Process variation aware transcoding for low power H.264 decoding

Weibelzahl

IEEE Commun. Surv. Tutorials

2014

Abstract-As mobile devices are becoming more powerful and affordable they are increasingly used for mobile learning activities. By enabling learners' access to educational content anywhere and anytime, mobile learning has both the potential to provide online learners with new opportunities, and to reach less privileged categories of learners that lack access to traditional e-learning services. Among the many challenges with mobile learning, the battery-powered nature of mobile devices and in particular their limited battery life, stands out as one issue that can significantly limit learners' access to educational content while on the move. Adaptation and personalisation solutions have widely been considered for overcoming the differences between learners and between the characteristics of their mobile devices. However, while various energy saving solutions have been proposed in order to provide mobile users with extended device usage time, the areas of adaptive mobile learning and energy conservation in wireless communications failed to meet under the same umbrella. This paper bridges the two areas by presenting an overview of adaptive mobile learning systems as well as how these can be extended to make them energy-aware. Furthermore, the paper surveys various approaches for energy measurement, modelling and adaptation, three major aspects that have to be considered in order to deploy energy-aware mobile learning systems. Discussions on the applicability and limitations of these approaches for mobile learning are also provided.

Section: ) Content Delivery-related Solutionsmentioning

confidence: 99%

Energy-Aware Mobile Learning:Opportunities and Challenges

Weibelzahl

IEEE Commun. Surv. Tutorials

2014

“…Baker et al [27] proposed a solution to generate H.264 compressed streams with low priority macroblocks that can be ignored by the decoder based on the user preferences, in order to reduce the CPU workload and the associated power consumption through DVFS. Amiri et al [28] proposed a transcoding scheme to generate H.264 streams that are tolerant to defective memory cells of the decoding buffer, enabling power saving through voltage scaling on the memories. This solution has good power saving potential, as memories increase their share of the mobile device power consumption with the shift towards System-on-Chips (SoCs).…”

Section: A Multimedia Content Adaptationmentioning

confidence: 99%

Subjective Assessment of BitDetect—A Mechanism for Energy-Aware Multimedia Content Adaptation

IEEE Trans. on Broadcast.

2012

Abstract-As mobile devices are becoming more compact and powerful and as they start to be increasingly used for accessing power-hungry multimedia streaming applications, there is an increasing need for mechanisms to efficiently manage the limited battery power resources. This is especially important as the battery capacity has not kept up with the power requirements of an increasing number of mobile device features and "always on" connected users. Adaptive multimedia-based power-saving mechanisms often decrease the clip bitrate to increase the mobile device battery life, without considering the effect of these degradations on the user-perceived quality. This paper proposes BitDetect, a mechanism that uses objective video quality assessment metrics to detect content-specific video bitrate levels that enable saving battery power while maintaining good user perceived quality. Results from a subjective study indicate that the recommended bitrate offers good user-perceived quality across different multimedia clips. Furthermore, experimental tests indicate that significant battery power can be saved by using the recommended bitrates when streaming multimedia clips to a mobile device.Index Terms-Battery power saving, bitrate estimation, objective assessment metrics, subjective video quality assessment.

“…Various power saving techniques were proposed for the particular case of multimedia streaming to mobile devices over Wireless LANs. Depending on where the battery power is mainly saved, these techniques can be classified in: reception-related techniques that aim to reduce the power consumption of the wireless network card [12], decodingrelated techniques that aim to reduce the power consumption of the CPU [13] and memory [14], and playing-related techniques that mainly focus on the device display [15].…”

Section: B Battery Power Savingmentioning

confidence: 99%

MediaMTool: Multimedia content management tool

Moraru

2011 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB)

2011

Abstract-With the proliferation of mobile devices, multimedia streaming over wireless networks has increased in popularity. To overcome a number of challenges as well as to enhance mobile users' experience, much research effort has been placed into multimedia content adaptation and personalisation. Supporting adaptive multimedia can pose itself a number of challenges, especially when considering the fast growing rate at which multimedia content is being produced. This paper explores the idea of automatic multimedia content management and authoring to support adaptive multimedia delivery to mobile devices. A multimedia content management tool (MediaMTool) is presented which automatically creates multiple versions of the multimedia clips based on a set of specified multimedia clip features. For testing purposes, MediaMTool was used in conjunction with EcoLearn, a m-learning system that adapts the quality of the educational multimedia clips in order to save battery power on the learner mobile device.Index Terms-multimedia content management, multimedia adaptation, mobile devices, battery power save.