Synchronization of Multi-Sourced Multimedia Data for Heterogeneous Target Systems

Accessing multimedia information in a networked environment introduces problems to an application designer that don't exist when the same information is fetched locally. These problems include "competing" for the allocation of network resources across applications, synchronizing data arrivals from various sources within an application, and supporting multiple data representations across heterogeneous hosts. In this paper, we present a general framework for addressing these problems that is based on the assumption that time-sensitive data can only be controlled by having the application, the operating system(s) and a set of active, intelligent information object coordinate their activities based on a

Distributed multimedia systems

A distributed multimedia system (DMS) is an integrated communication, computing, and information system that enables the processing, management, delivery, and presentation of synchronized multimedia information with quality-of-service guarantees. Multimedia information may include discrete media data, such as text, data, and images, and continuous media data, such as video and audio. Such a system enhances human communications by exploiting both visual and aural senses and provides the ultimate flexibility in work and entertainment, allowing one to collaborate with remote participants, view movies on demand, access on-line digital libraries from the desktop, and so forth. In this paper, we present a technical survey of a DMS. We give an overview of distributed multimedia systems, examine the fundamental concept of digital media, identify the applications, and survey the important enabling technologies.published_or_final_versio

An Open Framework for Integrating Widely Distributed Hypermedia Resources

The success of the WWW has served as an illustration of how hypermedia functionality can enhance access to large amounts of distributed information. However, the WWW and many other distributed hypermedia systems offer very simple forms of hypermedia functionality which are not easily applied to existing applications and data formats, and cannot easily incorporate alternative functions which would aid hypermedia navigation to and from existing documents that have not been developed with hypermedia access in mind. This paper describes the extension to a distributed environment of the open hypermedia functionality of the Microcosm system, which is designed to support the provision of hypermedia access to a wide range of source material and application, and to offer straightforward extension of the system to incorporate new forms of information access

Proceedings of the ECSCW'95 Workshop on the Role of Version Control in CSCW Applications

The workshop entitled "The Role of Version Control in Computer Supported Cooperative Work Applications" was held on September 10, 1995 in Stockholm, Sweden in conjunction with the ECSCW'95 conference. Version control, the ability to manage relationships between successive instances of artifacts, organize those instances into meaningful structures, and support navigation and other operations on those structures, is an important problem in CSCW applications. It has long been recognized as a critical issue for inherently cooperative tasks such as software engineering, technical documentation, and authoring. The primary challenge for versioning in these areas is to support opportunistic, open-ended design processes requiring the preservation of historical perspectives in the design process, the reuse of previous designs, and the exploitation of alternative designs. The primary goal of this workshop was to bring together a diverse group of individuals interested in examining the role of versioning in Computer Supported Cooperative Work. Participation was encouraged from members of the research community currently investigating the versioning process in CSCW as well as application designers and developers who are familiar with the real-world requirements for versioning in CSCW. Both groups were represented at the workshop resulting in an exchange of ideas and information that helped to familiarize developers with the most recent research results in the area, and to provide researchers with an updated view of the needs and challenges faced by application developers. In preparing for this workshop, the organizers were able to build upon the results of their previous one entitled "The Workshop on Versioning in Hypertext" held in conjunction with the ECHT'94 conference. The following section of this report contains a summary in which the workshop organizers report the major results of the workshop. The summary is followed by a section that contains the position papers that were accepted to the workshop. The position papers provide more detailed information describing recent research efforts of the workshop participants as well as current challenges that are being encountered in the development of CSCW applications. A list of workshop participants is provided at the end of the report. The organizers would like to thank all of the participants for their contributions which were, of course, vital to the success of the workshop. We would also like to thank the ECSCW'95 conference organizers for providing a forum in which this workshop was possible

Structured multimedia authoring

We present the user interface to the CMIF authoring environment for constructing and playing multimedia presentations. The CMIF authoring environment supports a rich hypermedia document model allowing structure-based composition of multimedia presentations and the specification of synchronization constraints between constituent media items. An author constructs a multimedia presentation in terms of its structure and additional synchronization constraints, from which the CMIF player derives the precise timing information for the presentation. We discuss the advantages of a structured approach to authoring multimedia, and describe the facilities in the CMIF authoring environment for supporting this approach. The authoring environment presents three main views of a multimedia presentation: the hierarchy view is used for manipulating and viewing a presentation's hierarchical structure; the channel view is used for managing logical resources and specifying and viewing precise timing constra..

Structured Multimedia Authoring

Authoring context sensitive, interactive multimedia presentations is much more complex than authoring either purely audiovisual applications or text. Interactions among media objects need to be described as a set of spatio-temporal relationships that account for synchronous and asynchronous interactions, as well as on-demand linking behavior. This article considers the issues that need to be addressed by an authoring environment. We begin with a partitioning of concerns based on seven classes of authoring problems. We then describe a selection of multimedia authoring environments within four different authoring paradigms: structured, timeline, graph and scripting. We next provide observations and insights into the authoring process and argue that the structured paradigm provides the most useful framework for presentation authoring. We close with an example application of the structured multimedia authoring paradigm in the context of our own structure-based system GRiNS