移動(dòng)Flash流媒體關(guān)鍵技術(shù)的研究
發(fā)布時(shí)間:2018-06-11 19:42
本文選題:Flash動(dòng)畫 + 移動(dòng)流媒體。 參考:《杭州電子科技大學(xué)》2009年碩士論文
【摘要】:隨著移動(dòng)網(wǎng)絡(luò)的發(fā)展、動(dòng)漫產(chǎn)業(yè)的興起,結(jié)合無線通信技術(shù)與矢量圖形技術(shù)的手機(jī)動(dòng)漫正逐漸成為無線增值產(chǎn)品中的一個(gè)重要組成部分。Flash作為一種優(yōu)秀的矢量圖形格式,非常適合在移動(dòng)網(wǎng)絡(luò)中傳輸與播放,是手機(jī)動(dòng)漫的主要呈現(xiàn)形式。目前移動(dòng)Flash的網(wǎng)絡(luò)應(yīng)用產(chǎn)品大多是離線或順序傳輸播放的,而沒有采用實(shí)時(shí)流媒體技術(shù),由于移動(dòng)網(wǎng)絡(luò)的高丟包率、高延時(shí)等特性使得其應(yīng)用存在一定局限性。為了保證Flash在移動(dòng)網(wǎng)絡(luò)中高效穩(wěn)定地傳輸播放,本文主要對移動(dòng)Flash流媒體關(guān)鍵技術(shù)進(jìn)行研究,包括分組封裝策略、傳輸協(xié)議、擁塞控制以及率平滑等。主要研究工作如下: (1)針對Flash流媒體文件格式、音視頻幀結(jié)構(gòu),提出一種Flash文件的解析方法以及Flash音視頻的RTP封裝策略,保證了一定的丟包容錯(cuò)能力,提高了網(wǎng)絡(luò)帶寬利用率,降低了接收端的解析復(fù)雜度。 (2)通過分析目前標(biāo)準(zhǔn)的實(shí)時(shí)流媒體傳輸協(xié)議,研究提出一種針對Flash流媒體的實(shí)時(shí)傳輸協(xié)議。新協(xié)議去除了標(biāo)準(zhǔn)協(xié)議中不必要的功能,重新設(shè)計(jì)了一些域,并制定了RTCP分組的發(fā)送機(jī)制。實(shí)驗(yàn)表明,新協(xié)議提高了媒體數(shù)據(jù)的可用帶寬,并有效控制了RTCP流的帶寬占用。 (3)針對目前擁塞控制算法無法準(zhǔn)確判斷移動(dòng)網(wǎng)絡(luò)擁塞狀況的問題,提出了一種針對移動(dòng)網(wǎng)絡(luò)的端到端擁塞控制算法。在接收端通過分組到達(dá)時(shí)間間隔判斷丟包原因,統(tǒng)計(jì)并反饋分組丟失率、間隔抖動(dòng)等QoS信息。在發(fā)送端通過分析反饋信息來判斷網(wǎng)絡(luò)狀態(tài),并基于二項(xiàng)式原理實(shí)現(xiàn)數(shù)據(jù)傳輸率的動(dòng)態(tài)調(diào)整。新算法在有效避免網(wǎng)絡(luò)擁塞的前提下,進(jìn)一步提高了數(shù)據(jù)傳輸效率。 (4)針對目前VBR視頻率平滑算法無法兼顧平滑質(zhì)量與時(shí)間效率的問題,提出一種基于漏斗的率平滑算法,以達(dá)到視頻的最佳平滑傳輸。新算法繼承了最短路徑平滑算法的思想,通過在率平滑模型中構(gòu)建漏斗結(jié)構(gòu)以實(shí)現(xiàn)最短路徑的快速求解,有效消減了傳輸比特率波峰、降低了傳輸比特率方差,并具有更低的時(shí)間復(fù)雜度。 最后,基于上述研究成果實(shí)現(xiàn)了一個(gè)移動(dòng)Flash流媒體播放系統(tǒng),實(shí)驗(yàn)結(jié)果表明Flash流媒體傳輸性能達(dá)到了預(yù)期目標(biāo)。
[Abstract]:With the development of mobile network and the rise of animation industry, mobile phone animation, which combines wireless communication technology with vector graphics technology, is gradually becoming an important component of wireless value-added products. Flash is an excellent vector graphics format. Very suitable for transmission and play in the mobile network, is the main form of mobile animation. At present, most of the network applications of Mobile Flash are transmitted offline or sequentially, but not real-time streaming media technology. Due to the characteristics of high packet loss rate and high delay in mobile network, there are some limitations in its application. In order to ensure the efficient and stable transmission and playback of Flash in mobile network, this paper mainly studies the key technologies of mobile Flash streaming media, including packet encapsulation strategy, transport protocol, congestion control and rate smoothing. The main research work is as follows: (1) aiming at Flash streaming media file format and audio / video frame structure, this paper proposes a Flash file parsing method and an RTP encapsulation strategy for Flash audio and video, which ensures a certain fault-tolerant ability of packet loss and improves the utilization of network bandwidth. By analyzing the current standard real-time streaming media transmission protocol, a real-time transmission protocol for Flash streaming media is proposed. The new protocol removes unnecessary functions in the standard protocol, redesigns some domains, and formulates the RTCP packet sending mechanism. Experiments show that the new protocol increases the available bandwidth of media data and effectively controls the bandwidth occupation of RTCP streams. An end-to-end congestion control algorithm for mobile networks is proposed. At the receiving end, the packet loss reason is judged by the time interval of packet arrival, and the QoS information such as packet loss rate and interval jitter are counted and feedback. The state of the network is judged by analyzing the feedback information at the transmitter, and the dynamic adjustment of the data transmission rate is realized based on the binomial principle. Under the premise of avoiding network congestion effectively, the new algorithm further improves the data transmission efficiency. (4) aiming at the problem that the current VBR video rate smoothing algorithm can not take into account the smooth quality and time efficiency, a rate smoothing algorithm based on funnel is proposed. To achieve the best smooth video transmission. The new algorithm inherits the idea of the shortest path smoothing algorithm. By constructing the funnel structure in the rate smoothing model to realize the fast solution of the shortest path, the peak of the transmission bit rate wave is effectively reduced and the variance of the transmission bit rate is reduced. Finally, a mobile Flash streaming media playback system is implemented based on the above research results. The experimental results show that the performance of Flash streaming media transmission has reached the desired goal.
【學(xué)位授予單位】:杭州電子科技大學(xué)
【學(xué)位級別】:碩士
【學(xué)位授予年份】:2009
【分類號】:TN919.8
【引證文獻(xiàn)】
相關(guān)博士學(xué)位論文 前2條
1 陳國斌;視頻編碼中質(zhì)量、復(fù)雜度和碼率控制[D];浙江大學(xué);2003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
,本文編號:2006453
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