The Research And Implementation Of Windows Mobile-based Mobile Streaming Media Client

Streaming media services over mobile communication network come to be possible because of the development of the mobile communication technology and the improvement of the mobile terminals performance.Based on 802.11 standards, we have submitted the framework of the mobile streaming media clients and it is implemented on the Windows Mobile platform through the analysis on the mobile streaming media network transport protocol and the features of H.264 video encoding format. A mobile streaming media client, comprised of network module, decoding module and AV playback module, operates in a wireless LAN environment. The network module implements RTP/RTCP/RTSP network protocols by dynamic libraries and the efficiency is improved by the design pattern of message queue. H.264 and AMR decoding module are ported and encapsulated to plug-in architecture from a PC platform. According to the resources from system, streaming media data playback module automatically selects optimal playback mode in terms of efficiency and universality.Considering the limitation on mobile network resources and the weak processing capability of mobile intelligence terminals, we have to extend the capability of LAN mobile streaming media clients, optimize the architecture of the streaming media players and improve the efficiency of the systems according to the global structure requirements of 3GPP mobile streaming media. Based on the design of the LAN streaming media clients, we implement the transport of streaming media data over mobile communication network using NAT to pass gateway of CMNET, and also apply transmission rate adaptation technology in network module to make the servers automatically adjust the data transmission rate according to the bandwidth of the mobile communication network. We make full use of the correlation between network packets, increase the queuing efficiency and modify the data queuing strategy in the buffer storage. The audio and video synchronous mode is improved to calculate synchronous time accurately. The streaming media client is tested in a Windows Mobile platform, GPRS and EDGE network environment. The client can play smoothly in a mobile communication network, satisfying the goal.