Mastering & Encoding
Cinema
DVD

 Mastering for Digital Cinema

Need to get your finished project screened in the cinema?. Now What? Unlike network television broadcasting, if a cinema chain is set up for digital cinema it most likely will not have D5 or HDCam decks to play back your project. Instead, there will be a theatre management system comprised of digital projectors, playback systems equiped with decryption to read forensic watermarking and other security devices that are necessary to play a movie out in a digital theatre. 

With the elimination of film projectors and videotape machines, the content itself must be packaged in the form of a 'DCP'- a DCI compliant, JPEG2000 file. This ensures compatible playback across a wide range of equipment worldwide at any DCI compliant theatre.

A finished project must comply with the specifications created by the DCI, or Digital Cinema Initiative; a consortium of 7 major movie studios and digital media facilities whos goal is to provide a standardized way to assure that universal playback capability, image quality and security is maintained between digital cinema mastering and the theatrical distribution journey.

At the end of the digital mastering process, not to be confused with digital cinema mastering, when all of the creative manipulation is finalised, a DSM, or Digital Source Master is created. A DSM can exist as any audio and image file format, including a set of image, audio, subtitle and auxiliary data, which complies, with the specifications of a digital cinema distribution master. A DCDM is simply an image sequence of uncompressed 12 bit TIFF files in XYZ colour space and sized to fill the proper container format for scope or flat aspect ratios. And audio is a single uncompressed 24 bit WAV file at 24fps, sampling at 48KHz. Wether a DSM or DCDM, content must be encoded and may be encrypted before it is packaged and played back. It is here that the image portion of a movie is compressed in JPEG2000 and then ready to be packaged. from the resulting encoded video and wrapped audio, a digital Cinema Package is created. The DCP is simply a set of MXF files containing the picture and sound, a set of XML files (Composition Play List and Packing List) containing information for each of the individual files which dictate the reel order for playback. Aditionally, if the JPEG2000 encode was encrypted, a key is necessary to 'unlock' the movie for presentation. The purpose of encryption is to protect the digital data and prevent piracy by securing playback with a key. The key is contained within a Key Delivery Message or KDM. A KDM is generated for every DCP and is specific to each digital cinema server at every theatre. The KDM's will determine and authorize who can play the movies, on which projection systems and at what times and dates. Distributing copies of the DCP to a digital cinema or several digital cinemas can involve delivery of assets via hard drive or satellite, most recently in the UK by Arquiva.

In the cinema non mainstream product is refered to as alternative content. Smaller projects can be mastered at HD1920 resolution in its original colour space without encryption. This is usefull for one off shows or a limited release.
Mastering  facilities can be expensive, an alternative is to use software for encoding on PC or Mac. The following links offer free trials.

Raptor - Mac plug in (2D only)
CineAsset

Cube
Easy DCP

 Mastering  DVD