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{{Short description|Lossless audio codec for home theater}}
{{Refimprove|date=January 2019 |talk=Ref Improve}}
{{Infobox product}}


'''DTS-HD Master Audio''' ('''DTS-HD MA'''; known as '''DTS++''' before 2004<ref name=":0">{{cite web|last=Thomson|first=Kristin|date=2004-11-01|title=DTD Unveils DTS-HD Brand For High Definition Media Formats|url=http://news.ecoustics.com/bbs/messages/10381/107453.html|access-date=2009-05-06}}</ref>) is a [[Surround sound|multi-channel]], [[Lossless data compression|lossless]] audio [[codec]] developed by [[DTS (sound system)|DTS]] as an extension of the [[Lossy compression|lossy]] [[DTS (sound system)#DTS Digital Surround|DTS Coherent Acoustics]] codec (DTS CA; usually itself referred to as just DTS). Rather than being an entirely new coding mechanism, DTS-HD MA encodes an audio master in lossy DTS first, then stores a concurrent stream of supplementary data representing whatever the DTS encoder discarded. This gives DTS-HD MA a lossy "core" able to be played back by devices that cannot decode the more complex lossless audio. DTS-HD MA's primary application is audio storage and playback for [[Blu-ray|Blu-ray Disc]] media; it competes in this respect with [[Dolby TrueHD]], another lossless surround format.
[[File:DTS-HD-MA.svg|180px|thumb|right|DTS-HD Master Audio logo]]
'''DTS-HD Master Audio''' ('''DTS-HD MA''') is a combined [[Lossless data compression|lossless]]/[[Lossy compression|lossy]] audio [[codec]] created by [[DTS (sound system)|DTS]] (formerly [[Digital Theater Systems]]), commonly used for surround-sound movie soundtracks on [[Blu-ray Disc]].It was (developed) by [[Google]].


== History ==
== Specifications ==
DTS-HD MA can store up to 8 discrete channels of audio ([[7.1 surround sound|7.1 surround]]) at up to a 24 bit [[Audio bit depth|sample depth]] and 192&nbsp;kHz [[Sampling (signal processing)#Sampling rate|sampling frequency]] (96&nbsp;kHz for 6.1 or 7.1 surround).<ref>{{cite web|date=January 10, 2012|title=DTS-HD Master Audio Specifications (DTS-HD Master Audio™ - DTS)|url=http://www.dts.com/professionals/sound-technologies/codecs/dts-hd-master-audio.aspx|url-status=dead|archive-url=https://web.archive.org/web/20120110052802/http://www.dts.com/professionals/sound-technologies/codecs/dts-hd-master-audio.aspx|archive-date=January 10, 2012|access-date=January 10, 2012|df=mdy-all}}</ref> Although DTS-HD MA, and the related DTS-HD, allow virtually any number of channels in the abstract,<ref>{{cite web|last=Morrison|first=Geoffrey|date=September 23, 2009|title=Dolby Pro Logic IIz vs. Audyssey DSX vs. DTS|url=http://www.hemagazine.com/Dolby_Pro_Logic_IIz_vs_Audyssey_DSX?page=0%2C3|url-status=dead|archive-url=https://web.archive.org/web/20101010011429/http://www.hemagazine.com/Dolby_Pro_Logic_IIz_vs_Audyssey_DSX?page=0%2C3|archive-date=2010-10-10|access-date=November 15, 2010|work=Home Entertainment|quote=DTS-HD can natively support over 2,000 individual channels, so according to DTS adding any number of discrete height channels would be easy.}}</ref> these limits are imposed for practical reasons of limited storage and [[Bit rate|bitrate]] availability. A DTS-HD MA bitstream may have a bitrate no greater than 24.5&nbsp;Mbit/s (instantaneous), of which no greater than 1.5&nbsp;Mbit/s may be lossy DTS (as per the DTS CA specification).<ref name="DTS-demos">{{cite web|last=DeBoer|first=Clint|date=2007-06-04|title=DTS Demos Master Audio via PC|url=https://www.audioholics.com/news/dts-demos-master-audio-via-pc.html|access-date=2019-01-01|website=Audioholics Online A/V Magazine|quote=DTS-HD Master Audio delivers sound that is bit-for-bit identical to the studio master. It can deliver audio at variable bit rates which are significantly higher than standard DVDs. DTS-HD Master Audio can provide up to 7.1 audio channels at a 96k sampling frequency / 24-bit depth or 5.1 audio channels at 192 kHz that are identical to the original master. The DTS-HD Master Audio bit stream also contains the DTS 1.5 Mbps core for backwards compatibility with existing DTS-enabled home theater systems, and delivery of 5.1 channels of sound at twice the resolution found on most standard DVDs.}}</ref>
DTS-HD Master Audio is an extension of DTS' previous [[DTS Coherent Acoustics]] codec. Prior to 2004, it had been known as ''DTS++''.<ref>{{cite web|last=Thomson |first=Kristin|title=DTD Unveils DTS-HD Brand For High Definition Media Formats|url=http://news.ecoustics.com/bbs/messages/10381/107453.html|work=|publisher=|date=2004-11-01|accessdate=2009-05-06}}</ref> Though it is an optional audio format for [[Blu-ray Disc]] format, by 2010, it had become the dominant Blu-ray lossless audio format over its competitor [[Dolby TrueHD]].<ref>{{cite web |url=http://www.blu-raystats.com/NewsLog/2010/01/15/dts-hd-master-audio-becoming-the-blu-ray-standard/ |title=DTS-HD Master Audio Becoming the Blu-ray Standard |author="Dave" |date=January 15, 2010 |work=Blu-raystats.com |accessdate=November 15, 2010}}</ref> DTS-HD Master Audio is also the carrier for home delivery of DTS:X. Users can create DTS-HD Master Audio content using the DTS:X encoder suite,<ref>{{cite web|title=DTS:X(R) Encoder Suite|url=http://dts.com/shop/dtsx-encoder-suite-0|website=DTS.com|access-date=2019-01-01 }}</ref> or the legacy DTS-HD Master Audio Suite.<ref>{{cite web|title=DTS-HD Master Audio Suite(TM)|url=http://dts.com/shop/dts-hd-master-audio-suite|access-date=2019-01-01|archive-url=https://web.archive.org/web/20180304031225/http://dts.com/shop/dts-hd-master-audio-suite|archive-date=2018-03-04|dead-url=yes|df=}}</ref>


The [[Blu-ray]] specification stipulates DTS-HD MA as an optional codec, which means that some Blu-ray hardware may not decode it. This is the reason for the bifurcated nature of a DTS-HD MA audio stream; DTS CA, unlike its MA extension, is mandatory, so a player that is not MA-capable can automatically default to an MA-encoded disc's base DTS stream and simply ignore the supplementary data.<ref name="DTS-demos" /> Alternatively, even if a player is MA-capable, the base stream may be needed for [[backward compatibility]] with an older [[AV receiver]] (for example, one manufactured during the [[DVD]] era).<ref>{{Cite web|title=DTS-HD Master Audio: What You Need to Know|url=https://www.lifewire.com/dts-hd-master-audio-1846891|url-status=live|website=Lifewire|archive-url=https://web.archive.org/web/20190317224002/https://www.lifewire.com/dts-hd-master-audio-1846891 |archive-date=2019-03-17 }}</ref>
== Features ==
DTS-HD Master Audio is a lossless compression codec containing a lossy DTS Digital core, thus allowing for bit-to-bit representation of the original movie's master soundtrack. DTS-HD Master Audio supports variable bit rates up to 24.5 Mbit/s. The format supports a maximum of 192&nbsp;kHz sampling frequency and 24-bit depth samples from 2 to 5.1 channels, and 96&nbsp;kHz/24bit resolution up to 7.1 channels.<ref>{{cite web|url=http://www.dts.com/professionals/sound-technologies/codecs/dts-hd-master-audio.aspx|title=DTS-HD Master Audio Specifications (DTS-HD Master Audio™ - DTS)|date=January 10, 2012|access-date=January 10, 2012|archive-url=https://web.archive.org/web/20120110052802/http://www.dts.com/professionals/sound-technologies/codecs/dts-hd-master-audio.aspx|archive-date=January 10, 2012|dead-url=yes|df=mdy-all}}</ref><ref name="DTS-demos">{{cite web |url=https://www.audioholics.com/news/dts-demos-master-audio-via-pc.html |title=DTS Demos Master Audio via PC |last=DeBoer |first=Clint |date=2007-06-04 |website=Audioholics Online A/V Magazine |access-date=2019-01-01 |quote=
DTS-HD Master Audio delivers sound that is bit-for-bit identical to the studio master. It can deliver audio at variable bit rates which are significantly higher than standard DVDs. DTS-HD Master Audio can provide up to 7.1 audio channels at a 96k sampling frequency / 24-bit depth or 5.1 audio channels at 192 kHz that are identical to the original master. The DTS-HD Master Audio bit stream also contains the DTS 1.5 Mbps core for backwards compatibility with existing DTS-enabled home theater systems, and delivery of 5.1 channels of sound at twice the resolution found on most standard DVDs.}}</ref> DTS-HD Master Audio is capable of virtually any number of discrete channels but is limited by storage media.<ref>{{cite web |url=http://www.hemagazine.com/Dolby_Pro_Logic_IIz_vs_Audyssey_DSX?page=0%2C3 |title=Dolby Pro Logic IIz vs. Audyssey DSX vs. DTS |last=Morrison |first=Geoffrey |date=September 23, 2009 |work=Home Entertainment |accessdate=November 15, 2010 |archive-url=https://web.archive.org/web/20101010011429/http://www.hemagazine.com/Dolby_Pro_Logic_IIz_vs_Audyssey_DSX?page=0%2C3 |archive-date=2010-10-10 |dead-url=yes |quote=DTS-HD can natively support over 2,000 individual channels, so according to DTS adding any number of discrete height channels would be easy.}}</ref>


As a 3D audio delivery format, a DTS:X encoded DTS-HD Master Audio stream is able to contain up to 7.1 channels as well as nine objects and its associated metadata at 96 kHz/24 bit.<ref>{{Cite web|url=http://www.digitaltrends.com/home-theater/dts-dtsx-object-based-surround-sound-system-released/#:YiLfabxBaGSrSA|title=Lookout Dolby Atmos, DTS just entered the next era of surround sound with DTS:X|date=2015-04-13|website=Digital Trends|first=Ryan |last=Waniata |language=en-US|access-date=2016-06-09}}</ref>
DTS-HD MA is the encoding format for [[DTS (sound system)#DTS:X|DTS:X]], an [[Sound object|object-based]] surround-sound format that competes with [[Dolby Atmos]]. A DTS-HD MA bitstream carrying DTS:X can contain up to 9 simultaneous sound objects, which are dynamically mapped to a user's speaker system during playback, unlike the rigid number and placement of speakers required by channel-based surround (a DTS marketing executive referred to DTS:X in an interview as "whatever.1").<ref>{{Cite web|last=Waniata|first=Ryan|date=2015-04-13|title=Lookout Dolby Atmos, DTS just entered the next era of surround sound with DTS:X|url=http://www.digitaltrends.com/home-theater/dts-dtsx-object-based-surround-sound-system-released/#:YiLfabxBaGSrSA|access-date=2016-06-09|website=Digital Trends|language=en-US}}</ref>


=== Combined lossless/lossy compression ===
=== Encoding process ===
DTS-HD MA is encoded in three steps. First, the audio master is fed to a DTS CA encoder, which generates the core (lossy) audio stream. Next, this lossy audio is decoded and compared to the master, with "residual" data being recorded wherever the two differ. Finally, the residual data is compressed losslessly and merged with the core into one bitstream. A DTS-HD MA decoder simply performs this process in reverse.<ref name="whitepaper">{{cite web|date=November 2006|title=DTS-HD Audio: Consumer White Paper for Blu-ray Disc Applications|url=https://www.fast-and-wide.com/images/stories/White_papers/dts_hd_whitepaper.pdf|access-date=2024-04-07}}</ref>
When played back on devices which do not support the Master Audio or [[DTS (sound system)#DTS-HD High Resolution Audio|High Resolution]] extension, it degrades to a "core" track which is [[Lossy compression|lossy]].<ref name="DTS-demos" />


DTS-HD MA audio, including DTS:X audio, can be created and edited using DTS's [https://dts.com/shop/dtsx-encoder-suite-0 DTS:X Encoder Suite]. The DTS-HD Master Audio Suite served the same function before the introduction of DTS:X, and can still be used for DTS-HD MA that does not carry DTS:X.<ref>{{cite web|title=DTS-HD Master Audio Suite(TM)|url=http://dts.com/shop/dts-hd-master-audio-suite|url-status=dead|archive-url=https://web.archive.org/web/20180304031225/http://dts.com/shop/dts-hd-master-audio-suite|archive-date=2018-03-04|access-date=2019-01-01}}</ref>
According to the DTS-HD White Paper,<ref name="whitepaper">{{cite web|title=DTS-HD Audio: Consumer White Paper for Blu-ray Disc Applications |url=http://www.dts.com/DownloadDocument.aspx?q=a7beda1e-cfe6-4ca4-b6b2-cda9554bb6a5 |work= |publisher= |date=November 2006 |accessdate=2009-05-06 }}{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> DTS-HD Master Audio contains 2 data streams: the original DTS core stream and the additional "residual" stream which contains the "difference" between the original signal and the lossy compression DTS core stream. The audio signal is split into two paths at the input to the encoder. One path goes to the core encoder for backwards compatibility and is then decoded. The other path compares the original audio to the decoded core signal and generates residuals, which are data over and above what the core contains that is needed to restore the original audio as bit-for-bit identical to the original. The residual data is then encoded by a lossless encoder and packed together with the core. The decoding process is simply the reverse.


== AV transport ==
== AV transport ==
DTS-HD Master Audio may be transported to AV receivers in [[5.1 surround sound|5.1]], 6.1 or [[7.1 surround sound|7.1]] channels, at [[Lossless audio#Lossless audio compression|lossless]] quality, in one of three ways depending on player and/or receiver support:<ref name="whitepaper" />
DTS-HD Master Audio may be transported to [[AV receiver]]s in [[5.1 surround sound|5.1]], 6.1, or [[7.1 surround sound|7.1]] channels, in full quality, in one of three ways depending on player and/or receiver support:<ref name="whitepaper" />
*Over 6, 7 or 8 [[RCA connector]]s as analog audio (not lossless), using the player's internal decoder and [[digital-to-analog converter]] (DAC).
*Over 6, 7 or 8 [[RCA connector]]s as analog audio, using the player's internal decoder and [[digital-to-analog converter]] (DAC).
*Over [[HDMI]] 1.1 (or higher) connections as 6-, 7- or 8-channel [[Linear pulse code modulation|linear PCM]], using the player's decoder and the AV receiver's DAC.
*Over [[HDMI]] 1.1 (or higher) connections as 6-, 7-, or 8-channel [[linear PCM]], using the player's decoder and the AV receiver's DAC.
*Over HDMI 1.3 (or higher) connections as the original DTS-HD Master Audio bitstream, with decoding and DAC both done by the AV receiver.
*Over HDMI 1.3 (or higher) connections as the original DTS-HD Master Audio bitstream, with decoding and DAC both done by the AV receiver. (This is the transport mode required for DTS:X playback.)
[[S/PDIF]] does not have the bandwidth to carry DTS-HD MA (or PCM in more than 2 channels). A setup using S/PDIF audio may output DTS-HD MA as either lossy DTS (which S/PDIF can carry) or downmixed [[Stereophonic sound|stereo]] PCM.

== See also ==
*[[Dolby TrueHD]], a competing audio codec


== References ==
== References ==

Latest revision as of 10:43, 11 September 2024

DTS-HD Master Audio

DTS-HD Master Audio (DTS-HD MA; known as DTS++ before 2004[1]) is a multi-channel, lossless audio codec developed by DTS as an extension of the lossy DTS Coherent Acoustics codec (DTS CA; usually itself referred to as just DTS). Rather than being an entirely new coding mechanism, DTS-HD MA encodes an audio master in lossy DTS first, then stores a concurrent stream of supplementary data representing whatever the DTS encoder discarded. This gives DTS-HD MA a lossy "core" able to be played back by devices that cannot decode the more complex lossless audio. DTS-HD MA's primary application is audio storage and playback for Blu-ray Disc media; it competes in this respect with Dolby TrueHD, another lossless surround format.

Specifications

[edit]

DTS-HD MA can store up to 8 discrete channels of audio (7.1 surround) at up to a 24 bit sample depth and 192 kHz sampling frequency (96 kHz for 6.1 or 7.1 surround).[2] Although DTS-HD MA, and the related DTS-HD, allow virtually any number of channels in the abstract,[3] these limits are imposed for practical reasons of limited storage and bitrate availability. A DTS-HD MA bitstream may have a bitrate no greater than 24.5 Mbit/s (instantaneous), of which no greater than 1.5 Mbit/s may be lossy DTS (as per the DTS CA specification).[4]

The Blu-ray specification stipulates DTS-HD MA as an optional codec, which means that some Blu-ray hardware may not decode it. This is the reason for the bifurcated nature of a DTS-HD MA audio stream; DTS CA, unlike its MA extension, is mandatory, so a player that is not MA-capable can automatically default to an MA-encoded disc's base DTS stream and simply ignore the supplementary data.[4] Alternatively, even if a player is MA-capable, the base stream may be needed for backward compatibility with an older AV receiver (for example, one manufactured during the DVD era).[5]

DTS-HD MA is the encoding format for DTS:X, an object-based surround-sound format that competes with Dolby Atmos. A DTS-HD MA bitstream carrying DTS:X can contain up to 9 simultaneous sound objects, which are dynamically mapped to a user's speaker system during playback, unlike the rigid number and placement of speakers required by channel-based surround (a DTS marketing executive referred to DTS:X in an interview as "whatever.1").[6]

Encoding process

[edit]

DTS-HD MA is encoded in three steps. First, the audio master is fed to a DTS CA encoder, which generates the core (lossy) audio stream. Next, this lossy audio is decoded and compared to the master, with "residual" data being recorded wherever the two differ. Finally, the residual data is compressed losslessly and merged with the core into one bitstream. A DTS-HD MA decoder simply performs this process in reverse.[7]

DTS-HD MA audio, including DTS:X audio, can be created and edited using DTS's DTS:X Encoder Suite. The DTS-HD Master Audio Suite served the same function before the introduction of DTS:X, and can still be used for DTS-HD MA that does not carry DTS:X.[8]

AV transport

[edit]

DTS-HD Master Audio may be transported to AV receivers in 5.1, 6.1, or 7.1 channels, in full quality, in one of three ways depending on player and/or receiver support:[7]

  • Over 6, 7 or 8 RCA connectors as analog audio, using the player's internal decoder and digital-to-analog converter (DAC).
  • Over HDMI 1.1 (or higher) connections as 6-, 7-, or 8-channel linear PCM, using the player's decoder and the AV receiver's DAC.
  • Over HDMI 1.3 (or higher) connections as the original DTS-HD Master Audio bitstream, with decoding and DAC both done by the AV receiver. (This is the transport mode required for DTS:X playback.)

S/PDIF does not have the bandwidth to carry DTS-HD MA (or PCM in more than 2 channels). A setup using S/PDIF audio may output DTS-HD MA as either lossy DTS (which S/PDIF can carry) or downmixed stereo PCM.

References

[edit]
  1. ^ Thomson, Kristin (2004-11-01). "DTD Unveils DTS-HD Brand For High Definition Media Formats". Retrieved 2009-05-06.
  2. ^ "DTS-HD Master Audio Specifications (DTS-HD Master Audio™ - DTS)". January 10, 2012. Archived from the original on January 10, 2012. Retrieved January 10, 2012.
  3. ^ Morrison, Geoffrey (September 23, 2009). "Dolby Pro Logic IIz vs. Audyssey DSX vs. DTS". Home Entertainment. Archived from the original on 2010-10-10. Retrieved November 15, 2010. DTS-HD can natively support over 2,000 individual channels, so according to DTS adding any number of discrete height channels would be easy.
  4. ^ a b DeBoer, Clint (2007-06-04). "DTS Demos Master Audio via PC". Audioholics Online A/V Magazine. Retrieved 2019-01-01. DTS-HD Master Audio delivers sound that is bit-for-bit identical to the studio master. It can deliver audio at variable bit rates which are significantly higher than standard DVDs. DTS-HD Master Audio can provide up to 7.1 audio channels at a 96k sampling frequency / 24-bit depth or 5.1 audio channels at 192 kHz that are identical to the original master. The DTS-HD Master Audio bit stream also contains the DTS 1.5 Mbps core for backwards compatibility with existing DTS-enabled home theater systems, and delivery of 5.1 channels of sound at twice the resolution found on most standard DVDs.
  5. ^ "DTS-HD Master Audio: What You Need to Know". Lifewire. Archived from the original on 2019-03-17.
  6. ^ Waniata, Ryan (2015-04-13). "Lookout Dolby Atmos, DTS just entered the next era of surround sound with DTS:X". Digital Trends. Retrieved 2016-06-09.
  7. ^ a b "DTS-HD Audio: Consumer White Paper for Blu-ray Disc Applications" (PDF). November 2006. Retrieved 2024-04-07.
  8. ^ "DTS-HD Master Audio Suite(TM)". Archived from the original on 2018-03-04. Retrieved 2019-01-01.