【作者】 陈文祥；

【导师】 孟利民；

【作者基本信息】 浙江工业大学 ， 通信与信息系统， 2007， 硕士

【摘要】 随着互联网的高速发展,人类跨入了一个崭新的信息时代。以视频、音频和数据相结合的多媒体通信作为这个时代的主题,受到人们越来越多的关注。多媒体传输系统是计算机技术、电子技术和自动化技术相结合的产物,其中多媒体压缩技术是其关键技术之一。现在已经有许多多媒体压缩标准,如MPEG-1、MPEG-2、MPEG-4、H.26X等。MEPG-4是最新推出的压缩标准,它覆盖了从低比特率到广播级视频质量的范围。基于MPEG-4的嵌入式多媒体传输系统将先进的嵌入式技术和MPEG-4压缩编码技术相结合,必将有良好的应用与发展前景,能广泛应用于图像通信、视频监控、网络流媒体、数字电视和IPTV等领域。本文设计了一个基于MPEG-4的嵌入式多媒体传输系统,在该系统中,对于视频数据的处理我们采用了高清晰度和低码率的MPEG-4格式压缩算法,嵌入式操作系统我们采用免费的源码公开嵌入式Linux。本文首先介绍了多媒体通信的概念、发展及其应用,给出了系统的总体结构设计,然后对MPEG-4视频压缩编码标准进行了分析,主要描述了MPEG-4的组成、编解码器结构及其原理,并给出了MPEG-4简单视频类编码的实现模型。在嵌入式操作系统方面,给出了选择嵌入式linux的理由,阐述了系统中u-boot的启动及功能,对u-boot的启动做了详细介绍。由于视频处理是整个多媒体系统中的重点,所以对系统的视频处理系统做了详细描述,给出了其中的VIA、ITU Input、ITU Output、MPEG-4 Encoder和MPEG-4 Decoder这几个模块的具体软件设计和接口函数。最后,对本系统作了总结与展望。更多还原

【Abstract】 With the high-speed development of Intenret, the mankind strides into a brand-new information age. As the theme of this age, the multimedia communication combining with video, audio and data is concerned by more and more people. Multimedia transmission system is produced by the combination of computer technology, electronic technology and automation technology, and the critical technique is the multimedia compression technology. Now there are many international standards about multimedia compressions, e.g.MPEG-1/2/4, H.26X. MPEG-4 is the latest standard by the ISO MPEG. It covers the applications from very low bitrate to broadcast equality video. This multimedia transmission system combines embedded technology and MPEG-4 compression coding technology, must be a good prospects for the application and development. It can be widely used in image communications, video surveillance, Network streaming media, IPTV areas and so on.In this paper, an embedded multimedia transmission system based on MPEG-4 is designed. In this systerm, the audio and video data are processed according to the MPEG-4 specification which has the high division and low bitrate, and the embedded Linux is selected as our embedded OS.Firstly, this paper has introduced the concept, development trend and application of multimedia communication. Then, MPEG-4 video compression coding standard has been analysed, in which composition, codecs structure and codecs principle have been mostly described. And the implementation model of MPEG-4 simple video coding has been given. In the embedded operating system, it has given the reasons of choosing linux. Then it expounded the start-up and function of the u-boot in this system. The video processing is the focus of the multimedia system, so the video processing of this system has been done a detailed description. It put forward the software design and API of the VIA、ITU Input、ITU Output、MPEG-4 Encoder and MPEG-4 Decoder module. Finally, the main research conclusions summarized, the prospect of further research work is also made.更多还原