Digital cinema refers to the use of digital technology to distribute and project motion pictures. The final movie can be distributed via hard drives, DVDs or satellite and projected using a digital projector instead of a conventional film projector. Although digital cinema is still video at its core, it is distinct from high-definition and in particular, is not dependent on using television or HDTV standards, aspect ratios, or frame rates. Digital projectors capable of 2K resolution began deploying in 2005, and in 2006, the pace has accelerated. HDTV and pre-recorded HD disks will put great pressure on theaters to offer something better to compete with the improved home HD experience.

Technology

To match or improve the theater experience of movie audiences, a digital cinema system must provide high quality image, sound, subtitles, and captions. Theater managers require server controls for managing and displaying content in multiple theaters, and studios want their content encrypted with secure delivery, playback, and reporting of play times to the distribution company.

In this article, 2K and 4K refer to images with 2048 and 4096 horizontal pixel resolution, respectively.

The Digital Cinema Initiatives (DCI), working in conjunction with members of the SMPTE standards committee, has published a system specification for digital cinema that was agreed upon by the major studios. A draft of this specificaton can be found at dcimovies.com (PDF file). Briefly, the specification calls for picture encoding using the ISO/IEC 15444-1 "JPEG2000" (.jp2) standard and use of the CIE XYZ color space at 12 bits per component encoded with a 1/2.6 gamma, and audio using the "Broadcast Wave" (.wav) format at 24 bits and 48 kHz or 96 kHz sampling, controlled by an XML-format Composition Playlist, into an MXF-compliant file at a maximum data rate of 250 Mbit/s. Details about encryption, key management, and logging are all discussed in the specification.