• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer

mkpeReport

top analysis covering digital cinema, 3-D, HFR, and laser illumination

  • Reports
  • About
  • mkpe.com
  • cinepedia.com

The Atmos Playback System

November 2012 by Michael Karagosian

Dolby Atmos is unique as cinema sound systems go. It utilizes both channel-based and object-based sound, and it requires a separate audio server to play and render sound for the auditorium. It’s a sophisticated system that requires more capability than the ordinary digital cinema system. That sophistication will make also make it difficult for non-Dolby servers and integrated media blocks (IMBs) to work with Atmos.

A normal digital cinema sound system receives audio from the 16-channel audio output of the server or IMB. An Atmos distribution, however, requires that a separate audio track file be loaded into the Dolby cinema processor. Notably, both the 16-channel audio track file and the separate Atmos track file must be present for the system to work. The Dolby cinema processor serves as a separate server in the system, but strictly for the Atmos mix. To synchronize Atmos audio to picture, a digital time code is needed between the IMB and the Dolby cinema processor. The time code is carried in the 16-channel audio track file, and is transmitted from a digital audio output of the IMB to the Dolby cinema processor. The time code signal will carry more than just timing information. It will also carry content identifier information and possibly other data useful to communicating to the Dolby cinema processor as to which Composition is currently playing. Dolby is proposing to standardize this time code signal in SMPTE DC21.

The Atmos sound track will need to be encrypted to meet studio security requirements. That also means that the Dolby cinema processor will need a FIPS-approved decryption engine, and a secondary KDM. Although not verified with Dolby, one would expect the secondary KDM to be a separate KDM coded to the unique public key of the Dolby cinema processor. The Dolby cinema processor will also need to forensically mark the Atmos audio tracks going to the speakers. It remains to be seen if Dolby intends to mark all 64 channels.

A block diagram for the Dolby Atmos signal path is shown below.

dolby-atmos-75

Upon examination, the block diagram begs a few questions. When first announcing Atmos, Dolby made it clear that it would not require a Dolby server and IMB to work. However, when fully integrated in the DCP, Dolby’s process will require that the system can identify the Atmos data track and move it to the Dolby cinema processor. As pictured by Dolby, the movement of that data requires a separate network segment, which may not be available on most products. Importantly, there may not be an outboard server at all given the most recent trend towards integrated media servers (IMS) where both server and media block are installed as a compact unit in the projector. At least one manufacturer has already expressed concern that their newly introduced IMS product may not be able to support Atmos.

Security key management will be more complex with the addition of a FIPS processing unit in the Dolby cinema processor. Dolby servers today are infamous for not being friendly with security key management systems. Dolby will have to work doubly hard to bring security management friendliness to its new systems. In addition, security key management companies will need to scratch their heads on this one, too.

Those concerned with the complexity of multiple versions of content inventory need not worry about Atmos adding to the number of versions. Instead, they should worry about the growth in size of the DCP. Compositions with Atmos tracks will also carry a main sound track file, which will contain either a 5.1 or 7.1 audio mix, in addition to the Atmos mix. Notably, there is nothing that prevents the 5.1 mix from also carrying Barco’s Auro3D format. If the Atmos system should fail, or is simply not installed, the digital cinema system can revert to the 5.1 or 7.1 mix. If Dolby’s distribution scheme is followed, only the size of the composition will increase, not the number of versions.

Just when users thought that digital cinema was becoming manageable, it will soon get more complicated. Atmos truly adds a new wrinkle to digital cinema.

Filed Under: Sound Tagged With: Dolby Atmos

Primary Sidebar

Search

Topics

  • 3-D
  • Accessibility
  • Alt Content & Advertising
  • Anti-Piracy
  • Color
  • Communications
  • Deployment Entities
  • Distributors
  • Exhibitors
  • Fulfillment
  • High Dynamic Range
  • Higher Frame Rates
  • Installations
  • Patents
  • Projectors
  • Servers and IMBs
  • Sound
  • Technical Bodies
  • Theatre Management Systems
  • Trade Organizations and Shows

Full Archives

a publication of
MKPE Consulting LLC

Footer

Important Stuff

  • About
  • Privacy Policy

Archives

  • Category & Monthly Archives
Archives date back to 2008.

MKPE

mkpeReport is a publication of MKPE, a world-class consultancy building business at the crossroads of cinema and technology.
Learn more about MKPE.

copyright © 2008 - 2023 mkpe consulting llc

We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept”, you consent to the use of all cookies.
Cookie settingsACCEPT
Manage consent

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
CookieDurationDescription
cookielawinfo-checbox-analytics11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checbox-others11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
Functional
Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.
Performance
Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.
Analytics
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
Advertisement
Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. These cookies track visitors across websites and collect information to provide customized ads.
Others
Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet.
SAVE & ACCEPT
Powered by CookieYes Logo