【作者】 戴琦；

【导师】 冉立新；

【作者基本信息】 浙江大学 ， 电子科学与技术， 2005， 硕士

【摘要】 随着当代计算机及、通信、半导体与微电子技术的发展，嵌入式系统的功能变得越来越强，内涵也越来越丰富，胜任的任务与场合越来越多。建立在各种嵌入式处理器与操作系统之上的嵌入式系统被广泛的应用于各专业领域，并在这些领域产生重要的影响。如今，嵌入式系统在国内外已经成为一个重要的专业应用领域。 本文介绍的内容即为以嵌入式系统为核心的MPEG4网络视频终端，是嵌入式技术在视频监控领域的一个应用。它以三星公司面向中低端低成本应用，包含高效的ARM7TDMI处理器核的S3C4510B作为嵌入式处理器，结合周边硬件电路构成嵌入式硬件核心，在此基础上通过扩展视频／音频采集电路和MPEG4硬件编码芯片等声像处理外围电路，构成了一个性能优良的嵌入式MPEG4视频服务器。在嵌入式核心平台所采用的uClinux操作系统之上，使用linux驱动程序和上层网络服务器程序，实现了视频数据高效率的采集与传输。 具体说来，本文首先简要介绍了嵌入式系统的基本概念、视频监控技术的现状，并进一步叙述了EITS嵌入式平台的软硬件特点。之后，结合音频、视频的数字化与压缩标准的基本知识，对嵌入式网络视频终端的视频／音频采集与编码电路的原理进行了详细论述。在此基础之上本文给出了使用Cadence公司EDA工具进行声像处理电路的原理图设计与PCB版图设计的过程与注意重点。使用uClinux下的应用程序建立起MPEG4编码功能测试软件，详细讨论了视频与音频编码电路的工作原理与操作方法，并在最后给出了uClinux环境下的设备驱动实现的例子。 归纳起来，本文主要具体工作如下： 1．嵌入式系统与视频监控技术基本概念的介绍 2．EITS嵌入式平台的软硬件介绍。 3．声像采集与编码电路的原理分析与设计 4．使用Cadence公司EDA工具进行原理图与PCB版图设计。 5．使用linux应用程序对视频与音频的采集、编码功能进行软件分析与调试。 6．设计实现了uClinux下的硬件设备驱动程序。 本文的设计成果，作为实验室的二次嵌入式应用项目，用于产品开发及教学工作。更多还原

【Abstract】 With the development of computer, communication, semiconductor and micro-electronics technology, embedded system became much more powerful and relate to more and more subjects. Embedded systems based on various microprocessors and operation systems have been used in many specialty areas and brought grate impact to these area. Today, embedded system has become an important professional application area round the world.This paper introduces a MPEG4 embedded network video terminal, which is an embedded system used in the video monitoring application area. It uses S3C4510B, which integrates a high performance RISC processor core ARM7TDMI, as its embedded microprocessor. Combined with other peripheral circuits, they compose into an embedded hardware core platform. Based on this hardware platform, we extend it with video/audio sampling and hardware MPEG4 encode circuit to build up this well performed MPEG4 video server. Under the uClinux embedded operation system, we realize efficient collection and transfer of video stream data with linux device driver and user space application program.Concretely, this dissertation first briefly introduces basic concept of embedded system and actuality of video monitoring area, followed with hardware and software characteristic of EITS embedded platform system. After this, it discusses the principle of video/audio sampling and encoding circuit in detail. Based on these discussions, this paper presents the design process and important details about using Cadence’ s EDA tools to develop schematic circuit diagram and PCB board diagram of video/audio hardware sampling and encoding circuit. Using MPEG4 encoding function-test software based on linux user space application progrom, we discuss the details of function and operation method of video/audio hardware sampling and encoding circuit. At the end of this paper, we give an example of linux device driver used to receive MPEG4 video stream data.The main work of this paper could therefore be summarized as follows:● Introduces basic concepts of embedded system and actuality of video monitoring application area.● Introduces hardware and software characteristic of EITS embedded platform system.● Principle analysing and design of video/audio sampling and encoding circuit.● Develop schematic circuit diagram and PCB board diagram of video/audio hardware sampling and encoding circuit with Cadence EDA tools.● Software analyse and debugging of sampling and collection of video signal and data with linux user space application progrom.● Development of linux device driver of hardware system.更多还原