Digital Cinema Worldwide
All major movie theaters today are digital cinemas, and Digital Cinema Package (DCP) is the worldwide technical standard for producing theater-quality digital video and sound.
With DCP, audiences experience movies as filmmakers intended. A bit-perfect movie reproduction can be screened at any venue equipped with DCP-compatible projection and sound.
DCP playback is contractually required for permission to screen all major movie studio releases and many smaller producers will only provide their content in this format. Film festivals also have embraced DCP in order to receive movies from content providers.
When digital cinema rapidly rolled out to multiplex theaters 20 years ago, DTA Digital Cinema focused on two underserved niches: DCP equipment rental with technical staffing for short term cinema events and, concurrently, installation of permanent DCP systems at performing arts centers, museums, universities, and other multiuse venues.
With more than one thousand installations completed, our industry-certified engineers have seen and solved hundreds of location-specific challenges.
Working with specialists in DCP image, audio and screens for more than two decades is beneficial to every organization interested in digital cinema today. Foremost, DTA is fluent at translating industry jargon to terms and concepts familiar at every technical level.
Whether your organization is looking to buy or rent, our priority is building confidence. With that mission in mind, DTA prepared this introduction to DCI Compliance, DCP terms, and key components of every Digital Cinema System.
What are DCI Standards?
DCI stands for Digital Cinema Initiatives, LLC, a joint venture of international motion picture studios including Disney, Fox, Paramount, Sony Pictures Entertainment, Universal, and Warner Brothers.
Why DCI Compliance Matters
The studios devised a universal standard for storage and playback of theatrical-quality digital content. When hosting a movie premiere, film festival, or a private screening of a studio release, the benefits of DCI-compliant equipment include:
- Theatrical Quality: Audiences see sharp, color-accurate, precision-timed images and hear audio precisely matching the original mix — and the creators intent
- Interoperability: A DCP film file created in one part of the world plays perfectly on every compliant system
- Content Security: Film creators can protect their works from piracy by encrypting movie files, knowing their content can only be unlocked on authorized equipment during specific time periods
Inside The DCP Movie File
A Digital Cinema Package (DCP) is a collection of digital files that store and convey high-resolution video, uncompressed multi-channel audio, subtitles, and technical metadata. A standard DCP holds the following elements:
- Image Track File: High-resolution visual content, typically 4K resolution, encoded in JPEG 2000 format to preserve color grading and visual effects flawlessly
- Sound Track File: Uncompressed, multi-channel AES/EBU digital audio tracks with complete fidelity to the original sound mix
- Subtitles and Captions: XML based files in multiple languages turned on or off as needed
- Composition Playlist: Instructions to the cinema server defining which assets to play and in what sequence
- Metadata: Essential technical details such as frame rate, aspect ratio, color space, and security information
Digital Cinema System Components
DCP playback is an orchestrated interplay between specialized hardware and software.
DCI-Compliant Projector
Cinema projectors not only read and display DCP files reliably, they are engineered for high brightness in theatrical environments, incomparable color accuracy, and remarkably even illumination across a projection screen.
- Light Source: Using discrete red, green and blue laser diodes, RGB direct laser projectors come closest to covering the extremely wide DCI-P3 (and Rec 2020) gamut for reproducing the entire visible color spectrum. Colors are accurate, pure, deeply saturated, and with elevated perceived brightness. Laser projectors are significantly more economical than lamp-powered equipment, and many operate for up to 30,000 hours.
- Image Engine: With three separate digital micromirror device (DMD) chips, one for each primary color, tiny hinged mirrors tilt thousands of times per second, either toward the lens for “on” or away from the lens for “off” to create projected images pixel by pixel. Digital Light Processing (DLP) circuits ensure deep black levels, high native contrast, and no visible flicker during high-frame-rate action scenes. Laser light sources paired with DLP chips are typically in a sealed optical module that is highly resistant to dust with no filters to clean.
- Brightness: Digital cinema projection units can output up to 60,000 Lumens, enough to illuminate a movie screen more than 100 feet wide
- Resolution: Pixel arrays 4096 x 2160 (4K) and 2048 x 1080 (2K) are standard
- Color Accuracy: DCI-compliant projectors use the X’Y’Z’ color space to ensure the filmmaker’s vision is preserved
Integrated Media Block (IMB)
The IMB or IMS (an acronym for Integrated Media Server) is a highly secure storage server that prevents unauthorized access to movie content. Typically located inside the projector, IMB/IMS functions can also be performed by an external storage server:
- Decryption: Highly-security task of unlocking encrypted movie files
- Decoding: Conversion of compressed DCP movie file data to raw signals routed to the projector’s image engine
Security: How KDMs Work
Studios encrypt DCP files to fight piracy, and possession of a KDM (Key Delivery Message) having each of the following characteristics is essential before pressing play.
- Digital Key: A unique alphanumeric character sequence supplied by the movie distributor to unlock encrypted DCP files
- Server Specific: The KDM digital characters unlock one IMB/IMS based on a DCP projector’s unique identification certificate transmitted to the movie distributor
- Time Limited: An individual KDM authorizes content playback in a precise day and time window
Digital Cinema Sound
Turning raw digital audio streaming from DCP files into theater-shaking sound, signal output from the IMB/IMS is connected to a special-purpose audio device.
- Cinema Audio Processor: Controls volume, applies room equalization, delays the sound to match the picture perfectly, and routes individual channels to theater amplifiers
Creating an Inclusive Experience
DCI standards tightly embrace accessibility, and an individual DCP can contain assets for audiences with different needs.
- Closed Captions (CCAP): Text displayed on a private device for hearing-impaired audience members
- Hearing Impaired (HI) Audio: An enhanced mono audio track broadcast to wireless headphones to help patrons hear dialogue more clearly
- Visually Impaired (VI) Narrative: An audio description track where a narrator describes the on-screen action to blind or visually impaired guests