DAVIC and interactive multimedia services

DAVIC is establishing the industry standard for end-to-end interoperability of broadcast and interactive digital audio-visual information. Its published specifications, DAVIC 1.0-1.4, are backward compatible and form the foundation for commercial interactive multimedia experiences. Each specification is market-driven and developed where possible in close synergy with the products and work in progress of other standards-developing organizations. In addition, DAVIC 1.3.1 has been submitted as a Draft International Standard to ISO/IEC JTC 1 in order to establish this industry specification as a recognized international standard and to contribute to the international standards community. DAVIC's future goals are clear, and significant progress is being made on achieving TV anytime/anywhere as the next stage to full interactive multimedia services     

Adaptive algorithms for interactive multimedia

Modeling multimedia content by identifying semantically meaningful entities can be arduous because it's difficult to simulate human perception. However, by creating an algorithm to respond interactively to user preference, content-retrieval systems can become more efficient and easier to use.     

Synchronization for interactive multimedia presentations

When multimedia presentations allow users to make online adjustments such as reverse, skip, freeze-restart, and scale, maintaining temporal synchrony among several media streams becomes a complex modeling problem. Our approach uses dynamic extended finite-state machines for the task-an “actor” DEFSM for each medium and a “synchronizer” DEFSM to orchestrate them. This model achieves clear state-transition control flow and allows concise, precise specifications     

Technologies for multimedia communications

A number of technologies-based upon the sensory modalities of sight, sound, and touch-are becoming well enough established that their coordinated application can expand capabilities for human/machine interaction. This paper examines evolving advances in natural language communication with machines, video, and audio compression, spatially realistic conferencing, tactile interaction, and high-speed data communication. It considers the integration of these technologies into networked information systems to achieve synergistic benefits for the human user     

The use of session control in DAVIC to provide interactive multimedia services

This paper begins with an introduction to DAVIC, with particular reference to its objectives and plans. It then considers the split of the functional model into the three roles — service consumer system, delivery system and service provider system. Once the vertical split of the functional model has been considered the horizontal split into S1-S4 levels is covered. The paper then expands on the concepts of session and connection control through the use of the S2, S3 and S4 levels in the set-up, transfer and release of a user-to-network session and the end-to-end control of the user-to-user session. Finally, future plans/directions for DAVIC are considered, along with the adoption of Internet technologies within the DAVIC specifications.     

EuroBridge: communications services for multimedia applications

The aim of the EuroBridge project is to provide a uniform communication service platform. This platform will provide true multimedia multipoint services including interactive video conferencing and store-and-forward data services. The project will enhance selected OSI application layer services to provide them with multimedia capabilities. Selection of the initial services as well as the identification of necessary functional enhancements were based on actual user requirements. To support the dedicated communication requirements imposed by multimedia and multipoint applications, the lower layers of the OSI model will be enhanced accordingly. This includes designing and implementing new lightweight session and presentation protocols, respectively. Furthermore, high-speed transport protocols will be utilised. The actual protocol stack used will be configured dynamically depending on the requested quality of service. Support of multicast capabilities will be a crucial issue. The service platform is being implemented to run on top of different high-speed networks, including FDDI and DQDB     

A multimedia interactive conferencing application for personalworkstations

The multimedia interactive conferencing application (MICA), a personal-workstation application for multipoint visual teleconferencing, is described. MICA allows people at two or more locations to share visual material such as documents, photographs, and computer screens in a highly interactive way. It supports the distribution, storage, retrieval, and high-quality display of visuals, real-time interaction by pointing and annotation, and meeting services facilities. The context of multimedia teleconferencing and computer-supported cooperative work is established, relating earlier research to the design of MICA. The services MICA offers are outlined. The handling, compression, and display of multiple media, and the design of a suitable user interface for MICA are discussed     

A temporal model for interactive multimedia scenarios

Many authoring tools let authors create scenarios, but very few let them create an active multimedia scenario that will not only play itself back, but will change course dynamically, depending on user interactions. Our temporal model provides a new way to represent asynchronous and synchronous temporal events, allowing authors to create scenarios that offer viewers seamless, transparent options     

Congestion control for multimedia services

The problem of congestion control in high-speed networks for multimedia traffic, such as voice and video, is considered. It is shown that the performance requirements of high-speed networks involve delay, delay-jitter, and packet loss. A framing congestion control strategy based on a packet admission policy at the edges of the network and on a service discipline called stop-and-go queuing at the switching nodes is described. This strategy provides bounded end-to-end delay and a small and controllable delay-jitter. The strategy is applicable to packet switching networks in general, including fixed cell length asynchronous transfer mode (ATM), as well as networks with variable-size packets     

An early implementation of a DAVIC V1.0 system — use of dynamic connections for interactive multimedia services

Advances in networking technology and the provision of greater wide area bandwidths are the catalysts for the emergence of new broadband services in both the business and residential market. This is in turn producing new, more complex, business models involving service consumers, content providers, service brokers and network connectivity providers. Such business models require the underlying technology to enable sophisticated network signalling to set up, monitor and tear down connections reliably and in real time.This paper describes the evolution of a broadband call control demonstrator believed to be the first of its kind in the world to provide a practical realisation of the signalling required in such business models. It focuses on signalling and switch control and has developed into an end-to-end implementation of a Digital Audio Visual Council (DAVIC) V1.0 system.The evolution of the switch control and signalling architecture is described, showing where existing standards have been implemented to provide basic connectivity across an ATM network. Additional capabilities are built upon this platform through the adoption of emerging signalling concepts, such as session control, and application control using distributed object-oriented principles, for the access and control of a video-on-demand service.To further understand the evolutionary path for emerging consumer systems, the paper illustrates how work was undertaken to separate set-top box (STB) functionality into a set-top unit (STU) and a network interface unit (NIU), allowing easier access to future broadband network capabilities.     

Lifelike talking faces for interactive services

Lifelike talking faces for interactive services are an exciting new modality for man-machine interactions. Recent developments in speech synthesis and computer animation enable the real-time synthesis of faces that look and behave like real people, opening opportunities to make interactions with computers more like face-to-face conversations. This paper focuses on the technologies for creating lifelike talking heads, illustrating the two main approaches: model-based animations and sample-based animations. The traditional model-based approach uses three-dimensional wire-frame models, which can be animated from high-level parameters such as muscle actions, lip postures, and facial expressions. The sample-based approach, on the other hand, concatenates segments of recorded videos, instead of trying to model the dynamics of the animations in detail. Recent advances in image analysis enable the creation of large databases of mouth and eye images, suited for sample-based animations. The sample-based approach tends to generate more naturally looking animations at the expense of a larger size and less flexibility than the model-based animations. Beside lip articulation, a talking head must show appropriate head movements, in order to appear natural. We illustrate how such "visual prosody" is analyzed and added to the animations. Finally, we present four applications where the use of face animation in interactive services results in engaging user interfaces and an increased level of trust between user and machine. Using an RTP-based protocol, face animation can be driven with only 800 bits/s in addition to the rate for transmitting audio.     

An interactive multimedia satellite telemedicine service

We present a telemedicine application, called the Medical Environment for Diagnostic Images (MEDI), that provides remote medical care services while taking advantage of the broadcast and multicast capabilities and the wide-band capacity of satellite systems. We developed the application in an open environment (Java) using a client-server architecture based on TCP/IP. We evaluated the performance of the application on satellite connections     

Delivering interactive multimedia documents over networks

A family of applications that consists of interactive multimedia documents, such as electronic magazines and interactive TV shows, is examined and the links between application architecture, user behavior, and network performance are investigated. The kinds of application-specific information that influence the end-to-end quality of service are discussed. The architecture and dynamics of the interactive document in terms of presentation objects (P-Objects), which are the segments of information accessed by the application and which are described according to their size, media composition, and access links, are described. The same structural characteristics that may make an interactive multimedia document appealing to the end user are the characteristics that are helpful during dynamic network performance optimization. This observation is based on the hypothesis that the P-Objects' access graph, together with viewing time statistics, is the information most useful to the network delivery control mechanism for optimizing network performance. Preliminary guidelines for both network and application designers to address each other's concerns are presented     

多屏数字动画的多媒体交互系统设计

针对传统的多媒体交互系统无法在多个显示器上进行承接的连续操作,设计了一种多屏数字动画的多媒体交互系统,硬件使用C/S架构,保证数字动画能够在多屏多媒体上进行连接,软件上建立了数据承接模型,保证多媒体的数字动画承接,同时能够进行及时的交互反馈。这样避免了双系统的操作难题,保证了交互过程的完整性,优化RTP和RTCP多媒体数据反馈,改变了传统交互反馈系统的差值性,这样可以根据不同的操作系统进行及时的数据反馈。为了验证设计的多屏数字动画的多媒体交互系统的有效性,设计了对比仿真实验,通过实验结果有效地证明了设计的多屏数字动画的多媒体交互系统能够在多屏下完成数字动画的多媒体交互。     

Accessing multimedia network services

An experiment in architecture design for multimedia network services is described. The results obtained suggest that reference models for generalized hypertext systems, commonly called hypermedia systems, may be more readily formulated within the object-oriented system paradigm than other approaches currently under consideration for hypertext alone. The development of the software architecture for Libernet.91, a system for remote access and control of multimedia source material, is discussed. Concepts of object-oriented database management systems are outlined. The underlying architecture of the implemented system is compared to the Dexter hypertext reference model     

Modelling mobile multimedia services

Future multimedia and Internet services will have more complex characteristics than the traditional service types. Accurate planning of mobile networks requires accurate prediction of traffic flows, which involves complex relationships between the services themselves, the mobility of users, and the business environment. This paper describes the work of the Mobile VCE services programme on new traffic models that take all three factors into account     

A signaling protocol for complex multimedia services

The author introduces a signaling protocol for user applications that invokes multimedia services provided by the EXPANSE research prototype, a broadband ISDN testbed. A generic framework that flexibly accommodates a wide variety of services involving multiple parties with heterogeneous terminals is described. The author describes the generic services supported, introduces the EXPANSE call model, discusses syntax and message flow procedures, and relates EXPANSE signaling to the ISDN signaling control part (ISCP) and long-term broadband ISDN signaling work currently under study by CCITT     

Policy-driven personalized multimedia services for mobile users

This paper proposes an agent-based service provisioning system for mobile users. It describes a set of cooperative agents distributed over different sites that work together to provide personalized services for mobile users over the Internet. Users moving outside the office are able to maintain an off ice-like environment at home, or at temporary locations such as a meeting at another company, a business trip, or a hotel. Agents representing the end-users and the system agents engage in a negotiation process to facilitate access to personalized services at other sites. This access is obtained in accordance with the users' home policies as well as those at their current location. An Adaptive Service Presentation agent is used to adapt the service presentation to the capabilities of the users' workstations, laptops, phones, PDAs, or other devices. This work is conducted in Canada as part of the Mobile Agent Alliance project involving the University of Ottawa, the National Research Council, and the Mitel Corporation.