What is digital cinema workflow?
Digital technology touches every aspect of the movie-making process. Below are the key steps to consider in the workflow.
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2K: a Digital Cinema picture that is 2048 pixels wide by 1080 pixels high - 6.67% more pixels than a consumer high definition TV picture, which is 1920 pixels wide by 1080 pixels high.
4K: a Digital Cinema picture with four times the number of pixels of 2K: 4096 wide by 2160 high. The 4K differences are visible, especially to viewers toward the front ofthe auditorium and especially with stadium seating.
-K: in computer-speak, K=two to the tenth power, or 1024.
2K/4K Compatibility: the Digital Cinema Initiative (DCI) specification that the exhibitor provides for seamless interoperability. 2K content is automatically resized for presentation on 4K projectors while extraction enables 4K content to be presented on 2K projectors.
24P: 24 Progressive frames per second - this is the frame rate required for Digital Cinema. Unlike television frames, which occasionally contain two images, or fields, which make up a single frame of television picture, Digital Cinema frames should never be shot using fields if possible.
Action: a physical signal that is sent by the Digital Cinema Server to an external device to complete a specific action such as shutting down the lights, opening the curtains, or powering the projector lamp.
Alternative Content: entertainment programming other than movies that can be played in a Digital Cinema environment. Examples include sports, concerts, educational content and other events. Alternative sources are usually connected via the second input of a digital cinema projector and a suitable cinema audio adapter.
Aspect Ratio: the displayed width divided by the displayed height of a specific image. Most common Digital Cinema aspect ratios are:
- 2.35:1 (Scope) - wider, more panoramic aspect ratio
- 1.85:1 (Flat) - used typically for lower budget projects, trailers, and ads
- 1.77 (16/9) - used most often for television and DVD content
Artifact: a visible effect caused by a specific technical limitation.
Automation Cue: a logical, digital signal, coded insde the data for a project, which executes a physical action at a specific moment in a theater. Examples include sending commands to a projector and even may include control of a theater's house light boards or interfacing with alarm systems.
Certificate: a digital document establishing the identity of security devices such as the IMB (decoder) or projector in order to create the security key (KDM).
Color Space: a set of numbers used to represent actual colors included in a specific paint palette or color model. The most common Digital Cinema color space used is XYZ or X'Y'Z'. The most common film color space is referred to as LOG, and a common video color space is REC709.
XYZ: the color space specified for Digital Cinema content in Jpeg2000. (Usually RGB or Video 709)
RGB: is a color space used for Digital Cinema in Mpeg-2.
Conform: Conform (or Conforming) is the Digital Cinema equivalent of cutting a negative.
CPL - Composition Playlist: a representation of a Digital Cinema project, such as a motion picture, or a trailer, advertisement, etc. The CPL consists of an ordered sequence of reels, each referencing track files, such as a sound or picture. Each reel is analogous to a film reel and the CPL controls the order and timing of the playout of the reels. One CPL contains all information needed to play a file for presentaion, and there is a separate CPL for each version of a motion picture or feature.
D-Cinema: Digital Cinema. Digital Cinema captures, distributes, and projects motion pictures using digital technology.
Data: Digital information. Data has the advantage of being able to be copied or transmitted over a digital network any number of times without adversely affecting quality. In Digital Cinema, instead of the moving images and sound being stored on celluloid film, they are stored as digital data in a file, typically on a hard disk.
DCDM: The Digital Cinema Distribution Master is the uncompressed and unencrypted electronic file with picture, sound and subtitles. (The DCDM is the equivalent of an interpositive.)
DCI specification: the specifications for digital projection agreed to by the Digital Cinema Initiatives (DCI). DCI was a joint venture of the six major studios, (Fox, Warner Bros., Paramount, Columbia, Universal, and Disney), which provided the green light for the industry's widespread digital cinema deployment. DCI specification provides future proofing and interoperability among multiple equipment vendors and service providers.
DCP (Digital Cinema Package): A DCP is a set of files containing the picture, sound, subtitles and metadata that are the result of the encoding, encryption and packaging process. This is the format that the majority of digital cinemas require. DCP often refers to the media containing the set of files, which is distributed to theaters. (The DCP is the digital equivalent of a film print, or an internegative.)
DI: Digital Intermediate. Refers to the celluloid film when it is in the stage between being scanned and printed. The DI stage is when all the grading and digital effects are applied. Grading facilities are referred to as DI facilities. The term DI is used in digital workflow terminology even though the content is digital throughout every step of the process.
DIT: Digital Imaging Technician. The DIT is the person onset responsible for handling, transferring, and archiving of the RAW digital file (or metadata) as well as digital dailies.
Digital Cinema Mastering: In Digital Cinema Mastering, a DCDM including all data, picture, and sound elements of a production is converted through compression and encryption and packaged into a DCP.
Digital Cinema Server: a device that transmits decoded image data to the projector from a hard drive, or DCP, in a Digital Cinema projection system.
Encoding: In encoding, the original data is compressed to reduce the size of the content. Typical compression standards (or Codecs) are:
- Jpeg2000: standard format used for Digital Cinema movie compression.
- Mpeg-2: alternative format used for Digital Cinema adverts, trailers or movie compression.
Encrypting: an anti-piracy measure, encrypting content contains ciphered data. Digital Cinema movies are always encrypted and require a decryption key (KDM) to enable the player to read the data from the DCP and access content.
eSATA: Serial AT Attachment. An external computer bus technology designed for transfer of data to and from hard disks, like USB2 or FireWire.
FIPS: Federal Information Processing Standard. A DCI compliant theater system must be certified to meet this standard, which includes security from physical intrusion. Current standard is FIPS 140-2 and is transitioning soon to FIPS 140-3.
FM (or Fingerprinting): Forensic Marking. The process of embedding invisible data (date, time, place) into the picture and sound track of digitally projected movies. This enables pirated content to be traced back to a specific auditorium and showing.
KDM: Key Delivery Message. An anti-piracy measure, the KDM is a set of data files that unlocks the Digital Cinema Package for presentation. For security, the KDM is delivered to the theater separately from the DCP.
LTO: Linear Tape-Open. LTO is a magnetic tape data storage technology used to backup and archive digital content.
LUT: Look Up Table. This is a file that converts a color space for an image if needed.
Metadata: Data about data. Metadata includes information such as title, playback duration, copyright details, etc. that a content provider considers useful or of value when associated with all content and playback data relating to a project.
ODS: Other Digital Stuff. ODS can include policy trailers, commercials, local advertising, live pay per view events and video gaming. To maximize theater revenues, digital projection is usually open to any digital content.
TMS: Theater Management System. A TMS manages content storage, keeps operational logs of what has been played or what will need to be played, movement of content to the auditorium and can interface with ticketing, contract management and key management.
VPF: Virtual Print Fee. A VPF is a risk-sharing financial agreement in which a distributor pays a fee per copy of each DCP to help finance the digital systems of the exhibitors. The VPF model was created to balance the inequalities in costs in making the switch from film to digital projection.