Abstract: Methods of encoding and decoding data in variable-length data structures, such as that found in motion picture data. Data in an MPEG standard format may be encoded in a format which is not easily subject to unauthorized copying, but which may be easily displayed in a real-time video and audio display. The encoded data may be less subject to errors in data distribution and data storage than known methods of data transformation. Encoded data may be multiplexed with non-encoded data, or may be multiplexed with data encoded by another technique, in such manner that recovery of the original motion picture video and audio may still be achieved in real time. The degree of encoding may take on differing values, so that, for example, all motion picture data is encoded for one video clip, while only some of data is encoded for a second video clip.

Abstract: Presentation of digital video and audio data in a computer system. Am application program may call upon a driver program to manipulate streams of video and audio data, including commands to present the video or audio to an operator, retrieve status information about the presentation, simultaneously present graphics with video data, halt or pause presentations, allocate or release resources for presentation, and group multiple streams for synchrony. The driver program may operate upon the grouped streams in synchrony in response to unified commands from the application program. An interface to the driver program may comprise a interrupt instruction invoked with a designated interrupt and a designated set of commands: initialization; open and close; play, pause, stop, seek, and step; group; set and get; installation; and termination.

Abstract: Methods of encoding and decoding data in variable-length data structures, such as that found in motion picture data. Data in an MPEG standard format may be encoded in a format which is not easily subject to unauthorized copying, but which may be easily displayed in a real-time video and audio display. The encoded data may be less subject to errors in data distribution and data storage than known methods of data transformation. Encoded data may be multiplexed with non-encoded data, or may be multiplexed with data encoded by another technique, in such manner that recovery of the original motion picture video and audio may still be achieved in real time. The degree of encoding may take on differing values, so that, for example, all motion picture data is encoded for one video clip, while only some of data is encoded for a second video clip.