Etude et mise en place d’une plateforme d’adaptation multiservice embarquée pour la gestion de flux multimédia à différents niveaux logiciels et matériels

On the one hand, technology advances have led to the expansion of the handheld devices market. Thanks to this expansion, people are more and more connected and more and more data are exchanged over the Internet. On the other hand, this huge amound of data imposes drastic constrains in order to achieve sufficient quality. The Internet is now showing its limits to assure such quality. To answer nowadays limitations, a next generation Internet is envisioned. This new network takes into account the content nature (video, audio, ...) and the context (network state, terminal capabilities ...) to better manage its own resources. To this extend, video manipulation is one of the key concept that is highlighted in this arising context. Video content is more and more consumed and at the same time requires more and more resources. Adapting videos to the network state (reducing its bitrate to match available bandwidth) or to the terminal capabilities (screen size, supported codecs, …) appears mandatory and is foreseen to take place in real time in networking devices such as home gateways. However, video adaptation is a resource intensive task and must be implemented using hardware accelerators to meet the desired low cost and real time constraints.In this thesis, content- and context-awareness is first analyzed to be considered at the network side. Secondly, a generic low cost video adaptation system is proposed and compared to existing solutions as a trade-off between system complexity and quality. Then, hardware conception is tackled as this system is implemented in an FPGA based architecture. Finally, this system is used to evaluate the indirect effects of video adaptation; energy consumption reduction is achieved at the terminal side by reducing video characteristics thus permitting an increased user experience for End-Users.Les avancées technologiques ont permis la commercialisation à grande échelle de terminaux mobiles. De ce fait, l’homme est de plus en plus connecté et partout. Ce nombre grandissant d’usagers du réseau ainsi que la forte croissance du contenu disponible, aussi bien d’un point de vue quantitatif que qualitatif saturent les réseaux et l’augmentation des moyens matériels (passage à la fibre optique) ne suffisent pas. Pour surmonter cela, les réseaux doivent prendre en compte le type de contenu (texte, vidéo, ...) ainsi que le contexte d’utilisation (état du réseau, capacité du terminal, ...) pour assurer une qualité d’expérience optimum. A ce sujet, la vidéo fait partie des contenus les plus critiques. Ce type de contenu est non seulement de plus en plus consommé par les utilisateurs mais est aussi l’un des plus contraignant en terme de ressources nécéssaires à sa distribution (taille serveur, bande passante, …). Adapter un contenu vidéo en fonction de l’état du réseau (ajuster son débit binaire à la bande passante) ou des capacités du terminal (s’assurer que le codec soit nativement supporté) est indispensable. Néanmoins, l’adaptation vidéo est un processus qui nécéssite beaucoup de ressources. Cela est antinomique à son utilisation à grande echelle dans les appareils à bas coûts qui constituent aujourd’hui une grande part dans l’ossature du réseau Internet. Cette thèse se concentre sur la conception d’un système d’adaptation vidéo à bas coût et temps réel qui prendrait place dans ces réseaux du futur. Après une analyse du contexte, un système d’adaptation générique est proposé et évalué en comparaison de l’état de l’art. Ce système est implémenté sur un FPGA afin d’assurer les performances (temps-réels) et la nécessité d’une solution à bas coût. Enfin, une étude sur les effets indirects de l’adaptation vidéo est menée

Etude et mise en place d'une plateforme d'adaptation multiservice embarquée pour la gestion de flux multimédia à différents niveaux logiciels et matériels

Les avancées technologiques ont permis la commercialisation à grande échelle de terminaux mobiles. De ce fait, l homme est de plus en plus connecté et partout. Ce nombre grandissant d usagers du réseau ainsi que la forte croissance du contenu disponible, aussi bien d un point de vue quantitatif que qualitatif saturent les réseaux et l augmentation des moyens matériels (passage à la fibre optique) ne suffisent pas. Pour surmonter cela, les réseaux doivent prendre en compte le type de contenu (texte, vidéo, ...) ainsi que le contexte d utilisation (état du réseau, capacité du terminal, ...) pour assurer une qualité d expérience optimum. A ce sujet, la vidéo fait partie des contenus les plus critiques. Ce type de contenu est non seulement de plus en plus consommé par les utilisateurs mais est aussi l un des plus contraignant en terme de ressources nécéssaires à sa distribution (taille serveur, bande passante, ). Adapter un contenu vidéo en fonction de l état du réseau (ajuster son débit binaire à la bande passante) ou des capacités du terminal (s assurer que le codec soit nativement supporté) est indispensable. Néanmoins, l adaptation vidéo est un processus qui nécéssite beaucoup de ressources. Cela est antinomique à son utilisation à grande echelle dans les appareils à bas coûts qui constituent aujourd hui une grande part dans l ossature du réseau Internet. Cette thèse se concentre sur la conception d un système d adaptation vidéo à bas coût et temps réel qui prendrait place dans ces réseaux du futur. Après une analyse du contexte, un système d adaptation générique est proposé et évalué en comparaison de l état de l art. Ce système est implémenté sur un FPGA afin d assurer les performances (temps-réels) et la nécessité d une solution à bas coût. Enfin, une étude sur les effets indirects de l adaptation vidéo est menée.On the one hand, technology advances have led to the expansion of the handheld devices market. Thanks to this expansion, people are more and more connected and more and more data are exchanged over the Internet. On the other hand, this huge amound of data imposes drastic constrains in order to achieve sufficient quality. The Internet is now showing its limits to assure such quality. To answer nowadays limitations, a next generation Internet is envisioned. This new network takes into account the content nature (video, audio, ...) and the context (network state, terminal capabilities ...) to better manage its own resources. To this extend, video manipulation is one of the key concept that is highlighted in this arising context. Video content is more and more consumed and at the same time requires more and more resources. Adapting videos to the network state (reducing its bitrate to match available bandwidth) or to the terminal capabilities (screen size, supported codecs, ) appears mandatory and is foreseen to take place in real time in networking devices such as home gateways. However, video adaptation is a resource intensive task and must be implemented using hardware accelerators to meet the desired low cost and real time constraints.In this thesis, content- and context-awareness is first analyzed to be considered at the network side. Secondly, a generic low cost video adaptation system is proposed and compared to existing solutions as a trade-off between system complexity and quality. Then, hardware conception is tackled as this system is implemented in an FPGA based architecture. Finally, this system is used to evaluate the indirect effects of video adaptation; energy consumption reduction is achieved at the terminal side by reducing video characteristics thus permitting an increased user experience for End-Users.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Cost-effective Hardware Design of a SPIHT Compression Algorithm

학위논문 (석사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. Jae Ha Kim.Set Partitioning In Hierarchical Trees (SPIHT) is one of most popular embedded coding algorithms applied for wavelet coding images. It allows progressive transmission of information and gives high coding efficiency. In addition, it can omit entropy coding of the bit stream by arithmetic code with only small loss in performance. Thus it offers a cheaper and faster hardware design. In this dissertation, a cost-effective design of a SPIHT-based algorithm is proposed. In this algorithm, an image is partitioned into 1x64 blocks, each of which is transformed by DWT to generate wavelet coefficients. The wavelet coefficients are coded by SPIHT to generate bit-stream. Due to the mismatch of the data structure between DWT and SPIHT, the large buffers are required. In order to reduce buffers, a new data structure of wavelet coefficients and partitioned SPIHT are proposed. A wavelet-based block is partitioned into small sub-blocks each of which is compressed independently. To minimize distortion due to the sub-block-based compression, a bit-allocation scheme is proposed. The proposed design is implemented in both software and hardware. Experimental results show that the proposed design reduces the buffer size while minimizing the degradation of the rate-distortion performance. It is proved that the proposed design outperforms previous designs in hardware cost.Chapter Ⅰ. Introduction 1 Chapter Ⅱ. Basic Architecture of the compression algorithm 5 Chapter Ⅲ. A Partitioned NLS Algorithm 17 Chapter Ⅳ. Adjustment of the target bit lengths for individual sub-blocks Chapter Ⅴ. Experimental Results 35 Chapter Ⅵ. Conclusion 48 References 50 Abstract 52 초록 53Maste

The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

H.264-based Low Power Heterogeneous Video Recording System

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 김수환.최근 영상 저장 장치의 사용이 증가함에 따라 한정된 배터리에서 저전력으로 영상 저장 장치를 동작하는 것이 중요하다. 영상 저장 장치에서 장기 저장을 수행하기 위해서는 영상 압축이 필수적이다. 기존 영상 저장 장치에서 영상 압축을 위해 보편적으로 사용되는 H.264/AVC 영상 압축 표준은 높은 압축률을 자랑하지만 높은 복잡도와 프레임 간의 인터 프레임 예측의 사용으로 전력 소모가 크다는 문제점을 갖는다. 본 논문에서는 이러한 문제점을 해결하기 위하여 두 가지 접근 기법을 통해 영상 저장 장치의 소모 전력 중, 가장 큰 비중을 차지하는 영상 압축에 소모 되는 전력을 감소시킨다. 우선, 멀티 압축 모듈을 통한 영상 저장 장치를 활용한다. Discrete Wavelet Transform과 Set Partitioning in Hierarchical Trees 압축에 기반한 경량화 압축 방식은 상대적으로 간단한 압축 방식으로 압축 효율은 H.264/AVC 인코더에 비해 낮으나 훨씬 더 적은 전력 소모로 동작할 수 있다. 본 논문에서는 기존의 영상 저장 장치와 다르게 H.264/AVC 인코더뿐만 아니라 경량화 압축 방식을 영상 저장 장치에 함께 활용하여 저전력 영상 저장 장치를 구성한다. 모든 영상 정보가 장기 저장 되어 보관될 필요가 있는 것이 아니기 때문에 H.264/AVC 인코더보다 압축 효율은 다소 낮지만 훨씬 낮은 전력에서 동작할 수 있는 경량화 압축 방식을 임시 저장 용도로 사용하고 이 영상 정보가 장기 저장될 필요가 있을 경우에만 영상 압축을 위해 H.264/AVC 인코더를 사용한다. 본 논문에서는 경량화 압축 방식의 활용뿐만 아니라 다운 샘플링 기법을 영상 저장 장치에 활용하여 낮은 bitrate 영역에서 더욱 큰 전력 감소 효과를 얻는다. 이러한 멀티 압축 모듈을 통한 방식은 장기 저장의 비율이 높아지면 결국 H.264/AVC 인코더가 사용되는 비율이 높아져서 전력 감소 효과가 크지 않다. 이러한 약점을 보완하기 위해서는 H.264/AVC 인코더 자체의 소모 전력을 감소시키는 것이 중요하다. 그렇기 때문에 본 논문에서는 H.264/AVC 인코더 내부의 전력 소모를 제어하는 power-aware design 기법을 영상 저장 장치에 활용한다. Power-aware design은 최소의 성능 저하로 최대의 전력 감소 효과를 얻는 기법으로 다양한 저전력 알고리즘의 동작 옵션들의 조합들 중에서 최적화된 알고리즘의 조합들로 power-level table을 정의하고 이를 인코더에 적용한다. 최적화된 조합을 찾기 위하여 알고리즘들 간의 상관 관계를 고려하여 개별 알고리즘의 전력 감소 효과를 통해 전체 시스템의 전력 감소 효과를 예측하는 모델을 활용하는데 이러한 전력 예측 모델을 사용하면 최적화된 알고리즘들의 조합을 찾기 위한 시뮬레이션 횟수가 현저하게 감소되기 때문에 여러 저전력 알고리즘이 함께 사용되더라도 최적의 조합을 쉽게 구성할 수 있다. 본 논문에서는 더 뛰어난 성능을 얻기 위해서 입력 영상의 크기와 움직임 여부에 따라서 네 가지의 다른 power-level table을 제시하며 이러한 power-level table이 사전에 정의되기 때문에 최적화된 저전력 알고리즘의 조합들이 실시간으로 인코더에 적용될 수 있다. 본 논문에서는 영상 저장 장치의 전력 감소를 위해 제시된 멀티 압축 모듈을 활용하는 방식과 H.264/AVC 인코더 내부의 전력 소모를 감소하는 방식을 모두 지원하는 통합 영상 저장 장치를 구현하고 통합된 영상 저장 장치 상에서 장기 저장의 비율과 bitrate 목표에 따른 분석을 통하여 동작 상황에 가장 알맞은 최적화된 영상 저장 장치를 활용한다. 이러한 최적화된 영상 저장 장치는 최소한의 성능 저하로 기존의 영상 저장 장치 대비 최대 72.5%의 전력 감소 효과를 갖는다.초 록 i 목 차 iv 그림 목차 viii 표 목 차 xi 제 1 장 서 론 1 1.1 연구 배경 1 1.2 연구 내용 3 1.3 논문 구성 7 제 2 장 관련 연구 8 2.1 영상 저장 장치의 동작 8 2.2 H.264/AVC 영상 압축 표준 12 2.2.1 H.264/AVC 인코더의 동작 12 2.2.2 저전력 H.264/AVC 인코더를 위한 기존 연구 15 2.3 경량화 압축 방식 알고리즘 19 2.3.1 1차원 Discrete Wave Transform 19 2.3.2 Set Partitioning in Hierarchical Trees 20 2.3.3 1차원 경량화 압축 방식 기법 21 제 3 장 멀티 압축 모듈을 통한 영상 저장 장치 22 3.1 경량화 압축 방식의 구현 22 3.1.1 구현 방식 22 3.1.2 구현 결과 및 성능 비교 28 3.2 경량화 압축 방식을 통한 영상 저장 장치의 구현 34 3.2.1 LWC 기반 영상 저장 장치 35 3.2.2 D-LPFC 기반 영상 저장 장치 38 3.2.3 제안된 영상 저장 장치의 분석 42 3.3 성능 평가 45 3.3.1 전력 측정 방법 45 3.3.2 모드 별 전력 분석 48 3.3.3 FRECORD에 따른 시스템 전체 전력 및 성능 분석 52 제 4 장 H.264/AVC 자체적인 전력 감소 기법 55 4.1 H.264/AVC 자체 전력 감소의 필요성 55 4.2 Power-Aware Design 56 4.2.1 Power Level Table의 생성 56 4.2.2 입력 영상의 특징이 미치는 영향 59 4.2.3 전력 레벨의 유동적 선택 기법 60 4.2.4 전력 레벨 적용 알고리즘 62 4.3 전력 예측 모델 65 4.4 Power-Aware Design의 예시 71 4.4.1 네 가지 저전력 알고리즘 71 4.4.2 전력 예측 모델의 예시 73 4.4.3 개별 알고리즘의 전력 소모 측정 76 4.4.4 최적화된 알고리즘 옵션의 선택 84 4.4.5 Power level table의 생성의 예시 87 4.5 성능 평가 92 4.5.1 Power-Aware Design의 성능 측정 92 4.5.2 기존 Power-Aware Design과의 성능 비교 105 4.5.3 Power-Aware Design의 영상 저장 장치 적용 113 제 5 장 최적화된 영상 저장 장치의 활용 기법 115 5.1 통합 영상 저장 장치 116 5.1.1 통합 영상 저장 장치의 구현 116 5.1.2 통합 영상 저장 장치의 FPGA 검증 119 5.2 최적화된 영상 저장 장치 122 5.2.1 최적화된 영상 저장 장치를 위한 분석 122 5.2.2 최적화된 영상 저장 장치 선택 기법 130 5.3 성능 평가 132 제 6 장 결론 137 참고문헌 139 Abstract 144Docto

ReSCon '10, Research Student Conference: Book of Abstracts

The third SED Research Student Conference (ReSCon2010) was hosted over three days, 21-23 June 2010, in the Hamilton Centre at Brunel University. The conference consisted of oral and poster presentations, which showcased the high quality and diversity of the research being conducted within the School of Engineering and Design. The abstracts and presentations were the result of ongoing research by postgraduate research students from the School. The conference is held annually, and ReSCon plays a key role in contributing to research and innovations within the School

A configurable vector processor for accelerating speech coding algorithms

The growing demand for voice-over-packer (VoIP) services and multimedia-rich applications has made increasingly important the efficient, real-time implementation of low-bit rates speech coders on embedded VLSI platforms. Such speech coders are designed to substantially reduce the bandwidth requirements thus enabling dense multichannel gateways in small form factor. This however comes at a high computational cost which mandates the use of very high performance embedded processors. This thesis investigates the potential acceleration of two major ITU-T speech coding algorithms, namely G.729A and G.723.1, through their efficient implementation on a configurable extensible vector embedded CPU architecture. New scalar and vector ISAs were introduced which resulted in up to 80% reduction in the dynamic instruction count of both workloads. These instructions were subsequently encapsulated into a parametric, hybrid SISD (scalar processor)–SIMD (vector) processor. This work presents the research and implementation of the vector datapath of this vector coprocessor which is tightly-coupled to a Sparc-V8 compliant CPU, the optimization and simulation methodologies employed and the use of Electronic System Level (ESL) techniques to rapidly design SIMD datapaths

Application of service composition mechanisms to Future Networks architectures and Smart Grids

Aquesta tesi gira entorn de la hipòtesi de la metodologia i mecanismes de composició de serveis i com es poden aplicar a diferents camps d'aplicació per a orquestrar de manera eficient comunicacions i processos flexibles i sensibles al context. Més concretament, se centra en dos camps d'aplicació: la distribució eficient i sensible al context de contingut multimèdia i els serveis d'una xarxa elèctrica intel·ligent. En aquest últim camp es centra en la gestió de la infraestructura, cap a la definició d'una Software Defined Utility (SDU), que proposa una nova manera de gestionar la Smart Grid amb un enfocament basat en programari, que permeti un funcionament molt més flexible de la infraestructura de xarxa elèctrica. Per tant, revisa el context, els requisits i els reptes, així com els enfocaments de la composició de serveis per a aquests camps. Fa especial èmfasi en la combinació de la composició de serveis amb arquitectures Future Network (FN), presentant una proposta de FN orientada a serveis per crear comunicacions adaptades i sota demanda. També es presenten metodologies i mecanismes de composició de serveis per operar sobre aquesta arquitectura, i posteriorment, es proposa el seu ús (en conjunció o no amb l'arquitectura FN) en els dos camps d'estudi. Finalment, es presenta la investigació i desenvolupament realitzat en l'àmbit de les xarxes intel·ligents, proposant diverses parts de la infraestructura SDU amb exemples d'aplicació de composició de serveis per dissenyar seguretat dinàmica i flexible o l'orquestració i gestió de serveis i recursos dins la infraestructura de l'empresa elèctrica.Esta tesis gira en torno a la hipótesis de la metodología y mecanismos de composición de servicios y cómo se pueden aplicar a diferentes campos de aplicación para orquestar de manera eficiente comunicaciones y procesos flexibles y sensibles al contexto. Más concretamente, se centra en dos campos de aplicación: la distribución eficiente y sensible al contexto de contenido multimedia y los servicios de una red eléctrica inteligente. En este último campo se centra en la gestión de la infraestructura, hacia la definición de una Software Defined Utility (SDU), que propone una nueva forma de gestionar la Smart Grid con un enfoque basado en software, que permita un funcionamiento mucho más flexible de la infraestructura de red eléctrica. Por lo tanto, revisa el contexto, los requisitos y los retos, así como los enfoques de la composición de servicios para estos campos. Hace especial hincapié en la combinación de la composición de servicios con arquitecturas Future Network (FN), presentando una propuesta de FN orientada a servicios para crear comunicaciones adaptadas y bajo demanda. También se presentan metodologías y mecanismos de composición de servicios para operar sobre esta arquitectura, y posteriormente, se propone su uso (en conjunción o no con la arquitectura FN) en los dos campos de estudio. Por último, se presenta la investigación y desarrollo realizado en el ámbito de las redes inteligentes, proponiendo varias partes de la infraestructura SDU con ejemplos de aplicación de composición de servicios para diseñar seguridad dinámica y flexible o la orquestación y gestión de servicios y recursos dentro de la infraestructura de la empresa eléctrica.This thesis revolves around the hypothesis the service composition methodology and mechanisms and how they can be applied to different fields of application in order to efficiently orchestrate flexible and context-aware communications and processes. More concretely, it focuses on two fields of application that are the context-aware media distribution and smart grid services and infrastructure management, towards a definition of a Software-Defined Utility (SDU), which proposes a new way of managing the Smart Grid following a software-based approach that enable a much more flexible operation of the power infrastructure. Hence, it reviews the context, requirements and challenges of these fields, as well as the service composition approaches. It makes special emphasis on the combination of service composition with Future Network (FN) architectures, presenting a service-oriented FN proposal for creating context-aware on-demand communication services. Service composition methodology and mechanisms are also presented in order to operate over this architecture, and afterwards, proposed for their usage (in conjunction or not with the FN architecture) in the deployment of context-aware media distribution and Smart Grids. Finally, the research and development done in the field of Smart Grids is depicted, proposing several parts of the SDU infrastructure, with examples of service composition application for designing dynamic and flexible security for smart metering or the orchestration and management of services and data resources within the utility infrastructure