Abstract: Given a hardware platform capable of capturing framed data in a multiplexed fashion from multiple sources, a method and apparatus are shown for providing a constant frame rate for each logical stream.

Abstract: Within a computer system, a system and method of providing timestamps for media stream input data is provided. A first clock count register is responsive to a first timebase, and a second clock count register is responsive to a second timebase. The first and second time bases can be correlated. When a frame of media stream input data is captured, the value of the first clock count register can be preserved. This value is a timestamp expressed in terms of the first timebase. The timestamp value in terms of the second timebase is computed and associated with the captured frame of media stream input data.

Abstract: An enhanced multimedia device driver for personal computers includes a polling process which performs polling of the hardware devices. The device driver creates a helper thread for each hardware device which executes in the client context. Each polling process wakes up at a regular interval at which time it polls the status register of the corresponding hardware device. If there is an event pending at the status register, then the polling process signals the event pending to all of the helper threads. Each helper thread wakes up and checks the reason for the wakeup. At this point, the helper thread will initiate a data transfer using programmed I/O if called for by the reason for the wakeup. Through the use of the present invention, the DMA controller, the system interrupt controller, and the kernel interrupt handler of the kernel are not employed in data transfers and the use of DMAs and/or IRQs for data transfers is eliminated.