standards/48-atsc-a52-standard |title=A/52B: Digital Audio Compression (AC-3) (E-AC-3) Standard, Rev. B |publisher=[[Advanced Television Systems Committee]] |access-date=2010-08-06 |archive-url=https://web.archive.org/web/20100918151932/http://atsc.org/cms/index.php/standards/published-standards/48-atsc-a52-standard |archive-date=2010-09-18 |url-status=dead }}</ref> or simply '''Dolby Digital''' ('''DD'''), is the common version containing up to six discrete channels of sound. Before 1996 it was marketed as '''Dolby Surround AC-3''', '''Dolby Stereo Digital''', and '''Dolby SRD'''.<ref name=":0">{{cite web|url=http://www.spannerworks.net/reference/10_3a.asp|archive-url=https://web.archive.org/web/20050311043636/http://www.spannerworks.net/reference/10_3a.asp|url-status=usurped|archive-date=March 11, 2005|title=Movie Sound Chronology|website=spannerworks.net|access-date=2017-04-02}}</ref>

The most elaborate mode of this codec in common use involves five channels for normal-range speakers ({{nowrap|20 Hz – 20,000 Hz}}) (right, center, left, right surround, left surround) and one channel ({{nowrap|20 Hz – 120 Hz}} allotted audio) for the [[subwoofer]] driven [[low-frequency effects]].<ref>{{cite web |url=http://www.dolby.com/uploadedFiles/Assets/US/Doc/Professional/42_DDFAQ.pdf|title=Dolby-Frequently Asked Questions |publisher=[[Dolby Laboratories]]}}</ref> [[monaural|Mono]] and [[stereo]] modes are also supported. AC-3 supports audio sample rates up to 48&nbsp;kHz.

In 1991, a limited experimental release of ''[[Star Trek VI: The Undiscovered Country]]'' in Dolby Digital played in 3 US theatres.<ref name=":0" /> In 1992, ''[[Batman Returns]]'' was the first movie to be released and presented in Dolby Digital.<ref name=":1">{{cite web|url=https://www.dolby.com/us/en/about/history.html|title=History: 50 YEARS OF INNOVATION|website=Dolby Laboratories|access-date=2017-03-22}}</ref><ref>{{Cite news|url=https://www.chicagotribune.com/1992/05/13/batman-returns-to-try-double-dolby/|title='Batman Returns' To Try Double Dolby|date=May 13, 1992|work=The Chicago Tribune|access-date=2017-03-22}}</ref> In 1995, the [[LaserDisc]] version of ''[[Clear and Present Danger (film)|Clear and Present Danger]]'' featured the first [[home theater]] Dolby Digital mix, quickly followed by ''[[True Lies]]'', ''[[Stargate (film)|Stargate]]'', ''[[Forrest Gump]]'', and ''[[Interview with the Vampire (film)|Interview with the Vampire]]'' among others.<ref>{{cite web|url=http://www.lddb.com/list.php?format=ld&list=ac3&start=75&sort=date,asc|title=Laserdisc Database Search By Date|website=Laserdisc Database|access-date=2017-04-02}}</ref><ref>{{cite web|url=http://www.lddb.com/laserdisc/21521/LV-32463-2WS/Clear-and-Present-Danger|title=LaserDisc Database Clear and Present Danger|website=LaserDisc Database|access-date=2017-04-02}}</ref>

=== Dolby Digital Surround EX ===
Dolby Digital Surround EX (sometimes shortened to Dolby Digital EX) is similar to Dolby's earlier [[Pro Logic]] format, which utilized [[matrix (sound recording)|matrix]] technology to add a [[center surround channel]] and single rear surround channel to stereo soundtracks.<ref>{{cite web |url=https://aes2.org/publications/par/num/ |title=Pro Audio Reference |at=6.1 |access-date=2024-08-08}}</ref> EX adds an extension to the standard [[5.1]] channel Dolby Digital codec in the form of matrixed rear channels, creating [[6.1]] or 7.1 channel output.

It provides an economical and backwards-compatible means for 5.1 soundtracks to carry a sixth, center-back surround channel for improved localization of effects. The [[extra surround channel]] is matrix encoded onto the discrete ''left surround'' and ''right surround'' channels of the 5.1 mix, much like the front [[center channel]] on Dolby Pro Logic encoded stereo soundtracks. The result can be played without loss of information on standard 5.1 systems or played in 6.1 or 7.1 on systems with Surround EX decoding and added speakers. A number of DVDs have a Dolby Digital Surround EX audio option.

The theater version of ''Dolby Digital Surround EX'' was introduced in 1999, when Dolby and [[THX]], a division of [[Lucasfilm Ltd.]], co-developed ''Dolby Digital Surround EX''™ for the release of ''[[Star Wars: Episode I – The Phantom Menace]]''.<ref name=":1" /><ref name=":2">{{cite web|url=http://investor.dolby.com/ReleaseDetail.cfm?releaseid=164165|title=Dolby Launches Dolby Digital Cinema in Theatres Worldwide with Star Wars Episode III: Revenge of the Sith|website=Dolby Investor Relations|access-date=2017-03-22 |author1=Nurun }}</ref> Dolby Digital Surround EX has since been used on the DVD releases of the ''Star Wars'' prequel and original trilogies.<ref name=":2" />
[[File:Dolby Near.JPG|thumb|upright|A Dolby home theater badge on a laptop computer]]

=== Dolby Digital Live ===
Dolby Digital Live (DDL) is a real-time encoding technology for interactive media such as video games. It converts any audio signals on a PC or game console into a 5.1-channel 16-bit/48&nbsp;kHz Dolby Digital format at {{nowrap|640 kbit/s}} and transports it via a single [[S/PDIF]] cable.<ref name="DDL">{{cite web|title=Dolby Digital Live|url=http://www.dolby.com/consumer/technology/dolby_live.html|url-status=dead|archive-url=https://web.archive.org/web/20070208012537/http://www.dolby.com/consumer/technology/dolby_live.html|archive-date=Feb 8, 2007|access-date=Nov 16, 2021|website=dolby.com|publisher=[[Dolby Laboratories]]}}</ref> A similar technology known as [[DTS Connect]] is available from competitor [[DTS (sound system)|DTS]]. An important benefit of this technology is that it enables the use of digital multichannel sound with consumer sound cards, which are otherwise limited to digital [[PCM]] stereo or analog multichannel sound because S/PDIF over RCA, BNC, and TOSLINK can only support two-channel PCM, Dolby Digital multichannel audio, and DTS multichannel audio. [[HDMI]] was later introduced, and it can carry uncompressed multichannel PCM, lossless compressed multichannel audio, and lossy compressed digital audio. However, Dolby Digital Live is still useful with HDMI to allow transport of multichannel audio over HDMI to devices that are unable to handle uncompressed multichannel PCM.

Dolby Digital Live is available in sound cards using various manufacturers' audio chipsets. The [[SoundStorm]], used for the [[Xbox (console)|Xbox]] game console and certain [[nForce2]] motherboards, used an early form of this technology. DDL is available on motherboards with codecs such as [[Realtek]]'s ALC882D,<ref name=ddl882>{{cite web |url=http://www.anandtech.com/printarticle.aspx?i=2773 |title=Nvidia nForce 500: Biostar and MSI Aim for the Gold |publisher=[[AnandTech]]| first=Gary | last=Key| date=June 8, 2006}}</ref> ALC888DD and ALC888H. Other examples include some [[C-Media]] PCI sound cards and Creative Labs' X-Fi and Z series sound cards, whose drivers have enabled support for DDL.

NVIDIA later decided to drop DDL support in their motherboards due to the cost of involved royalties, leaving an empty space in this regard in the sound cards market.
Then in June 2005 came [[Auzentech]], which with its X-Mystique PCI card, provided the first consumer sound card with Dolby Digital Live support.

Initially, no Creative X-Fi-based sound cards supported DDL (2005~2007) but a collaboration of Creative and [[Auzentech]] resulted in the development of the Auzentech Prelude, the first X-Fi card to support DDL. Originally planned to extend DDL support to all X-Fi-based sound cards (except the 'Xtreme Audio' line which is incapable of DDL hardware implementation), the plan was dropped because Dolby licensing would have required a royalty payment for all X-Fi cards and, problematically, those already sold.<ref name="DDL license issue of X-Fi">{{cite web |url=http://www.parkoz.com/zboard/view.php?id=dm_audio_qna&no=15261 |title=A Korean reply comment (the fifth), which explains Dolby license royalty issue of X-Fi. Since the information leaked from SoundPrime, the Korean partner of Auzentech, all sources about this information are Korean. |access-date=2009-11-27 |archive-date=2015-09-24 |archive-url=https://web.archive.org/web/20150924064328/http://www.parkoz.com/zboard/view.php?id=dm_audio_qna&no=15261 |url-status=dead }}</ref>
In 2008, Creative released the X-Fi Titanium series of sound cards which fully supports Dolby Digital Live while leaving all PCI versions of Creative X-Fi still lacking support for DDL.

Since September 2008, all Creative X-Fi-based sound cards support DDL (except the 'Xtreme Audio' and its derivatives such as Prodigy 7.1e, which is incapable of DDL in hardware). [[X-Fi (audio chip)|X-Fi]]'s case differs.

While they forgot about the plan, programmer Daniel Kawakami made a hot issue by applying Auzentech Prelude DDL module back to Creative X-Fi cards by disguising the hardware identity as Auzentech Prelude.<ref>{{cite web |url=http://www.parkoz.com/zboard/view.php?id=dm_audio_qna&no=12661 |title=What Daniel_K wrote "This utility was written from scratch and does not contain any copyrighted code. Creative's director of developer relations, George Thorn told me, in a chat session, that is OK to provide mods as patches. It does not modify any executable or DLL, so it is NOT a crack." Daniel_K's driver MOD itself did not include any DDL module, until it began to support Creative's official DDL pack. Daniel_K's 'DDLUnlocker.exe' merely used disguise to install Auzentech Prelude DDL module}}</ref>

Creative Labs alleged Kawakami violated their intellectual property and demanded he cease distributing his modified drivers.<ref>{{cite web |url=http://blog.wired.com/gadgets/2008/04/daniel_k-who-fi.html |title=Daniel_K, Who Fixed Creative's Broken Vista Drivers, Speaks Out |website=Wired.com | first=Rob| last=Beschizza| date=April 1, 2008}}</ref><ref name=BrokenBlaster>{{cite web |url=http://forums.creative.com/t5/Sound-Blaster/SB-Audigy-Series-Support-Pack-3-6-11-09-2009/td-p/540934/page/2 |title=There is BrokenBlaster blame about CL – Creative Labs, its much later than the issue but show common case who blame Creative Labs and admire Daniel_K |publisher=[[Creative Technology]]}}</ref><ref name=daniel_k_2>{{cite magazine |url=http://blog.wired.com/gadgets/2008/03/silence-from-so.html |title=Silence From Sound Card Maker After Customer Revolt |magazine=[[Wired (magazine)|Wired]]| first=Rob | last=Beschizza | date=March 31, 2008}}</ref>

Eventually Creative struck an agreement with Dolby Laboratories regarding the Dolby license royalty by arranging that the licensing cost be folded into the purchase price of the Creative X-Fi PCI cards rather than as a royalty paid by Creative themselves.<ref name="DDL license issue of X-Fi"/> Based on the agreement, in September 2008 Creative began selling the ''Dolby Digital Live'' packs enabling Dolby Digital Live on Creative's X-Fi PCI series of sound cards. It can be purchased and downloaded from Creative. Subsequently, Creative added their ''DTS Connect'' pack to the DDL pack at no added cost.<ref name="Dolby Digital Live pack">{{cite web |url=http://buy.soundblaster.com/_creativelabsstore/cgi-bin/pd.cgi?frompage=category&page=product_detail&fromcategory=Software&category=Software&pid=F2222DDN6Z2H2ADDEZD |title=Dolby Digital Live pack, its DDL pack but also say "Get DTS Connect Pack FREE! for every purchase of Dolby Digital Live Pack." |publisher=[[Creative Technology]]}}</ref>

=== Dolby Digital Plus ===
{{Main|Dolby Digital Plus}}
{{Infobox file format
|name = Dolby E-AC-3
|extension = 
|mime = audio/eac3
|uniform type = public.enhanced-ac3-audio<ref>{{cite web |url=https://developer.apple.com/documentation/avfoundation/avfiletypeenhancedac3 |title=AVFileTypeEnhancedAC3 |work=Apple Developer Documentation |publisher=[[Apple Inc]]}}</ref>
}}
E-AC-3 (Dolby Digital Plus) is an enhanced coding system based on the AC-3 [[codec]]. It offers increased [[bit rate]]s (up to {{nowrap|6.144 Mbit/s}}), support for even more [[audio channel]]s (up to 15.1 discrete channels<ref>{{Cite web|url=https://www.dolby.com/us/en/technologies/dolby-digital-plus-audio-coding-tech-paper.pdf|title=Dolby Digital Plus Audio Coding Tech Paper|access-date=2017-04-24|archive-date=2019-05-02|archive-url=https://web.archive.org/web/20190502061841/https://www.dolby.com/us/en/technologies/dolby-digital-plus-audio-coding-tech-paper.pdf|url-status=dead}}</ref> in the future), and improved coding techniques (only at low data rates) to reduce [[compression artifacts]], enabling lower data rates than those supported by AC-3 (e.g. 5.1-channel audio at {{nowrap|256 kbit/s}}). It is not backward compatible with existing AC-3 hardware, though E-AC-3 [[codec]]s generally are capable of [[transcoding]] to AC-3 for equipment connected via [[S/PDIF]]. E-AC-3 decoders can also decode AC-3 bitstreams. The fourth generation Apple TV supports E-AC-3.<ref>{{cite web|url=https://www.apple.com/tv/specs/|title=Apple TV – Tech Specs|access-date=1 January 2017}}</ref> The discontinued [[HD DVD]] system directly supported E-AC-3. [[Blu-ray Disc]] offers E-AC-3 as an option to [[wikt:graft|graft]] added channels onto an otherwise [[5.1]] AC-3 stream, as well as for delivery of secondary audio content (e.g. director's commentary) that is intended to be mixed with the primary audio soundtrack in the Blu-ray Disc player.

=== Dolby AC-4 ===
{{main|Dolby AC-4}}

Dolby AC-4 is an audio compression standard supporting multiple audio channels and/or audio objects. Support for 5.1 channel audio is mandatory and additional channels up to 7.1.4 are optional.<ref name=DolbyAC4ServicesJune2015Dolby>{{cite news |title=Dolby AC-4: Audio Delivery for Next-Generation Entertainment Services |publisher=[[Dolby Laboratories]] |url=http://www.dolby.com/us/en/technologies/ac-4/Next-Generation-Entertainment-Services.pdf |date=2015-06-01 |access-date=2016-04-26 |archive-date=2019-05-30 |archive-url=https://web.archive.org/web/20190530051301/https://www.dolby.com/us/en/technologies/ac-4/Next-Generation-Entertainment-Services.pdf |url-status=dead }}</ref> AC-4 provides a 50% reduction in bit rate over AC-3/[[Dolby Digital Plus]].<ref name=DolbyAC4ServicesJune2015Dolby/>

=== Dolby TrueHD ===
{{Main|Dolby TrueHD}}
Dolby TrueHD, developed by Dolby Laboratories, is an advanced lossless audio codec based on [[Meridian Lossless Packing]]. Support for the codec was mandatory for HD DVD and is optional for [[Blu-ray Disc]] hardware. Dolby TrueHD supports 24-bit bit depths and sample rates up to 192 kHz. Maximum bit rate is {{nowrap|18 Mbit/s}} while it supports up to 16 audio channels (HD DVD and Blu-ray Disc standards currently limit the maximum number of audio channels to eight). It supports metadata, including dialog normalization and Dynamic Range Control.