基于rtp的linux实时语音通信系统的设计与实现本科毕设论文.doc

PAGEII毕业论文（设计）题目：基于RTP的linux实时语音通信系统的设计与实现摘要随着信息社会的高速发展，Internet已经成为很多人生活不可缺少的一部分。当前Internet中流动的“比特”所代表的内容已从原来的数据逐渐向实时多媒体数据演变，它们的特点是对实时性要求非常高。但是，Internet是建立在TCP/IP之上的计算机网络，最初设计时的定位决定了它不适合实时数据的传输。因此，1996年1月IETF音视频传输工作颁布了针对实时应用的实时传输协议RTP/RTCP。RTP/RTCP使Internet从理论上具备了处理实时业务的能力，解决了媒体同步问题和满足了多媒体通信业务的要求，现在在IP电话、网络多媒体会议、远程网络教学和远程网络诊断等领域都有着重大的应用。本文结合RTP/RTCP高实时性的特点，主要针对局域网，提出了音频数据采用G729a压缩，传输数据采用ortp库，在linux平台下开发的实时语音通信系统。本文首先介绍了实时传输协议的简单应用后，详细分析了RTP/RTCP协议；接着介绍系统的具体实现，主要分三个部分：音频数据的采集和播放，音频数据的解码和编码以及音频数据包的发送和接收。最后简单阐述了本系统在其他领域的可扩展性及前景。【关键词】实时性，音频传输，RTP/RTCP，音频压缩AbstractWiththerapiddevelopmentofinformationsociety,theInternethasbecomeanindispensablepartofalotofpeoplelife.ThecurrentflowsthroughtheInternet"bits"representedbythecontentsofwhichhavebeengraduallyfromtheoriginaldatatoreal-timemultimediadata,thecharacteristicofthemisveryhighdemandforreal-time.However,theInternetisbasedonTCP/IPcomputernetworks,theinitialdesignoflocationdeterminesitisnotsuitableforreal-timedatatransmission.Therefore,IETFaudioandvideotransmissionworkinJanuary1996issuedforreal-timeapplicationofreal-timetransmissionprotocolRTP/RTCP.RTP/RTCPmakeInternettheoreticallywiththereal-timeabilityofthebusiness,themediasynchronizationproblemsandmeettherequirementsofthemultimediacommunicationservice,theIPtelephone,network,multimediaconference,remotenetworkteachingandremotediagnosis,etcallhaveimportantapplications.Inthispaper,combiningwiththecharacteristicsofRTP/RTCPhighreal-timeperformance,mainlyforlocalareanetwork(LAN),isputforwardusingG729aaudiodatacompression,datatransmissionusingortplibrary,developmentofreal-timevoicecommunicationsystemontheLinuxplatform.Thispaperfirstintroducesthesimpleapplicationofreal-timetransportprotocol,RTP/RTCPprotocolareanalyzedindetail.Thenthispaperintroducestheimplementationofsystem,mainlydividedintothreeparts:audiodataacquisitionandplayback,audiodatadecodingandencodingandaudiopacketssentandreceived.Thelastsimplyexpoundsthesystemscalabilityandprospectsinotherareas.【Keywords】Realtimea