low·est common denominator (lō′ĭst)
The most basic, least sophisticated level of taste, sensibility, or opinion among a group of people.
[from The Free Dictionary]
In digital cinema, the lowest common denominator wins. While engineers work to add new capabilities, distributors are left with the task of raising the lowest common denominator if any new feature is to be useful.
The first release of SMPTE DCP was in 2009 (there have been a few additions since), following which there has been an increasingly strong interest in putting it to work in the field. SMPTE DCP offers some important features not found in Interop DCP. It delivers subtitle and caption files in a manner that allows encryption to be employed. It offers a more sophisticated way to manage audio. It can arguably be said to be too sophisticated, as it has yet to be implemented properly in all media blocks. It will soon offer a way to deliver additional metadata in a machine-readable manner. Although it can be argued that this, too, will not be of much use in terms of replacing the weak Digital Cinema Naming Convention for many years. But of special interest to distributors is that it will soon be able to deliver 3D subtitles and captions in text form, as is already done with 2D subtitles and captions.
In spite of its feature set, five years after its formalization as a standard, SMPTE DCP remains a novelty. It is used only with special-case distributions, such as Dolby Atmos. Studios are fearful of distributing in the format, as it’s well known that many of the features of the format will not work on certain systems in the field. This is particularly true of Series 1 projectors, and the older servers that support them, of which around 18,000 such systems are installed around the world. Interop DCP, on the other hand, works just fine, even on Series 1 projectors. Interop DCP, the lowest common denominator, continues to win.
This is frustrating to content owners, who seek to gain from the advantages of SMPTE DCP. The most recent addition to the SMPTE DCP family is 3D subtitles, the use of which can bring real savings to studios, and therefore has their attention. Without the option of text delivery, 3D subtitles and captions must be “burned” into the picture, adding a family of massive 3D picture files to the distribution. With 2D subtitles, only a small text-based file containing subtitles for a given language is created. Smaller distributions are simpler to support, and satellite friendly, an option that is becoming more important to distributors eager to lower costs.
Freshly motivated to make SMPTE DCP work, studios are now scheming how to do it. The latest thinking would distribute all 3D movies in SMPTE DCP, starting on a region-by-region basis. Those using Series 1 projectors in 3D auditoriums will be asked to swap them with Series 2 projectors installed elsewhere. It’s a novel scheme, with the only devil being that of shifting Series 1 projectors to 2D screens, assuming such options exist for every exhibitor.
SMPTE 21DC is currently engaged in updating the top level SMPTE DCP document, 429-2, as the finishing touch towards fully standardizing 3D subtitling. That effort is expected to wrap up end of this year. If all things go according to plan, exhibitors could find themselves shifting Series 1 projectors around as early as next year.