Dvd navigation system with multiple threads

Abstract

A navigation system for a digital versatile disc system includes multiple synchronized threads, each of which separately performs a single task so that several tasks can be performed concurrently. In one embodiment, a stream parser thread, a navigation thread and a user interface thread are always created when the DVD player begins operation. In addition, a highlight thread may also be created if the DVD data stream contains highlight information. The stream parser thread receives the DVD data stream and extracts navigation commands and DVD content data from the stream. The navigation commands are sent to the navigation thread for processing, but the content data is sent to system decoders for display. The navigation thread operates separately from the stream parser thread and processes the retrieved navigation commands to select portions of the DVD data stream for display. The user interface thread also operates separately from the stream parser thread and the navigation thread and responds to user commands generated by a user input device, such as a mouse or keyboard, for highlighting buttons on the DVD display screen. Although the threads operate separately, they are synchronized by means of an event control mechanism which may be part of the conventional operating system.