A system of distributing video and/or audio information employs digital signal processing to achieve high rates of data compression. The compressed and encoded audio and/or video information is sent over standard telephone, cable or satellite broadcast channels to a receiver specified by a subscriber of the service, preferably in less than real time, for later playback and optional recording on standard audio and/or video tape.

Audio and video transmission and receiving system

A multimedia interface (150) presents information and receives user commands for a computer system (160). The multimedia interface (150) operates in parallel with another application software module (52, 54), such as an expert system. To add multimedia features to the application software module (52, 54), the module is modified so as to generate multimedia commands at the same time as it displays text on a text monitor. The multimedia commands, which are held in a queue (74), provide additional information in the form of video images and generated speech corresponding to the displayed text. In addition, the multimedia commands are split into at least two sets: one set which is dispatched to the user substantially immediately after displaying the corresponding text, and one set which is dispatched only upon request by the user. In the preferred embodiment, the multimedia interface (150) presents information to the user through text, graphics, video, speech production, and printed output. User inputs are made through a special-function keypad (56) and voice recognition (62). The preferred embodiment is a portable expert system which fits in a single portable suitcase sized package (200).

Multimedia interface and method for computer system

We address the unique requirements of a multimedia file system such as continuous storage and retrieval of media, maintenance of synchronization between multiple media streams, and efficient manipulation of huge media objects. We present a model that relates disk and device characteristics to the recording rate, and derive storage granularity and scattering parameters that guarantee continuous access. In order for the file system to support multiple concurrent requests, we develop admission control algorithms for determining whether a new request can be accepted without violating the realtime constraints of any of the requests.We define a strand as an immutable sequence of continuously recorded media samples, and then present a multimedia rope abstraction which is a collection of individual media strands tied together by synchronization information. We devise operations for efficient manipulation of multi-stranded ropes, and develop an algorithm for maintaining the scattering parameter during editing so as to guarantee continuous playback of edited ropes.We have implemented a prototype multimedia file system, which serves as a testbed for experimenting with policies and algorithms for multimedia storage. We present our initial experiences with using the file system.

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Designing file systems for digital video and audio

A framework is presented for the specification of performance requirements, and several high-level design principles for performance-driven ATM traffic controls based on resource reservation are developed. Simulation results illustrate that to guarantee performance levels, bursty traffic should be statistically multiplexed only if connection peak rates are low relative to the network link speed or burst durations are short. A pragmatic traffic management approach that favors simplicity and robustness in the traffic control design rather than optimizing bandwidth efficiency is stressed. >

Multimedia traffic management principles for guaranteed ATM network performance

The problem of collocational storage of media strands, which are sequences of continuously recorded audio samples or video frames, on disk to support the integration of storage and transmission of multimedia data with computing is examined. A model that relates disk and device characteristics to the playback rates of media strands and derives storage patterns so as to guarantee continuous retrieval of media strands is presented. To efficiently utilize the disk space, mechanisms for merging storage patterns of multiple media strands by filling the gaps between media blocks of one strand with media blocks of other strands are developed. Both an online algorithm suitable for merging a new media strand into a set of already stored strands and an offline merging algorithm that can be applied a priori to the storage of a set of media strands before any of them have been stored on disk are proposed. As a consequence of merging, storage patterns of media strands may become perturbed slightly. To compensate for this read-ahead and buffering are required so that continuity of retrieval remains satisfied are also presented. >

Efficient storage techniques for digital continuous multimedia

New technology is changing the way we store documents. This experimental system features flexible document retrieval, a distributed architecture, and the capacity to store many very large documents.

Y. Yeorgaroudakis

Papers

Muse: A Multimedia Filing System