【正文】 本 科 生 畢 業(yè) 論 文 題 目： 基于 嵌入式平臺 的 無線視頻傳輸 系統(tǒng)的設(shè)計與實現(xiàn) 院 系： 軟件學(xué)院 專 業(yè)： 軟件工程（ 嵌入式軟件與系統(tǒng) ） 學(xué)生姓名： 李浩 學(xué) 號： 08386144 指導(dǎo)教師： 李曉寧（ 高級工程師 ） 二〇 一二 年 四 月 i 摘 要 隨著多媒體技術(shù)、網(wǎng)絡(luò)技術(shù)的迅猛發(fā)展和后 PC 時代的到來，利用嵌入式系統(tǒng)實現(xiàn)視頻會議、可視電話和視頻監(jiān)控等應(yīng)用已經(jīng)成為可能。 由于網(wǎng)絡(luò)帶寬的限制，需要 對原始圖像數(shù)據(jù)進(jìn)行編碼壓縮后傳輸。 而現(xiàn)有的嵌入式音視頻設(shè)備，由于處理器性能的限制，視頻的編解碼需要外接編解碼器或者采用軟件方式實現(xiàn)，編解碼效率較低。 另外，傳統(tǒng)的有線視頻傳輸系統(tǒng)在特定的環(huán)境下存在著布線困難等問題，不能靈活而快速地搭建視頻傳輸系統(tǒng)。因此，有必要開發(fā)編解碼效率較高、組網(wǎng)靈活的 嵌入式 無線視頻傳輸系統(tǒng) 。 本論文設(shè)計并實現(xiàn)了一套 嵌入式 無線視頻傳輸系統(tǒng) 。它 通過 API 調(diào)用 S3C6410處理器 的 MFC 模塊 實現(xiàn) 的硬編解碼 ， 在保證視頻質(zhì)量的前提下有效減少網(wǎng)絡(luò)帶寬的需求 ，并且相對于軟件解碼器 提高了編解碼效率 ； 通過 對 AdHoc 動態(tài)路由協(xié)議 AODV 協(xié)議的移植和各個節(jié)點的 網(wǎng)絡(luò) 配置 實現(xiàn) 了 AdHoc 傳輸網(wǎng)絡(luò) ，可靈活搭建視頻傳輸系統(tǒng)。 本論文首先分析了無線視頻傳輸系統(tǒng)的特點，在總結(jié)已有的視頻傳輸系統(tǒng)優(yōu)缺點及國內(nèi)外研究現(xiàn)狀的基礎(chǔ)上 ，提出了 無線視頻傳輸系統(tǒng) 的主要任務(wù)。在進(jìn)行了需求分析后， 設(shè)計出了系統(tǒng)的架構(gòu) ，包括系統(tǒng)總體架構(gòu)，網(wǎng)絡(luò)架構(gòu)和三種節(jié)點的軟硬件結(jié)構(gòu) 。 然后， 本論文 通 過研究 三種節(jié)點 的 軟硬件 模塊 的共性， 設(shè)計出了無線視頻傳輸系統(tǒng)的各個軟硬件模塊。最后根據(jù)模塊設(shè)計 實現(xiàn)了 無線視頻傳輸系統(tǒng) 各個軟硬件模塊 。通過上述軟硬件的開發(fā)，實現(xiàn)了三種節(jié)點的各項功能， 從而實現(xiàn)了整個無線視頻傳輸 系統(tǒng)。 實驗驗證表明系統(tǒng)能夠穩(wěn)定地 實現(xiàn)視頻采集無線傳輸功能。 關(guān)鍵詞： 嵌入式開發(fā)； 視頻采集； 視頻傳輸；無線自組網(wǎng)； ii Abstract As the rapid development of multimedia technology and work technology and the arrival of the postPC era, it is possible to implement video conference, video telephone and video surveillance with embedded system. Due to work bandwidth limitations, it is required to encode to press the original video data before transmission. However, current embedded audio and video equipment, due to the limitations of processor performance, encodes/decodes the original video data with external codec or in software method, which is less efficient. Besides, traditional wired video transmission system has problems of wiring under certain circumstance。 we can’ t set up video transmission system flexibly and quickly in wired way. Therefore, it is necessary to develop an embedded wireless video transmission system which is more efficient in codec and more flexible work. In this paper, an embedded wireless video transmission system is designed and implemented. Through API, the system is capable of calling MFC module of the S3C6410 processor to realize hard codec of , it is effective to reduce the demand for work bandwidth in premise of ensuring video quality, and the efficiency of the codec is improved pared to software method。 Through the transplantation of the AdHoc dynamic routing protocol AODV and the work configuration of each node, AdHoc transmission work is set up, it is easy to set up video transmission system flexibly. In this paper, the characteristics of the wireless video transmission system is firstly analyzed, on the basis of summarizing the research status at home and abroad, advantages and disadvantages of the current video transmission system, the main tasks of the wireless video transmission system is put forward. Following the needs analysis, the system architecture design is introduced, including the overall system architecture, work architecture and hardware and software structure of the three kinds of nodes. Then, various hardware and software modules for wireless video transmission system are designed according to the similarity of hardware and software modules of the three kinds of nodes. Finally, the software and hardware modules of the wireless video transmission system are implemented according to the modules design. Through the development of these abovementioned software and hardware, the various functions of the three types of nodes are achieved, thus, the wireless video transmission system is also achieved. Verified by experiments, the system can steadily achieve the video capture wireless transmission functions. Keywords: Embedded development。 Video capture。 Video transmission。 Mobile AdHoc works。 iii 目 錄 第一章 前言 ..................................................................................................................................................... 1 項目背景和意義 .................................................................................................................. 1 研究開發(fā)現(xiàn)狀分析 ............................................................................................................. 1 視頻編解碼算法的研究現(xiàn)狀 .................................................................................................................2 無線傳輸技術(shù)研究現(xiàn)狀 ............................................................................................................................2 嵌入式操作系統(tǒng)的研究現(xiàn)狀 .................................................................................................................3 視頻傳輸節(jié)點研究現(xiàn)狀 ............................................................................................................................5 項目的目標(biāo)和范圍 ............................................................................................................. 5 論文結(jié)構(gòu)簡介 ....................................................................................................................... 6 第二章 需求建 模 ............................................................................................................................................ 7 需求概述 ................................................................................................................................. 7 需求分析 ................................................................................................................................. 7 系統(tǒng)建模 ................................................................................................................................. 8 本章小節(jié) ................................................................................................................................. 9 第三章 架構(gòu)設(shè)計 ....................................................................................................................