Synchronization properties in multimedia systems
IBM1
TL;DR: The concept of multimedia objects as components of an object-based model for a multimedia system is introduced and the essential new synchronization requirement is restricted blocking together with synchronization features covering real-time aspects.
Abstract: Multimedia is defined as the integrated generation, representation, processing, storage, and dissemination of independent machine-processable information expressed in multiple time-dependent and time-independent media such as data, graphics, drawings, voice, audio, and video. The characteristics of synchronization mechanisms desirable for central and distributed multimedia systems are addressed. The concept of multimedia objects as components of an object-based model for a multimedia system is introduced. The essential new synchronization requirement is restricted blocking together with synchronization features covering real-time aspects. Existing synchronization mechanisms can be altered or new ones defined to meet these requirements. >
Citations
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Patent•
15 May 2000
TL;DR: In this paper, an automated communications system operates to transfer data, metadata and methods from a provider computer to a consumer computer through a communications network, including responses by the consumer computer, updating of information, and processes for future communications.
Abstract: An automated communications system operates to transfer data, metadata and methods from a provider computer to a consumer computer through a communications network. The transferred information controls the communications relationship, including responses by the consumer computer, updating of information, and processes for future communications. Information which changes in the provider computer is automatically updated in the consumer computer through the communications system in order to maintain continuity of the relationship. Transfer of metadata and methods permits intelligent processing of information by the consumer computer and combined control by the provider and consumer of the types and content of information subsequently transferred. Object oriented processing is used for storage and transfer of information. The use of metadata and methods further allows for automating may of the actions underlying the communications, including communication acknowledgements and archiving of information. Service objects and partner servers provide specialized data, metadata, and methods to providers and consumers to automate many common communications services and transactions useful to both providers and consumers. A combination of the provider and consumer programs and databases allows for additional functionality, including coordination of multiple users for a single database.
2,304Â citations
Patent•
03 Jan 1992
TL;DR: In this paper, a system of distributing video and audio information employs digital signal processing to achieve high rates of data compression, and the compressed and encoded audio and 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.
Abstract: 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.
1,032Â citations
IBM1
TL;DR: This survey summarizes briefly synchronization requirements, presents a multimedia synchronization reference model, shows details of various specification approaches and applies the reference model to compare existing prominent approaches as case studies.
Abstract: Researchers have addressed multimedia synchronization from various perspectives. The major issues include how to specify and how to implement synchronization. Especially in the specification area a variety of techniques have been published and implemented. This survey summarizes briefly synchronization requirements, presents a multimedia synchronization reference model, shows details of various specification approaches and applies the reference model to compare existing prominent approaches as case studies.
523Â citations
TL;DR: A quantitative study of techniques for designing a high-performance multiuser multimedia on-demand information service is presented, and the feedback technique guarantees synchronous playback of media streams transmitted by the multimedia server to subscribers over metropolitan-area networks.
Abstract: A quantitative study of techniques for designing a high-performance multiuser multimedia on-demand information service is presented. The problem of maintaining continuity of playback of each media stream in the presence of multiple subscriber requests is formulated, and admission control algorithms that permit a multimedia server to satisfy the maximum number of subscribers simultaneously are presented. A feedback technique in which a multimedia service uses lightweight messages called feedback units that are transmitted back to it by subscribers' mediaphones to detect asynchrony among them and steer them back to synchrony thereafter is presented. The feedback technique guarantees synchronous playback of media streams transmitted by the multimedia server to subscribers over metropolitan-area networks. >
505Â citations
IBM1
TL;DR: The results show that skews between related data streams may still give the effect that the data is 'in sync' and the author uses the findings to develop a scheme for the processing of nontrivial synchronization skew between more than two data streams.
Abstract: Multimedia synchronization comprises both the definition and the establishment of temporal relationships among media types. The presentation of 'in sync' data streams is essential to achieve a natural impression, data that is 'out of sync' is perceived as being somewhat artificial, strange, or even annoying. Therefore, the goal of any multimedia system is to enable an application to present data without no or little synchronization errors. The achievement of this goal requires a detailed knowledge of the synchronization requirements at the user interface. The paper presents the results of a series of experiments about human media perception that may be used as 'quality of service' guidelines. The results show that skews between related data streams may still give the effect that the data is 'in sync' and gives some constraints under which jitter may be tolerated. The author uses the findings to develop a scheme for the processing of nontrivial synchronization skew between more than two data streams.
475Â citations
References
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TL;DR: It is suggested that input and output are basic primitives of programming and that parallel composition of communicating sequential processes is a fundamental program structuring method.
Abstract: This paper suggests that input and output are basic primitives of programming and that parallel composition of communicating sequential processes is a fundamental program structuring method. When combined with a development of Dijkstra's guarded command, these concepts are surprisingly versatile. Their use is illustrated by sample solutions of a variety of a familiar programming exercises.
11,419Â citations
TL;DR: This paper identifies the major concepts and describes some of the more important language notations for writing concurrent programs and three general classes of concurrent programming languages are identified and compared.
Abstract: Much has been learned in the last decade about concurrent programming. This paper identifies the major concepts and describes some of the more important language notations for writing concurrent programs. The roles of processes, communication and syhchronization are discussed from both an operational and an axiomatic viewpoint. Language notations for expressing concurrent execution and for specifying process interaction are surveyed. Synchronization primitives based on shared variables and on message passing are described. Finally, three general classes of concurrent programming languages are identified and compared.
540Â citations
TL;DR: The article describes four document systems developed or under development at Brown University that illustrate many of the different necessary functions of electronic document systems.
293Â citations
Book•
02 Jan 1991
TL;DR: The author presents an overview of fiber distributed data interface (FDDI) technology and explores the basis for its success, and particular emphasis is placed on the technical specifications for an upwards-compatible version of FDDI, FDDi-II, which adds the capability for circuit-switched services to the packet services of the basic F DDI, thus creating an integrated services LAN.
Abstract: Updating earlier efforts in previously published work, the author presents an overview of fiber distributed data interface (FDDI) technology and explores the basis for its success. Particular emphasis is placed on the technical specifications for an upwards-compatible version of FDDI, FDDI-II, which adds the capability for circuit-switched services to the packet services of the basic FDDI, thus creating an integrated services LAN. >
288Â citations
[...]
TL;DR: The authors discuss QPSX (queued packet and synchronous switch), a distributed switch/network that will fulfil the requirements of a public metropolitan area network (MAN) and has wide telephone industry support.
Abstract: The authors discuss QPSX (queued packet and synchronous switch), a distributed switch/network that will fulfil the requirements of a public metropolitan area network (MAN) and has wide telephone industry support. The dual-bus architecture of QPSX and its extension, the looped-bus architecture, are described. The architecture of the public MAN is examined, particularly with respect to QPSX as a proposal for IEE P802.6 standardization. The distributed queueing protocol, segmentation and reassembly scheme, and reliability features of the QPSX network are discussed. >
251Â citations