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Dolby Atmos

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Dolby Atmos

Dolby Atmos is the name of a surround sound technology announced by Dolby Laboratories in April 2012 and released in June of the same year, first utilized in Pixar's Brave.

Contents

History

The first installation was in the Dolby Theater in Hollywood, California, for the premiere of Brave in June 2012. Throughout 2012, it saw a limited release of about 25 installations worldwide, with an increase to 300 locations in 2013. There were over 2,100 locations as of February 2015. Dolby Atmos has also been adapted to a home theater format and is the audio component of Dolby Cinema.

Technology

Dolby Atmos technology allows up to 128 audio tracks plus associated spatial audio description metadata (most notably, location or pan automation data) to be distributed to theaters for optimal, dynamic rendering to loudspeakers based on the theater capabilities. Each audio track can be assigned to an audio channel, the traditional format for distribution, or to an audio "object." Audio tracks that are assigned to channels, such as ambient sounds or center dialogues, are pre-mixed to a "7.1.4" multichannel format: Dolby Atmos home theaters can be built upon traditional 5.1 and 7.1 layouts. For Dolby Atmos, the nomenclature differs slightly: a 7.1.4 Dolby Atmos system is a traditional 7.1 layout with four overhead or Dolby Atmos enabled speakers.

With audio objects, Dolby Atmos enables the re-recording mixer using a Pro Tools plugin (available from Dolby) or a Dolby Atmos equipped large format audio mixing console such as AMS Neve's DFC or Harrison's MPC5, to designate the apparent source location in the theater for each sound, as a three-dimensional rectangular coordinate relative to the defined audio channel locations and theater boundaries.

During playback, each theater's Dolby Atmos system renders the audio objects in real-time such that each sound is coming from its designated spot with respect to the loudspeakers present in the target theater. By way of contrast, traditional multichannel technology essentially burns all the source audio tracks into a fixed number of channels during post-production. This has traditionally forced the re-recording mixer to make assumptions about the playback environment that may not apply very well to a particular theater. The addition of audio objects allow the mixer to be more creative, to bring more sounds off the screen, and be confident of the results.

The first generation cinema hardware, the "Dolby Atmos Cinema Processor" supports up to 128 discrete audio tracks and up to 64 unique speaker feeds. The technology was initially created for commercial cinema applications, and was later adapted to home cinema. In addition to playing back a standard 5.1 or 7.1 mix using loudspeakers grouped into arrays, the Dolby Atmos system can also give each loudspeaker its own unique feed based on its exact location, thereby enabling many new front, surround, and even ceiling-mounted height channels for the precise panning of select sounds such as a helicopter or rain.

Home theaters

At the end of June 2014, Dolby Labs' hardware partners announced that Dolby Atmos would soon be coming to home theaters.

Among them were several established manufacturers of audio-visual home entertainment devices announcing new products that have now brought Dolby Atmos into home theaters across the globe. Products offered range from premium home cinema receivers and preamplifiers to mid-range home-theater-in-a-box (HTiB) packages of well-known brands such as Denon, Marantz, Onkyo, Pioneer and Yamaha plus further models from lesser-known manufacturers and brands.

The first movie to be released on Blu-ray with Dolby Atmos was Transformers: Age of Extinction. The first video game to use Dolby Atmos was Star Wars: Battlefront.

It remains to be seen if consumers are willing to embrace more speakers in a market that may demand less than believed by some of the authorities in the audio industry.

Differences from commercial installations

Because of limited bandwidth and lack of processing power, Atmos in home theaters is not rendered the same way as in cinemas. A spatially-coded substream is added to Dolby TrueHD or Dolby Digital Plus. This substream only represents an abbreviated representation of the object-based mix. This substream does not include all 128 discrete objects separated. This is not a matrix-encoded channel, but a spatially-encoded digital channel. Atmos in home theaters can support 24.1.10 channels, and uses the spatially-encoded object audio substream to mix the audio presentation to match the installed speaker configuration. The spatial audio coding tool is applied to the cinematic object audio mix when filmmakers remix and render the TrueHD and Dolby Digital Plus soundtracks with Dolby Media Producer.

References

Dolby Atmos Wikipedia


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