Digital System Architecture

Digitizing film material produces enormous amounts of data. During a complete digital film production several terabytes of data can be produced. Therefor a two-tier architecture model seems to be suitable to handle these amounts and at the same time to archive them in high quality for a long-term period.

Digital material will be generated and stored in two quality layers:

• The highest level available is the so called Master Archive Package (MAP). In this format digital images can be stored with a resolution which represents for the analogue feed material the highest available digital quality. The amount of data is being reduced using a lossless coding method. However the amount is still too high to directly work with these data. The format can be used for example for digital restoration. For a rapid access to the movie data a so called Intermediate Archive Package is extracted out of the MAP by an automatic conversion process. For this purpose the image material is transcoded to a fixed low-resolution level, if necessary. The material is lossy coded to enable easy handling of the data amount.
• Metadata can be automatically extracted from the IAP and can be transferred into a database for online access. The user can search using these metadata to find the desired material. For preview direct access to the media data within the package is possible. Having found the desired movie, the whole motion picture or only the footage can be ordered in the necessary and suitable data format. Again an automated process generates a Dissemination Package out of the IAP for download or streaming. The advantage is that different user whether it is a movie theater, a broadcast station or a private user group can be served out of the same data base.

Standardized Format for Archiving

The precondition for long-term archiving is the use of established, well-documented open standards. That is the only way to guarantee that future generations can read and interpret the archived digital material. For archiving JPEG2000 is the preferred coding format, because of features such as scalable coding regarding resolution and screening quality and the easy creation of low resolutions. For an IAP also a Digital Cinema Package (DCP) can be easily created for the screening in a movie theater. JPEG2000 is also the SMPTE standard for Digital Cinema.

For media data packaging and synchronization and for metadata storage of image and sound the MXF (Metadata Exchange Format) is used. MXF is an established standard, too, which offers the required flexibility for access and archiving purposes. E. g. different meta data structures of different archives can be implemented without changing the whole system.