12 research outputs found
Towards Computational Efficiency of Next Generation Multimedia Systems
To address throughput demands of complex applications (like Multimedia), a next-generation system designer needs to co-design and co-optimize the hardware and software layers. Hardware/software knobs must be tuned in synergy to increase the throughput efficiency. This thesis provides such algorithmic and architectural solutions, while considering the new technology challenges (power-cap and memory aging). The goal is to maximize the throughput efficiency, under timing- and hardware-constraints
Arquitectura hĂbrida para el estĂĄndar de compresiĂłn de vĂdeo H.265/HEVC
En las Ășltimas dĂ©cadas las aplicaciones multimedia han evolucionado enormemente. Los estĂĄndares de compresiĂłn de vĂdeo han contribuido notablemente a este avance convirtiĂ©ndose en esenciales para la transmisiĂłn de datos multimedia. Desde 1980, los estĂĄndares de compresiĂłn de vĂdeo han enfocado sus principales esfuerzos a reducir la tasa de datos generada y proporcionar un alto nivel de calidad visual. Debido a la creciente demanda de contenido digital, hoy en dĂa resulta de vital importancia optimizar el ancho de banda utilizado para la transmisiĂłn de vĂdeo digital, buscando obtener grandes tasas de compresiĂłn de datos sin pĂ©rdidas apreciables en la calidad del servicio. Veinte años atrĂĄs se consideraba a la compresiĂłn de vĂdeo como algo novedoso, actualmente es algo ubicuo. La mayorĂa de dispositivos que constituyen la electrĂłnica de consumo hacen uso de una manera u otra de la compresiĂłn de vĂdeo. Aunque la mayorĂa de usuarios asume que estas mejoras son el resultado de los avances generales que se han producido en la electrĂłnica de consumo, lo cierto es que son principalmente debidas a la compresiĂłn de vĂdeo..
Optimisation du codage HEVC par des moyens de pré-analyse et/ou de pré-codage du contenu
La compression vidĂ©o HEVC standardisĂ©e en 2013 offre des gains de compression supĂ©rieurs dĂ©passant les 50% par rapport au standard de compression prĂ©cĂ©dent MPEG4-AVC/H.264. Ces gains de compression se paient par une augmentation trĂšs importante de la complexitĂ© de codage. Si on ajoute Ă cela lâaugmentation de complexitĂ© gĂ©nĂ©rĂ©e par lâaccroissement de rĂ©solution et de frĂ©quence images du signal vidĂ©o dâentrĂ©e pour passer de la Haute DĂ©finition (HD) Ă lâUltra Haute DĂ©finition (UHD), on comprend vite lâintĂ©rĂȘt de techniques de rĂ©duction de complexitĂ© pour le dĂ©veloppement de codeurs Ă©conomiquement viables. En premier lieu, un effort particulier a Ă©tĂ© rĂ©alisĂ© pour rĂ©duirela complexitĂ© des images Intra. Nous proposons une mĂ©thode dâinfĂ©rence des modes de codage Ă partir dâun prĂ©-codage dâun version rĂ©duite en HD de la vidĂ©o UHD. Ensuite, nous proposons une mĂ©thode de partitionnement rapide basĂ©e sur la prĂ©-analyse du contenu. La premiĂšre mĂ©thode offre une rĂ©duction de complexitĂ© dâun facteur 3 et la deuxiĂšme, dâun facteur 6, contre une perte de compression proche de 5%. En second lieu, nous avons traitĂ© le codage des images Inter. En mettant en oeuvre une solution dâinfĂ©rence des modes de codage UHD Ă partir dâun prĂ©-codage au format HD, la complexitĂ© de codage est rĂ©duite dâun facteur 3 en considĂ©rant les 2 flux produits et dâun facteur 9.2 sur le seul flux UHD, pour une perte en compression proche de 3%. AppliquĂ© Ă une configuration de codage proche dâun systĂšme rĂ©ellement dĂ©ployĂ©, lâapport de notre algorithme reste intĂ©ressant puisquâil rĂ©duit la complexitĂ© de codage du flux UHD dâun facteur proche de 2 pour une perte de compression limitĂ©e Ă 4%. Les stratĂ©gies de rĂ©duction de complexitĂ© mises en oeuvre au cours de cette thĂšse pour le codage Intra et Inter offrent des perspectives intĂ©ressantes pour le dĂ©veloppement de codeurs HEVC UHD plus Ă©conomes en ressources de calculs. Elles sont particuliĂšrement adaptĂ©es au domaine de la WebTV/OTT qui prend une part croissante dans la diffusion de la vidĂ©o et pour lequel le signal vidĂ©o est codĂ© Ă des rĂ©solutions multiples pour adresser des rĂ©seaux et des terminaux de capacitĂ©s variĂ©es.The High Efficiency Video Coding (HEVC) standard was released in 2013 which reduced network bandwidth by a factor of 2 compared to the prior standard H.264/AVC. These gains are achieved by a very significant increase in the encoding complexity. Especially with the industrial demand to shift in format from High Definition (HD) to Ultra High Definition (UHD), one can understand the relevance of complexity reduction techniques to develop cost-effective encoders. In our first contribution, we attempted new strategies to reduce the encoding complexity of Intra-pictures. We proposed a method with inference rules on the coding modes from the modes obtained with pre-encoding of the UHD video down-sampled in HD. We, then, proposed a fast partitioning method based on a preanalysis of the content. The first method reduced the complexity by a factor of 3x and the second one, by a factor of 6, with a loss of compression efficiency of 5%. As a second contribution, we adressedthe Inter-pictures. By implementing inference rules in the UHD encoder, from a HD pre-encoding pass, the encoding complexity is reduced by a factor of 3x when both HD and UHD encodings are considered, and by 9.2x on just the UHD encoding, with a loss of compression efficiency of 3%. Combined with an encoding configuration imitating a real system, our approach reduces the complexity by a factor of close to 2x with 4% of loss. These strategies built during this thesis offer encouraging prospects for implementation of low complexity HEVC UHD encoders. They are fully adapted to the WebTV/OTT segment that is playing a growing part in the video delivery, in which the video signal is encoded with different resolution to reach heterogeneous devices and network capacities
Architectures for Adaptive Low-Power Embedded Multimedia Systems
This Ph.D. thesis describes novel hardware/software architectures for adaptive low-power embedded multimedia systems. Novel techniques for run-time adaptive energy management are proposed, such that both HW & SW adapt together to react to the unpredictable scenarios. A complete power-aware H.264 video encoder was developed. Comparison with state-of-the-art demonstrates significant energy savings while meeting the performance constraint and keeping the video quality degradation unnoticeable
Autonomous Recovery Of Reconfigurable Logic Devices Using Priority Escalation Of Slack
Field Programmable Gate Array (FPGA) devices offer a suitable platform for survivable hardware architectures in mission-critical systems. In this dissertation, active dynamic redundancy-based fault-handling techniques are proposed which exploit the dynamic partial reconfiguration capability of SRAM-based FPGAs. Self-adaptation is realized by employing reconfiguration in detection, diagnosis, and recovery phases. To extend these concepts to semiconductor aging and process variation in the deep submicron era, resilient adaptable processing systems are sought to maintain quality and throughput requirements despite the vulnerabilities of the underlying computational devices. A new approach to autonomous fault-handling which addresses these goals is developed using only a uniplex hardware arrangement. It operates by observing a health metric to achieve Fault Demotion using Recon- figurable Slack (FaDReS). Here an autonomous fault isolation scheme is employed which neither requires test vectors nor suspends the computational throughput, but instead observes the value of a health metric based on runtime input. The deterministic flow of the fault isolation scheme guarantees success in a bounded number of reconfigurations of the FPGA fabric. FaDReS is then extended to the Priority Using Resource Escalation (PURE) online redundancy scheme which considers fault-isolation latency and throughput trade-offs under a dynamic spare arrangement. While deep-submicron designs introduce new challenges, use of adaptive techniques are seen to provide several promising avenues for improving resilience. The scheme developed is demonstrated by hardware design of various signal processing circuits and their implementation on a Xilinx Virtex-4 FPGA device. These include a Discrete Cosine Transform (DCT) core, Motion Estimation (ME) engine, Finite Impulse Response (FIR) Filter, Support Vector Machine (SVM), and Advanced Encryption Standard (AES) blocks in addition to MCNC benchmark circuits. A iii significant reduction in power consumption is achieved ranging from 83% for low motion-activity scenes to 12.5% for high motion activity video scenes in a novel ME engine configuration. For a typical benchmark video sequence, PURE is shown to maintain a PSNR baseline near 32dB. The diagnosability, reconfiguration latency, and resource overhead of each approach is analyzed. Compared to previous alternatives, PURE maintains a PSNR within a difference of 4.02dB to 6.67dB from the fault-free baseline by escalating healthy resources to higher-priority signal processing functions. The results indicate the benefits of priority-aware resiliency over conventional redundancy approaches in terms of fault-recovery, power consumption, and resource-area requirements. Together, these provide a broad range of strategies to achieve autonomous recovery of reconfigurable logic devices under a variety of constraints, operating conditions, and optimization criteria
Smart Sensor Technologies for IoT
The recent development in wireless networks and devices has led to novel services that will utilize wireless communication on a new level. Much effort and resources have been dedicated to establishing new communication networks that will support machine-to-machine communication and the Internet of Things (IoT). In these systems, various smart and sensory devices are deployed and connected, enabling large amounts of data to be streamed. Smart services represent new trends in mobile services, i.e., a completely new spectrum of context-aware, personalized, and intelligent services and applications. A variety of existing services utilize information about the position of the user or mobile device. The position of mobile devices is often achieved using the Global Navigation Satellite System (GNSS) chips that are integrated into all modern mobile devices (smartphones). However, GNSS is not always a reliable source of position estimates due to multipath propagation and signal blockage. Moreover, integrating GNSS chips into all devices might have a negative impact on the battery life of future IoT applications. Therefore, alternative solutions to position estimation should be investigated and implemented in IoT applications. This Special Issue, âSmart Sensor Technologies for IoTâ aims to report on some of the recent research efforts on this increasingly important topic. The twelve accepted papers in this issue cover various aspects of Smart Sensor Technologies for IoT
Image Processing Using FPGAs
This book presents a selection of papers representing current research on using field programmable gate arrays (FPGAs) for realising image processing algorithms. These papers are reprints of papers selected for a Special Issue of the Journal of Imaging on image processing using FPGAs. A diverse range of topics is covered, including parallel soft processors, memory management, image filters, segmentation, clustering, image analysis, and image compression. Applications include traffic sign recognition for autonomous driving, cell detection for histopathology, and video compression. Collectively, they represent the current state-of-the-art on image processing using FPGAs
Energy-aware adaptive solutions for multimedia delivery to wireless devices
The functionality of smart mobile devices is improving rapidly but these devices are limited
in terms of practical use because of battery-life. This situation cannot be remedied by simply
installing batteries with higher capacities in the devices. There are strict limitations in the
design of a smartphone, in terms of physical space, that prohibit this âquick-fixâ from being
possible. The solution instead lies with the creation of an intelligent, dynamic mechanism for
utilizing the hardware components on a device in an energy-efficient manner, while also
maintaining the Quality of Service (QoS) requirements of the applications running on the
device.
This thesis proposes the following Energy-aware Adaptive Solutions (EASE):
1. BaSe-AMy: the Battery and Stream-aware Adaptive Multimedia Delivery (BaSe-AMy)
algorithm assesses battery-life, network characteristics, video-stream properties and
device hardware information, in order to dynamically reduce the power consumption of
the device while streaming video. The algorithm computes the most efficient strategy for
altering the characteristics of the stream, the playback of the video, and the hardware
utilization of the device, dynamically, while meeting applicationâs QoS requirements.
2. PowerHop: an algorithm which assesses network conditions, device power consumption,
neighboring node devices and QoS requirements to decide whether to adapt the
transmission power or the number of hops that a device uses for communication.
PowerHopâs ability to dynamically reduce the transmission power of the deviceâs
Wireless Network Interface Card (WNIC) provides scope for reducing the power
consumption of the device. In this case shorter transmission distances with multiple hops
can be utilized to maintain network range.
3. A comprehensive survey of adaptive energy optimizations in multimedia-centric wireless
devices is also provided.
Additional contributions:
1. A custom video comparison tool was developed to facilitate objective assessment of
streamed videos.
2. A new solution for high-accuracy mobile power logging was designed and implemented