| 摘要 |
A method and apparatus for composing and presenting multimedia programs usin g the MPEG-4 standard at a multimedia terminal (100). A composition engine (12 0) maintains and updates a scene graph (124) of the current objects, including their relative position in a scene and their characteristics, and provides a corresponding list of objects (126) to be displayed to a presentation engine (150). In response, the presentation engine begins to retrieve the corresponding decoded object data that is stored in respective composition buffers (176, . . . 186). The presentation engine assembles the decoded objects to provide a scene for presentation on output devices such as a vide o monitor (240) and speakers (242), or for storage. A terminal manager (110) receives user commands and causes the composition engine to update the scene graph and list of objects accordingly. The terminal manager also forwards th e information contained in the object descriptors to a scene decoder (122) at the composition engine. |
