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The micro-electronics industry has been boosting the capabilities of multimedia mobile devices, but the battery, which is the only power source of most mobile devices, is experiencing relatively slow development. Therefore, determining how to optimize the energy consumption of mobile devices under a predefined performance requirement has become a critical issue. The video decoder, as one of the main energyconsuming multimedia applications, is the target application of this manuscript. This paper presents control algorithms for power regulation under the limited battery capacities of multimedia hand-held devices while executing a decoder application and maintaining a reasonable quality of user experience. A control system, which includes a real-time closedloop control subsystem and a power-control governor (PCG), has been implemented in the operating system of a low-cost development board. Instead of using any specific power sensor, a PMC (performance monitoring counter)-based estimator is used as the feedback signal in the closed-loop subsystem. After a theoretical system model has been obtained, classic controllers have been implemented in the development board. The control system is able to regulate the power consumption and the battery discharge rate in the presence of fluctuations in the decoder power-consumption demand. The proposed PCG can extend the battery lifetime by 15.5% and 12.8% in comparison with the conservative and ondemand governors of Linux, respectively. [ABSTRACT FROM PUBLISHER]

New multimedia portable devices support increasing spatial and temporal video resolutions as well as new and more efficient video codecs. This scenario leads to the use of multicore chips in order to comply with the higher computational loads. In a context dominated by the time to market pressure, the programming of multicore chips is a challenge. In this work, a method based on a combination of dataflow models and OpenMP is proposed for quick design of HEVC decoders using multicore chips. The proposed method has been automated by its integration into an open source framework. Tests have been carried out by implementing the same HEVC decoder targeted on three different multicore chips.1 [ABSTRACT FROM PUBLISHER]

Video coding is one of the most demanding applications, in terms of computational cost, for portable multimedia terminals. In the last years, the new video coding standards, like High Efficiency Video Coding (HEVC), and the increasing resolutions of video codecs have overtaken the capacities of the single core processors in embedded systems. In consequence, multicore architectures are used in current multimedia systems. Besides, new methodologies and frameworks are arising to speed-up the design cycle. In this paper, a methodology based on the Reconfigurable Video Coding CAL Actor Language (RVC-CAL) and the OpenMP API has been used to implement an HEVC decoder based on a multicore DSP. A RVC-CAL description of the HEVC decoder has been used as starting point. The Open RVC-CAL compiler framework (Orcc) has been used to generate C-code from the RVC-CAL specification. This code and the OpenMP library have been ported to the multicore DSP environment. Decoders running on 1, 2, 3 and 4 cores have been tested. Also, the multi DSP based HEVC decoder has been compared with other implementations based on multicore GPPs. [ABSTRACT FROM AUTHOR]