A Study On Key Technique Of Mobile Flash Streaming Media

With the development of mobile networks and the rise of animation industry, Mobile animation combined with wireless communication technology and vector graphics technology are becoming an important component of wireless value-added products. As an excellent vector graphics format, Flash is very suitable for mobile networks to transmit and playback, so it become the main present form of mobile animation. Most of the current network applications of mobile Flash are offline play or transferred in order to play without using real-time streaming technology. Due to the high packet loss rate of mobile networks, high latency and other features, there are some limitations of these applications. For the efficient and stable transmission and playback of Flash in the mobile network, several key technologies of mobile Flash streaming media is studied in this paper, including packet encapsulation strategies, Transport protocol, Congestion control, the rate of smoothing and so on. The following is the main research work:(1) For the file formats of Flash streaming media, structures of audio and video frame, a Flash file parsing method and Flash packetization strategy on RTP are proposed, ensure a certain loss-tolerant, improve the utilization of network bandwidth, and reduce the complexity of packet parse on the receive side.(2) By analyzing current standard transport protocol of real time streaming media, we study and propose a new real time transport protocol for Flash streaming media. The new protocol eliminates unnecessary features from standard protocols, re-design a number of domains, and draw up the delivery mechanism of RTCP packet. Experimental result shows that the new protocol increases the available bandwidth of the media data, and keeps down the bandwidth occupied by RTCP stream effectively.(3) In view of the current Congestion control algorithms can not accurately determine the congestion state of the Mobile network issue, we propose an end to end Congestion control algorithms for Mobile networks; The receiver figures out reasons of packet loss from the packet arrival time intervals;caculate and feedback QoS information such as packet loss, interval jitter.The sender analyzes the feedback information to figure out network status, and dynamic adjust data transfer rate based on the binomial theorem. The new algorithm effectively improve data tranfer efficiency under the premise of avoiding network congestion.(4) In view of current VBR video rate-smoothing algorithm can not give consideration to smooth quality and time efficiency problems, we propose a rate-smoothing algorithm based on the funnel in order to achieve the best smooth video transmission. The new algorithm inherits the idea of the shortest path smoothing algorithm, by building a funnel structure in the rate smoothing model, it can achieve rapid solution for the shortest path, effective reduction of the peak bit rate and the variance of bit rate, lower time complexity.Finally, based on the above study results, we achieved a system for playing Mobile Flash Streaming media, experimental results show that the transmission performance of Flash Streaming media achieve the expected goal.