Search and retrieval of multimedia content from open platforms such as the Internet and IPTV platforms has long been found to be hugely inefficient. It has been noted that a major cause of such inefficient results is the improper labeling or incomplete description of multimedia content by its creators. The lack of adequate description of video content by the proper annotation of video content with the relevant metadata leads to poor search and retrieval yields. The creation of such metadata itself is a major problem as there are various metadata description standards which users could employ. On the other hand there are tools such as FFprobe that can retrieve important features of video that can be used in searching and retrieval. The combination of such tools and metadata description standards could be the solution to the metadata problem. The Multimedia Content Description Interface (MPEG-7) is an example of a metadata description standard. It has been adopted by TISPAN for the description of IPTV multimedia content. The MPEG-7 standard is rather complex, seeing as it has over 1200 global Descriptors and Description Schemes which a user would have to know in order to implement such technology. This complexity is a nuisance when we consider the existence of multitudes of amateur video producers. These multimedia content creators have no idea how to use the MPEG-7 standard to annotate their creations with metadata. Consequently, overloading of the IPTV platform with content that has not been annotated in a standardized manner occurs, making search and retrieval of the multimedia content (videos, in this instance) inefficient. Therefore, it was imperative to try and determine whether the use of the MPEG-7 standard could be made much easier by creating a tool that is MPEG-7 enabled which will allow for the annotation of video content by any user without concerning themselves about how to use the MPEG-7 standard. In attempting to develop a tool for metadata generation, it was incumbent for us to understand the issues associated with metadata generation for users wishing to create IPTV services. An extensive literature review on IPTV standardization was carried out to determine the issues associated with metadata generation for IPTV and their proposed solutions. An experimental research approach was taken in an attempt to figure out if our proposed solution to the lack of technical expertise by users about the MPEG-7 standard could be the final solution to the metadata generation problem. We developed a Multimedia Content Description and Management System (MCDMS) prototype which enabled us to describe video content by annotating it with 16 different metadata elements and storing the descriptions in XML MPEG-7 format. Incremental development and re-use oriented development were used during the development phase of this research. The MCDMS underwent functional testing; smoke testing of the individual system components and Big Bang integration testing for the combined components. Our results indicate that the more metadata is appended to a video as description the better it is to search for and retrieve. The MCDMS hides the complexity of MPEG-7 metadata creation from the users. With the effortless creation of MPEG-7 based metadata, it becomes easier to annotate videos. Consequently, search and retrieval of video content becomes more efficient. It is important to note that the description of multimedia content remains a complex feat. Even with the metadata elements laid out for users, there still exist other issues that affect metadata creation such as polysemy and the semantic gap. However, the provision of a tool that does the MPEG-7 standardizing behind the scenes for users when they upload a video makes the description of multimedia content in a standardized manner a much easier feat to achieve.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação. / Made available in DSpace on 2013-07-16T01:36:19Z (GMT). No. of bitstreams: 1 221367.pdf: 1132156 bytes, checksum: 0a4a1c09ee4ea4a796432b7d837a0198 (MD5) / Cada vez mais cresce a necessidade de novas abordagens no desenvolvimento de Sistemas de Gerenciamento de Ensino (LMS - Learning Management Systems) que permitam o compartilhamento de conhecimentos entre estudante e instrutor através do ambiente de aprendizado estruturado. Um LCMS (Learning Content Management System) é um sistema que permite o gerenciamento de objetos educacionais (por exemplo, textos e vídeos) permitindo a elaboração e acesso a esses objetos. Esta dissertação considera especialmente LCMS para gerenciamento de vídeos educacionais. Neste tipo de sistema, formas de segmentação e indexação de vídeos devem ser estudadas no sentido de melhor aproveitar seu potencial educacional. No trabalho de pesquisa aqui apresentado, é investigada a aplicação da Teoria da Criação do Conhecimento na segmentação e a indexação de vídeos educacionais visando um melhor aproveitamento dos conteúdos educacionais. Mais especificamente, nesta dissertação propõe-se uma metodologia para segmentação e indexação de vídeos educacionais utilizando o padrão MPEG-7 dentro da abordagem da Teoria da Criação do Conhecimento. Foi também implementada uma ferramenta de geração de objetos MPEG-7 aplicando parte da metodologia proposta.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia Elétrica / Made available in DSpace on 2013-07-15T23:01:57Z (GMT). No. of bitstreams: 1 221466.pdf: 1101553 bytes, checksum: 186aa359357eb479e774a391068292f1 (MD5) / A difusão de dados, conhecida como datacasting, se mostra como a base para o surgimento de novos serviços na Televisão Digital (TVD). Neste contexto, este trabalho busca propor e implementar um modelo fim a fim de datacasting, direcionado à difusão de aplicativos e demais dados correlacionados, que suporte esses novos serviços. O modelo foi baseado em especificações abertas de TVD, assim como em trabalhos encontrados na Literatura. Foram estudados os mecanismos de difusão de dados sobre os padrões de TVD, utilizados pelos sistemas abertos, assim como investigadas suas principais características, vantagens e desvantagens. A implementação foi concretizada através do desenvolvimento de parte dos componentes previstos no modelo, e da integração destes com determinadas soluções de softwares livres já existentes.

A transportation plan is a byproduct from the calculation of the Kantorovich distance between two images. It describes a transformation from one of the images to the other. This master thesis shows how transportation plans can be used for video coding and how to process the transportation plans to achieve a good bitrate/quality ratio. Various parameters are evaluated using an implemented transportation plan video coder. The introduction of transform coding with DCT proves to be very useful, as it reduces the size of the resulting transportation plans. DCT coding roughly gives a 10-fold decrease in bitrate with maintained quality compared to the nontransformed transportation plan coding. With the best settings for transportation plan coding, I was able to code a test sequence at about 5 times the bitrate for MPEG coding of the same sequence with similar quality. As video coding using transportation plans is a very new concept, the thesis is ended with conclusions on the test results and suggestions for future research in this area.

The purpose of this project was the specification, design and implementation of a prototype 2-D MPEG-4 authoring tool. A literature study was conducted of the MPEG-4 standard and multimedia authoring tools to determine the specification and design of a prototype 2- D MPEG-4 authoring tool. The specification and design was used as a basis for the implementation of a prototype 2-D MPEG-4 authoring tool that complies with the Complete 2-D Scene Graph Profile. The need for research into MPEG-4 authoring tools arose from the reported lack of knowledge of the MPEG-4 standard and the limited implementations of MPEG-4 authoring tools available to content authors. In order for MPEG-4 to reach its full potential, it will require authoring tools and content players that satisfy the needs of its users. The theoretical component of this dissertation included a literature study of the MPEG-4 standard and an investigation of relevant multimedia authoring systems. MPEG-4 was introduced as a standard that allows for the creation and streaming of interactive multimedia content at variable bit rates over high and low bandwidth connections. The requirements for the prototype 2-D MPEG-4 authoring system were documented and a prototype system satisfying the requirements was designed, implemented and evaluated. The evaluation of the prototype system showed that the system successfully satisfied all its requirements and that it provides the user with an easy to use and intuitive authoring tool. MPEG-4 has the potential to satisfy the increasing demand for innovative multimedia content on low bandwidth networks, including the Internet and mobile networks, as well as the need expressed by users to interact with multimedia content. This dissertation makes an important contribution to the understanding of the MPEG-4 standard, its functionality and the design of a 2-D MPEG-4 Authoring tool. Keywords: MPEG-4; MPEG-4 authoring; Binary Format for Scenes.

Ingeniero Civil Eléctrico / En tiempos modernos la envergadura del contenido multimedia avanza más rápido que el desarrollo de las tecnologías necesarias para su correcta difusión a través de la red. Es por esto que se hacen necesarios nuevos protocolos que sirvan como puente entre ambas entidades para así obtener un máximo de provecho del contenido a pesar de que la tecnología para distribuirlos aún no sea la adecuada. Es así, que dentro de las últimas tecnologías de compresión de video se encuentra Scalable Video Coding (SVC), la cual tiene por objetivo codi car distintas calidades en un único bitstream capaz de mostrar cualquiera de las calidades embebidas en éste según se reciba o no toda la información. En el caso de una conexión del tipo streaming, en donde es necesaria una uidez y delidad en ambos extremos, la tecnología SVC tiene un potencial muy grande respecto de descartar un mínimo de información para privilegiar la uidez de la transmisión. El software utilizado para la creación y manipulación de estos bitstreams SVC es Joint Scalable Video Model (JSVM). En este contexto, se desarrolla el algoritmo de deadline en Matlab, que omite informaci ón del video SVC de acuerdo a qué tan crítico sea el escenario de transmisión. En este escenario se considera la percepción de uidez del usuario como medida clave, por lo cual se prioriza mantener siempre una tasa de 30 fps a costa de una pérdida de calidad mínima. El algoritmo, omite información de acuerdo a qué tan lejos se esté de este deadline de 30 fps, si se está muy lejos, se omite información poco relevante, y si se está muy cerca, información más importante. Los resultados se contrastan con TCP y se evalúan para distintos valores de RTTs, cumpliendo totalmente el objetivo para valores menores a 150 ms que resultan en diferencias de hasta 20 s a favor del algoritmo de deadline al término de la transmisión. Esta mejora en tiempo de arribo no descarta información esencial y sólo degrada ligeramente la calidad del video en pos de mantener la tasa de 30fps. Por el contrario, en escenarios muy adversos de 300 ms en RTT, las omisiones son de gran envergadura y comprometen frames completos, en conjunto con una degradación generalizada del video y la aparición de artefactos en éste. Por tanto la propuesta cumple los objetivos en ambientes no muy adversos. Para toda la simulación se uso un video en movimiento de 352x288 y 150 frames de largo.

Au cours de cette dernière dizaine d’années, l’intérêt pour la diffusion en temps réel de séquences vidéo sur réseaux sans fil ad-hoc a grandi sans cesse, en raison de l'attrayante propriété d’être capable de déployer un système de communication visuelle à tout moment et en tout lieu, sans la nécessité d'une infrastructure préexistante. Une large gamme d'applications des opérations militaires et de sauvetage, jusqu'aux applications commerciales, éducatives, récréatives, a été envisagée, ce qui a crée un grand intérêt pour toutes les technologies concernées. L'objectif de cette thèse est de fournir un service efficace et robuste de diffusion vidéo en temps réel sur réseaux mobiles ad-hoc, avec un aperçu des solutions disponibles à ce moment, et de proposer de nouvelles solutions qui permettraient de surmonter les limites de celles actuelles. Nos contributions touchent à plusieurs aspects du paradigme mobile vidéo streaming : une nouvelle technique de codage vidéo par descriptions multiples, qui fournit une qualité vidéo acceptable, même en présence d'un taux élevé de pertes ; un protocole cross-layer pour la création et le maintien d'un réseau de overlay, qui, avec un échange de messages limité, géré de façon repartie un ensemble d'arbres de multicast, un pour chaque description du flux ; un cadre original de fonctions distribuées pour l'optimisation congestion-distorsion, qui, grâce à une représentation compacte des informations de topologie, permet aux nœuds d'apprendre la structure du overlay et d'optimiser leur comportement en conséquence ; et enfin, une intégration avec le paradigme émergent du codage réseau. / During the last decade, real-time video streaming over ad-hoc networks has gathered an increasing interest, because of the attractive property of being able to deploy a visual communication system anytime and anywhere, without the need for a pre-existing infrastructure. A wide range of target applications, from military and rescue operations, to business, educational, and recreational scenarios, has been envisaged, which has created great expectations with respect to the involved technologies. The goal of this thesis is to provide an efficient and robust real-time video streaming system over mobile ad-hoc networks, proposing cross-layer solutions that overcome the limitations of both the application and network solutions available at this time. Our contributions cover several aspects of the mobile video streaming paradigm: a new multiple description video coding technique, which provides an acceptable video quality even in presence of high loss rates; a novel cross-layer design for an overlay creation and maintenance protocol, which, with a low overhead, distributedly manages a set of multicast trees, one for each description of the stream; an original distributed congestion-distortion optimisation framework, which, through a compact representation of the topology information, enables the nodes to learn the structure of the overlay and optimise their behaviour accordingly; and, finally, an integration with the emerging network coding paradigm.

Le codage de source distribué est un paradigme qui consiste à encoder indépendamment deux sources corrélées et à les décoder conjointement. Wyner et Ziv ont montré que le codage de source distribué peut atteindre les mêmes performances débit-distorsion que le codage de source conjoint, pourvu que certaines contraintes soient satisfaites. Cette caractéristique rend le codage de source distribué très attractif pour des applications qui demandent un encodeur à faible complexité ou pour ne pas être obligé à avoir des communications entre les sources. Dans le cadre du codage vidéo distribué, les trames corrélées sont encodées séparément et décodées conjointement. Dans l'architecture ainsi dite de Stanford, le flux vidéo est séparée en trames clés et Wyner-Ziv. Les trames clés sont encodées INTRA. Les trames Wyner-Ziv sont données en entrée à un codeur de canal systématique ; seulement les bits de parité sont envoyés. Au décodeur, on produit une estimation de la trame Wyner-Ziv, appelée information adjacente, en interpolant les trames clés reçues. L'information adjacente, considérée comme une version bruitée de la trame Wyner-Ziv, est corrigée par les bits de parité. Dans cette thèse, nous proposons plusieurs algorithmes pour la génération de l'information adjacente et pour l'interpolation temporelle et inter-vue. On propose aussi un algorithme de fusion bayésienne des deux interpolations. Tous les algorithmes proposés donnent des résultats meilleurs par rapport à l'état de l'art en termes de performance débit-distorsion. Nous proposons aussi plusieurs algorithmes pour l'estimation de la trame Wyner-Ziv dans le cadre de la vidéo multi-vues plus profondeur. / Distributed source coding is a paradigm that consists in encoding two correlated sources independently, provided that they are decoded jointly.Wyner and Ziv proved that distributed source coding can attain the same rate distortion performance of joint coding, under some constraints.This feature makes distributed source coding very attractive for applications that require a low-complexity encoder or for avoiding communication between the sources. In distributed video coding, correlated frames are encoded separately but decoded jointly. In the Stanford Architecture, the video is split into Key Frames and Wyner-Ziv Frames. The Key Frames are INTRA coded. The Wyner-Ziv Frames are fed into a systematic channel coder and only the parity bits are sent to the decoder. At the decoder side, an estimation of the Wyner-Ziv Frame, called side information, is produced by interpolating the available frames. The side information, that can be considered as a noisy version of the real Wyner-Ziv Frame, is corrected by the parity bits sent by the encoder. In this thesis, we propose several algorithms for side information generation both for the temporal and inter-view interpolation. We also propose a Bayesian fusion of the two estimations. All our algorithms outperform the state-of-the-art in terms of rate distortion performance. We also propose several algorithms for Wyner-Ziv estimation in the context of multiview video plus depth.

<P> Video coding standards have been designed to support many applications such as broadcasting systems, movie industries and media storage. All video coding standards try to reduce data in video sequences as much as possible by exploiting spatial and temporal redundancies. Although those video coding standards are suitable for a wide variety of applications, some applications require low encoder complexity specifically for real time video encoding. Most of the computational complexity of a video encoder can be attributed to the motion estimation function. </p> <p> Motion estimation using multiple reference frames is widely used as the basis for recent video coding standards (eg. H.264/ AVC) to achieve increased coding efficiency. However, this increases the complexity of the encoding process. In this thesis, new techniques for efficient motion estimation are proposed. A combination of multiple reference frame selection and image residue-based mode selection is used to improve motion estimation time. By dynamic selection of an initial reference frame in advance, the number of reference frames to be considered is reduced. In addition, from examination of the residue between the current block and reconstructed blocks in preceding frames, variable block size mode decisions are made. Modified initial motion vector estimation and early stop condition detection are also adopted to speed up the motion estimation procedure. Experimental results compare the performance of the proposed algorithm with state of the art motion estimation algorithms and demonstrate significantly reduced motion estimation time while maintaining PSNR performance. </p> <p> In addition a new side information generation algorithm using dynamic motion estimation and post processing is proposed for improved distributed video coding. Multiple reference frames are employed for motion estimation at the side information frame generation block of the decoder. After motion estimation and compensation, post processing is applied to improve the hole and overlapped areas on the reconstructed side information frame. Both median filtering and residual-based block selecting algorithms are used to deal with hole and overlapped areas, respectively. The proposed side information method contributes to improving the quality of reconstructed frames at the distributed video decoder. The average encoding time of the distributed video coding is shown to be around 15% of H.264 inter coding and 40% of H.264 intra coding. The proposed side generation algorithm is implemented in a frequency domain distributed system and tested throughout various test sequences. The proposed side information based distributed video coding demonstrates improved performance compared with that of H.264 intra coding. </p> <p> Experimental implementations of the proposed algorithms are demonstrated using a set of video test sequences that are widely used and freely available. </p> / Thesis / Doctor of Philosophy (PhD)

No description available.