Cinema Without Walls

by Michael Karagosian
©2012 MKPE Consulting LLC All rights reserved worldwide
originally published in the 15 December 2012 issue of Digital Cinema Report


By the end of 2012, it's expected that at least 85,000, or 70%, of the world's cinema screens will be converted to digital projection. The transition is taking place at a rapid pace, driven by 3-D, and fulfilled by the fast execution of virtual print fee deals around the world by the major studios. It won't be long before the manufacturers of DCI-compliant equipment will be looking back at the good ol' days. But for the art of cinema, this is only the beginning. The Hobbit gives a clue.

Center stage in this transition, from the technology side, has been the DCI Digital Cinema System Specification (DCSS). (DCI stands for Digital Cinema Initiatives.) It is the system specification to which studios agree to deliver digital content. At the time of this writing, nine manufacturers are listed on the DCI website that sell projectors, servers, and/or integrated media blocks having passed the DCI Compliance Test Plan, the suite of tests that ensure compliance to the DCSS.

The DCSS plays multiple roles in the digital cinema narrative. It is not widely appreciated that the DCSS has a purpose in the securing of financing for digital projection equipment. Consider that some US$4-5B has been invested in digital projection equipment worldwide, for an unparalleled transition of technology in cinema. Virtual print fee subsidies make it possible for exhibitors to convert film systems with digital projection systems, but the risks of financing these deals can be difficult for banks to assess, as they are dependent upon the delivery of content. The DCSS brings assurance that major studios will distribute digital content to systems that are compliant.

Notably, for this assurance to be credible, the specification must also be stable. For this reason, studios are incentivized to not “evolve” the specification. If the specification is changed in a manner that leads to upgrades in installed and already-approved equipment, studios could be responsible for the associated costs, dependent upon contractual arrangements with deployment entities and exhibitors.

As a result, the DCSS is a baseline specification for digital cinema. It does not necessarily represent the latest and greatest. For example, the DCSS does not specify 3-D functionality. It does not specify high frame rate capability. These additional features build on top of the specification, and are not incorporated in the specification. There is significant value in this, as it implies that no matter what features are introduced in digital cinema equipment, the core formats of 24 fps 2K and 4K, and 48 fps 2K, as specified by DCI, will continue to be supported.

No specification is perfect, and there is room for improvement in the DCSS. The specification has always lacked description of a complete, automatable security key management system. Seven years after introduction of the spec, and after much pain felt by the mismanagement of security keys, a viable mezzanine layer of security key management is slowly being adopted. It has not been standardized, however, and it doesn't extend into the products themselves, where the public keys reside to which movie keys (KDMs) must be made.

You may also be surprised to learn that in spite of the efforts to bring digital cinema products into compliance with the DCI specification, studios have yet to distribute DCI-compliant movies. The specification stipulates that a standardized content packaging method is to be used. However, all digital first release motion pictures to date have been distributed using an informal, non-standardized content packaging method called Interop DCP. This oddity occurs because standards weren't available at the time that the digital cinema rollout began.

This gap in standards, however, has long been crossed with the standardization of SMPTE DCP. DCI-compliant products support the standardized SMPTE DCP, but DCI's specification does not go far enough to ensure interoperability with legacy content. Notably, the HFR 3D version of Hobbit was to be the first to employ SMPTE DCP, driven by the desire to discontinue further work on the non-standard Interop and to not extend it with HFR capability. But that noble effort failed, because some manufacturers had not implemented a feature called audio routing, which is required in all SMPTE DCP-compliant products for backwards compatibility with legacy Interop content. Audio routing, however, is not mentioned in the DCI specification.

Outside of these few gaps, the potential to add new capabilities to the DCI feature set without modification of the core specification is hugely significant. This strength comes from the fact that digital cinema is the most extensible media format ever created. When the DCI specification was first introduced, there was significant concern that it would place shackles on the creativity possible with this new digital technology. But in fact, the opposite is true, paving the way for all kinds of creative formats to emerge. To coin a phrase from cinematographer and visual effects expert David Stump ASC, the extensibility of digital cinema makes possible “cinema without walls.”

Digital cinema unties the director's hands of the shackles of frame rate, dimension, and sound. Underpinning this newfound flexibility is the DCI specification and the significant suite of SMPTE standards that now exist for digital cinema, providing a foundation of security and core interoperability upon which new innovations can be added. We are only at the beginning of a new age for cinema.