Versions Dolby Digital

1 versions

1.1 dolby digital
1.2 dolby digital ex
1.3 dolby digital surround ex
1.4 dolby digital live
1.5 dolby digital plus
1.6 dolby ac-4
1.7 dolby truehd

versions

dolby digital has similar technologies, included in dolby digital ex, dolby digital live, dolby digital plus, dolby digital surround ex, dolby digital recording, dolby digital cinema, dolby digital stereo creator , dolby digital 5.1 creator.

dolby digital

dolby digital logo shown @ start of broadcasts, feature films, , video games



the former dolby digital logo

dolby digital common version containing 6 discrete channels of sound. elaborate mode in common use involves 5 channels normal-range speakers (20 hz – 20,000 hz) (right, center, left, right surround, left surround) , 1 channel (20 hz – 120 hz allotted audio) subwoofer driven low-frequency effects. mono , stereo modes supported. ac-3 supports audio sample-rates 48 khz.

this format has different names:

dolby digital
dd (an abbreviation dolby digital, combined channel count; instance, dd 2.0, dd 5.1)
ac-3 (audio codec 3, advanced codec 3, acoustic coder 3. [these backronyms. adaptive transform acoustic coding 3 separate format developed sony.])
atsc a/52 (name of standard)
before 1996, marketed dolby surround ac-3, dolby stereo digital, , dolby srd.

in 1991, limited experimental release of star trek 6 in dolby digital played in 3 theatres. in 1992, batman returns first movie released in dolby digital. in 1995, laserdisc version of clear , present danger featured first home theater dolby digital mix, followed true lies, stargate, forest gump, , interview vampire among others.

dolby digital ex

dolby digital ex similar in practice dolby s earlier pro-logic format, utilized matrix technology add center surround channel , single rear surround channel stereo soundtracks. ex adds extension standard 5.1 channel dolby digital codec in form of matrixed rear channels, creating 6.1 or 7.1 channel output.

dolby digital surround ex

it provides economical , backwards-compatible means 5.1 soundtracks carry sixth, center surround channel improved localization of effects. surround channel matrix encoded onto discrete left surround , right surround channels of 5.1 mix, front center channel on dolby pro logic encoded stereo soundtracks. result can played without loss of information on standard 5.1 systems, or played in 6.1 or 7.1 on systems surround ex decoding , added speakers. dolby digital surround ex has since been used star wars prequels on dvd versions , remastered original star wars trilogy. number of dvds have dolby digital surround ex audio option.

the cinema version of dolby digital ex introduced in 1999, when dolby , skywalker sound, division of lucasfilm ltd., codeveloped dolby digital surround ex™ release of star wars: episode – phantom menace. dolby digital surround ex has since been used star wars prequels on dvd versions , remastered original star wars trilogy.

a dolby home theater badge on laptop


dolby digital live

dolby digital live (ddl) real-time encoding technology interactive media such video games. converts audio signals on pc or game console 5.1-channel 16-bit/48 khz dolby digital format @ 640 kbit/s , transports via single s/pdif cable. similar technology known dts connect available competitor dts. important benefit of technology enables use of digital multichannel sound consumer sound cards, otherwise limited digital pcm stereo or analog multichannel sound because s/pdif on rca, bnc, , toslink can support two-channel pcm, dolby digital multichannel audio, , dts multichannel audio. hdmi later introduced, , can carry uncompressed multichannel pcm, lossless compressed multichannel audio, , lossy compressed digital audio. however, dolby digital live still useful hdmi allow transport of multichannel audio on hdmi devices unable handle uncompressed multichannel pcm.

dolby digital live available in sound cards using various manufacturers audio chipsets. soundstorm, used xbox game console , nforce2 motherboards, used form of technology. ddl available on motherboards codecs such realtek s alc882d, alc888dd , alc888h. other examples include c-media pci sound cards , creative labs x-fi , z series sound cards, drivers have enabled support ddl.

nvidia later decided drop ddl support in motherboards due cost of involved royalties, leaving empty space in regard in sound cards market. in june 2005 came auzentech, x-mystique pci card, provided first consumer sound card dolby digital live support.

initially no creative x-fi based sound cards supported ddl (2005~2007) collaboration of creative , auzentech resulted in development of auzentech prelude, first x-fi card support ddl. planned extend ddl support x-fi based sound cards (except xtreme audio line incapable of ddl hardware implementation), plan dropped because dolby licensing have required royalty payment x-fi cards and, problematically, sold. in 2008, creative released x-fi titanium series of sound cards supports dolby digital live while leaving pci versions of creative x-fi still lacking support ddl.

since september 2008, creative x-fi based sound cards support ddl (except xtreme audio , based line such prodigy 7.1e, incapable of ddl in hardware). x-fi s case differs.

while forgot plan, programmer daniel kawakami made hot issue applying auzentech prelude ddl module creative x-fi cards disguising hardware identity auzentech prelude.

creative labs alleged kawakami violated intellectual property , demanded cease distributing modified drivers.

eventually creative struck agreement dolby laboratories regarding dolby license royalty arranging licensing cost folded purchase price of creative x-fi pci cards rather royalty paid creative themselves. based on agreement, in september 2008 creative began selling dolby digital live packs enabling dolby digital live on creative s x-fi pci series of sound cards. can purchased , downloaded creative. subsequently creative added dts connect pack ddl pack @ no added cost.

dolby digital plus

e-ac-3 (dolby digital plus) enhanced coding system based on ac-3 codec. offers increased bitrates (up 6.144 mbit/s), support more audio channels (up 15.1 discrete channels in future), , improved coding techniques (only @ low data rates) reduce compression artifacts, enabling lower data rates supported ac-3 (e.g. 5.1-channel audio @ 256 kbit/s). not backward compatible existing ac-3 hardware, though e-ac-3 codecs capable of transcoding ac-3 equipment connected via s/pdif. e-ac-3 decoders can decode ac-3 bitstreams. fourth generation apple tv supports e-ac-3. discontinued hd dvd system directly supported e-ac-3. blu-ray disc offers e-ac-3 option graft added channels onto otherwise 5.1 ac-3 stream, delivery of secondary audio content (e.g. director s commentary) intended mixed primary audio soundtrack in blu-ray disc player.

dolby ac-4

dolby ac-4 audio compression standard supporting multiple audio channels and/or audio objects. support 5.1 channel audio mandatory , additional channels 7.1.4 optional. ac-4 provides 50% reduction in bit rate on ac-3/dolby digital plus.

dolby truehd

dolby truehd, developed dolby laboratories, advanced lossless audio codec based on meridian lossless packing. support codec mandatory hd dvd , optional blu-ray disc hardware. dolby truehd supports 24-bit, 96 khz audio channels @ 18 mbit/s on 14 channels (hd dvd , blu-ray disc standards limit maximum number of audio channels eight). supports metadata, including dialog normalization , dynamic range control.