Abstract: The invention provides a system and method of enhancing efficiency in a data processing system having a processor, a memory, and a multitasking operating system for managing the processor and the memory. A normal and an expedited scheduling path are provided for scheduling tasks on the processor. The tasks are each assigned a priority for execution on the processor. A queue is provided for the placement of tasks ready for execution. Upon entry into the ready-to-run queue, the execution priority of the new task is compared to the execution priority of the executing task. Responsive to the new task holding a higher execution priority or to absence of an executing task, the expedited scheduling path is invoked. Otherwise the normal scheduling path is invoked.

Abstract: A multimedia data processing system includes a memory for storing multimedia application programs and a multitasking operating system. Extensions to the operating system control data streaming from source devices to target devices to provide real-time, continuous streaming. The extensions provide central buffer management with a user buffer option, bi-level priority support for data stream handlers, support for interleaved streams, and data stream event detection and notification.

Abstract: A data stream is created for moving data from a source to a target in accordance with a stream protocol defined by controlling stream protocol control blocks (SPCBs) created from a predefined source SPCB and a predefined target SPCB. The controlling SPCBs include information establishing a plurality of data buffers that are used to efficiently stream or transfer data on a real-time basis. The controlling SPCBs are formed by a process of negotiation in which differences between the source and target SPCBs are reconciled in accordance with rules of negotiation. Once the data stream is created, it is then started by the application program and data is streamed until an end of stream is reached.

Abstract: A personal computer based, multimedia, data processing system includes a software solution to the problem of synchronizing two or more data streams which output data to two or more multimedia output devices. One stream is a master and each other stream is a slave. The master stream generates sync pulses that can be handled in two different synchronization methods, master-slave independent synchronization or master-driven slave synchronization. Sync pulses are generated with a predetermined granularity, and synchronization is achieved when a slave stream is out of tolerance. Adaptive resynchronization may be used to speed up or slow down a slave stream.