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1.
Adaptive progressive download based on the MPEG-4 file format 总被引：1，自引：0，他引：1
FRBER Nikolaus DHLA Stefan ISSING Jochen Multimedia Transport Dept. Audio Fraunhofer Institute for Integrated Circuits IIS Erlangen Germany 《浙江大学学报(A卷英文版)》2006,7(Z1)
In this paper we describe how progressive download and adaptive streaming can be combined into a simple and efficient streaming framework. Based on the MPEG-4 file format (MP4) we use HTTP for transport and argue that these two components are sufficient for specifying an open streaming architecture. The client selects appropriate chunks from the MP4 file to be transferred based on (1) the header information (i.e. the "moov" box) in the first part of the file and (2) his observation of network throughput. The framework is completely client driven which allows for better server scalability and reduces signalling overhead. We discuss architecture and implementation issues such as complexity, interoperability and scalability and compare to 3GPP PSS Re1-6 adaptive streaming when appropriate. Measurements from a simple MP4/HTTP streaming client are presented showing that appropriate chunks are selected such that increased reliability is achieved. 相似文献
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HTTP动态自适应流技术利用现有的内容分发网络和互联网基础设施,部署方便、快捷,具有良好的防火墙穿透能力、NAT转换功能,成为网络视频分发业务的主流技术。为保证媒体传输的流畅性,为用户提供良好的用户体验质量（QoE）,需要采用合理的码率选择算法,由此码率自适应选择算法成为研究热点,大量新方法不断涌现。对HTTP动态自适应流技术背景和概念进行了概述,从流媒体传输涉及的服务端和客户端两个决策实体出发,对大量方法进行了分类阐述,指出该领域存在的问题,对研究趋势进行了展望。 相似文献
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A P2P streaming service architecture with distributed caching 总被引：3，自引：1，他引：3
GUO Pan-hong YANG Yang LI Xin-you 《浙江大学学报(A卷英文版)》2007,8(4):605-614
Multimedia streaming served through peer-to-peer (P2P) networks is booming nowadays. However, the end-to-end streaming quality is generally unstable due to the variability of the state of serve-peers. On the other hand, proxy caching is a bandwidth-efficient scheme for streaming over the Internet, whereas it is a substantially expensive method needing dedicated powerful proxy servers. In this paper, we present a P2P cooperative streaming architecture combined with the advantages of both P2P networks and multimedia proxy caching techniques to improve the streaming quality of participating clients. In this frame- work, a client will simultaneously retrieve contents from the server and other peers that have viewed and cached the same title before. In the meantime, the client will also selectively cache the aggregated video content so as to serve still future clients. The associate protocol to facilitate the multi-path streaming and a distributed utility-based partial caching scheme are detailedly dis- cussed. We demonstrate the effectiveness of this proposed architecture through extensive simulation experiments on large, Inter- net-like topologies. 相似文献
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INTRODUCTION Video streaming service nowadays enjoys ex- plosive adoptions over all kinds of underlying net- works. To enjoy the freedom of tether-less connection over the wireless local area network (WLAN), we need to overcome many challenges of unstable wire- less channel due to fading, interference and so on. The scarce and fluctuating available bandwidth (together with time-varying delays and random/burst losses) can cause the video quality at the streaming client to be seriously deg… 相似文献
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CHOU Philip A 《浙江大学学报(A卷英文版)》2006,7(5):737-748
INTRODUCTION Many applications, such as software distribution, Internet TV/video streaming, video conferencing, multiplayer gaming, personal media distribution and P2P web content duplication, distribute the same content from one source node to many destination nodes. For these applications, IP multicast is an ideal network layer solution. A distribution tree rooted at the source can be formed to reach an arbitrary number of receivers. During content distribution, every single piece of… 相似文献
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HUSTserver:一种可靠的高性能附网存储系统的实现 总被引：2，自引：0，他引：2
1 Introduction Emergingapplicationssuchasdatawarehousing ,multimediacontentdistribution ,electroniccom merce ,medicaldatabaseandsatellitedatabaseshavesubstantialstoragerequirementsthataregrowingatadramaticallyrate .Suchapplicationsrequirescalable ,highly availableandcost effectivestoragesystems .Traditionalstoragesystemsrelyonacentralcon troller (fileserver ,diskarraycontroller)toaccessstorageandcopydatabetweenstoragedevicesandclients,whichlimitstheirscalability .Withthedra maticshifttowards… 相似文献
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徐时仪 《南阳师范学院学报》2013,12(1):23-32
《朱子语类》中一些口语常用句式形成词组层面的语块,如口语惯用的搭配语、缩略语、插入语和框式待嵌组合格式语等。这些凝固或半凝固的语块属于动态的言语单位,既不同于成语、谚语等固定语,也不同于自由词组,具有一定黏聚力,呈现出框式组合的类格式化特点,体现了"言语意义←→语言意义"的动态演变。 相似文献
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REN Yong-feng 《教育技术导刊》2008,(3)
介绍一种基于模块化的技术来实现面向服务和消息驱动的架构,并且基于标准建模语言来对资源、事件和应用进行建模。该技术能够实现动态事件发布和订阅、事件轮询、事件过滤和指示。 相似文献
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Future multimedia communication systems have to support the user‘s needs, the terminal capabilities, the content specification and the underlying networking technologies. The related protocols and applications must be designed from this integration perspective in a cross-layer centric manner. In this paper, we propose an implementation of a streaming service (e.g.,Television over IP service) with a unified QoS management concept that enables an IP driven integration of different system components (terminal, user, content, and network). The MPEG-21 framework is used to provide a common support for implementing and managing the end-to-end QoS. The main focus of this paper is on the architecture design, protocols specification and implementation evaluation. Performance evaluations using PSNR and SSIM objective video quality metrics show the benefit of the proposed MPEG-21-enabled cross-layer adaptation. 相似文献
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高建清 《河北职业技术学院学报》2013,(5):27-30
针对学校机房进行上机考试的文件同步上传问题,设计利用FTP服务器、上机考试服务端和上机考试客户端相结合的考试系统,客户端通过登录验证后,可以进行试题的下载,答题结果会实时地自动上传到服务器,在客户端机器出现故障时,也能保证文件不丢失,具有安装容易、设置简单以及操作方便等特点。 相似文献
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黄雄 《广东职业技术师范学院学报》2014,(11):20-25
目前主流的视频传输技术是流媒体技术,但是视频传输过程中都需要依赖Flash插件,视频传输过程更需要选择流媒体格式,或者安装播放器的客户端.HTML5的Video标签能够支持WEB浏览器摆脱Flash插件的使用,并丰富浏览器端的网页应用.基于流媒体技术中的RTP,RTSP传输协议,本文构造了支持HTML5的视频播放器,该播放器具有视频的传输、控制、离线存储和播放等功能. 相似文献
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参照Biber的词块研究框架体系,运用CEM语料库,将英语专业学生议论文中四词词块的使用特点和本族语者语料库（EDC）进行对比研究发现：学习者语料库中的词块数量远远超过本族语者语料库,但学习者使用的词块类型单一,不如本族语者丰富,所使用的词块类型往往也不为本族语者使用;学习者词块中空缺处单词的可变性不强,可填入的单词数量和类型也较少。此项研究对当前英语教学具有一定的启示作用。 相似文献
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In the daily life, people often repeat regular routes in certain periods. In this paper, a mining system is developed to find the continuous route patterns of personal past trips. In order to count the diversity of personal moving status, the mining system employs the adaptive GPS data recording and five data filters to guarantee the clean trips data. The mining system uses a client/server architecture to protect personal privacy and to reduce the computational load. The server conducts the main mining procedure but with insufficient information to recover real personal routes. In order to improve the scalability of sequential pattern mining, a novel pattern mining algorithm, continuous route pattern mining （CRPM）, is proposed. This algorithm can tolerate the different disturbances in real routes and extract the frequent patterns. Experimental results based on nine persons＇ trips show that CRPM can extract more than two times longer route patterns than the traditional route pattern mining algorithms. 相似文献
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INTRODUCTION With the emergence of wireless technology, various multimedia services, e.g., audio and/or video, are reaching us today through portable devices any- time, anywhere and even more increasingly accessi- ble in the near future. High quality video streaming over wireless IP is one of the most attractive applica- tions by ongoing deployment of wireless local area network (WLAN) hotspots and even powerful Wi- MAX mobile coverage. However, the present Internet is not providing a… 相似文献
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基于FMS的实时视频答疑系统的设计与实现 总被引：5，自引：0，他引：5
刘辉 《重庆职业技术学院学报》2008,17(6):103-105
目前,网络教育中的视频答疑系统在使用时,往往需要安装相应的客户端软件或插件．这会给那些学习时间、场所不固定的学习者带来很大的麻烦。能否在B／S模式下实现实时的语音视频答疑．这正是本文所探讨解决的问题。本文详细介绍了采用FLV流媒体格式．基于Flash Media Server的实时视频答疑系统的设计思路与实现方法。 相似文献
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为了适应当今制造业对网络化制造人才的需求,在分析了数控实验室现场实际条件的基础上,以无线串口服务器为核心,构建了无线DNC(direct numerical control)实验网络,建立了无线DNC实验系统软件框架,并探讨了系统实现中的一些关键技术,开发了一个无线DNC实验系统。该系统具有机床状态监控、NC程序收发、NC程序及相关文档管理等功能。使用结果表明,该实验系统部署简单、使用方便、维护工作量少,适合学校数控实验室使用。 相似文献
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It is expected that by 2003 continuous media will account for more than 50% of the data available on origin servers, this will provoke a significant change in Internet workload. Due to the high bandwidth requirements and the long-lived nature of digital video, streaming server loads and network bandwidths are proven to be major limiting factors. Aiming at the characteristics of broadband network in residential areas, this paper proposes a popularity-based server-proxy caching strategy for streaming media. According to a streaming media popularity on streaming server and proxy, this strategy caches the content of the streaming media partially or completely. The paper also proposes two formulas that calculate the popularity coefficient of a streaming media on server and proxy, and caching replacement policy. As expected, this strategy decreases the server load, reduces the traffic from streaming server to proxy, and improves client start-up latency. 相似文献