多功能IP摄像机的设计实现及流媒体传输的研究

【作者】 张翔；

【导师】 李式巨；

【作者基本信息】 浙江大学 ， 信息与通信工程， 2008， 硕士

【摘要】 随着互联网的普及和网络传输技术的进步,使得基于有线或者无线IP网的多媒体通信成为现实。基于IP网的多媒体通信终端极大的降低了通信成本,使通信更加灵活、方便、快捷,内容更加丰富。本文提出了一种多功能IP摄像机的设计实现方案,能够通过有线或者无线IP网络进行多媒体全双工通信,还能够与公共电话网进行互联,适用于大型工厂、车间、企业以及家庭门禁安防系统。在野外缺少通信基础设施的情况下,还能通过无线自组网实现通信。多功能IP摄像机基于嵌入式硬件平台开发,以Z228高性能多媒体处理芯片为核心,内嵌MPEG-4硬件编解码器,能够实时地对视频信息进行编解码,具有很强的多媒体处理能力和网络交互能力。多功能IP摄像机采用了嵌入式Linux操作系统,负责对系统硬件和软件的管理,对资源的分配和回收,并提供人机交互接口。本文主要完成了多功能IP摄像机模块化驱动程序和应用软件的开发。其中应用软件的设计与实现是本文的重点,主要包括:基于socket interface异步并发处理服务器模型的构建,基于实例的模块化应用程序结构的设计与具体功能的实现,多功能IP摄像机专用通信协议的设计与实现,基于参考窗口的帧率控制算法的设计实现和性能分析、基于闭环控制原理的网络带宽自适应控制器,并初步实现了通过RTP协议进行流媒体的传输。目前已经成功实现了多功能IP摄像机之间的消息通信,全双工多媒体实时通信,远程控制和管理,用户管理,较为精确和稳定的帧率控制,网络带宽自适应控制,基于RTP协议的流媒体传输。更多还原

【Abstract】 With the development of network transmission technology and prevalence of Internet, the dream of multimedia communication based on LAN or WLAN can be translated into reality. Generally speaking, multimedia communication based on LAN or WLAN is lower cost, faster, more flexible and convenience.In this thesis, we propose a design for a kind of multi-function IP camera which is developed as a platform for full-duplex and real-time multimedia communication through LAN or WLAN, and interconnection with public telephone network. This IP camera can be used in large-scale factories, workshop, enterprise and family monitor & security system. Additional, in outdoors IP cameras are able to communicate with each other base on MANET(Mobile Ad Hoc Network), without communication infrastructure, such as base station, rely station and so on.The development of multi-function IP camera is based on embedded hardware platform, whose kernel is Z228 high performance processor. For integrated with MPEG-4 hardware encoder and decoder, Z228 provide high capability for multimedia process and network transmission.The Linux operation system is ported to embedded hardware system of the IP camera, which is responsible for system resources management and providing friendly interactive interface with local user.The work in this thesis is related with development of modularized driver program and application program. And in this thesis, a great emphases is put on design for application program, including design for currency handle architecture based on asynchronous socket interface, modularized application program development in instantiation method, design and performance analysis for frame rate controller based on reference window time algorithm, design for multi-function IP camera communication protocol, implementation of network automatic adaptation control based on loop control theory, and streaming media transmission by RTP protocol.In this thesis, the following functions have been implemented: message communication between multi-function IP cameras, full-duplex and real-time multimedia communication, remote control and management, user information management, relatively precise and stable frame rate control, network automatic adaptation control and streaming media transmission by RTP protocol.更多还原