Video on demand (VoD) services are becoming more and more popular today. As high bandwidth communication infrastructure is being established in many countries around the world, high bandwidth communication lines will reach millions of family in the near future. Due to the increasing improvement of communication technology, more and more families enjoy the VoD services which are provided by telecommunication companies and cable TV provider via the Internet. In such a case, scalability and fault tolerance will be the key issues. We propose an architecture for VoD services which is based on multi-server circumstance. In our proposed architecture, each movie is replicated on a subset of the servers. When a server crashes or disconnects from its clients, it is replaced by another server in a transparent way. Regarding of load balancing problem, clients are also migrated from one server to another when a new server is brought up. The benefit of our service is to use common hardware and general network technologies (e.g. TCP/IP). In addition, we provide a machine-independent environment to let the servers and clients execute on any machine through the network. Furthermore, we can get the media players from a web browser by utilizing the cross-platform characteristics of Java. The client host does not need to install any relevant applications. Since Java Media Framework (JMF) provides a unified architecture and messaging protocol for managing the acquisition, processing, and delivery of time-based media data. It can support many standard media content types, such as AIFF, AVI, MIDI, MPEG, QuickTime, and WAV. Using JMF, we can create applets and applications to present, manipulate, and store time-based media.

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Master’s thesis is trying to create opensource IM application for communication in Jabber network. In nowadays it is getting more and more popularity as at providers, so mainly at end users. In first half of thesis are explained basics of whole issues and in second half is described resulting application, which has been created by using of object oriented programming language Java. Java is very extended between programmers for her simplicity and great support. Thanks this is available a many external libraries and extensions. Application has been written on Smack library in version 3.04 and VoIP module on JMF (Java Media Framework). Graphic interface has been created by using of standard Java visual components (javax.swing).

The main goal of this thesis is to design videoconferential system by Java Media Framework. This means to write two programs. One will capture multimedia data from webcam and will sent it into network. The second application which can receive this data is supposed to be on another computer. The multimedia data are transmitted by using Java Media Framework library. We suppose one lector and group of students. Video and audio channel is transmitted to all students. Communication between lector and student  is solved using chat. Lector has possibility open another audio or video channel with all students. Multimedia data will be transferred using Real-time Transport Protocol (RTP). The message including information about student is transferred by Transmission Control Protocol (TCP).

Com a rápida evolução tecnológica e o crescimento da aplicação de novas tecnologias digitais na educação - em especial em cursos a distância - o mais importante tem sido a criação de novos ambientes de aprendizagem que estimulam a interatividade, desenvolvem a capacidade de formular, de resolver questões e, acima de tudo, possibilitam a participação de forma colaborativa, embora estando fisicamente distante. A idéia de uma escola \"expandida\" visa atender a diversas áreas de ensino, entre elas a necessidade de treinamentos no setor corporativo para os profissionais que já estão no mercado de trabalho, a formação escolar para jovens e adultos que enfrentam dificuldades pela distância ou indisponibilidade de horário, ou mesmo a qualificação docente em grande demanda por aperfeiçoamento. Para atingir um nível bom de participação em encontros virtuais, faz-se necessário contar com tecnologias de comunicação e informação que medeiam a interação entre os envolvidos no processo de ensino. Afinal, a aprendizagem, que não é apenas individual mas coletiva, se baseia na convivência entre os participantes, na troca de informações entre eles. Quando um conteúdo é ministrado a distância, por meio da Internet, em videoconferência, permite-se criar um espaço ideal para uma colaboração distribuída. Por conta dessa necessidade, este trabalho apresenta um ambiente que oferece a comunicação por vídeo, voz e texto, para aulas ao vivo entre vários participantes, cuja participação é controlada pelo moderador, ao mesmo tempo em que conta com um sistema de registro de atividades para interação assíncrona. Além do ambiente desenvolvido, o trabalho introduz um breve estudo de conceitos envolvidos na videoconferência, as tecnologias disponíveis, bem como as utilizadas para o desenvolvimento deste projeto. Alguns resultados foram obtidos após realização de testes e utilização do ambiente, tal como a análise de desempenho a partir dos recursos disponíveis na rede. / With the fast technological evolution and the growth of the new digital technologies application in the education, in special in long-distance education courses is observed that the majority of these courses has favored great parcel of people. The most important it has been the creation of new learning environment that stimulates the participation, developing the capacity to formulate, to decide questions and all above of everything participating in a collaborative way. The idea of a expanded school aims at to take care of diverse areas of education, between them the necessity of training in the corporative sector for the professionals who already are in the work market, the formation pertaining to school for young and adult that faces difficulties for the distance or non-availability of schedule or the teaching qualification in great demand for perfectioning. A learning that is not only individual, but collective, is basead on the relationship between the participants, in the exchange of information between them. Therefore, in the long-distance education makes necessary the communication technologies and information that measured the interaction between the involved education process. When a content is given in the distance, by means of the Internet, video conferencing and video lessons, is allowed to create an ideal space for the distributed contribution. For this necessity, this work show an environment for lessons live between some participants, that offers the communication by video, voice and text. The participation is controlled by moderator, being able to be a professor or the person that give a lecture. Contains also a system of register of activities for asynchronous interaction. Beyond the developed environment, the work introduces a briefing study of involved concepts in the video conferencing, the available technologies, as well as the used ones for the development of this project. Some results had been gotten after accomplishment of tests, allowing to verify different performances depending on the available resources in the net.

Com a rápida evolução tecnológica e o crescimento da aplicação de novas tecnologias digitais na educação - em especial em cursos a distância - o mais importante tem sido a criação de novos ambientes de aprendizagem que estimulam a interatividade, desenvolvem a capacidade de formular, de resolver questões e, acima de tudo, possibilitam a participação de forma colaborativa, embora estando fisicamente distante. A idéia de uma escola \"expandida\" visa atender a diversas áreas de ensino, entre elas a necessidade de treinamentos no setor corporativo para os profissionais que já estão no mercado de trabalho, a formação escolar para jovens e adultos que enfrentam dificuldades pela distância ou indisponibilidade de horário, ou mesmo a qualificação docente em grande demanda por aperfeiçoamento. Para atingir um nível bom de participação em encontros virtuais, faz-se necessário contar com tecnologias de comunicação e informação que medeiam a interação entre os envolvidos no processo de ensino. Afinal, a aprendizagem, que não é apenas individual mas coletiva, se baseia na convivência entre os participantes, na troca de informações entre eles. Quando um conteúdo é ministrado a distância, por meio da Internet, em videoconferência, permite-se criar um espaço ideal para uma colaboração distribuída. Por conta dessa necessidade, este trabalho apresenta um ambiente que oferece a comunicação por vídeo, voz e texto, para aulas ao vivo entre vários participantes, cuja participação é controlada pelo moderador, ao mesmo tempo em que conta com um sistema de registro de atividades para interação assíncrona. Além do ambiente desenvolvido, o trabalho introduz um breve estudo de conceitos envolvidos na videoconferência, as tecnologias disponíveis, bem como as utilizadas para o desenvolvimento deste projeto. Alguns resultados foram obtidos após realização de testes e utilização do ambiente, tal como a análise de desempenho a partir dos recursos disponíveis na rede. / With the fast technological evolution and the growth of the new digital technologies application in the education, in special in long-distance education courses is observed that the majority of these courses has favored great parcel of people. The most important it has been the creation of new learning environment that stimulates the participation, developing the capacity to formulate, to decide questions and all above of everything participating in a collaborative way. The idea of a expanded school aims at to take care of diverse areas of education, between them the necessity of training in the corporative sector for the professionals who already are in the work market, the formation pertaining to school for young and adult that faces difficulties for the distance or non-availability of schedule or the teaching qualification in great demand for perfectioning. A learning that is not only individual, but collective, is basead on the relationship between the participants, in the exchange of information between them. Therefore, in the long-distance education makes necessary the communication technologies and information that measured the interaction between the involved education process. When a content is given in the distance, by means of the Internet, video conferencing and video lessons, is allowed to create an ideal space for the distributed contribution. For this necessity, this work show an environment for lessons live between some participants, that offers the communication by video, voice and text. The participation is controlled by moderator, being able to be a professor or the person that give a lecture. Contains also a system of register of activities for asynchronous interaction. Beyond the developed environment, the work introduces a briefing study of involved concepts in the video conferencing, the available technologies, as well as the used ones for the development of this project. Some results had been gotten after accomplishment of tests, allowing to verify different performances depending on the available resources in the net.

<p>The last ten years have been the witnesses of the emergence of any kind of video content. Moreover, the appearance of dedicated websites for this phenomenon has increased the importance the public gives to it. In the same time, certain individuals are deaf and occasionally cannot understand the meanings of such videos because there is not any text transcription available. Therefore, it is necessary to find solutions for the purpose of making these media artefacts accessible for most people. Several software propose utilities to create subtitles for videos but all require an extensive participation of the user. Thence, a more automated concept is envisaged. This thesis report indicates a way to generate subtitles following standards by using speech recognition. Three parts are distinguished. The first one consists in separating audio from video and converting the audio in suitable format if necessary. The second phase proceeds to the recognition of speech contained in the audio. The ultimate stage generates a subtitle file from the recognition results of the previous step. Directions of implementation have been proposed for the three distinct modules. The experiment results have not done enough satisfaction and adjustments have to be realized for further work. Decoding parallelization, use of well trained models, and punctuation insertion are some of the improvements to be done.</p>

The last ten years have been the witnesses of the emergence of any kind of video content. Moreover, the appearance of dedicated websites for this phenomenon has increased the importance the public gives to it. In the same time, certain individuals are deaf and occasionally cannot understand the meanings of such videos because there is not any text transcription available. Therefore, it is necessary to find solutions for the purpose of making these media artefacts accessible for most people. Several software propose utilities to create subtitles for videos but all require an extensive participation of the user. Thence, a more automated concept is envisaged. This thesis report indicates a way to generate subtitles following standards by using speech recognition. Three parts are distinguished. The first one consists in separating audio from video and converting the audio in suitable format if necessary. The second phase proceeds to the recognition of speech contained in the audio. The ultimate stage generates a subtitle file from the recognition results of the previous step. Directions of implementation have been proposed for the three distinct modules. The experiment results have not done enough satisfaction and adjustments have to be realized for further work. Decoding parallelization, use of well trained models, and punctuation insertion are some of the improvements to be done.