Real-time software-based video coder for multimedia communication systems

A novel software-based video compression algorithm, the Popular Video Coder (PVC), is presented in this paper, and a video phone system, the Popular Phone, is also implemented based on the PVC. The PVC simplifies the traditional video coder by removing the transform and the motion estimation parts and modifies the quantizer and entropy coder. Two novel coding algorithms, the adaptive quantizer and the modified windowed Huffman-like coder, are used in the PVC to encode the video data with a quality picture at a high compression ratio. The video quality of the proposed coder is as good as that of the MPEG coder when the input is a low-resolution and slow-motion video, and the computational complexity of the PVC is much lower than that of the Motion Picture Expert Group (MPEG). Since no compression hardware is needed for the PVC to encode and decode video data, the cost and complexity of developing multimedia applications, such as video phone and multimedia e-mail systems, can be greatly reduced. Furthermore, some networking issues, such as error control and flow control, are discussed in connection with applying the PVC to implement the Popular Phone.     

DIPCS: An interprocess communication architecture for distributed multimedia systems

This paper presents the Distributed InterProcess Communication System (DIPCS) as a framework for managing communication in a distributed multimedia system. Within DIPCS, connection level management is provided through a novel distributed process group model called ADP-Group communication. The ADP-Group paradigm defines a new type of group message passing, calledqos-reliable. Qos-reliable semantics are appropriate to controlling real-time multimedia communication, by allowing a spectrum of performance and reliability specifications to co-exist within one group. DIPCS also provides an abstract programming model of multimedia devices, easing control of a heterogeneous multimedia system. Distributed multimedia applications can be rapidly developed using simple group operation primitives. We show how ADP-Group message delivery semantics can be directly mapped into an efficient Integrated Services Network support policy.Supported by Computational Diagnostics, Inc., and the Benjamin Franklin Fund for the Commonwealth of Pennsylvania.Supported by the Rome Laboratory (RL) of the Air Force Material Command and the Defense Advanced Research Projects Agency (Contract F30602-93-C-0038).     

An approximate model for performance evaluation of real-time multimedia communication systems

A Markov Modulated Poisson Process (MMPP) is a doubly stochastic Poisson process which has recently received a lot of attention due to its ability to model a highly correlated arrival stream while retaining analytical tractability. In this paper, the cell arrival process from integrated voice and data sources is approximated by a two-state MMPP with batch arrivals (BMMPP). We propose a new matching technique which leads to more accurate performance prediction than other recent work for both delay estimation and evaluation of tail probabilities. While using BMMPP in the model does not noticeably increase the computational complexity over MMPP, it allows better representation of traffic sources with significantly higher burstiness. Another major contribution of the proposed model is its simplicity which makes the model suitable for real-time traffic control. An extended version of the model for integrated video, voice and data sources is also given with numerical examples again showing that the accuracy is quite satisfactory.     

Information assimilation framework for event detection in multimedia surveillance systems

Most multimedia surveillance and monitoring systems nowadays utilize multiple types of sensors to detect events of interest as and when they occur in the environment. However, due to the asynchrony among and diversity of sensors, information assimilation – how to combine the information obtained from asynchronous and multifarious sources is an important and challenging research problem. In this paper, we propose a framework for information assimilation that addresses the issues – “when”, “what” and “how” to assimilate the information obtained from different media sources in order to detect events in multimedia surveillance systems. The proposed framework adopts a hierarchical probabilistic assimilation approach to detect atomic and compound events. To detect an event, our framework uses not only the media streams available at the current instant but it also utilizes their two important properties – first, accumulated past history of whether they have been providing concurring or contradictory evidences, and – second, the system designer’s confidence in them. The experimental results show the utility of the proposed framework.     

CMSNS: a communication middleware for social networking and networked multimedia systems

Multimedia Tools and Applications - In this paper, we propose a communication middleware for social networking services (CMSNS) in order to reduce the development effort and to support high...     

Towards Environment-to-Environment (E2E) multimedia communication systems

We present an approach to connect multiple remote environments over web for natural interaction among people and objects. Focus of current communication and telepresence systems severely restrict user affordances in terms of movement, interaction, peripheral vision, spatio-semantic integrity and even information flow. These systems allow information transfer rather than experiential interaction. We propose Environment-to-Environment (E2E) as a new paradigm for communication which allows users to interact in natural manner using text, audio, and video by connecting environments. Each Environment is instrumented using as many different types of sensors as may be required to detect presence and activity of objects. This object position and activity information is used by a scalable event-based multimodal information system called EventServer to share the appropriate experiential information with other environments as well as to present incoming multimedia information on right displays and speakers. This paper describes the design principles for E2E communication, discusses system architecture, and gives our experience in implementing prototypes of such systems in telemedicine and office collaboration applications. We also discuss the research challenges and a road-map for creating more sophisticated E2E applications in near future.

Cybersecurity,intelligent multimedia systems for threat detection and data protection

Multimedia Tools and Applications -     

Transport protocol for real-time multimedia communication

With the advancements in multimedia and networking technologies, many distributed multimedia applications have been developed recently. These new applications rely on the underlying network support to transmit the multimedia real-time data between sites. Multimedia Transport Protocol (MMTP) is an experimental protocol designed for transmission of various multimedia data. MMTP uses multiple priority queues to support different levels of service requirements, and it discards packets from the transmission queue to reduce the network loading, and to ensure packets transmitted will meet the real-time constraint required by the data streams.     

Test generation for interaction detection in feature-rich communication systems

This paper proposes two techniques to generate test sequences to check the conformance of an implementation of a feature-rich communication system to its specification, as well as to detect the interactions between the features of the system. Concepts color span and feasible combination of features are introduced to measure the extent and possibility of the interactions between different features. Several algorithms are proposed to produce an approximate minimum-cost and minimum color span tour of the transition graph of a finite-state machine. Test generation using the proposed algorithms for the SIP-based Internet telephony end system and for the Link Management Protocol is reported.     

Termination detection for dynamically distributed systems with non-first-in-first-out communication

We propose a new algorithm for detecting termination of distributed systems. The algorithm works correctly whether the system is static or dynamic, whether the interprocess communication is synchronous or asynchronous, and whether the communication channels are first-in-first-out or not. The algorithm requires, in the worst case, O(nm) control messages in all, where n is the number of processes in the system and m is the total number of messages transmitted during the operation of the system. After the system terminates, the algorithm is able to detect the termination using only O(n) control messages; it is optimal if the system concerned is static.     

High-definition multimedia for multiparty low-latency interactive communication

We describe a high-quality collaborative environment that uses High-Definition (HD) video to achieve near realistic perception of a remote site. The capture part, consisting of a HD camera, Centaurus HD-SDI capture card, and UltraGrid software, produces a 1.5 Gbps UDP data stream of uncompressed HD video that is transferred over a 10GE network interface to the high-speed IP network. The HD video stream displaying uses either a software-based solution with color depth down-sampling and field de-interlacing, or another Centaurus card. Data distribution to individual participants of the videoconference is achieved using a user-controlled UDP packet reflector based on the Active Element idea. The viability of this system has been demonstrated at the iGrid 2005 conference for a three-way high quality videoconference among sites in the Czech Republic, Louisiana, and California.     

Real-time data analytics and event detection for IoT-enabled communication systems

Enterprise Communication Systems are designed in such a way to maximise the efficiency of communication and collaboration within the enterprise. With users becoming mobile, the Internet of Things (IoT) can play a crucial role in this process, but is far from being seamlessly integrated into modern online communications. In this paper, we present a semantic infrastructure for gathering, integrating and reasoning upon heterogeneous, distributed and continuously changing data streams by means of semantic technologies and rule-based inference. Our solution exploits semantics to go beyond today’s ad-hoc integration and processing of heterogeneous data sources for static and streaming data. It provides flexible and efficient processing techniques that can transform low-level data into high-level abstractions and actionable knowledge, bridging the gap between IoT and online Enterprise Communication Systems. We document the technologies used for acquisition and semantic enrichment of sensor data, continuous semantic query processing for integration and filtering, as well as stream reasoning for decision support. Our main contributions are the following, (i) we define and deploy a semantic processing pipeline for IoT-enabled Communication Systems, which builds upon existing systems for semantic data acquisition, continuous query processing and stream reasoning, detailing the implementation of each component of our framework; (ii) we present a rich semantic information model for representing and linking IoT data, social data and personal data in the Enterprise Communication scenario, by reusing and extending existing standard semantic models; (iii) we define and develop an expressive stream reasoning component as part of our framework, based on continuous query processing and non-monotonic reasoning for semantic streams, (iv) we conduct experiments to comparatively evaluate the performance of our data acquisition and semantic annotation layer based on OpenIoT, and the performance of our expressive reasoning layer in the scenario of Enterprise Communication.     

Multicriteria decision making for enhanced perception-based multimedia communication

This paper proposes an approach that integrates technical concerns with user perceptual considerations for intelligent decision making in the construction of tailor-made multimedia communication protocols. Thus, the proposed approach, based on multicriteria decision making (MDM), incorporates not only classical networking considerations, but, indeed, user preferences as well. Furthermore, in keeping with the task-dependent nature consistently identified in multimedia scenarios, the suggested communication protocols also take into account the type of multimedia application that they are transporting. Lastly, this approach also opens the possibility for such protocols to dynamically adapt based on a changing operating environment and user's preferences.     

基于SIP协议实现多媒体通信的研究

由IETF工作组发布的会话初始化协议(session initiation protocol,SIP)相关标准已经成为通信和网络界的研究热点.随着协议的不断完善,SIP的应用范围不断扩大,被广泛的应用于多媒体会议、VoIP、多媒体分发等领域.介绍了SIP协议的历史,介绍了SIP URI、SIP协议的4个主要网络组成要素.通过对SIP与H.323两种协议的对比,可以看出SIP的简单性和可扩展性等特点.实现了一个基于SIP协议的通信模型.     

Cognitive computing for intelligent multimedia systems

Multimedia Tools and Applications -     

Robust fault detection for Markovian jump systems with unreliable communication links

This article addresses the problem of robust fault detection for Markovian jump linear systems with unreliable communication links. In the network communication channel, the effects of signal quantisation and measurement missing, which appears typically in a network environment, are taken into consideration simultaneously. A stochastic variable satisfying the Bernoulli random binary distribution is utilised to model the phenomenon of the measurements missing. The aim is to design a fault detection filter such that, for all unknown input and incomplete measurements, the error between the residual and weighted faults is made as small as possible. A sufficient condition for the existence of the desired fault detection filter is established in terms of a set of linear matrix inequalities. A simulation example is provided to illustrate the effectiveness and applicability of the proposed techniques.     

A spatio-temporal semantic model for multimedia database systemsand multimedia information systems

As more information sources become available in multimedia systems, the development of abstract semantic models for video, audio, text, and image data is becoming very important. An abstract semantic model has two requirements: it should be rich enough to provide a friendly interface of multimedia presentation synchronization schedules to the users and it should be a good programming data structure for implementation in order to control multimedia playback. An abstract semantic model based on an augmented transition network (ATN) is presented. The inputs for ATNs are modeled by multimedia input strings. Multimedia input strings provide an efficient means for iconic indexing of the temporal/spatial relations of media streams and semantic objects. An ATN and its subnetworks are used to represent the appearing sequence of media streams and semantic objects. The arc label is a substring of a multimedia input string. In this design, a presentation is driven by a multimedia input string. Each subnetwork has its own multimedia input string. Database queries relative to text, image, and video can be answered via substring matching at subnetworks. Multimedia browsing allows users the flexibility to select any part of the presentation they prefer to see. This means that the ATN and its subnetworks can be included in multimedia database systems which are controlled by a database management system (DBMS). User interactions and loops are also provided in an ATN. Therefore, ATNs provide three major capabilities: multimedia presentations, temporal/spatial multimedia database searching, and multimedia browsing