Sidebar 3 to 'Apple QuickTime 3.0 and the Avid/Microsoft Advanced Authoring Format ' Article
Standardization and Registration of Metadata

SMPTE has been a leader in standardizing metadata and file format for video. The SMPTE wipe standards are well known and supported by many nonlinear editors (and by QuickTime 3), though the resulting effects are boring compared to the dazzling transitions and filters in today's nonlinear editors. SMPTE Universal Labels, a central key to enable interoperability, are already standardized as SMPTE 298M-1997. Metadata about a video stream is needed in production, post-production, and distribution. Plans are to automate the capture of production metadata well beyond time code and camera settings, to geographic information and production credits, and possibly keywords or automatic pattern recognition indices to facilitate picture search and retrieval.

In post-production the metadata is compositional information, plus information about where all the original video streams and archived analog material are located. When the video is more than a cuts-only edit, complex content may include much more than sophisticated effects. A single image frame may be composited from many video layers, and a succession of manual keyframes or motion algorithms may fly these image layers around and manipulate them without limit. Metadata architects are designing file formats, a data model, and an object-oriented storage model or container suite that can link data with the executable code for all these algorithms, wherever this code may be. The goal is a single overall data model which is a superset of all application-specific data models, and to which every company can provide a bidirectional converter. Work on this data model has been under way in SMPTE since early 1997, combining the work of DAVIC, OMFI and the Department of Defense.

For digital distribution a number of streaming formats must be standardized. There will probably be different standards for each application domain or interconnect technology, for example streaming an "offline" project to an "online" facility for finishing, and streaming a finished program via broadcast, digital satellite, and the Internet to viewers receivers. These can all interoperate via SMPTE Universal Labels. Today's streaming formats like Microsoft ASF, and Microsoft's planned streaming use for AAF, 'flatten' the streams and remove metedata when they are sent to the viewing 'client' or end user.

Posted: May 1998
Bob Lamm, SMPTE/New England Newsletter/Web Page Editor
blamm@cync.com