In this paper, we present an object-oriented multimedia data processing model to support a wide variety of applications requiring network-transparent accesses to stored multimedia data, real-time multimedia input devices, and multimedia processing components. Most multimedia solutions address the problem of authoring, storing, and downloading hypermedia data. But these solutions fall short in supporting long-time and continuous media I/O and communications. Our model addresses primitive objects and their compositions for real-time data interleaving, synchronization, routing and delivery, as well as acquisition, filtering, and output. These capabilities are abstracted and aggregated within an object-oriented paradigm. As an illustration, an audiovisual teleconference with a shared remote multimedia presentation is interpreted in this paradigm.