45 research outputs found

    End to end Multi-Objective Optimisation of H.264 and HEVC Codecs

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    All multimedia devices now incorporate video CODECs that comply with international video coding standards such as H.264 / MPEG4-AVC and the new High Efficiency Video Coding Standard (HEVC) otherwise known as H.265. Although the standard CODECs have been designed to include algorithms with optimal efficiency, large number of coding parameters can be used to fine tune their operation, within known constraints of for e.g., available computational power, bandwidth, consumer QoS requirements, etc. With large number of such parameters involved, determining which parameters will play a significant role in providing optimal quality of service within given constraints is a further challenge that needs to be met. Further how to select the values of the significant parameters so that the CODEC performs optimally under the given constraints is a further important question to be answered. This thesis proposes a framework that uses machine learning algorithms to model the performance of a video CODEC based on the significant coding parameters. Means of modelling both the Encoder and Decoder performance is proposed. We define objective functions that can be used to model the performance related properties of a CODEC, i.e., video quality, bit-rate and CPU time. We show that these objective functions can be practically utilised in video Encoder/Decoder designs, in particular in their performance optimisation within given operational and practical constraints. A Multi-objective Optimisation framework based on Genetic Algorithms is thus proposed to optimise the performance of a video codec. The framework is designed to jointly minimize the CPU Time, Bit-rate and to maximize the quality of the compressed video stream. The thesis presents the use of this framework in the performance modelling and multi-objective optimisation of the most widely used video coding standard in practice at present, H.264 and the latest video coding standard, H.265/HEVC. When a communication network is used to transmit video, performance related parameters of the communication channel will impact the end-to-end performance of the video CODEC. Network delays and packet loss will impact the quality of the video that is received at the decoder via the communication channel, i.e., even if a video CODEC is optimally configured network conditions will make the experience sub-optimal. Given the above the thesis proposes a design, integration and testing of a novel approach to simulating a wired network and the use of UDP protocol for the transmission of video data. This network is subsequently used to simulate the impact of packet loss and network delays on optimally coded video based on the framework previously proposed for the modelling and optimisation of video CODECs. The quality of received video under different levels of packet loss and network delay is simulated, concluding the impact on transmitted video based on their content and features

    Algorithms for compression of high dynamic range images and video

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    The recent advances in sensor and display technologies have brought upon the High Dynamic Range (HDR) imaging capability. The modern multiple exposure HDR sensors can achieve the dynamic range of 100-120 dB and LED and OLED display devices have contrast ratios of 10^5:1 to 10^6:1. Despite the above advances in technology the image/video compression algorithms and associated hardware are yet based on Standard Dynamic Range (SDR) technology, i.e. they operate within an effective dynamic range of up to 70 dB for 8 bit gamma corrected images. Further the existing infrastructure for content distribution is also designed for SDR, which creates interoperability problems with true HDR capture and display equipment. The current solutions for the above problem include tone mapping the HDR content to fit SDR. However this approach leads to image quality associated problems, when strong dynamic range compression is applied. Even though some HDR-only solutions have been proposed in literature, they are not interoperable with current SDR infrastructure and are thus typically used in closed systems. Given the above observations a research gap was identified in the need for efficient algorithms for the compression of still images and video, which are capable of storing full dynamic range and colour gamut of HDR images and at the same time backward compatible with existing SDR infrastructure. To improve the usability of SDR content it is vital that any such algorithms should accommodate different tone mapping operators, including those that are spatially non-uniform. In the course of the research presented in this thesis a novel two layer CODEC architecture is introduced for both HDR image and video coding. Further a universal and computationally efficient approximation of the tone mapping operator is developed and presented. It is shown that the use of perceptually uniform colourspaces for internal representation of pixel data enables improved compression efficiency of the algorithms. Further proposed novel approaches to the compression of metadata for the tone mapping operator is shown to improve compression performance for low bitrate video content. Multiple compression algorithms are designed, implemented and compared and quality-complexity trade-offs are identified. Finally practical aspects of implementing the developed algorithms are explored by automating the design space exploration flow and integrating the high level systems design framework with domain specific tools for synthesis and simulation of multiprocessor systems. The directions for further work are also presented

    Architecture and algorithms for the implementation of digital wireless receivers in FPGA and ASIC: ISDB-T and DVB-S2 cases

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    [EN] The first generation of Terrestrial Digital Television(DTV) has been in service for over a decade. In 2013, several countries have already completed the transition from Analog to Digital TV Broadcasting, most of which in Europe. In South America, after several studies and trials, Brazil adopted the Japanese standard with some innovations. Japan and Brazil started Digital Terrestrial Television Broadcasting (DTTB) services in December 2003 and December 2007 respectively, using Integrated Services Digital Broadcasting - Terrestrial (ISDB-T), also known as ARIB STD-B31. In June 2005 the Committee for the Information Technology Area (CATI) of Brazilian Ministry of Science and Technology and Innovation MCTI approved the incorporation of the IC-Brazil Program, in the National Program for Microelectronics (PNM) . The main goals of IC-Brazil are the formal qualification of IC designers, support to the creation of semiconductors companies focused on projects of ICs within Brazil, and the attraction of semiconductors companies focused on the design and development of ICs in Brazil. The work presented in this thesis originated from the unique momentum created by the combination of the birth of Digital Television in Brazil and the creation of the IC-Brazil Program by the Brazilian government. Without this combination it would not have been possible to make these kind of projects in Brazil. These projects have been a long and costly journey, albeit scientifically and technologically worthy, towards a Brazilian DTV state-of-the-art low complexity Integrated Circuit, with good economy scale perspectives, due to the fact that at the beginning of this project ISDB-T standard was not adopted by several countries like DVB-T. During the development of the ISDB-T receiver proposed in this thesis, it was realized that due to the continental dimensions of Brazil, the DTTB would not be enough to cover the entire country with open DTV signal, specially for the case of remote localizations far from the high urban density regions. Then, Eldorado Research Institute and Idea! Electronic Systems, foresaw that, in a near future, there would be an open distribution system for high definition DTV over satellite, in Brazil. Based on that, it was decided by Eldorado Research Institute, that would be necessary to create a new ASIC for broadcast satellite reception. At that time DVB-S2 standard was the strongest candidate for that, and this assumption still stands nowadays. Therefore, it was decided to apply to a new round of resources funding from the MCTI - that was granted - in order to start the new project. This thesis discusses in details the Architecture and Algorithms proposed for the implementation of a low complexity Intermediate Frequency(IF) ISDB-T Receiver on Application Specific Integrated Circuit (ASIC) CMOS. The Architecture proposed here is highly based on the COordinate Rotation Digital Computer (CORDIC) Algorithm, that is a simple and efficient algorithm suitable for VLSI implementations. The receiver copes with the impairments inherent to wireless channels transmission and the receiver crystals. The thesis also discusses the Methodology adopted and presents the implementation results. The receiver performance is presented and compared to those obtained by means of simulations. Furthermore, the thesis also presents the Architecture and Algorithms for a DVB-S2 receiver targeting its ASIC implementation. However, unlike the ISDB-T receiver, only preliminary ASIC implementation results are introduced. This was mainly done in order to have an early estimation of die area to prove that the project in ASIC is economically viable, as well as to verify possible bugs in early stage. As in the case of ISDB-T receiver, this receiver is highly based on CORDIC algorithm and it was prototyped in FPGA. The Methodology used for the second receiver is derived from that used for the ISDB-T receiver, with minor additions given the project characteristics.[ES] La primera generaci贸n de Televisi贸n Digital Terrestre(DTV) ha estado en servicio por m谩s de una d茅cada. En 2013, varios pa铆ses completaron la transici贸n de transmisi贸n anal贸gica a televisi贸n digital, la mayor铆a de ellas en Europa. En Am茅rica del Sur, despu茅s de varios estudios y ensayos, Brasil adopt贸 el est谩ndar japon茅s con algunas innovaciones. Jap贸n y Brasil comenzaron a prestar el servicio de Difusi贸n de Televisi贸n Digital Terrestre (DTTB) en diciembre de 2003 y diciembre de 2007 respectivamente, utilizando Radiodifusi贸n Digital de Servicios Integrados Terrestres (ISDB-T), tambi茅n conocida como ARIB STD-B31. En junio de 2005, el Comit茅 del 脕rea de Tecnolog铆a de la Informaci贸n (CATI) del Ministerio de Ciencia, Tecnolog铆a e Innovaci贸n de Brasil - MCTI aprob贸 la incorporaci贸n del Programa CI-Brasil, en el Programa Nacional de Microelectr贸nica (PNM). Los principales objetivos de la CI-Brasil son la formaci贸n de dise帽adores de CIs, apoyar la creaci贸n de empresas de semiconductores enfocadas en proyectos de circuitos integrados dentro de Brasil, y la atracci贸n de empresas de semiconductores interesadas en el dise帽o y desarrollo de circuitos integrados. El trabajo presentado en esta tesis se origin贸 en el impulso 煤nico creado por la combinaci贸n del nacimiento de la televisi贸n digital en Brasil y la creaci贸n del Programa de CI-Brasil por el gobierno brasile帽o. Sin esta combinaci贸n no hubiera sido posible realizar este tipo de proyectos en Brasil. Estos proyectos han sido un trayecto largo y costoso, aunque meritorio desde el punto de vista cient铆fico y tecnol贸gico, hacia un Circuito Integrado brasile帽o de punta y de baja complejidad para DTV, con buenas perspectivas de econom铆a de escala debido al hecho que al inicio de este proyecto, el est谩ndar ISDB-T no fue adoptado por varios pa铆ses como DVB-T. Durante el desarrollo del receptor ISDB-T propuesto en esta tesis, se observ贸 que debido a las dimensiones continentales de Brasil, la DTTB no ser铆a suficiente para cubrir todo el pa铆s con la se帽al de televisi贸n digital abierta, especialmente para el caso de localizaciones remotas, apartadas de las regiones de alta densidad urbana. En ese momento, el Instituto de Investigaci贸n Eldorado e Idea! Sistemas Electr贸nicos, previeron que en un futuro cercano habr铆a un sistema de distribuci贸n abierto para DTV de alta definici贸n por sat茅lite en Brasil. Con base en eso, el Instituto de Investigaci贸n Eldorado decidi贸 que ser铆a necesario crear un nuevo ASIC para la recepci贸n de radiodifusi贸n por sat茅lite, basada el est谩ndar DVB-S2. En esta tesis se analiza en detalle la Arquitectura y algoritmos propuestos para la implementaci贸n de un receptor ISDB-T de baja complejidad y frecuencia intermedia (IF) en un Circuito Integrado de Aplicaci贸n Espec铆fica (ASIC) CMOS. La arquitectura aqu铆 propuesta se basa fuertemente en el algoritmo Computadora Digital para Rotaci贸n de Coordenadas (CORDIC), el cual es un algoritmo simple, eficiente y adecuado para implementaciones VLSI. El receptor hace frente a las deficiencias inherentes a las transmisiones por canales inal谩mbricos y los cristales del receptor. La tesis tambi茅n analiza la metodolog铆a adoptada y presenta los resultados de la implementaci贸n. Por otro lado, la tesis tambi茅n presenta la arquitectura y los algoritmos para un receptor DVB-S2 dirigido a la implementaci贸n en ASIC. Sin embargo, a diferencia del receptor ISDB-T, se introducen s贸lo los resultados preliminares de implementaci贸n en ASIC. Esto se hizo principalmente con el fin de tener una estimaci贸n temprana del 谩rea del die para demostrar que el proyecto en ASIC es econ贸micamente viable, as铆 como para verificar posibles errores en etapa temprana. Como en el caso de receptor ISDB-T, este receptor se basa fuertemente en el algoritmo CORDIC y fue un prototipado en FPGA. La metodolog铆a utilizada para el segundo receptor se deriva de la utilizada para el re[CA] La primera generaci贸 de Televisi贸 Digital Terrestre (TDT) ha estat en servici durant m茅s d'una d猫cada. En 2013, diversos pa茂sos ja van completar la transici贸 de la radiodifusi贸 de televisi贸 anal貌gica a la digital, i la majoria van ser a Europa. A Am猫rica del Sud, despr茅s de diversos estudis i assajos, Brasil va adoptar l'est脿ndard japon茅s amb algunes innovacions. Jap贸 i Brasil van comen莽ar els servicis de Radiodifusi贸 de Televisi贸 Terrestre Digital (DTTB) al desembre de 2003 i al desembre de 2007, respectivament, utilitzant la Radiodifusi贸 Digital amb Servicis Integrats de (ISDB-T), coneguda com a ARIB STD-B31. Al juny de 2005, el Comit茅 de l'脌rea de Tecnologia de la Informaci贸 (CATI) del Ministeri de Ci猫ncia i Tecnologia i Innovaci贸 del Brasil (MCTI) va aprovar la incorporaci贸 del programa CI Brasil al Programa Nacional de Microelectr貌nica (PNM). Els principals objectius de CI Brasil s贸n la qualificaci贸 formal dels dissenyadors de circuits integrats, el suport a la creaci贸 d'empreses de semiconductors centrades en projectes de circuits integrats dins del Brasil i l'atracci贸 d'empreses de semiconductors centrades en el disseny i desenvolupament de circuits integrats. El treball presentat en esta tesi es va originar en l'impuls 煤nic creat per la combinaci贸 del naixement de la televisi贸 digital al Brasil i la creaci贸 del programa Brasil CI pel govern brasiler. Sense esta combinaci贸 no hauria estat possible realitzar este tipus de projectes a Brasil. Estos projectes han suposat un viatge llarg i cost贸s, tot i que digne cient铆ficament i tecnol貌gica, cap a un circuit integrat punter de baixa complexitat per a la TDT brasilera, amb bones perspectives d'economia d'escala perqu猫 a l'inici d'este projecte l'est脿ndard ISDB-T no va ser adoptat per diversos pa茂sos, com el DVB-T. Durant el desenvolupament del receptor de ISDB-T proposat en esta tesi, va resultar que, a causa de les dimensions continentals de Brasil, la DTTB no seria suficient per cobrir tot el pa铆s amb el senyal de TDT oberta, especialment pel que fa a les localitzacions remotes allunyades de les regions d'alta densitat urbana.. En este moment, l'Institut de Recerca Eldorado i Idea! Sistemes Electr貌nics van preveure que, en un futur pr貌xim, no hi hauria a Brasil un sistema de distribuci贸 oberta de TDT d'alta definici贸 a trav茅s de sat猫l驴lit. D'acord amb aix貌, l'Institut de Recerca Eldorado va decidir que seria necessari crear un nou ASIC per a la recepci贸 de radiodifusi贸 per sat猫l驴lit. basat en l'est脿ndard DVB-S2. En esta tesi s'analitza en detall l'arquitectura i els algorismes proposats per l'execuci贸 d'un receptor ISDB-T de Freq眉猫ncia Interm猫dia (FI) de baixa complexitat sobre CMOS de Circuit Integrat d'Aplicacions Espec铆fiques (ASIC). L'arquitectura ac铆 proposada es basa molt en l'algorisme de l'Ordinador Digital de Rotaci贸 de Coordenades (CORDIC), que 茅s un algorisme simple i eficient adequat per implementacions VLSI. El receptor fa front a les defici猫ncies inherents a la transmissi贸 de canals sense fil i els cristalls del receptor. Esta tesi tamb茅 analitza la metodologia adoptada i presenta els resultats de l'execuci贸. Es presenta el rendiment del receptor i es compara amb els obtinguts per mitj脿 de simulacions. D'altra banda, esta tesi tamb茅 presenta l'arquitectura i els algorismes d'un receptor de DVB-S2 de cara a la seua implementaci贸 en ASIC. No obstant aix貌, a difer猫ncia del receptor ISDB-T, nom茅s s'introdueixen resultats preliminars d'implementaci贸 en ASIC. Aix貌 es va fer principalment amb la finalitat de tenir una estimaci贸 primerenca de la zona de dau per demostrar que el projecte en ASIC 茅s econ貌micament viable, aix铆 com per verificar possibles errors en l'etapa primerenca. Com en el cas del receptor ISDB-T, este receptor es basa molt en l'algorisme CORDIC i va ser un prototip de FPGA. La metodologia utilitzada per al segon receptor es deriva de la utilitzada per al receptor IRodrigues De Lima, E. (2016). Architecture and algorithms for the implementation of digital wireless receivers in FPGA and ASIC: ISDB-T and DVB-S2 cases [Tesis doctoral no publicada]. Universitat Polit猫cnica de Val猫ncia. https://doi.org/10.4995/Thesis/10251/61967TESI

    On-board processing satellite network architecture and control study

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    The market for telecommunications services needs to be segmented into user classes having similar transmission requirements and hence similar network architectures. Use of the following transmission architecture was considered: satellite switched TDMA; TDMA up, TDM down; scanning (hopping) beam TDMA; FDMA up, TDM down; satellite switched MF/TDMA; and switching Hub earth stations with double hop transmission. A candidate network architecture will be selected that: comprises multiple access subnetworks optimized for each user; interconnects the subnetworks by means of a baseband processor; and optimizes the marriage of interconnection and access techniques. An overall network control architecture will be provided that will serve the needs of the baseband and satellite switched RF interconnected subnetworks. The results of the studies shall be used to identify elements of network architecture and control that require the greatest degree of technology development to realize an operational system. This will be specified in terms of: requirements of the enabling technology; difference from the current available technology; and estimate of the development requirements needed to achieve an operational system. The results obtained for each of these tasks are presented

    Potential markets for advanced satellite communications

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    This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies

    Energy efficient hardware acceleration of multimedia processing tools

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    The world of mobile devices is experiencing an ongoing trend of feature enhancement and generalpurpose multimedia platform convergence. This trend poses many grand challenges, the most pressing being their limited battery life as a consequence of delivering computationally demanding features. The envisaged mobile application features can be considered to be accelerated by a set of underpinning hardware blocks Based on the survey that this thesis presents on modem video compression standards and their associated enabling technologies, it is concluded that tight energy and throughput constraints can still be effectively tackled at algorithmic level in order to design re-usable optimised hardware acceleration cores. To prove these conclusions, the work m this thesis is focused on two of the basic enabling technologies that support mobile video applications, namely the Shape Adaptive Discrete Cosine Transform (SA-DCT) and its inverse, the SA-IDCT. The hardware architectures presented in this work have been designed with energy efficiency in mind. This goal is achieved by employing high level techniques such as redundant computation elimination, parallelism and low switching computation structures. Both architectures compare favourably against the relevant pnor art in the literature. The SA-DCT/IDCT technologies are instances of a more general computation - namely, both are Constant Matrix Multiplication (CMM) operations. Thus, this thesis also proposes an algorithm for the efficient hardware design of any general CMM-based enabling technology. The proposed algorithm leverages the effective solution search capability of genetic programming. A bonus feature of the proposed modelling approach is that it is further amenable to hardware acceleration. Another bonus feature is an early exit mechanism that achieves large search space reductions .Results show an improvement on state of the art algorithms with future potential for even greater savings

    Energy efficient enabling technologies for semantic video processing on mobile devices

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    Semantic object-based processing will play an increasingly important role in future multimedia systems due to the ubiquity of digital multimedia capture/playback technologies and increasing storage capacity. Although the object based paradigm has many undeniable benefits, numerous technical challenges remain before the applications becomes pervasive, particularly on computational constrained mobile devices. A fundamental issue is the ill-posed problem of semantic object segmentation. Furthermore, on battery powered mobile computing devices, the additional algorithmic complexity of semantic object based processing compared to conventional video processing is highly undesirable both from a real-time operation and battery life perspective. This thesis attempts to tackle these issues by firstly constraining the solution space and focusing on the human face as a primary semantic concept of use to users of mobile devices. A novel face detection algorithm is proposed, which from the outset was designed to be amenable to be offloaded from the host microprocessor to dedicated hardware, thereby providing real-time performance and reducing power consumption. The algorithm uses an Artificial Neural Network (ANN), whose topology and weights are evolved via a genetic algorithm (GA). The computational burden of the ANN evaluation is offloaded to a dedicated hardware accelerator, which is capable of processing any evolved network topology. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design. To tackle the increased computational costs associated with object tracking or object based shape encoding, a novel energy efficient binary motion estimation architecture is proposed. Energy is reduced in the proposed motion estimation architecture by minimising the redundant operations inherent in the binary data. Both architectures are shown to compare favourable with the relevant prior art
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