the exchange of technical information and international co-operation. It is predominantly made up of Japanese manufacturers and the Japanese Ministry of Posts and Telecoms and has produced ISDB, a specification for digital broadcasting in Japan. See also: ISDB Website: www.dibeg.org

Digital Asset Management (DAM) The management tasks and decisions surrounding the ingestion, annotation, cataloguing, storage, retrieval and distribution of digital assets. The term “digital asset management” (DAM) also refers to the protocol for downloading, renaming, backing up, rating, grouping, archiving, optimizing, maintaining, thinning, and exporting files. Media asset management (MAM) is a sub-category of Digital Asset Management, mainly for audio, video and other media content.

In general the asset being managed is collected and stored in a digital format. There is usually a target version of that referred to as “essence” and is generally the highest resolution and fidelity representation. The asset is detailed by its metadata.

A B C D E F G H I J

K L

M N O P Q R S T U V

W X Y Z

Digital Betacam See: Betacam

Digital Cinema

Refers to the digital distribution and projection of cinema material. With nearly all films now using the DI process, the next step is to distribute and replay digital material. Thanks to the DCI’s Digital Cinema System Specification (July 2005), a set of standards is in place and many thousands of cinemas have already been converted to digital. Installations started in the USA, and Europe is following. The digital cinema chain includes DCI-compliant equipment for mastering which includes JPEG 2000 encoding and encryption, and players and digital film projectors using usually using DLP, D-ILA and other technologies at the cinemas. These allow high quality viewing on large screens. The lack of all-too-familiar defects such as scratches and film weave – even after a few showings – has its appeal. Besides quality issues, D-cinema introduces potential new digital methods of duplication, security and distribution as well as more flexibility in screening. In addition, stereo cinema (a.k.a. 3D) is easy to set up and present using just one ‘film’ projector (not two), along with a left and right eye selective viewing system. This is having further implications with trials of live 3D events screened in cinemas creating new business models in the media industry. See also: DCI, DLP-cinema, D-ILA, SXRD

Digital cinematography Shooting movies with digital cameras – not film. This growing practice generally makes use of cameras designed specifically for the purpose. These differ from the television application in that the full range of brightness captured by the image sensors is offered at the output as raw data, allowing color grading, format changes, etc. to be executed as a part of the digital intermediate process. Television cameras are designed to work live, and so they include front-end processing for gamma correction, set-up for the required color look and clipping to suit home viewing conditions. See also: VFR Websites: www.panasonic.com/pbds www.thomsongrassvalley.com/ products/cameras/viper www.red.com www.arri.com

Digital disk recorder (DDR) Disk systems that record digital video and generally intended as drop-in replacements for VTRs or as video caches to provide extra digital video

sources for far less cost than a DVTR. They have the advantage of not requiring pre-rolls or spooling but they are not necessarily able to randomly access video frames in realtime. DDRs can also offer the higher data rates needed for uncompressed recordings at an economic price – for SD as well as HD and 2K/4K (film) resolutions. See also: Linear, True random access

Digital intermediate (DI) The DI refers to the process that accepts exposed video or film footage and eventually delivers edited and graded masters, which either can be internegatives for the production labs to generate large numbers of release prints or as digital masters. Initially the term arose to describe a digital version of the traditional chemical intermediate lab where film is graded, cut and copied from camera negative to several interpositives and then to many internegatives. The internegatives are then distributed to the production labs to make the release prints for cinemas. These processes include creating possibly thousands of release prints from a single set of camera negatives. Although the boundaries may vary, generally the DI lab accepts developed camera negative, or data from digital movie/HD cameras, and outputs the edited and graded internegative master for a whole or part of a feature. However, the operational and decision-making processes may differ greatly from the traditional film lab, not least because of the interactive nature of the operation. In the DI lab, decisions become on-screen reality and are seen in full context as they are prepared – no waiting for the ‘chemical’ lab. Grading, dissolves, cuts and effects can be seen immediately and on a big screen – if needed. The interactive process can be more creative and gives complete confidence that the decisions work well. Also grading can take place after the footage is cut together, so the shots are seen, as graded, in context. The availability of large-scale digital storage means that whole movies can be sent for output to the digital lab’s film recorder, exposing 1000ft reels at a time and no final grading required. To help feed the growing number of digital cinemas, the DI lab can produce a DSM (Digital Source Master) – digital cinema’s equivalent of internegatives.

Digital keying and chroma keying Digital keying differs from analog chroma keying in that it can key uniquely from any one of the billion colors of component digital video. It is then possible to key from relatively subdued colors, rather than relying on highly saturated colors which can cause color-spill problems on the foreground. A high quality digital chroma keyer examines each of the three components Y, B-Y, R-Y or R, G, B of the picture and generates a linear key for each. These are then combined into a linear key for the final keying operation. The use of three keys allows much greater subtlety of selection than with a chrominance-only key. See also: Chroma keying, Keying

Digital lab

A facility where digital intermediate work is carried out. Digital mixing

Digital mixing requires ‘scaling’ each of two digital signals and then adding them. See also: Binary, Dynamic Rounding

Digital negative

Digital image material that contains all the detail (spatial and dynamic/ latitude) held in the original camera negative (OCN) film. This allows all latitude headroom to be included on the material for use in a DI process so adjustments of color and exposure can be made to the same degree as with film. See also: Camera negative

60

GLOSSARY OF TERMS