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INTRODUCTION
Digital Theatre System (Digital cinema, or d-cinema) is perhaps the most significant challenge to the cinema industry since the introduction of sound on film. As with any new technology, there are those who want to do it fast, and those who want to do it right. Both points of view are useful. This new technology will completely replace the conventional theatre system having projectors, film boxes, low quality picture, sound system.
Let's not forget the lesson learned with the introduction of digital audio for film in the '90s. Cinema Digital Sound, a division of Optical Radiation Corporation, was the first to put digital audio on 35mm film. Very, very few remember CDS, who closed their doors long ago. Such are the rewards for being first.
1999 / 2000: MEETING THE CHALLENGE
Various forms of electronic cinema have been around for many years. Public demonstrations of modern day digital cinema, however, began in 1999 as an experimental effort privately funded by major motion picture studios. What better way to learn the many issues of a new technology than to jump in with both feet?
The block diagram below represents the typical trial digital exhibition system in the year 2000. Many of these systems are still in use today.
In the initial trial stage, the server used for storage and play out was a QuBit unit, manufactured by QuVis. The QuVis server is loaded with the digital movie from either discs or tape, compressed with a proprietary wavelet compression algorithm. Data is scrambled on the hard drive for protection. But digital image data sent to the projector was not protected. For early trial systems, no one seemed too concerned about the potential security risks of these systems, given that it would take a knowledgeable person and a very expensive recorder to pirate the movie. (As it turns out, no digital thefts from the projection booth have ever been reported, and the patron with a digital camcorder has become the threat.) Security remained an issue, but one for a later phase.
Star Wars Episode I and An Ideal Husband were the first motion pictures to be released to the big screen in digital in June of 1999. Star Wars Episode I was displayed on four digital systems, two in Los Angeles, and two in New York. Two Hughes/JVC ILA-12K projectors, and two early prototype DLP-Cinema projectors from Texas Instruments were used for the Star Wars demonstrations. The digital demonstrations of An Ideal Husband were presented only on the Hughes/JVC ILA-12K. The ILA-12K produced a good looking picture, but was difficult to maintain in a day-to-day theatrical environment. The projector technology of choice quickly became DLP Cinema from Texas Instruments. In the early days, the only projectors available were prototypes built by TI. Today, TI has three licensees: Barco, Christie, and NEC/Digital Projection. TI is the only game in town today, but that could change in 2004.
The server provides digital audio as multiple AES/EBU (AES3) streams. Some cinema processors can be configured to directly accept digital audio, and digital audio can be converted to analog for legacy cinema processors. The server also has the ability to command "house controls", i.e., lights and curtains. No improvements were made upon this system until the later half of 2001.
STEPS FORWARD
On July 17, 2001, a digital cinema milestone was crossed with the digital premiere of Jurasic Park III in Los Angeles. This particular presentation was compressed with a version of MPEG 2, as developed for digital cinema applications by Grass Valley Group. Called MPEG+, GVG's compression was based upon the MPEG 2 decompression standard, making this the first public digital cinema presentation to use an almost standard decompression scheme. Within weeks, a true MPEG 2 presentation was held in New York for Tim Burton's Planet of the Apes, this time using an Avica digital cinema server. Together, these presentations marked the beginning of a new phase for digital cinema by bringing new components to the scene.
A third server company, EVS, whose product is also based on MPEG, later jumped in with both Grass Valley and Avica to create interoperable servers. While a noble goal, it did not lead to true interoperability. GVG dropped out of the digital cinema game, and EVS and Avica were not able to demonstrate products that were fully interoperable.
Security got a little boost during this period, though. TI and GVG developed a page link encryption method, called Cinelink for the protection of the (SMPTE 292) digital page link between server and projector. While promoted by the server companies, it was not implemented in either of the GVG or Avica presentation mentioned above. Link encryption is pictured in the block diagram below.
Cinelink page link encryption was introduced by Texas Instruments in their Mark VII version of the DLP Cinema projector. Link encryption encrypts the image data as it is sent to the projector, offering some security to the system. Full security, however, required encryption of the content stored on the server, which had yet to be introduced.
This phase began with the promise of file interoperability, but failed to deliver. It did produce page link encryption, however, which was a step towards addressing the security issue.
INTRODUCING SECURITY
By early 2002, digital cinema installations were numbered in the 40's. They utilized several types of servers, including the QuBit, Avica, and EVS servers already mentioned, as well as the Technicolor Digital Cinema server designed by Qualcomm. These systems represented three different compression schemes, and four file formats.
On May 16th, 2002, another digital cinema milestone was crossed with the digital release of Star Wars: Episode II. Although they didn't financially contribute to the digital presentation of their movie, Lucasfilm heavily promoted that it should be seen as such, and the heyday increased the digital installation count to over 100. The movie was released in all four digital formats -- which proved to be a challenge all of its own.
Episode II broke ground by being the first digital movie released employing content encryption. Not all systems were capable of supporting content security, but those employed by Boeing/Avica/EVS and Technicolor/Qualcomm certainly was. The introduction of fully secure presentation systems was a major step forward.
Many thought this phase would signal a rollout of digital cinema. But numerous issues remained, the least of which were the many incompatibilities in data packaging, encryption, key manangement, and compression. Exhibitors now had enough experience to know that they had operational issues, too. To add to the problems, not all cinematographers, studios, and exhibitors thought the quality level was good enough to replace film. And the overriding issue remained: there wasn't a sound business model. Studios stood to save significantly each year by not paying for film distribution, and exhibitors stood to pay significantly for the new digital equipment. While 3rd parties attempted to intermediate as system and service providers, none were successful. The business partners needed to talk.