This part of ISO/IEC 14478 describes a set of Object types and non-Object types to provide the construction of, presentation of, and the interaction with Multimedia information. The multimedia information tan be graphics, Video, audio, or other types of presentable media. This information tan be enhanced by time aspects. Throughout this document this part of ISO/IEC 14478 will also be referred to as "Modelling, Rendering and Interaction", and abbreviated as MRI. The Modelling, Rendering and Interaction Component constitutes a framework of ?Middleware', System Software components lying between the generic operating System and computing environment, and a specific application operating as a client of the Services and type definitions provided by this component. It provides a framework over the foundation objects and multimedia Systems Services defined in other Parts of the international Standard for the development of a distributed and heterogeneous network of devices for creating multimedia models, rendering these models, and interacting with this process.

The Modelling, Rendering and Interaction Component encompasses the following characteristics:

a) Provision of a hierarchy of multimedia primitives as an abstract framework for describing the capabilities of modelling and rendering devices, and for enabling their interoperation;

b) within the primitive hierarchy, specific Provision for describing the temporal structure of multimedia data through the stepwise construction of structured primitives from component data;

c) Provision of abstract types for modelers, renderers and other supporting devices, enabling the integration of such devices or any future subtypes representing real Software or hardware, into a processing network of such devices;

d) provision of an Object type to map synchronization requirements expressed within multimedia primitives into control of the stream and synchronization mechanisms provided by ISO/IEC 14478-2 and ISO/IEC 14478-3.

The Modelling, Rendering and Interaction Component relies on the Object types and Services defined in PREMO Part 2: Foundation Components (ISO/IEC 1447%2), and PREMO Part 3: Multimedia Systems Services (ISO/IEC 14478-3).