Digital Cinema

What is it?

It’s a platform (Like 35 mm film is a platform): Fully spec’d and standardized. High quality motion pictures in the age of files. It works the same everywhere. Anyone can target it, be it a major studio or so-called Indies. Results are reproducible, be it on a digital screen in Bombay or in Anchorage.

Another aspect of the platform is its quality level. A digital cinema projection will give you back the detail and fidelity you’ve been creating in acquisition and post: 4:4:4, 10 to 12bpc, upto 500Mbps, 5.1, 6.1 or 7.1 uncompressed audio.

Update Dec 2011: According to ISDCF Meeting Notes there are 58200 digital screens in 13700 locations worldwide (33000 3D).

What’s the benefit?

• A digital cinema package (DCP, digital cinema’s equivalent of a distribution print) can carry a number of sound/language versions, title versions, subtitles, even different edits of the film if it’s called for. It’s a very flexible format.

• A digital cinema projector can be color-corrected. Which means authors — for the first time in film history — can actually get their graded colors back from theatre’s screens. Ever saw a black and white feature on a standard changeover setup? Every reel change means a jump in color temperature. With digital cinema projectors color calibration and correction is built-in.

• Pristine image quality from opening night until the end of time. No more mutilated prints (What some projectionists do to film prints goes well beyond a motion picture engineer’s worst nightmares. It’s nothing short of a miracle we have any film history artefacts left.¹).

• 3D presentation is a built-in capability.

• Digital cinema offers strong content protection which in turn allows for easy distribution.² As opposed to film prints which are being accompanied by armed security personnel to press screenings and opening nights.

• With digital cinema it’s inherently easy and cheap to reach the big screen with no/low/modest budget productions. Current quotes from post facilities and labs offering digital cinema services might suggest the opposite. But this will change.

How does it work?

Basically an image sequence (the motion picture) is compressed and encoded to a well-defined, cinema-specific JPEG 2000 codestream. Packed up (alongside with sound and subtitles) in MXF containers and composed through the means of descriptive XML to what will be shown on the screen. These compositions are what make DCP such a powerful and flexible format. Final package gets copied onto a harddrive (or flash disk, optical medium etc.) and ingested on a digital cinema server. Finally, someone hits Play.³

Can I do it?

Yes. Absolutely. Keep in mind that Digital Cinema will not, through some magic spells, turn 8bpc material into smooth 12bpc delight. It will not make up for the shortcomings of acquisition gear and problematic decisions in post. It might turn a dull story into epic drama, though, and it just might deliver world peace in due time.

¹ What’s a release print got to do with anything? you might wonder. In film preservation and restoration very often the only surviving materials are release prints. Also, when you deal with color film, a release print often is the only surviving color/contrast etc. reference. Think of a day for night shot on camera negative: Without a release reference you might end up with a re-release which has a peculiar daylight scene noone has ever seen before … So, apart from the obvious relevance for contemporary audiences, that’s why the state of release prints matters.

² See Cinemaslides for a proof-of-concept implementation to build encrypted DCPs and KDMs (key delivery messages).

³ Of course, like with any technology, a number of things can go wrong: Like any other equipment the digital projector can be in bad shape, badly maintained, badly or not at all calibrated. Projector presets can be wrong. Cinema servers and projectors can have bugs in their software, may not support all DCP features correctly etc. Staff will not always be able to tackle problems on site. I think it is useful to think of these problems as teething problems. Once the technology settles in it will actually be as easy to handle as described above.