An Early History of Digital Cinema Technology

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. There was another layer to the problem: MPEG interoperability was a profitable goal for manufacturers, but for digital cinema, MPEG 2 has serious limitations in the eyes of many stakeholders. This was only one of several instances where the goals of stakeholders were ignored in favor of pushing profitable technology.

Security got a little boost during this period, though. TI and GVG developed a link encryption method, called Cinelink(tm) for the protection of the SMPTE 292 digital 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. (click to enlarge)

Cinelink(tm) 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 link encryption, however, which was a step towards addressing the security issue.

Next: 2002: Introducing Security