BS ISO/IEC 14478-3:1998

Information technology. Computer graphics and image processing. Presentation environment for multimedia objects (PREMO). Multimedia systems services | Status: Current, Under review

1 Scope This part of ISO/IEC 14478 defines a standard set of multimedia system services that can be used by multimedia application developers in a variety of computing environments. The focus is on enabling multimedia applications in a heterogeneous, distributed computing environment. Throughout this part of ISO/IEC 14478, this component will also be referred to as “Multimedia Systems Services”, and abbreviated as MSS. The Multimedia Systems Services constitutes a framework of “middleware” — system software components lying in the region between the generic operating system and specific applications. As middleware, the Multimedia Systems Services marshals lower-level system resources to the task of supporting multimedia processing, providing a set of common services which can be used by multimedia application developers. The Multimedia Systems Services encompasses the following characteristics:

1. a) provision of an abstract type for a media processing node, extensible through subtyping to support abstractions of real media processing hardware or software;
2. b) provision of an abstract type for the data flow path or the connection between media processing nodes, encapsulating low-level connection and transport semantics;
3. c) grouping of multiple processing nodes and connections into a single unit for purposes of resource reservation and stream control;
4. d) provision of a media dataflow abstraction, with support for a variety of position, time and/or synchronization capabilities;
5. e) separation of the media format abstractions from the dataflow abstraction;
6. f) synchronous exceptions and asynchronous events;
7. g) application visible characterization of object capabilities;
8. h) registration of objects in a distributed environment by location and capabilities;
9. i) retrieval of objects in a distributed environment by location and constraints;
10. j) definition of a Media Stream Protocol to support media independent transport and synchronization.

The Multimedia Systems Services rely on the object model of ISO/IEC 14478‑1 (Fundamentals of PREMO) and the object types and non-object data types defined in ISO/IEC 14478‑2 (PREMO Foundation Component).