This article presents a low complexity dual tone multiple frequency (DTMF) signal detector that meets the International Telecommunication Union (ITU) Q.24 DTMF standard while implemented on a general purpose Digital Signal Processor (DSP). The proposed DTMF detector is based on the Goertzel algorithms and is well suited for a multichannel implementation. Our solution ofiers increased accuracy and noise margins, while preserving the inherited advantages of the Goertzel algorithm (less memory require- ments and computational complexity).

Este artigo apresenta um detector de tons duplos de múltiplas freqüências(DTMF) de baixa complexidade, implementado em Processador Digital de Sinais(DSP) de propósito geral, que atende ao padrão Q.24 DTMF da União Internacional de Telecomunicações (ITU). O detector DTMF proposto é baseado no algoritmo de Goertzel e bem adequado para implementação multicanal. Nossa solução oferece elevada precisão e margens de ruído, enquanto preservada vantagem inerente do algoritmo de Goertzel(menor necessidade de memóriae baixa complexidade computacional).

This paper presents a fast video search method that uses the durations of scenes of a query clip to find similar clips in an existing large database of videos. Using scene durations is a very fast method; however it returns a large number of false candidates and will not find the correct candidates if some scene changes are missed in the query clip or the database videos. The first problem can be solved by further refining the results of the scene duration search by comparing these results with the query clip using other, more detailed characteristics like brightness histogram. The second problem can be solved by introducing flexibility in the duration and existence of a scene. Numerical results show the efficiency of the scene duration search and its robustness against drawbacks of the basic scene detection algorithm. The presented methodology is used in the video search part of project DIVAS of the EU Framework Programme.

The DIVAS system is a content based search engine for locating multimedia fragments in large video repositories mainly found across the Internet. DIVAS performs searching using only audiovisual characteristics, unlike other, metadata-based solutions. Metadata based search methods are used as complementary services to DIVAS, in order to help and refine the overall search procedure, instead of using it as the primary search method. Thus it achieves a totally automated indexing and search scheme. This paper is focused on techniques adopted by DIVAS for analyzing, indexing and searching video content directly on the compressed domain. Significant improvement on search time can be achieved when avoiding decompression of the content which is one of the most time consuming processes when dealing with video processing. The generic DIVAS architecture is also presented in this paper highlighting its modularity and providing to the researcher and the developer the ability to easily add new features and to improve the performance and the accuracy of results.

In this paper we examine the methodology, architectural issues and preliminary statistical results for identifying the presence and position of a given query clip within a massive collection of video content. This work is part of the European Union FP6 1ST Programme project DIVAS (Direct Video & Audio Content Search Engine). The concept is applicable to a number of use cases ranging from video clip search into large repositories, to DRM and content policing in the Internet.

This is a brief description of demo "Direct Searching of Multimedia Content Based on Video Characteristics Extracted from Compressed Domain".

In this paper, the most recent version of the DIVAS system is presented. The system designs and develops a multimedia search engine based on advanced direct video and audio search techniques operating directly on compressed content. The basic scheme explores novel media content indexing and search technologies and integrates them into a scalable multimedia search engine. The developed algorithms facilitate for direct searching in large repositories of compressed audiovisual content, providing an alternative and complementary path for metadata based audio/video search. In addition, DIVAS adopts a module-based, expandable architecture, facilitating the ongoing expansion of the system based on researcherspsila contributions. In this study, the high-level architecture of the DIVAS system is provided, giving rise to the functional components of the main framework and the basic scheme incorporated for indexing and searching audiovisual repositories.

It is a common understanding that the surveillance video market is moving to standard, wireline and wireless IP based solutions because of the many advantages over the proprietary RF-based solutions that were deployed previously. State of the art solutions are using the very popular H.264 standard for the video compression. Surveillance video applications differentiate from other video streaming applications in the fact that the delivery of the video has to be very reliable, thus, especially for wireless environments, the usage of UDP as transmission mechanism is not the ideal solution. On the other hand, surveillance video potentially needs to be distributed to many viewers, something that would significantly increase the bandwidth usage if a non UDP-multicasting transmission is used. In this work a solution is proposed to the problem of transmission of surveillance video in a reliable manner, by combining the best of both worlds: An intermediate multicast video server is used for receiving video streams through TCP from the IP camera and transmitting through multicast UDP to the viewers. An implementation of our proposal is described and experimental results are presented and verify the proposed methodology.

High-k dielectric materials are being considered as replacement for SiO2 as the gate dielectric while retaining the low equivalent oxide thickness (EOT) required next generation metal oxide semiconductor field effect transistors (MOSFETs). ...

Although QoS provision has been researched extensively for B-ISDN (ATM based) networks and it is also under research for IP networks (Internet), until recently there was no real service environment to provide such QoS to end users. Demonstrators and laboratory experiments aimed mainly at proving specific technologies and architectures. Recent advances in the commercialisation of technology and respective standardisation effort have changed the scenery. End to end networks, capable of QoS support, are in a maturity status that will enable commercial deployment within the next few years. Still, there are no applications to take advantage of such services. It would be most desirable to enhance the way users use current applications (such as the established WEB browser), than to try to introduce new application S/W. This paper proposes a method based on the Open Service Gateway initiative (OSGi) specification [1] that enables the Quality of Service (QoS) for bandwidth demanding applications such as multimedia applications, by introducing S/W modules as enhancements into the existing applications. This method targets to the end-user, when using the network topolgy that is being standarised by the Full Services Access Network (FSAN) [2].

This article presents a low complexity dual tone multiple frequency (DTMF) signal detectort hat meets they ternation a Telecommunication Union (ITU) Q.24 DTMF standard while implemented on a general purpose Digital Signal Processor(DSP). The proposed DTMF detectoris based on the Goertzel algorithms and is well suited for a multichannel implementation. Our solution offers increased accuracy and noise margins, while preserving the inherited advantages of the Goertzel algorithm (less memory requirements and computational complexity).