INFORMATION TECHNOLOGY – GENERIC CODING OF AUDIO-VISUAL OBJECTS Part 1: Systems ISO/IEC 14496-1 Final Committee Draft of International Standard
The Systems part of this Final Committee Draft of International Standard describes a system for communicating interactive audiovisual scenes. Such scenes consist of: 1. the coded representation of natural or synthetic, 2D or 3D objects that can be manifested audibly and/or visually (media objects); 2. the coded representation of the spatio-temporal positioning of media objects as well as their behavior in response to interaction (scene des cription); and 3. the coded representation of information related to the management of information streams (synchronization, identification, des cription and association of stream content). The overall operation of a system communicating such audiovisual scenes is as follows. At the sending side, audiovisual scene information is compressed, supplemented with synchronization information and passed to a delivery layer that multiplexes it in one or more coded binary streams that are transmitted or stored. At the receiver these streams are demultiplexed and decompressed. The media objects are composed according to the scene des cription and synchronization information and presented to the end user. The end user may have the option to interact with the presentation. Interaction information can be processed locally or transmitted to the sender. This specification defines the semantic and syntactic rules of bitstreams that convey such scene information, as well as the details of their decoding processes. In particular, the Systems part of this Final Committee Draft of International Standard specifies the following tools: · a terminal model for time and buffer management; · a coded representation of interactive audiovisual scene des cription information (Binary Format for Scenes – BIFS); · a coded representation of identification and des cription of audiovisual streams as well as the logical dependencies between stream information (Object and other Des criptors); · a coded representation of synchronization information (Sync Layer – SL); · a multiplexed representation of individual streams in a single stream (FlexMux); and · a coded representation of des criptive audiovisual content information (Object Content Information – OCI). These various elements are described functionally in this clause and specified in the normative clauses that follow.
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