【摘要】：當(dāng)今社會(huì)人們對(duì)視頻傳輸?shù)囊笤絹碓礁?隨著技術(shù)的發(fā)展,基于HTTP(Hypertext Transfer Protocol)的動(dòng)態(tài)自適應(yīng)流媒體技術(shù)越來越受到人們的關(guān)注�；贖TTP的動(dòng)態(tài)自適應(yīng)視頻流傳輸(DASH:Dynamic Adaptive Streaming based on HTTP)的技術(shù)原理是把相同的視頻編碼為多份不同質(zhì)量的視頻文件,然后把這些文件分為很多的視頻分段存儲(chǔ)在服務(wù)器端,在流媒體傳輸過程中,客戶端可以根據(jù)當(dāng)前帶寬變化來選擇適應(yīng)此網(wǎng)絡(luò)帶寬的質(zhì)量分段進(jìn)行傳輸。但是,DASH標(biāo)準(zhǔn)并沒有規(guī)定客戶端選擇視頻文件分段時(shí)所應(yīng)采取的策略,這使得客戶端可以決定采取什么策略來進(jìn)行高效的傳輸,特別是針對(duì)時(shí)變性很強(qiáng)的無線信道而言。客戶端如何根據(jù)時(shí)變的無線網(wǎng)絡(luò)帶寬選擇合適的視頻質(zhì)量分段成為了當(dāng)今流媒體傳輸技術(shù)的一個(gè)研究熱點(diǎn)。本文在前人工作的基礎(chǔ)上,進(jìn)一步研究了基于馬爾科夫決策過程理論的流媒體傳輸系統(tǒng)模型,基于模型求解得到最優(yōu)傳輸策略。重點(diǎn)討論和分析了在自適應(yīng)傳輸過程中,分段質(zhì)量和播放時(shí)限是如何影響最佳策略的,并分析了在馬爾科夫決策過程理論模型中,下載時(shí)間離散化對(duì)系統(tǒng)模型準(zhǔn)確度的影響。本文研究的主要內(nèi)容為:1.參考國內(nèi)外已有研究工作,對(duì)馬爾科夫決策過程理論(MDP)進(jìn)行學(xué)習(xí)與總結(jié),進(jìn)一步研究了流媒體傳輸中的馬爾科夫決策過程系統(tǒng)建模。2.基于該模型,求解得到無線網(wǎng)絡(luò)流媒體傳輸過程中的最優(yōu)傳輸策略,即根據(jù)當(dāng)前系統(tǒng)狀態(tài)選擇最優(yōu)的視頻分段質(zhì)量,以期達(dá)到最好的用戶觀看體驗(yàn)。3.基于最優(yōu)策略,設(shè)計(jì)仿真程序進(jìn)行仿真,驗(yàn)證了最優(yōu)策略的有效性,并通過仿真分析了系統(tǒng)模型在計(jì)算中存在的誤差因素,即系統(tǒng)狀態(tài)離散化帶來的誤差。
[Abstract]:With the development of technology, the dynamic adaptive streaming media technology based on HTTP (Hypertext Transfer Protocol) has attracted more and more attention. Dynamic Adaptive Video Stream Transmission based on HTTP (the principle of DASH:Dynamic Adaptive Streaming based on HTTP) is to encode the same video into multiple video files of different quality, and then divide these files into many video segments and store them on the server side. In the process of streaming media transmission, the client can select the quality segment which adapts to the network bandwidth according to the current bandwidth change. However, the DASH standard does not specify the strategy to be adopted when the client selects video file segmentation, which enables the client to decide what strategy to adopt for efficient transmission, especially for the time-varying wireless channel. How to select the appropriate video quality segment according to the time-varying wireless network bandwidth has become a hot topic in streaming media transmission technology. In this paper, based on the previous work, the model of streaming media transmission system based on Markov decision process theory is further studied, and the optimal transmission strategy is obtained based on the solution of the model. This paper mainly discusses and analyzes how segment quality and playback time affect the optimal strategy in adaptive transmission, and analyzes the influence of download time discretization on the accuracy of system model in Markov decision process theory model. The main contents of this paper are: 1: 1. Referring to the existing research work at home and abroad, the Markov decision process theory (MDP) is studied and summarized, and the Markov decision process modeling in streaming media transmission is further studied. Based on this model, the optimal transmission strategy in the process of streaming media transmission in wireless network is solved, that is, the optimal video segment quality is selected according to the current system state, in order to achieve the best user viewing experience. 3. Based on the optimal strategy, a simulation program is designed to verify the effectiveness of the optimal strategy, and the error factors in the calculation of the system model are analyzed by simulation, that is, the error caused by the discretization of the system state.
【學(xué)位授予單位】：西華師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN919.8

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 祝谷喬;宋皓;;MPEG-DASH與HLS流傳輸技術(shù)的比較分析[J];電信科學(xué);2015年04期

2 熊永華;吳敏;賈維嘉;;實(shí)時(shí)流媒體傳輸技術(shù)研究綜述[J];計(jì)算機(jī)應(yīng)用研究;2009年10期

相關(guān)博士學(xué)位論文 前4條

1 鄧錢華;無線網(wǎng)絡(luò)視頻傳輸?shù)馁|(zhì)量控制[D];北京郵電大學(xué);2009年

2 范英磊;無線流媒體傳輸?shù)姆⻊?wù)質(zhì)量關(guān)鍵問題研究[D];北京郵電大學(xué);2007年

3 楊波;流媒體系統(tǒng)的關(guān)鍵技術(shù)研究[D];北京郵電大學(xué);2006年

4 陳敏;網(wǎng)絡(luò)實(shí)時(shí)視頻傳輸研究[D];華南理工大學(xué);2004年

相關(guān)碩士學(xué)位論文 前5條

1 王元?jiǎng)?基于MPEG-DASH的流媒體視頻傳輸系統(tǒng)設(shè)計(jì)與實(shí)現(xiàn)[D];西南交通大學(xué);2016年

2 曹玉銘;動(dòng)態(tài)流媒體技術(shù)MPEG-DASH的研究與實(shí)現(xiàn)[D];上海交通大學(xué);2015年

3 丁雪瑤;基于DASH協(xié)議的自適應(yīng)流媒體傳輸系統(tǒng)研究[D];北京郵電大學(xué);2013年

4 李凌波;微軟新一代流媒體技術(shù)研究及原型實(shí)現(xiàn)[D];大連理工大學(xué);2011年

5 譚美;網(wǎng)絡(luò)帶寬自適應(yīng)流媒體傳輸系統(tǒng)的研究[D];華南理工大學(xué);2011年

，

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