Spelling suggestions: "subject:"[een] MPEG"" "subject:"[enn] MPEG""
141 |
Codage audio stéréo avancé / Advanced stereo audio codingCapobianco, Julien 03 June 2015 (has links)
Depuis une dizaine d’années, des techniques de codage joint, exploitant les relations et les redondances entre canaux audios, ont été développées afin de réduire davantage la quantité d’information nécessaire à la représentation des signaux multicanaux. Dans cette thèse, nous étudions plus particulièrement le codage des signaux audio stéréo en l’absence d’informations à priori sur la nature des sources en présences, leur nombre et la manière dont elles sont spatialisées. Cette situation correspond à l’immense majorité des enregistrements commerciaux dans l’industrie de la musique et du multimédia de manière générale. Nous étudions des approches paramétrique et signal de la problématique de codage de ces sources, où les deux sont souvent mêlées. Dans ce contexte, trois types d’approches sont utilisés. L’approche paramétrique spatiale consiste à réduire le nombre de canaux audio de la source à coder et à recréer le nombre de canaux d’origine à partir des canaux réduits et de paramètres spatiaux, extraits des canaux d’origine. L’approche signal conserve le nombre de canaux d’origine, mais encode des canaux construits à partir de ces derniers et présentant moins de redondances. Enfin, l’approche mixte introduite dans MPEG USAC utilise un signal audio et un signal résiduel, issu d’une prédiction, et dont les paramètres sont codés conjointement. Dans cette thèse, nous analysons tout d’abord les caractéristiques d’un signal stéréo issu d’un enregistrement commercial et les techniques de production associées. Cette étude nous mène à une réflexion sur les rapports entre les modèles paramétriques d’émetteur, obtenus en analysant les techniques de production des enregistrements commerciaux, et les modèles de récepteur qui sont au coeur du codage spatial paramétrique. A partir de cette mise en perspective nous présentons et étudions les trois approches évoquées plus haut. Pour l’approche purement paramétrique, nous montrons l’impossibilité d’arriver à la transparence pour la majorité des sources audios, nous menons une réflexion sur les représentations paramétriques et proposons des techniques afin de réduire le débit de leurs paramètres et d’améliorer la qualité audio. Ces améliorations passent par une meilleur segmentation du signal audio, basée sur les transitoires, sur des caractéristiques perceptives de certains indices spatiaux et sur une meilleur estimation des indices spatiaux. L’approche mixte étant récemment standardisée dans MPEG USAC, nous l’étudions en détail, puis nous proposons une nouvelle technique de codage qui exploite au mieux l’allocation du résidu aux bandes fréquentielles, lorsque celui-ci n’est pas utilisé sur l’ensemble de la bande passante du signal. Enfin, nous concluons en évoquant l’avenir du codage audio spatial généraliste et mettons l’accent sur l’importance de développer des techniques de classification et de segmentation audio pour optimiser le rapport qualité/débit. / During the last ten years, technics for joint coding exploiting relations and redundancies between channels have been developped in order to further reduce the amount of information needed to represent multichannel audio signals.In this document, we focus on the coding of stereo audio signals where prior informations on the nature of sources in presence, their number or the manner they are spatialized is unknown. Such signals are actually the most representative in commercial records of music industry and in multimedia entertainment in general. To address the coding problematic of these signals, we study parametric and signal approaches, where both of them are often mixed.In this context, three types of approaches are used. The spatial parametric approach reduce the number of audio channels of the signal to encode and recreate the original number of channels from reduced channels and spatial parameters extracted from original channels. The signal approach keep the original number of channels, but encode mono signals, built from the combination of the original ones and containing less redundancies. Finally, the hybrid approach introduced in the MPEG USAC standard keep the two channels of a stereo signal, but one is a mono downmix and the other is a residual signal, resulting from a prediction on the downmix, where prediction parameters are encoded as side information.In this document, we first analyse the characteristics of a stereo audio signal coming from a commercial recording and the associated production techniques. This study lead us to consider the relations between the emitter parametric models, elaborated from our analysis of commercial recording production techniques, and the receiver models which are the basis of spatial parametric coding. In the light of these considerations, we present and study the three approaches mentioned earlier. For the parametric approach, we show that transparency cannot be achieved for most of the stereo audio signals, we have a reflection on parametric representations and we propose techniques to improve the audio quality and further reduce the bitrate of their parameters. These improvements are obtained by applying a better segmentation on the signal, based on the significant transient, by exploiting perceptive characteristics of some spatial cues and by adapting the estimation of spatial cues. As the hybrid approach has been recently standardized in MPEG USAC, we propose a full review of it, then we develop a new coding technique to optimize the allocation of the residual bands when the residual is not used on the whole bandwidth of the signal to encode. In the conclusion, we discuss about the future of the general spatial audio coding and we show the importance of developping new technics of segmentation and classification for audio signals to further adapt the coding to the content of the signal.
|
142 |
Program pro analýzu transportního toku DVB-T / DVB-T transport stream analysis softwareMacek, Libor January 2013 (has links)
This thesis deals with development and implementation of program which enables DVB transport stream service information analysis. Theoretical part is focused on MPEG2 source coding of video signal and multiplexing into DVB transport stream. Practical part deals with program’s individual software modules implementation, which are used for data reading, their processing and presentation in form of service information. The program enables analysis of service information from live terrestrial television broadcasting DVB-T by PC card TechniSat AirStar 2 usage.
|
143 |
Kvalitetsmätning av videoströmmar hos en internetleverantör : En jämförelse mellan en kommersiell och en open source-lösningGranbäck, Andreas January 2022 (has links)
In this work, an open source-based solution for measuring the quality of video streams from an ISP has been developed. The goals with the work has been to see how much cheaper the open source solution is in comparison with the company’s already implemented commercial solution, if the data collected by the new solution is as reliable as the existing solution, and to see if the microcontroller that is used is powerful enough to replace the current one. The microcontroller used was a Raspberry Pi 4 model b. To see how much load the microcontroller could handle a stress test was conducted where the number of parallel video streams was increased until the resources on the device were maxed out. Measurement points in the unit that were checked during the stress test were CPU. The measurements showed that it was able to monitor 15 parallel currents before resources ran out. The open source-based solution cost SEK 1548 per unit while the cost for the commercial solution was SEK 10898kr per unit. The data collected by the open source solution proved to be as reliable as the commercial solution / I det här arbetet har en open source-baserad lösning för att mäta kvaliteten på videoströmmar hos en internetleverantör tagits fram. Målen med arbetet har varit att se hur mycket billigare open source-lösningen är i jämförelse med företagets redan implementerade kommersiella lösning, om den nya lösningens insamlade data är lika tillförlitlig somden befintliga lösningens, samt se om mikrocontrollern som används är kraftig nog att ersätta den nuvarande. Mikrocontrollern som användes var en Raspberry Pi 4 modell b. För att mäta hur mycket belastning den klarade utfördes ett stresstest där antalet parallella videoströmmar att monitorera ökades tills resurserna på enheten var belastade till max. Mätpunkter i enheten som kontrollerades under stresstestet var CPU. Mätningarna visade att den klarade av att monitorera 15 parallella strömmar innan resurserna tog slut. Den open source-baserade lösningen kostade 1548 kronor per enhet medans den implementerade kostade 10898kr. Datan som samlades in av open source-lösningen visade sig vara lika tillförlitlig som den kommersiella lösningen.
|
144 |
Kvalitetsmätning av videoströmmar hos en internetleverantör : En jämförelse mellan en kommersiell- och en open source-lösningPassi, Magnus January 2022 (has links)
Företaget är en tjänsteleverantör av olika tjänster, bl.a. IPTV. De använder sig idag av en kostsam lösning för att monitorera och analysera IPTV-strömmar och ser sig därför efter en mer kostnadseffektiv lösning. Målet med detta examensarbete har varit att svara på om det finns ett tillförlitligt open source-verktyg för detta, om en mikrokontroller kan ersätta deras befintliga hårdvara med avseende för IPTV-monitorering och vad skillnaden i kostnad kan vara. För att kunna besvara dessa frågor har metoder använts för att upprätta en kravställning på vad ett potentiellt verktyg ska kunna mäta, hur mycket det får kosta, samt att utföra stresstest på den utvalda hårdvaran, vilket var en Raspberry Pi 4 Modell B. Allt detta skedde i en uppsatt testmiljö som företaget bistod med. Det resulterade i en produkt som uppfyller de krav som företaget ställde och mätvärdena presenterades övergripande och tydligt i ett webbgränssnitt. Då tester av den framtagna lösningen och den befintliga lösningen inte utfördes i samma testmiljö så kan inte frågorna om open source-verktygets tillförlitlighet och om mikrokontrollerns förmåga inte besvaras på ett tillfredsställande sätt. Jämförelse mellan kostnaderna visar att den framtagna lösningen är mycket billigare då det är en engångskostnad i jämförelse med befintlig lösning som är en årskostnad. Vad som bör beaktas vid eventuell implementering av framtagen lösning är säkerhet, fortsätta studera verktyget och beräkna indirekta kostnader som utbildning, implementering och personalkostnad. / The company is a service provider of various services, including IPTV. Today they use a costly solution for monitoring and analyzing IPTV streams and is therefore looking for a cheaper solution. The goal with this thesis has been to answer if there is a reliable open source tool for monitoring and analyzing IPTV-streams, if a microcontroller can replace the existing hardware for IPTV monitoring and how much the difference in cost can be. To be able to answer these questions methods have been used to establish a set of requirements on what a potential tool should be able to measure, how much it may cost, and to perform stress test on selected hardware which was a Raspberry Pi 4 Model B. All this took place in a test environment which the company provided. This resulted in a product that is able to measure the measurements that the company had as a requirement. The measurement values are presented in a overall and clear way in a web interface. The tests of the developed solution and the existing solution was not performed in the same test environment so the questions of open source tool reliability and microcontroller ability is not answered satisfactorily. Comparison between the costs show that the solution developed is much cheaper because it is a one-time cost compared to existing solution that is an annual cost. What should be considered in any implementation of developed solution is security, continue to study the open source tool and calculate indirect costs such as training, implementation and staff costs.
|
145 |
Analyse et enrichissement de flux compressés : application à la vidéo surveillance / Compressed streams analysis and enrichment : application to video surveillanceLeny, Marc 17 December 2010 (has links)
Le développement de réseaux de vidéosurveillance, civils ou militaires, pose des défis scientifiques et technologiques en termes d’analyse et de reconnaissance des contenus des flux compressés. Dans ce contexte, les contributions de cette thèse portent sur : - une méthode de segmentation automatique des objets mobiles (piétons, véhicules, animaux …) dans le domaine compressé, - la prise en compte des différents standards de compression les plus couramment utilisés en surveillance (MPEG-2, MPEG-4 Part 2 et MPEG-4 Part 10 / H.264 AVC), - une chaîne de traitement multi-flux optimisée depuis la segmentation des objets jusqu’à leur suivi et description. Le démonstrateur réalisé a permis d’évaluer les performances des approches méthodologiques développées dans le cadre d’un outil d’aide à l’investigation, identifiant les véhicules répondant à un signalement dans des bases de données de plusieurs dizaines d’heures. En outre, appliqué à des corpus représentatifs des différentes situations de vidéosurveillance (stations de métro, carrefours, surveillance de zones en milieu rural ou de frontières ...), le système a permis d’obtenir les résultats suivants : - analyse de 14 flux MPEG-2, 8 flux MPEG-4 Part 2 ou 3 flux AVC en temps réel sur un coeur à 2.66 GHZ (vidéo 720x576, 25 images par seconde), - taux de détection des véhicules de 100% sur la durée des séquences de surveillance de trafic, avec un taux de détection image par image proche des 95%, - segmentation de chaque objet sur 80 à 150% de sa surface (sous ou sur-segmentation liée au domaine compressé). Ces recherches ont fait l’objet du dépôt de 9 brevets liés à des nouveaux services et applications rendus opérationnels grâce aux approches mises en oeuvre. Citons entre autres des outils pour la protection inégale aux erreurs, la cryptographie visuelle, la vérification d’intégrité par tatouage ou l’enfouissement par stéganographie / The increasing deployment of civil and military videosurveillance networks brings both scientific and technological challenges regarding analysis and content recognition over compressed streams. In this context, the contributions of this thesis focus on: - an autonomous method to segment in the compressed domain mobile objects (pedestrians, vehicles, animals …), - the coverage of the various compression standards commonly used in surveillance (MPEG-2, MPEG-4 Part 2, MPEG-4 Part 10 / H.264 AVC), - an optimised multi-stream processing chain from the objects segmentation up to their tracking and description. The developed demonstrator made it possible to bench the performances of the methodological approaches chosen for a tool dedicated to help investigations. It identifies vehicles from a witness description in databases of tens of hours of video. Moreover, while dealing with corpus covering the different kind of content expected from surveillance (subway stations, crossroads, areas in countryside or border surveillance …), the system provided the following results: - simultaneous real time analysis of up to 14 MPEG-2 streams, 8 MPEG-4 Part 2 streams or 3 AVC streams on a single core (2.66 GHz; 720x576 video, 25 fps), - 100% vehicles detected over the length of traffic surveillance footages, with a image per image detection near 95%, - a segmentation spreading over 80 to 150% of the object area (under or over-segmentation linked with the compressed domain). These researches led to 9 patents linked with new services and applications that were made possible thanks to the suggested approaches. Among these lie tools for Unequal Error Protection, Visual Cryptography, Watermarking or Steganography
|
146 |
Contributions pour la réduction du temps de zapping dans un réseau IPTV Multicast / Contributions for the zapping time reduction in IPTV Multicast networkSarni, Mounir 14 December 2010 (has links)
Cette thèse concerne l'investigation détaillée du problème du temps de zapping dans les réseaux d'opérateurs offrant un service IPTY basé sur la technologie multicast. Cette investigation a conduit à plusieurs contributions qui permettent de substantiellement améliorer le temps de zapping dans ce type de réseau. Notre première contribution concerne la partie purement réseau. Nous avons proposé d'optimiser le processus de changement de chaîne et ceci pour chaque version du protocole IGMP. Cette optimisation réduit la latence due au réseau sans pour autant augmenter la consommation de bande passante d'une manière significative. Nous avons modélisé le service IPTV Multicast pour estimer les pics de consommation de la bande passante pour permettre à l'opérateur de dimensionner son réseau. La deuxième contribution concerne la partie traitement du flux IPTV par le récepteur. Dans cette partie, nous avons proposé d'associer au flux principal un flux secondaire, version retardée du principal. La construction du flux secondaire se fait en donnant une priorité élevée aux paquets transportant des éléments d'une I-Frame par rapport à d'autres types d'éléments (P Frame, B-Frame, Voix et Data). Cette nouvelle règle de construction permet de réduire le délai d'attente de la première IFrame nécessaire pour commencer la phase de décodage tout en réduisant le temps de remplissage du buffer. Dans un environnement réel, nous avons évalué cette contribution et constaté une réduction remarquable du temps de zapping. / This thesis involves a detailed investigation of the problem of IPTV zapping time in networks of operators providing IPTV service based on multicast technology. This investigation led to some contributions that can substantially improve the channel change time in this type of network.Our first contribution concerns the pure network. We proposed an optimization of the channels changing process for each version of the IGMP protocol. This optimization reduces network latency without significantly increasing the bandwidth consumption. We proposed also a model of multicast IPTV service that we used to estimate the maximum bandwidth demand. This model enables the operator to size the bandwidth availability in its network.The second contribution relates to the processing part of stream IPTV on the receiver. In this section, we proposed to combine the main flow to a secondary flow, delayed version of the main stream. The construction of the secondary stream is clone by giving high priority to packets carrying elements of an I-frame compared to other types of elements (P-Frame, B-Frame, Voice and Data). This rule of construction can reduce the First I-Frame Delay required to start the decoding phase and at the same time reduce the Buffering Delay. In a real environment, we evaluated this contribution and measured a remarkable decline of the zapping time with our proposal.
|
147 |
Redução da taxa de transmissão de vídeo digital por meio da aplicação de segmentação de objetos aplicado ao estudo de abelhas. / Digital video transmission rates reduction by object segmentation applied to bees study.Amâncio, Silvio Miyadaira 02 December 2008 (has links)
A utilização de vídeos em laboratórios baseados em redes de computadores (weblabs) para pesquisa de abelhas está sendo conduzida como parte do projeto ViNCES (Virtual Network Center of Ecosystem Services), um consórcio de pesquisa composto pelo LAA (Laboratório de Automação Agrícola da Escola Politécnica da Universidade de São Paulo) e o Laboratório de Abelhas do Departamento de Ecologia do Instituto de Biociências da Universidade de São Paulo. O ViNCES é um membro do Kyatera, uma rede de computadores acadêmica de alta velocidade que tem como objetivos o desenvolvimento de aplicações e tecnologias para a Internet Avançada. Nesse contexto, o Weblab de abelhas, denominado BBBee, permite a realização de pesquisa e observação à distância da entrada de uma colméias, sendo coletadas e transmitidas informações de condições climáticas, de áudio e vídeo. O áudio e o vídeo da colméia são transmitidos em rede local e pela Internet por meio de streaming em tempo real. Os requisitos de largura de banda para transmissões de vídeo costumam ser elevados, e a qualidade obtida após o processo de compressão convencional, em geral, é baixa, podendo afetar ou dificultar a pesquisa. Além disso, está prevista a transmissão de vídeos de Alta Definição para weblab com o objetivo de melhorar a qualidade da informação, o que irá demandar maior largura de banda. Este trabalho propõe um algoritmo de codificação de vídeo para melhorar a qualidade das imagens transmitidas, ao mesmo tempo em que se reduzem os requisitos de largura de banda de transmissão e armazenagem, por meio da aplicação de técnicas de segmentação e rastreamento de objetos de vídeo. O algoritmo proposto foi implementado e testado utilizando vídeos capturados nas colméias e os resultados das análises em diversas condições são apresentados neste documento. Para avaliar a qualidade resultante do processo, foi utilizada uma métrica objetiva que permite avaliar a qualidade das imagens em relação às imagens de origem. Os resultados das análises proveram informações e direções para melhorias e futuras implementações. / The use of videos in web based laboratories over computer networks, known as weblabs, is being conducted for bee research as part of the ViNCES (Virtual Network Center of Ecosystem Services) project, a research consortium composed by: LAA (Laboratório de Automação Agrícola da Escola Politécnica) and the Laboratório de Abelhas of the Ecology Department of the Biosciences Institute. ViNCES is a member of Kyatera, a high speed academic computer network which aims at developing aplications and technologies for the Advanced Internet. The bee weblab, called BBBee, allows the research and observation of the interior of a beehive, in which are collected climate, audio and video data. Real time audio and video are broadcasted over the Internet and through a local network using streaming format. The bandwidth requirements for video transmission are usually high and the video quality after conventional compression standards is, in general, low and can interfere in the biological research. Also, High-Definition video transmission for weblab is planned to be implemented in order to provide better tools for the researcher, which will demand even higher network bandwidth. On this scenario, this work intends to provide a video codification algorithm to enhance the quality of the transmitted images, at the region of interest, and also reduce the transmission and storage requirements for some situations by using segmentation and tracking techniques for videos. A complete CODEC was implemented and tested with actual video, quality and data rates were measured and evaluated using an objective metric. The results of the analysis provided some indications of directions for future enhancements and implementations.
|
148 |
Desenvolvimento de aplicações multimídia baseado em arquitetura orientada a serviços e nos padrões MPEG-7 e MPEG-21. / Developing multimedia applications using service oriented architectures and the MPEG-7 and MPEG-21 standards.Matushima, Reinaldo 31 August 2007 (has links)
Aplicações multimídia caracterizam-se por necessitar de grandes recursos computacionais e de rede. Frente a estes requisitos, os modelos de desenvolvimento sempre consideraram arquiteturas altamente especializadas e integradas, resultando em estruturas monolíticas que restringem o reuso, bem como exigem grande esforço para realização de alterações. Este tipo de direcionamento limita e dificulta o desenvolvimento de aplicações multimídia complexas e de larga escala. Existe uma demanda por diretrizes de desenvolvimento que consigam atender escopos cada vez mais amplos, suportando aplicações escaláveis, flexíveis, interoperáveis e de fácil programação. Neste contexto, este trabalho propõe o uso conjunto de Arquiteturas Orientadas a Serviço e os padrões MPEG-7 e MPEG-21. Apresenta-se como estas tecnologias podem facilitar o desenvolvimento de novas aplicações multimídia, diminuindo o custo e o esforço de desenvolvimento, e dando suporte às crescentes e diversificadas demandas por novos tipos de aplicações multimídia. O que deu base para o trabalho foi a busca por uma solução que atendesse a alguns requisitos adicionais verificados ao longo do projeto de uma Plataforma de Gerência de Vídeo. Entre outras coisas, é apresentado como as tecnologias que dão suporte ao desenvolvimento de arquiteturas orientadas a serviço se posicionam frente ao desenvolvimento de aplicações multimídia e, como elas, conjuntamente com os padrões MPEG-7 e MPEG-21 estão sendo utilizadas para melhorar a plataforma citada. É apresentado também um processo para modelagem de aplicações segundo os princípios de orientação a serviço, generalizando a solução apresentada para o desenvolvimento de aplicações multimídia quaisquer. Como resultado, pode-se verificar que, apesar de ainda existirem algumas questões a serem tratadas, as tecnologias apresentadas representam conjuntamente uma ferramenta ampla para o desenvolvimento de aplicações multimídia. / Multimedia applications are characterized for demanding huge network and computing resources. Because these demands, the current development models always were based on highly specialized and integrated architectures. Thus, they present monolithic structures which limits reuse, as well requiring a lot of efforts to perform changes. This approach limits the development of complex and large scale multimedia applications. There are demand for development models for enabling larger scopes application, supporting scalable, flexible and ease programming applications. In this context this work proposes the conjugated use of Service Oriented Architectures and the MPEG-7 and MPEG-21 standards. It presents how these technologies can allow multimedia applications ease development, minimizing coasts and efforts. Besides, it is also showed how they answer for the raising and multiple demands for new multimedia applications types. This work motivation was to create a solution to support some additional requirements verified during the design of a Video Management Platform. Among the diversified issues treated in this work, it is presented how technologies supporting Service Oriented Architectures are positioned regarding multimedia applications development, and how they together MPEG-7 and MPEG-21 standards are being used to improve the Platform. It is also presented an analysis process for applying the principles of Service Orientation in the multimedia applications development. The aim is generalizing the presented solution to be applied in any multimedia application development. As result from the whole work, it can be verified that, although there are some issues to be covered, the technologies presented represent a complete tool for multimedia applications development.
|
149 |
Metodologia de reconfiguração de hardware utilizando o sinal de TV DigitalOliveira, Rodrigo Ribeiro de 27 March 2015 (has links)
Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-06-18T18:45:56Z
No. of bitstreams: 1
Tese-Rodrigo Ribeiro de Oliveira.pdf: 2799682 bytes, checksum: 60b9680a231c5e27560663458d4e673d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-19T20:40:50Z (GMT) No. of bitstreams: 1
Tese-Rodrigo Ribeiro de Oliveira.pdf: 2799682 bytes, checksum: 60b9680a231c5e27560663458d4e673d (MD5) / Made available in DSpace on 2015-06-19T20:40:50Z (GMT). No. of bitstreams: 1
Tese-Rodrigo Ribeiro de Oliveira.pdf: 2799682 bytes, checksum: 60b9680a231c5e27560663458d4e673d (MD5)
Previous issue date: 2015-03-27 / This PhD thesis presents a novel hardware reconfiguration methodology, which uses the
digital TV broadcast signal for reconfiguring hardware modules in digital TV receivers.
The proposed methodology allows hardware cores to be signaled, during the transport
stream generation step, transmitted and then reassembled. At the receiver, the recovered
cores are then used to reconfigure reprogrammable field programmable gate array (FPGA)
devices, which are integrated into each receiver unit. Besides, content signaling allows
receivers to choose between FPGA cores synthesized for different manufacturers, which
enables receivers to select broadcast hardware cores related to the employed FPGA
models. The results of the performed experiments, which were carried out during the
development of this work, consist in a proof of concept and show the technical feasibility
of this methodology, regarding reconfiguration of pre-synthesized hardware cores through
the digital TV environment. Receiver manufacturers could benefit from this methodology
for developing reconfigurable architectures, which would allow the incorporation of
technological advances into receiver hardware and provide better control regarding product
life cycle. As a result, future revisions of DTV standards could occur without the need for
device replacement. / Esta tese de doutorado apresenta uma metodologia de reconfiguração de hardware, que
utiliza o sinal da emissora de TV digital como base para atualizar módulos de receptores de
TV digital. A metodologia proposta permite que núcleos de hardware sejam sinalizados,
durante a geração do fluxo de transporte, transmitidos e posteriormente remontados. Desse
modo, os núcleos recebidos são usados na reconfiguração de dispositivos baseados em
lógica reprogramável (field programable gate array - FPGA), que estão integrados ao
hardware de cada unidade receptora. Além disso, a sinalização de conteúdo permite a
distinção entre núcleos sintetizados para FPGAs de diferentes fabricantes, o que habilita
receptores de TV digital a selecionar somente núcleos de hardware relativos aos modelos
de FPGA utilizados. Os resultados obtidos com os experimentos realizados, durante o
desenvolvimento deste trabalho, consistem em uma prova de conceito e demonstram a
viabilidade técnica do uso desta metodologia de transmissão e reconfiguração, para núcleos
pré-sintetizados de hardware enviados em um ambiente de televisão digital. Fabricantes de
receptores poderiam utilizar os benefícios desta metodologia para o desenvolvimento de
arquiteturas reconfiguráveis, o que permitiria a incorporação de avanços tecnológicos às
funções de hardware do receptor e um maior controle do ciclo de vida de produto. Como
resultado, futuras revisões de normas de TV Digital não resultariam em troca de
equipamento.
|
150 |
Desenvolvimento de aplicações multimídia baseado em arquitetura orientada a serviços e nos padrões MPEG-7 e MPEG-21. / Developing multimedia applications using service oriented architectures and the MPEG-7 and MPEG-21 standards.Reinaldo Matushima 31 August 2007 (has links)
Aplicações multimídia caracterizam-se por necessitar de grandes recursos computacionais e de rede. Frente a estes requisitos, os modelos de desenvolvimento sempre consideraram arquiteturas altamente especializadas e integradas, resultando em estruturas monolíticas que restringem o reuso, bem como exigem grande esforço para realização de alterações. Este tipo de direcionamento limita e dificulta o desenvolvimento de aplicações multimídia complexas e de larga escala. Existe uma demanda por diretrizes de desenvolvimento que consigam atender escopos cada vez mais amplos, suportando aplicações escaláveis, flexíveis, interoperáveis e de fácil programação. Neste contexto, este trabalho propõe o uso conjunto de Arquiteturas Orientadas a Serviço e os padrões MPEG-7 e MPEG-21. Apresenta-se como estas tecnologias podem facilitar o desenvolvimento de novas aplicações multimídia, diminuindo o custo e o esforço de desenvolvimento, e dando suporte às crescentes e diversificadas demandas por novos tipos de aplicações multimídia. O que deu base para o trabalho foi a busca por uma solução que atendesse a alguns requisitos adicionais verificados ao longo do projeto de uma Plataforma de Gerência de Vídeo. Entre outras coisas, é apresentado como as tecnologias que dão suporte ao desenvolvimento de arquiteturas orientadas a serviço se posicionam frente ao desenvolvimento de aplicações multimídia e, como elas, conjuntamente com os padrões MPEG-7 e MPEG-21 estão sendo utilizadas para melhorar a plataforma citada. É apresentado também um processo para modelagem de aplicações segundo os princípios de orientação a serviço, generalizando a solução apresentada para o desenvolvimento de aplicações multimídia quaisquer. Como resultado, pode-se verificar que, apesar de ainda existirem algumas questões a serem tratadas, as tecnologias apresentadas representam conjuntamente uma ferramenta ampla para o desenvolvimento de aplicações multimídia. / Multimedia applications are characterized for demanding huge network and computing resources. Because these demands, the current development models always were based on highly specialized and integrated architectures. Thus, they present monolithic structures which limits reuse, as well requiring a lot of efforts to perform changes. This approach limits the development of complex and large scale multimedia applications. There are demand for development models for enabling larger scopes application, supporting scalable, flexible and ease programming applications. In this context this work proposes the conjugated use of Service Oriented Architectures and the MPEG-7 and MPEG-21 standards. It presents how these technologies can allow multimedia applications ease development, minimizing coasts and efforts. Besides, it is also showed how they answer for the raising and multiple demands for new multimedia applications types. This work motivation was to create a solution to support some additional requirements verified during the design of a Video Management Platform. Among the diversified issues treated in this work, it is presented how technologies supporting Service Oriented Architectures are positioned regarding multimedia applications development, and how they together MPEG-7 and MPEG-21 standards are being used to improve the Platform. It is also presented an analysis process for applying the principles of Service Orientation in the multimedia applications development. The aim is generalizing the presented solution to be applied in any multimedia application development. As result from the whole work, it can be verified that, although there are some issues to be covered, the technologies presented represent a complete tool for multimedia applications development.
|
Page generated in 0.0284 seconds