by Alan Yeung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 53-[56]). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- MPEG Overview --- p.5 / Chapter 3 --- Framework of Frame-Skipping Lossy Aggregation --- p.10 / Chapter 3.1 --- Video Frames Delivery using Round-Robin Scheduling --- p.10 / Chapter 3.2 --- Underflow Safety Margin on Receiver Buffers --- p.12 / Chapter 3.3 --- Algorithm in Frame-Skipping Aggregation Controller --- p.13 / Chapter 4 --- Replacement of Skipped Frames in MPEG Sequence --- p.17 / Chapter 5 --- Subjective Assessment Test on Frame-Skipped Video --- p.21 / Chapter 5.1 --- Test Settings and Material --- p.22 / Chapter 5.2 --- Choice of Test Methods --- p.23 / Chapter 5.3 --- Test Procedures --- p.25 / Chapter 5.4 --- Test Results --- p.26 / Chapter 6 --- Performance Study --- p.29 / Chapter 6.1 --- Experiment 1: Number of Supportable Streams --- p.31 / Chapter 6.2 --- Experiment 2: Frame-Skipping Rate When Multiplexing on a Leased T3 Link --- p.33 / Chapter 6.3 --- Experiment 3: Bandwidth Usage --- p.35 / Chapter 6.4 --- Experiment 4: Optimal USMT --- p.38 / Chapter 7 --- Implementation Considerations --- p.41 / Chapter 8 --- Conclusions --- p.45 / Chapter A --- The Construction of Stuffed Artificial B Frame --- p.48 / Bibliography --- p.53

The growing popularity of video sensor networks and video celluar phones has generated the need for low-complexity and power-efficient multimedia systems that can handle multiple video input and output streams. While standard video coding techniques fail to satisfy these requirements, distributed source coding is a promising technique for ??uplink?? applications. Wyner-Ziv coding refers to lossy source coding with side information at the decoder. Based on recent theoretical result on successive Wyner-Ziv coding, we propose in this thesis a practical layered Wyner-Ziv video codec using the DCT, nested scalar quantizer, and irregular LDPC code based Slepian-Wolf coding (or lossless source coding with side information) for noiseless channel. The DCT is applied as an approximation to the conditional KLT, which makes the components of the transformed block conditionally independent given the side information. NSQ is a binning scheme that facilitates layered bit-plane coding of the bin indices while reducing the bit rate. LDPC code based Slepian-Wolf coding exploits the correlation between the quantized version of the source and the side information to achieve further compression. Different from previous works, an attractive feature of our proposed system is that video encoding is done only once but decoding allowed at many lower bit rates without quality loss. For Wyner-Ziv coding over discrete noisy channels, we present a Wyner-Ziv video codec using IRA codes for Slepian-Wolf coding based on the idea of two equivalent channels. For video streaming applications where the channel is packet based, we apply unequal error protection scheme to the embedded Wyner-Ziv coded video stream to find the optimal source-channel coding trade-off for a target transmission rate over packet erasure channel.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 112-118).

Thesis (M.S.)--University of Florida, 2002. / Title from title page of source document. Document formatted into pages; contains vii, 67 p.; also contains graphics. Includes vita. Includes bibliographical references.

Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: Streaming MPEG, User Study, Video Quality, Forward Error Correction, Temporal Scaling, Quality Scaling. Includes bibliographical references (p.186-198).

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 93-99).

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação / Made available in DSpace on 2012-10-18T10:32:19Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-25T20:53:58Z : No. of bitstreams: 1 181350.pdf: 4168422 bytes, checksum: 2d241c00d2a71342000a9e91be0b2eb0 (MD5) / Os servidores de armazenamento multimídia surgiram da necessidade de manipulação das informações multimídia. Diante das características deste tipo de informação, as quais diferenciam -se amplamente das informações alfanuméricas, o conceito de Qualidade de Serviço (QoS) precisou ser incorporado ao projeto deste tipo de servidor, visando proporcionar a entraga satifatória dos serviços solicitados. Aqualidade originalmente associada ao serviço, a fim de atender as necessidades dos usuários, pode ser modificada e desta forma, passar por um processo de adaptação às novas exigências dos mesmos. O trabalho de Dissertação de Mestrado apresentado tem como objetivo propor um modelo para a transmissão de fluxos MPEG-2 com QoS, a partir de servidores de armazenamento multimídia. Esta contribuição poderá posteriormente fazer parte de uma infra-estrutura maior, haja visto que o modelo proposto trata ainda dos processos de mapeamento e negociação dos parâmetros de Qualidade e Serviço executado durante a fase de configuração destas tranmissões. O presente trabalho baseia-se especificamente em servidores de vídeo MPEG-2 tendo como meio de transporte a Rede ATM, um vez que o mesmo interessa-se somente na definição de QoS ao nível desta tecnologia. A fim de que o embasamento necessário para a apresentação desta Dissertação fosse obtido, a exposição de alguns conceitos iniciais tornou-se essencialmente importante. Portanto, este trabalho introduz também os principais conceitos relativos a Aplicações Multimídia Distribuídas, Padrão de Compressão MPEG-2, Qualidade de Serviço, Tecnologia ATM e Sistema de Gerenciamento de Banco de Dados Multimídia e Servidores de Armazenamento Multimídia.

Les codeurs vidéo état de l’art utilisent des transformées pour assurer une représentation compacte du signal. L’étape de transformation constitue le domaine dans lequel s’effectue la compression, pourtant peu de variabilité dans les types de transformations est constatée dans les systèmes de codage vidéo normalisés : souvent, une seule transformée est considérée, habituellement la transformée en cosinus discrète (DCT). Récemment, d’autres transformées ont commencé à être considérées en complément de la DCT. Par exemple, dans le dernier standard de compression vidéo, nommé HEVC (High Efficiency Video Coding), les blocs de taille 4x4 peuvent utiliser la transformée en sinus discrète (DST), de plus, il est également possible de ne pas les transformer. Ceci révèle un intérêt croissant pour considérer une pluralité de transformées afin d’augmenter les taux de compression. Cette thèse se concentre sur l’extension de HEVC au travers de l’utilisation de multiples transformées. Après une introduction générale au codage vidéo et au codage par transformée, une étude détaillée de deux méthodes de construction de transformations est menée : la transformée de Karhunen Loève (KLT) et une transformée optimisée en débit et distorsion sont considérées. Ces deux méthodes sont comparées entre-elles en substituant les transformées utilisées par HEVC. Une expérimentation valide la pertinence des approches. Un schéma de codage qui incorpore et augmente l’utilisation de multiples transformées est alors introduit : plusieurs transformées sont mises à disposition de l’encodeur, qui sélectionne celle qui apporte le meilleur compromis dans le plan débit distorsion. Pour ce faire, une méthode de construction qui permet de concevoir des systèmes comportant de multiples transformations est décrite. Avec ce schéma de codage, le débit est significativement réduit par rapport à HEVC, tout particulièrement lorsque les transformées sont nombreuses et complexes à mettre en oeuvre. Néanmoins, ces améliorations viennent au prix d’une complexité accrue en termes d’encodage, de décodage et de contrainte de stockage. En conséquence, des simplifications sont considérées dans la suite du document, qui ont vocation à limiter l’impact en réduction de débit. Une première approche est introduite dans laquelle des transformées incomplètes sont motivées. Les transformations de ce type utilisent un seul vecteur de base, et sont conçues pour travailler de concert avec les transformations de HEVC. Cette technique est évaluée et apporte une réduction de complexité significative par rapport au précédent système, bien que la réduction de débit soit modeste. Une méthode systématique, qui détermine les meilleurs compromis entre le nombre de transformées et l’économie de débit est alors définie. Cette méthode utilise deux types différents de transformée : basés sur des transformées orthogonales séparables et des transformées trigonométriques discrètes (DTT) en particulier. Plusieurs points d’opération sont présentés qui illustrent plusieurs compromis complexité / gain en débit. Ces systèmes révèlent l’intérêt de l’utilisation de transformations multiples pour le codage vidéo. / State of the art video codecs use transforms to ensure a compact signal representation. The transform stage is where compression takes place, however, little variety is observed in the type of transforms used for standardised video coding schemes: often, a single transform is considered, usually a Discrete Cosine Transform (DCT). Recently, other transforms have started being considered in addition to the DCT. For instance, in the latest video coding standard, High Efficiency Video Coding (HEVC), the 4x4 sized blocks can make use of the Discrete Sine Transform (DST) and, in addition, it also possible not to transform them. This fact reveals an increasing interest to consider a plurality of transforms to achieve higher compression rates. This thesis focuses on extending HEVC through the use of multiple transforms. After a general introduction to video compression and transform coding, two transform designs are studied in detail: the Karhunen Loève Transform (KLT) and a Rate-Distortion Optimised Transform are considered. These two methods are compared against each other by replacing the transforms in HEVC. This experiment validates the appropriateness of the design. A coding scheme that incorporates and boosts the use of multiple transforms is introduced: several transforms are made available to the encoder, which chooses the one that provides the best rate-distortion trade-off. Consequently, a design method for building systems using multiple transforms is also described. With this coding scheme, significant amounts of bit-rate savings are achieved over HEVC, especially when using many complex transforms. However, these improvements come at the expense of increased complexity in terms of coding, decoding and storage requirements. As a result, simplifications are considered while limiting the impact on bit-rate savings. A first approach is introduced, in which incomplete transforms are used. This kind of transforms use one single base vector and are conceived to work as companions of the HEVC transforms. This technique is evaluated and provides significant complexity reductions over the previous system, although the bit-rate savings are modest. A systematic method, which specifically determines the best trade-offs between the number of transforms and bit-rate savings, is designed. This method uses two different types of transforms based separable orthogonal transforms and Discrete Trigonometric Transforms (DTTs) in particular. Several designs are presented, allowing for different complexity and bitrate savings trade-offs. These systems reveal the interest of using multiple transforms for video coding.

<p>A method for constructing a highly scalable bit stream for video coding is presented in detail and implemented in a demo application with a GUI in the Windows Vista operating system.</p><p>The video codec uses the Discrete Wavelet Transform in both spatial and temporal directions together with a zerotree quantizer to achieve a highly scalable bit stream in the senses of quality, spatial resolution and frame rate.</p> / <p>I detta arbete presenteras en metod för att skapa en mycket skalbar videoström. Metoden implementeras sedan i sin helhet i programspråken C och C++ med ett grafiskt användargränssnitt på operativsystemet Windows Vista.</p><p>I metoden används den diskreta wavelettransformen i såväl de spatiella dimensionerna som tidsdimensionen tillsammans med en nollträdskvantiserare för att åstakomma en skalbar videoström i avseendena bildkvalitet, skärmupplösning och antal bildrutor per sekund.</p>

A method for constructing a highly scalable bit stream for video coding is presented in detail and implemented in a demo application with a GUI in the Windows Vista operating system. The video codec uses the Discrete Wavelet Transform in both spatial and temporal directions together with a zerotree quantizer to achieve a highly scalable bit stream in the senses of quality, spatial resolution and frame rate. / I detta arbete presenteras en metod för att skapa en mycket skalbar videoström. Metoden implementeras sedan i sin helhet i programspråken C och C++ med ett grafiskt användargränssnitt på operativsystemet Windows Vista. I metoden används den diskreta wavelettransformen i såväl de spatiella dimensionerna som tidsdimensionen tillsammans med en nollträdskvantiserare för att åstakomma en skalbar videoström i avseendena bildkvalitet, skärmupplösning och antal bildrutor per sekund.