Energy/quality-aware hardware solutions for the residual coding loop components of the high efficiency video coding standard

• Ano de defesa: 2018
• Autor(a) principal: Braatz, Luciano Almeida
• Orientador(a): Porto, Marcelo Schiavon
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Computação
• Departamento: Centro de Desenvolvimento Tecnológico
• País: Brasil
• Palavras-chave em Português: Computação; Video coding; HEVC; Residual coding loop; Hardware design; Energy/quality awareness; Codificação de vídeo; Laço de codificação residual; Projeto de hardware; Foco em qualidade e energia
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::CIENCIA DA COMPUTACAO
• Link de acesso: http://guaiaca.ufpel.edu.br/handle/prefix/8523

Multimedia applications, such as digital videos, are very popular nowadays, especially on mobile devices. Moreover, there is an expectation of continuous growth of the Internet-based digital videos traffic throughout the next years. Video coders, e.g. the High Efficiency Video Coding (HEVC), are very important in this context as the video coders can rationalize Internet resources by reducing the amount of video-related data flowing through the network. Unfortunately, this data reduction requires a huge computational effort. Thus, hardware accelerators can be used as a feasible solution, providing high-throughput on low-power. The HEVC residual coding loop (RCL), composed of direct transform, direct quantization, inverse quantization, and inverse transform, is a highly-requested stage of video coding standards since it is used multiple times to test several coding modes (CMs). Therefore, the objective of this work is to provide multiple energy/quality-aware dedicated hardware solutions to increase throughput for the components of RCL in HEVC, allowing real time processing of many CM by the RCL. Thus, the HEVC encoder using the presented solutions is expected to be more coding efficient than the ones using the solution proposed by the existing related works. Innovative solutions are proposed in this work to increase throughput, which has direct impact on the coding efficiency in the RCL components, with low power dissipation. A direct DCT was proposed based on the Fast Fourier Transform (FFT), which allows an intensive hardware reuse, and energy-consumption reduction, able to operate up to 2.54 GHz while dissipating 12.33 mW of power; an energy/quality scalable inverse DCT is presented using a bypass engine based on statistical analysis, setting a trade-off between coding-efficiency and energy-efficiency, which operates up to 737.46 MHz and dissipates between 13.87 mW and 16.84 mW; and a project space exploration of quantization architectures is also presented, with power dissipation of 152.13 mW and 31.15 mW at 888.10 Mhz and 1.36 GHz, respectively, including an integrated direct/inverse quantization, which reduces the number of arithmetical operations by integrating direct quantization and inverse quantization, dissipating 369.37 mW at 1.68 GHz. The developed hardware architectures are able to process up to 108, 32, 38, 58, and 72 CM of UHD 4K videos at 60fps for the DCT, IDCT, direct quantization, inverse quantization, and integrated direct/inverse quantization hardware architectures, respectively. When compared with related works, the developed RCL components hardware architectures can operate on higher frequencies, present higher throughputs, and are more energy efficient.