移动Flash流媒体关键技术的研究

发布时间：2018-06-11 19:42

本文选题：Flash动画 + 移动流媒体　；参考：《杭州电子科技大学》2009年硕士论文

【摘要】：随着移动网络的发展、动漫产业的兴起,结合无线通信技术与矢量图形技术的手机动漫正逐渐成为无线增值产品中的一个重要组成部分。Flash作为一种优秀的矢量图形格式,非常适合在移动网络中传输与播放,是手机动漫的主要呈现形式。目前移动Flash的网络应用产品大多是离线或顺序传输播放的,而没有采用实时流媒体技术,由于移动网络的高丢包率、高延时等特性使得其应用存在一定局限性。为了保证Flash在移动网络中高效稳定地传输播放,本文主要对移动Flash流媒体关键技术进行研究,包括分组封装策略、传输协议、拥塞控制以及率平滑等。主要研究工作如下: (1)针对Flash流媒体文件格式、音视频帧结构,提出一种Flash文件的解析方法以及Flash音视频的RTP封装策略,保证了一定的丢包容错能力,提高了网络带宽利用率,降低了接收端的解析复杂度。 (2)通过分析目前标准的实时流媒体传输协议,研究提出一种针对Flash流媒体的实时传输协议。新协议去除了标准协议中不必要的功能,重新设计了一些域,并制定了RTCP分组的发送机制。实验表明,新协议提高了媒体数据的可用带宽,并有效控制了RTCP流的带宽占用。 (3)针对目前拥塞控制算法无法准确判断移动网络拥塞状况的问题,提出了一种针对移动网络的端到端拥塞控制算法。在接收端通过分组到达时间间隔判断丢包原因,统计并反馈分组丢失率、间隔抖动等QoS信息。在发送端通过分析反馈信息来判断网络状态,并基于二项式原理实现数据传输率的动态调整。新算法在有效避免网络拥塞的前提下,进一步提高了数据传输效率。 (4)针对目前VBR视频率平滑算法无法兼顾平滑质量与时间效率的问题,提出一种基于漏斗的率平滑算法,以达到视频的最佳平滑传输。新算法继承了最短路径平滑算法的思想,通过在率平滑模型中构建漏斗结构以实现最短路径的快速求解,有效消减了传输比特率波峰、降低了传输比特率方差,并具有更低的时间复杂度。最后,基于上述研究成果实现了一个移动Flash流媒体播放系统,实验结果表明Flash流媒体传输性能达到了预期目标。
[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.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：TN919.8

【引证文献】