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Adaptive Initial Quantization Parameter Determination for H. 264/AVC Video transcoding

IEEE TRANSACTIONS ON BROADCASTING 2012年第2期58卷 277-284页

作者： Wu, Zhenyu Yu, Hongyang Tang, Bin Chen, Chang Wen Univ Elect Sci & Technol China Chengdu 610054 Peoples R China SUNY Buffalo Buffalo NY 14260 USA

Video adaptation through transcoding can provide both bit-rate reduction and resolution reduction to meet various requirements from display devices to network links. One important issue in video transcoding is the design of rate control algorithm in order to achieve target bit rate by adjusting certain coding parameters. Among them, proper selection of initial quantization parameter (QP) has been shown to induce noticeable impact on the performance of video transcoding scheme. Current approaches in initialQP determination are either too complicated or lacking adequate accuracy. This paper presents an adaptive QP initialization for H.264/AVC transcoding. First, we carefully build the models of R-MSE and QP-PSNR. Then, we introduce an R-QP model and allocate an optimal target buffer to the first frame by considering its temporal importance. The analysis and the R-QP model lead to a novel scheme to determine the initial QP adaptively to achieve more accurate estimation. Experiments have been carried out to demonstrate that substantial gains in objective quality measures can be consistently obtained. Without increasing complexity in transcoding system, the proposed adaptive initial QP scheme outperforms current existing schemes for various video sequences tested in this research.

关键词： Adaptive quantization rate control rate-quantization model transcoding

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Improving Cluster Resource Efficiency with Oversubscription

Improving Cluster Resource Efficiency with Oversubscription

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IEEE Annual International Computer Software and Applications Conference (COMPSAC)

作者： Jie Chen Chun Cao Ying Zhang Xiaoxing Ma Haiwei Zhou Chengwei Yang Department of Computer Science and Technology State Key Laboratory for Novel Software Technology Nanjing China iQiyi Inc.

ISBN: (纸本)9781538626672

Volumes of studies on resource scheduling are proposed to improve the efficiency of computing clusters. As users usually overestimate the resource requirements for their jobs, further, most schedulers ignore the dynamic variation of jobs' runtime resource usage, the utilization of real-world clusters is significantly limited. In this paper, we argue that resource oversubscription, which allocates more resources than the physical capacity, is a necessary complement to existing systems. To alleviate resource contention, we augment oversubscription with lightweight prediction and dynamic CPU throttling. We implemented our approach called Datom, which is an extension module of the Apache Mesos cluster manager. We evaluated Datom with real-world video transcoding workloads and simulations with Google cluster trace. The results show that comparing to original Mesos, Datom increased CPU utilization, memory utilization and overall task throughput by up to 22%, 23%, 20% respectively, and shortened jobs' complete time by up to 20%, at the expenses of moderate penalty on job execution.

关键词： Task analysis Resource management transcoding Throughput Estimation Processor scheduling Dynamic scheduling

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AN EFFICIENT transcoding SCHEME FOR G.729 AND G.723.1 SPEECH CODECS: INTEROPERABILITY OVER THE INTERNET

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INTERNATIONAL JOURNAL OF INNOVATIVE COMPUTING INFORMATION AND CONTROL 2012年第7A期8卷 4635-4660页

作者： Lin, Rong-San Wang, Jia-Yu Pan, Jeng-Shyang So Taiwan Univ Dept Comp Sci & Informat Engn Tainan 710 Taiwan Natl Kaohsiung Univ Appl Sci Dept Elect Engn Kaohsiung 807 Taiwan

This paper proposes an efficient conversion algorithm for G.729 and G.723.1 speech codecs to reduce computational complexity of the communications between the G.729 and G.723.1 speech codecs. The proposed transcoding method incorporates four processes: line spectral pair (LSP) interpolation, pitch conversion, fast adaptive-codebook search, and fast fixed-codebook search. To reduce search computations, we propose a fast adaptive codebook search algorithm that uses residual signals to predict the candidate gain-vectors of the adaptive codebook. For the fixed codebook, we propose a fast search algorithm that uses an energy function to predict the candidate pulse positions. Other codec parameters are directly converted in parametric levels without executing the decoding process. Simulation results show that the proposed methods can reduce total computational complexity by 65.8%, with a shorter coding delay compared with the commonly used decode-then-encode tandem approach. Objective and subjective evaluations were used to verify that the proposed transcoding scheme provides speech quality comparable to the tandem approach.

关键词： Speech coding G.723.1 G.729 transcoding Tandem Fast codebook search LSP Pitch

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Edge Assisted DASH Video Caching Mechanism for Multi-access Edge Computing

Edge Assisted DASH Video Caching Mechanism for Multi-access ...

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International Symposium on Advanced Networks and Telecommunication Systems (ANTS)

作者： Shashwat Kumar Doddala Sai Vineeth Antony Franklin A Computer Science and Engineering Indian Institute of Technology Hyderabad Telangana India

ISBN: (纸本)9781538681350;9781538681343

Proliferation in mobile devices and the increase in video data consumption on these devices has led to an unprecedented surge of data usage in mobile networks. It is both challenging and expensive for network operators to scale up the network capacity and tackle this ever increasing data demand. Cellular network operators require alternative solutions, like in-network-caching, to solve this problem. Popular streaming services like YouTube use Dynamic Adaptive Streaming over HTTP (DASH) for video streaming where videos are divided into several small segments, and multiple bit-rate versions of each segment are stored in the server. Using store and forward caching method, in the network, may not help as the video segments cached in one session might not be usable for other users. This problem of unusability emerges as different users request different bit-rates of the same video segment. Also, it is not efficient to cache all versions of the video segments at the edge of the network, due to limited storage at the edge. In this paper, we propose a Multi-access Edge Computing (MEC) based video caching mechanism, where only the highest available bit-rate video is cached and by using the processing power available at the MEC it is transcoded to the requested lower bit-rate version. We develop a test-bed to evaluate the performance of the proposed caching mechanism in real time. Through various experimental results, we demonstrate that the proposed method reduces the backhaul traffic load and video load time and increases the cache hit-rate as compared to traditional store and forward caching mechanism.

关键词： Streaming media Servers transcoding Cache storage Edge computing Cellular networks Computer architecture

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Resource Allocation for Virtual Streaming Media Server Cluster in Cloud-based Multi-version VoD

Resource Allocation for Virtual Streaming Media Server Clust...

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International Conference on Computer Supported Cooperative Work in Design

作者： Hui Zhao Jing Wang Feng Liu Quan Wang Nan Luo Weizhan Zhang School of Computer Science and Technology Xidian University Xi'an China Department of Computer Science and Technology Xi'an Jiaotong University Xi'an China

ISBN: (纸本)9781538614839

With the rapid development of mobile Internet and smart devices, VoD (video on demand) providers build media cloud to offer multi-bitrate video streaming services to users at a reduced cost, called as cloud-based multi-version VoD. In cloud-based multi-version VoD, we need to solve the problem of allocating appropriate resources for virtual streaming media server cluster with the aim of optimizing the user experience and reducing the service cost. To address this problem, a resource allocation for virtual streaming media server cluster in cloud-based multi-version VoD is proposed in this paper. We firstly analyze the user historical learning logs to mine the user behavior characteristics, including the average user request arrival rate, the video playing time distribution, and the video popularity distribution, etc. Then, based on the user behavior characteristics and the queueing theory, a resource allocation model for the virtual streaming media server cluster is introduced. It predicts the user arrival rate at first and then allocates appropriate resources dynamically to solve the resources allocation irrationality problem. Simulation results have proved the proposed method can allocate appropriate resources for virtual streaming media server cluster, which can ensure the user experience satisfaction and improve the resources utilization.

关键词： Streaming media Resource management Servers transcoding Cloud computing Bandwidth Queueing analysis

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transcoding the news: An investigation into multimedia journalism published on *** 2000-2008

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NEW MEDIA & SOCIETY 2012年第5期14卷 867-885页

作者： Jacobson, Susan Temple Univ Dept Journalism Philadelphia PA 19122 USA

Manovich (2001) describes the changes that result from translating an established cultural product into a new technology as 'transcoding'. This study investigates the form that the journalism of The New York Times takes when transcoded to the Web by evaluating multimedia news packages published on *** from 2000-2008. The number and sophistication of the multimedia packages grew over time to include new interfaces that incorporated elements native to digital environments such as hypertextual links, interactivity, elements borrowed from digital games and social media tools. Most packages were produced as sidebars to stories published in the newspaper, suggesting that multimedia was used as an extension of the written word, not as a primary storytelling format.

关键词： games hypertext journalism multimedia new media social media transcoding

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Fast Coding-Unit Mode Decision for HEVC Transrating 17

Fast Coding-Unit Mode Decision for HEVC Transrating

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17th IEEE International Conference on Computer and Information Technology (CIT) / IEEE Int Workshop on Secure and Resource-Efficient Edge Computing (SecureEdge) / IEEE Int Symposium on Recent Advances of Computer and Information Technologies (RACIT)

作者： Yang, Shih-Hsuan Zhong, Chong-Cheng Natl Taipei Univ Technol Dept Comp Sci & Informat Engn 1Sect 3Zhong Xiao E Rd Taipei 10608 Taiwan

ISBN: (纸本)9781538609583

Transrating is a bitrate transcoding technique that facilitates video applications in heterogeneous environments. This paper presents a fast coding-unit (CU) mode decision algorithm for transrating a once-encoded HEVC bitstreams to lower bitrate versions of diverse quality levels. The proposed method comprises three major parts. First, an early SKIP decision is based on the modes and motion vectors of the correlated CUs. Second, the CU depth search is restricted to a range estimated by a weighted average of the depth levels of correlated CUs and the weights are adapted to the quantization parameter. Third, a CU with a higher rate-distortion (RD) cost (judging from the RD costs of correlated CUs) will be directly divided into smaller CUs without evaluating RD costs of the remaining partitioning modes at the current depth level. Experimental results substantiate the superiority of the proposed method, which averagely reduces the encoding time by 55.01% with only 0.09 dB BD-PSNR degradation and 2.26% BD-rate increase.

关键词： transcoding transrating fast encoding high efficiency video coding (HEVC)

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Design of a Caching System for SHVC-coded Videos 6

Design of a Caching System for SHVC-coded Videos

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IEEE 6th Global Conference on Consumer Electronics (GCCE)

作者： Hsu, Tz-Heng Hong, Wei-Ze Southern Taiwan Univ Sci & Technol Dept Comp Sci & Informat Engn Tainan Taiwan

ISBN: (纸本)9781509040452

To support mobile devices with different screen resolutions, social video sharing sites need to provide distinctive versions of the videos for mobile users to choose, resulting in the consumption of massive storage space. Scalable Extensions of the High Efficiency Video Coding (SHVC) can reduce about 15-30% storage of distinctive video spatial resolution. Meanwhile, traditional video caching technology is not applicable to multi-layer SHVC video structure. In this paper, we propose a novel SHVC caching system that can reduce the content delivery and start-up delay of video transmissions. The proposed system also supports the transcoding of various video formats for mobile devices that are incapable of decoding SHVC videos.

关键词： SHVC transcoding Caching

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Twisting Web Pages for Saving Energy 17th

Twisting Web Pages for Saving Energy

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17th International Conference on Web Engineering (ICWE)

作者： Koksal, Eda Yesilada, Yeliz Harper, Simon Middle East Tech Univ Northern Cyprus Campus Mersin 10 Guzelyurt Turkey Univ Manchester Schoool Comp Sci Manchester Lancs England

ISBN: (纸本)9783319601311;9783319601304

Battery capacity (energy density) is increasing at around 3% per year. However, the increasing requirements of the mobile platform is placing higher demands on this capacity. In this case, there are three options: decrease our expectations of the mobile platform, increase the capacity and therefore size and weight of our batteries, or create energy saving solutions to extend battery-life with minimal effect on platform performance. Here we present a system called Twes+ which is inline with the last option and aims to transcode web pages for increasing battery-life when surfing-the-web without changing the look and feel. Our evaluation results show that there is a statistically significant energy saving when using our Twes+ transcoder. Our redirect service brings a 4.6% cumulative processor energy reduction, while image transcoding service, brings a 7% cumulative processor energy reduction. These savings equate to between a 40 to 60min saving depending on the mobile device.

关键词： transcoding Energy Green computing Mobile web

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A Green Video Control Plane with Fixed-Mobile Convergence and Cloud-RAN 29

A Green Video Control Plane with Fixed-Mobile Convergence an...

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29th Int Teletraffic Congress (ITC) / 1st International Conference on Networking Science and Practice / 1st International Workshop on Softwarized Infrastructures for 5G and Fog Computing (Soft5) / PhD Workshop on Modelling Communication Networks

作者： Aparicio-Pardo, Ramon Sassatelli, Lucile Univ Cote Azur CNRS I3S Sophia Antipolis France

ISBN: (纸本)9780988304536

Video traffic is a key-challenge for fixed and mobile operators facing variable and massive load and variety of Over-The-Top (OTT) videos. Energy consumption is also a heavy Opex component, where the Fixed-Mobile Convergence is a promising solution, built on on economical optic fibers and LTE base-band operations consolidation. By combining Future Internet Architectures (FIA) principles such as ubiquitous caching, SDN and NFV, and FMC, we propose a complete, fully dynamic setup which optimizes both for power consumption and Quality of Experience (QoE), by choosing proper infrastructure (turning on a minimum number of computing and networking equipments) and operational (routing and caching) configurations. Our control plane named ViRCA is scalable thanks to data analytics techniques, and fully reactive to the dynamics of load and catalog both in time and space. Numerical assessments in realistic settings show power gains of up to 30% while the scores on different QoE metrics are maximized. Enabling elastic co-location of caches and radio base-band operations turns out to be crucial for both power and QoE objectives.

关键词： Streaming media Routing Servers Mobile communication Power demand transcoding

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