Multimedia Services Design And Realization Based On Embedded Real Time Middleware

With the rapid increasing of network balldwidth the real-time transmissiontechnology of streaming media data has been becoming one of the key researches on thearea of modern network technology in recent years. However, multimedia applicationsare not keep a similar rate with increasing of network bandwith. One key reason is thattraditional multimedia application is process-oriented and based on network protocol oflow level, system design and implement related to many detail of underlying networkprotocol. However, traditional middleware is limited in its ability to supportadaptation．The current best-effort Intemet does not offer any quality of service(QoS)guarantees to real-time streaming media, becauseits bandwidth and delay change withtime．Under this background, this paper researches the CORBA(The Common ObjectRequest Broker Architecture) and the real-time transmission of streaming media deeply,then consult OMG A/V streaming specification and design the streaming mediamiddleware based on CORBA, that is called RTCStream in this paper． RTCStreamsupport streaming connect, adaptive QoS control, adaptive swapping of protocol stacks.To provide an adaptive QoS control framework the RTCStream Architecture is designedto segregate the control and management of eonneetion，quality of service and streams.Firstly this paper summarizes essence of streaming media application, then on thebasis of analysing paper’s purpose deeply, put forward software design pattem based onCORBA, this pattern solves the problem of reuse in software. Subsequently introducesstreaming media,middleware, streaming media middleware, and describes keytechnique of streaming media,standard specification of streaming media middlewafe.Onthe basis of analyzing CORBA framework and OMG A/V streaming specification,designs the streaming mesa framework, Connect manager, QoS manager, adaptiveprotocol stack, compartmentalizes main function model of system. Finally, we analysisand test the model of MPEG CPU occupancy rate, A/Vstream throughput, flowestablishment time delay.