视频通信基础知识.pdf

《视频通信基础知识.pdf》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、视频通信基础知识CollaborationTeam©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential1因为80%的信息是无法纯靠语言传递的，所以面对面的沟通是最有效的手段！©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential2•视频终端由编解码器（CODEC）和外接设备组成©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential3•视频与音频的采集•编码与解

2、码•视频与音频的输出©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential4视频通信传输过程IP网络难易Network接收解码/解压重格式化输出输入格式化编码/压缩发送Codec=COder/DECoder©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential5UserInterfacesPeripheralsDisplaysCablesSoundMixersandSpeakersEchoCancellationNetworksCode

3、csCamerasMicrophones3GISDNInternet/LAN/IPECHOCANCELLEREchoTANDENGINEBERG©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential6©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential7MultipointControlUnit(MCU)©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential8

4、H.320AudioVideoDataControlG.711H.261T.120H.221G.722H.263BONDingAAC-LDH.264©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential9H.323AudioVideoDataControlG.711H.261H.239H.225G.722H.263RASAAC-LDH.264Q.931H.245©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential10SIPAudioV

5、ideoDataControlG.711H.261BFCPSIPG.722H.263AAC-LDH.264©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential11IETFITUSIPH.323HTTPISDNSMTPPSTN©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential12•SIP由IETF开发，H.323由ITU开发•SIP为Internet优化，H.323为LAN优化•SIP支持Presence（状态呈现），H.323不支

6、持•SIP支持IM（即时消息），H.323不支持•SIP支持原生支持DNS和URL应用，H.323不支持•SIP获得更多应用平台支持©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential13gatekeeperEndpointAEndpointBRASRASQ.931Q.931H.245,H.245,Audio/Video©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential14EndpointAEndpointBRASRASRASen

7、tails:RRQ(E.164alias,H.323IDandIPaddress)−RCF−RRJARQ(CalledunitsE.164alias/H.323ID,SourcedialdigitsandsourceIPaddressandrequestedbandwidth)−ACF−ARJ©2010Ciscoand/oritsaffiliates.Allrightsreserved.CiscoConfidential15H.323–H.