13 research outputs found

    MTP: A Movie Transmission Protocol for Multimedia Applications

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    Typical color video adapters of today's PCs and workstationsuse 8 bits per pixel as an index into the color lookup table (CLUT). Full color pictures and movies have to be reduced to 256 colors. In order to avoid false colors between two frames of a digital movie, a novel technique for computing the CLUT's is proposed: A subset of the CLUT entries is reserved for new colors of the next frame. The paper presents an algorithm for the gradual adaption of the color lookup table during the transmission of a movie. First experience is reported in the framework of the XMovie project

    Performance Bottlenecks in Digital Movie Systems

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    Digital movie systems offer great perspectives for multimedia applications. But the large amounts of data involved and the demand for isochronous transmission and playback are also great challenges for the designers of a new generation of file systems, database systems, operating systems, window systems, video encoder/decoder and networks. Today's research prototypes of digital movie systems suffer from severe performance bottlenecks, resulting in small movie windows, low frame rates or bad image quality (or all of these!). We consider the performance problem to be the most important problem with digital movie systems, preventing their widespread use today. In this paper we address performance issues of digital movie systems from a practical perspective. We report on performance experience gained with the XMovie system and new algorithms and protocols to overcome some of these bottlenecks

    Effiziente Verarbeitung von multimedialen Datenströmen in Window-Systemen

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    Fensterorientierte Oberflaechen haben sich auf Workstations aller Leistungsklassen durchgesetzt. Deshalb liegt es nahe, Multimedia-Anwendungen in solche Oberflaechen zu integrieren. Dieser Artikel gibt zunaechst eine Uebersicht ueber die verschiedenen technischen Moeglichkeiten zur Integration von Multimedia-Datenstroemen in ein Fenstersystem; die Vor- und Nachteile der einzelnen Ansaetze werden gegenuebergestellt. Waehrend Loesungen mit Hardware-Unterstuetzung im allgemeinen schneller sind, sind reine Software-Implementierungen flexibler und portabler. Als ein Beispiel fuer eine Software-Loesung werden Architektur, Implementierung und Leistungsanalyse eines netzwerkfaehigen Filmsystems fuer das X-Window-System ausfuehrlich diskutiert. Es zeigt sich, dass die Uebertragung und Darstellung von digitalen Filmen auf modernen Workstations in Hochgeschwindigkeitsnetzen ohne spezielle Hardware in Realzeit moeglich ist. Außerdem werden neue Ansaetze zur Gestaltung der Mensch-Maschine-Schnittstelle mit multimedialen Komponenten vorgestellt

    Architektur und Implementierung eines Anwendungsprotokolls fĂŒr digitale Filme

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    Das Movie Transmission Protocol ist ein portables Anwendungsprotokoll zur Übertragung von kontinuierlichen Medien. Es ist vollstĂ€ndig implementiert und setzt auf den Internet-Transportprotokollen auf. Die FunktionalitĂ€t der existierenden Transportschnittstellen muss MTP allerdings um vorausschauende Fehlerkorrektur und ratenbasierte Flusskontrolle erweitern. In dieser Arbeit werden nach einer EinfĂŒhrung in die Architektur des XMovie-Systems zunĂ€chst die funktionalen Einheiten von MTP vorgestellt. Danach wird der Dienst von MTP beschrieben und die Spezifikation des Protokolls skizziert sowie auf einige Implementierungsdetails eingegangen

    Experimental Evaluation of a Video Capture Board for Networked Workstations

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    This thesis examines the architectural issues in the design of a video capture board intended for use in multimedia videoconferencing. The major issues examined are: Control of reception and transmission of multimedia video streams, (i) Quality of service and service provision (ii) Compression requirements and solutions (iii) Data buffering and card connection strategies (iv) Handling multiple video streams Results of measurements for prototype boards designed and constructed at Penn are also given

    XMovie: Architecture and Implementation of a Distributed Movie System

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    We describe a system for storing, transmitting and presenting digital movies in a computer network. The hardware used in the system is standard hardware, as found in typical workstations today; no special hardware is required. The movies are shown in windows of the X window system. This allows full integration with the classical components of computer applications such as text, color graphics, menus and icons. The XMovie system has several innovative features: First, it contains a new algorithm for the gradual adaptation of the color lookup table during the presentation of the movie to ensure optimal color quality on low-end workstations. Second, it is a multi-standard system supporting the compression techniques MPEG, H.261, Motion JPEG, and a newly developed extension to the well known Color Cell Compression method. Third, we introduce AdFEC, a new adaptable forward error correction method for our movie transmission protocol

    An Integrated Network Architecture for a High Speed Distributed Multimedia System.

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    Computer communication demands for higher bandwidth and smaller delays are increasing rapidly as the march into the twenty-first century gains momentum. These demands are generated by visualization applications which model complex real time phenomena in visual form, electronic document imaging and manipulation, concurrent engineering, on-line databases and multimedia applications which integrate audio, video and data. The convergence of the computer and video worlds is leading to the emergence of a distributed multimedia environment. This research investigates an integrated approach in the design of a high speed computer-video local area network for a distributed multimedia environment. The initial step in providing multimedia services over computer networks is to ensure bandwidth availability for these services. The bandwidth needs based on traffic generated in a distributed multimedia environment is computationally characterized by a model. This model is applied to the real-time problem of designing a backbone for a distributed multimedia environment at the NASA Classroom of the Future Program. The network incorporates legacy LANs and the latest high speed switching technologies. Performance studies have been conducted with different network topologies for various multimedia application scenarios to establish benchmarks for the operation of the network. In these performance studies it has been observed that network topologies play an important role in ensuring that sufficient bandwidth is available for multimedia traffic. After the implementation of the network and the performance studies, it was found that for true quality of service guarantees, some modifications will have to be made in the multimedia operating systems used in client workstations. These modifications would gather knowledge of the channel between source and destination and reserve resources for multimedia communication based on specified requirements. A scheme for reserving resources in a network consisting legacy LAN and ATM is presented to guarantee quality of service for multimedia applications

    Distributed video through telecommunication networks using fractal image compression techniques

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    The research presented in this thesis investigates the use of fractal compression techniques for a real time video distribution system. The motivation for this work was that the method has some useful properties which satisfy many requirements for video compression. In addition, as a novel technique, the fractal compression method has a great potential. In this thesis, we initially develop an understanding of the state of the art in image and video compression and describe the mathematical concepts and basic terminology of the fractal compression algorithm. Several schemes which aim to the improve of the algorithm, for still images are then examined. Amongst these, two novel contributions are described. The first is the partitioning of the image into sections which resulted insignificant reduction of the compression time. In the second, the use of the median metric as alternative to the RMS was considered but was not finally adopted, since the RMS proved to be a more efficient measure. The extension of the fractal compression algorithm from still images to image sequences is then examined and three different schemes to reduce the temporal redundancy of the video compression algorithm are described. The reduction in the execution time of the compression algorithm that can be obtained by the techniques described is significant although real time execution has not yet been achieved. Finally, the basic concepts of distributed programming and networks, as basic elements of a video distribution system, are presented and the hardware and software components of a fractal video distribution system are described. The implementation of the fractal compression algorithm on a TMS320C40 is also considered for speed benefits and it is found that a relatively large number of processors are needed for real time execution

    A distributed programming system for media applications

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (leaves 104-106).by Brent M. Phillips.M.S
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