Research On The Key Streaming Media Playing Technologies Of Mobile Terminal And Its Implementation

With the development of the Internet, the streaming media application has become the main way to transmit media in network. In recent years, since the commercial application of the mobile phone, PDA and other mobile devices have been improved and the bandwidth of wireless network transmission has been increased, the mobile streaming media technology has been on the focus of academic and industry. However, the instability of the wireless communication will affect the quality of streaming media playback on the client. How to solve the technical difficulties of high quality playback in complex network condition is of great significance. This thesis aims at improving the effect of key factors affecting streaming media playback in the mobile terminal, and use the transmission control technology and caching mechanism to pursue the researches. It also establishes the basic framework for the streaming media system, and recommends strategies for the problems raised in the study process. Main contents and results are listed as follows:1. By analyzing characteristics of transmission streaming media and disadvantageous of wireless network, it chooses UDP protocol to transmit audio and video streams to improve the TFRC algorithm in wireless network when network is congested, and smoothes the sending rate while network condition changes suddenly. In addition, the algorithm is simulated for jitter and throughput process, and results show that the performance is better than TFRC. Moreover, by optimizing the mobile network redirection, the time connected to network is decreased.2. The designing of caching mechanism is of importance to play streaming media smoothly. For the limited storage of mobile terminals, and cutting down the starting time, this thesis chooses circle structure. A method for assigning memory dynamic based on network transmission rate is presented. Then the data which was transmitted is stored by segmentation. Comparing with replacing played data directly, the method increases hit rate of user back operation.3. The thesis selects open source Darwin server by comparing with some streaming media server. Transmission control implements by secondary development of the module for sending RTP data. And by sending punch packages, the problem of NAT punching is solved.4. The thesis develops a streaming media player based on the mobile platform of MTK. The detail functions such as interactive network, synchronism, player interface and application response are carried out while deciding on designing of the project. The project is compiled by ADS1.2 before downloading to the mobile phone with MT6238 chips, also significance for future project development.