DTS (an initialism of its original name, Digital Theater Systems) is an American company that makes multichannel audio technologies for film and video. Based in Calabasas, California, the company introduced its DTS technology in 1993 as a competitor to Dolby Laboratories, incorporating DTS in the film Jurassic Park (1993). The technology is used in surround sound formats for both commercial/theatrical and consumer-grade applications. It was known as The Digital Experience until 1995. DTS licenses its technologies to consumer electronics manufacturers.
DTS, Inc. was acquired by Tessera Technologies Inc., in December 2016 and combined under the newly created Tessera Holding Corporation. The combined company was renamed to Xperi Corporation in February 2017.
History
DTS was founded by Terry Beard, an audio engineer and Caltech graduate. Beard, speaking to a friend of a friend, was able to get in touch with Steven Spielberg to audition a remastering of Spielberg's film Close Encounters of the Third Kind mixed in DTS. Spielberg then selected DTS sound for his next film, Jurassic Park (1993). With the backing of Universal and its then-parent Matsushita Electric, over 1,000 theatres in the United States adopted the DTS system.
Work on the new audio format started in 1991, four years after Dolby Laboratories started work on its new codec, Dolby Digital.
The basic and most common version of the format is a 5.1-channel system. This is similar to a Dolby Digital setup, which encodes the audio as five primary (full-range) channels plus a special LFE (low-frequency effects) channel for the subwoofer.
Encoders and decoders support numerous channel combinations, and stereo, four-channel, and four-channel+LFE soundtracks have been released commercially on DVD, CD, and Laserdisc.
Other, newer DTS variants are also available, including versions that support up to seven primary audio channels plus one LFE channel (DTS-ES). These variants are generally based on DTS's core-and-extension philosophy, in which a core DTS data stream is augmented with an extension stream which includes the additional data necessary for the new variant in use. The core stream can be decoded by any DTS decoder, even if it does not understand the new variant. A decoder which does understand the new variant decodes the core stream, and then modifies it according to the instructions contained in the extension stream. This method allows backward compatibility.
DTS's main competitors in multichannel theatrical audio are Dolby Digital and SDDS, although only Dolby Digital and DTS are used on DVDs and implemented in home theater hardware.
One of DTS Inc.'s initial investors was film director Steven Spielberg, who felt that theatrical sound formats up until the company's founding were no longer state of the art, and as a result were no longer optimal for use on projects where quality sound reproduction was of the utmost importance. Spielberg debuted the format with his 1993 production of Jurassic Park, which came slightly less than a full year after the official theatrical debut of Dolby Digital (Batman Returns). In addition, Jurassic Park also became the first home video release to contain DTS sound when it was released on LaserDisc in January 1997, two years after the first Dolby Digital home video release (Clear and Present Danger on LaserDisc), which debuted in January 1995. Universal Pictures would exclusively support DTS until late 1997.
In 2008, the theater division was divested to form DTS Digital Cinema. In 2009, DTS Digital Cinema was purchased by Beaufort International Group Plc. and became known as Datasat Digital Entertainment.
SRS Labs In 2012, DTS acquired the business of SRS Labs (Sound Retrieval System), a psychoacoustic 3D audio processing technology, including over 1,000 audio patents and trademarks.
Manzanita Systems In 2014, DTS acquired Manzanita Systems, a provider of MPEG software for digital television, VOD, and digital ad insertion.
Phorus Phorus, a subsidiary of DTS, Inc., is a Los Angeles-based technology group dedicated to wireless audio for connected devices.
HD Radio (iBiquity) On September 2, 2015, iBiquity announced that it was being purchased by DTS for US$172 million, uniting iBiquity's HD Radio digital radio broadcast technology with DTS' digital audio surround sound systems.
Theatrical use In theatrical use, a proprietary 24-bit time code is optically imaged onto the film. An LED reader scans the timecode data from the film and sends it to the DTS processor, using the time code to synchronize the projected image with the DTS soundtrack audio. The multi-channel DTS audio is recorded in compressed form on standard CD-ROM media at a bitrate of 882 kbit/s. The audio compression used in the theatrical DTS system (which is very different and completely unrelated to the home Coherent Acoustics-based DTS Digital Surround format) is the APT-X100 system. Unlike the home version of DTS or any version of Dolby Digital, the APT-X100 system is fixed at a 4:1 compression ratio. Data reduction is accomplished via sub-band coding with linear prediction and adaptive quantization. The theatrical DTS processor acts as a transport mechanism, as it holds and reads the audio discs. When the DTS format was launched, it used one or two discs with later units holding three discs, thus allowing a single DTS processor to handle two-disc film soundtracks along with a third disc for theatrical trailers. The DTS time code on the 35 mm print identifies the film title which is matched to the individual DTS CD-ROMs, guaranteeing that the disc cannot be played with the wrong film. Each DTS CD-ROM contains a DOS program that the processor uses to play back the soundtrack, allowing system improvements or bug fixes to be added easily. Unlike Dolby Digital and SDDS, or the home version of DTS, the theatrical DTS system only carries 5 discrete channels on the CD-ROMs. The .1 LFE subwoofer track is mixed into the discrete surround channels on the disc and recovered via low-pass filters in the theater.
DTS technologies Most DTS consumer codec techniques are documented in ETSI. DTS Digital Surround, DTS-ES, DTS 96/24, and DTS-HD are recorded in ETSI TS 102 114. DTS:X is recorded in ETSI TS 103 491.
DTS Digital Surround
On the consumer level, DTS is the oft-used shorthand for the DTS Coherent Acoustics (DCA) codec, transportable through S/PDIF and part of the LaserDisc, DVD, and Blu-ray specifications. This system is the consumer version of the DTS standard, using a similar codec without needing separate DTS CD-ROM media.
DTS is related to the aptX audio coding format, and it is based on the adaptive differential pulse-code modulation (ADPCM) audio data compression algorithm. In contrast, Dolby Digital (AC-3) is based on the modified discrete cosine transform (MDCT) compression algorithm.
Both music and movie DVDs allow delivery of a DTS audio signal, but DTS was not part of the original DVD specification (it was added later in 1997), so early DVD players do not recognize DTS audio tracks at all. The DVD specification was revised to allow optional inclusion of DTS audio tracks. The DVD title must carry one or more primary audio tracks in AC-3 or LPCM format (in Europe, MPEG-1 Audio Layer II is also an allowed primary track format). The DTS audio track, if present, can be selected by the user. Subsequent DVD players now decode DTS natively or pass it through to an external decoder. Nearly all standalone receivers and many integrated DVD players/receivers can decode DTS.
A small number of LaserDiscs carry DTS soundtracks. The NTSC LaserDisc format allows for either analog audio only or both analog and digital audio tracks. LaserDiscs encoded with DTS sound replace the LPCM digital audio track with the DTS soundtrack. This soundtrack is output via digital coaxial or optical audio outputs and requires an external decoder to process the bitstream. Playback of DTS audio CDs, such as those marketed by DTS as 5.1 Music Discs, using a standard CD player similarly requires an external decoder. As with standard CD players, DVD and Blu-ray Disc players cannot decode audio from DTS audio CDs.
For PC playback, many software players support the decoding of DTS. The VideoLAN project has created a decoding module for DTS called libdca (formerly libdts), which is the first open source implementation of DTS.
Sony's PlayStation 3 and Microsoft's Xbox 360 are capable of DTS decoding and output via TOSLINK or HDMI as LPCM. However, HDMI output on the Xbox 360 is only found on the "Elite" model and newer models available since mid-2007, with the release of the Falcon motherboard revision. Also, the Xbox 360 cannot decode DTS from DTS audio CDs. PlayStation 3 consoles can bitstream DTS over HDMI, but cannot decode audio from DTS audio CDs. The newer "slim" models are able to bitstream DTS-HD MA as well, but also cannot decode audio from DTS CDs.
Comparison with Dolby Digital DTS and Dolby Digital (AC-3), DTS's chief competitor in the cinema and home theater markets, are often compared because of their similarity in product goals, though Dolby believed that the surround channels should be diffused and DTS said they should be directional. In theatrical installations, AC-3 audio is placed between sprocket holes on the 35 mm film itself, leaving the audio content susceptible to physical damage from film wear and mishandling. DTS audio is stored on a separate set of CD-ROM media, with greater storage capacity that affords the potential to deliver greater audio fidelity and is not subject to the usual wear and damage suffered by the film print during the normal course of the movie's theatrical screening. Disregarding the separate CD-ROM assembly as a potential point of failure, the DTS audiopath is comparatively impervious to film degradation, unless the film-printed timecode is completely destroyed.
Dolby claims its competing AC-3 codec achieves similar transparency at its highest coded bitrate (640 kbit/s). However, in program material available to home consumers (DVD, broadcast, and subscription digital TV), neither AC-3 nor DTS typically run at their highest allowed bitrate. DVD and broadcast (ATSC) HDTV cap AC-3 bitrate at 448 kbit/s. But even at that rate, consumer audio gear already enjoys better audio performance than theatrical (35 mm movie) installations, in which AC-3 is limited to 320 kbit/s. When DTS audio was introduced to the DVD specification, a few studios authored DTS tracks on some DVDs at the full bitrate (1509.75 kbit/s). Most later DVD titles that offered DTS tracks were encoded at 754.5 kbit/s (about half the rate of 1509 kbit/s). At this reduced rate, DTS no longer retains audio transparency. This was done to make room for more audio tracks and content to reduce costs of spreading extra material on multiple discs.
Dolby Digital 5.1 can compress the same data to less, taking up minimal space. Conversely, DTS proponents claim that the extra bits give higher fidelity and more dynamic range, providing a richer and more lifelike sound. But no conclusion can be drawn from their respective bitrates, as each codec relies on different coding tools and syntax to compress audio.
In addition to the standard 5.1-channel DTS Surround codec, the company has several other technologies in its product range designed to compete with similar systems from Dolby Labs. Those which conceptually extend DTS (to add more channels or more accurate sound reproduction) are implemented as extensions to a core DTS Coherent Acoustics data stream. The core stream is compatible with DTS decoders which do not support the extension(s); the extension(s) provide the additional data required to implement the additional functionality.
DTS 70 mm