基于嵌入式Linux的无线多媒体传输系统设计与实现
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摘要
近年来,多媒体技术与网络技术的迅速发展,以声音、图形、图像、文本等为主的多媒体通信成为时代的主题,受到人们越来越多的关注。同时,随着高速无线通信的发展,多媒体和无线通信这两个领域技术相互交叉,产生了新的技术——无线多媒体技术。而随着计算机技术逐步步入所谓的“后PC时代”,无线多媒体终端也相应地向小型化,嵌入式方向发展,其强大的功能和广阔的应用前景,使之成为近年来该领域的一个研究热点。
本课题来源于浙江省科技厅资助项目“基于DSP技术的全数字实时无线多媒体传输系统的研制”,通过对相关国际标准、关键技术和现有产品的研究和分析,完成系统整体设计方案,并实现了原型系统以进行技术验证。本论文的主要研究内容和成果如下:
1.通过比较和研究多种音频、视频编解码标准,提出了适合在资源受限系统中应用的编解码规则,并且利用音视频同步算法和回音消除算法进行优化,使系统更好地满足了音视频传输实时性的需要;
2.提出了无线多媒体系统的总体框架,介绍了基于ARM9(S3C2410)处理器为硬件平台,嵌入式Linux操作系统为软件平台,WLAN为传输媒介的平台构架和环境搭建,其中包括软硬件选型,交叉编译环境的建立、Bootloader、Linux内核镜像、文件系统的编译、配置和下载;
3.实现了上层应用程序模块化设计,从功能上分为五大模块:音视频采集模块、RTP协议无线传输模块、音视频同步模块、音视频播放/显示模块和回音消除模块,并通过Linux多线程编程技术实现了各个模块的代码化,论文给出了各个模块实现的关键技术和算法流程。
最后的实验结果表明,媒体流能在整个系统中得到平稳、实时、同步地处理。本课题所研究的基于嵌入式Linux的无线多媒体系统可广泛应用于视频监控、信息家电、智能小区、远程抄表等领域,具有很强的实用价值,同时也对未来嵌入式系统研究和无线多媒体技术研究起到一定的参考作用。
With the progress of the multimedia and networking technology in recent years, multimedia communications have become the theme of this age and being concerned by more and more people. Meanwhile, as the computer technology has gradually gotten onto the so-called "post-PC era", wireless multimedia system is encountering to the corresponding small, embedded development. It will become a hotspot in recent years for its outstanding performance and a broad application prospects in many fields.
With the project of "Real-Time Digital Transmission System based on the DSP Application" which is supported by Zhejiang Science& Technology Department, via research to related key point of standards and theories, this thesis complete the design and implementation of the system and analyzes and tests the system performance finally.
Firstly, through studying and comparison towards some kinds of audio and video codec, the simplified codec algorithm is introduced to meet the needs of the resource-limited system.
Secondly, a total block diagram of a wireless video system is been put forward and the system based on the ARM9 (S3C2410) processor as hardware, the Embedded Linux as software and WLAN as transmission medium is been describes and built on, including how to make choice, cross-compile environment building, Bootloader, Linux kernel, file system compiling, configuring and downloading.
Subsequently, the five parts: AV capture block, RTP protocol wireless transmission block, AV synchronization block, AV display block and echo-elimination block are well modularized and their functions are realized by utilizing the multi-thread technology provided by Linux. The thesis gives the key issues and flow chart of every module.
Finally, the test result shows the whole system successfully managed the media stream in a smooth, real-time and synchronous way. It can be widely applied on video controlling, information household appliances, intellectual district, remote meter reading etc. and it can provide reference for the future research of Embedded system and wireless multimedia.
本课题来源于浙江省科技厅资助项目“基于DSP技术的全数字实时无线多媒体传输系统的研制”,通过对相关国际标准、关键技术和现有产品的研究和分析,完成系统整体设计方案,并实现了原型系统以进行技术验证。本论文的主要研究内容和成果如下:
1.通过比较和研究多种音频、视频编解码标准,提出了适合在资源受限系统中应用的编解码规则,并且利用音视频同步算法和回音消除算法进行优化,使系统更好地满足了音视频传输实时性的需要;
2.提出了无线多媒体系统的总体框架,介绍了基于ARM9(S3C2410)处理器为硬件平台,嵌入式Linux操作系统为软件平台,WLAN为传输媒介的平台构架和环境搭建,其中包括软硬件选型,交叉编译环境的建立、Bootloader、Linux内核镜像、文件系统的编译、配置和下载;
3.实现了上层应用程序模块化设计,从功能上分为五大模块:音视频采集模块、RTP协议无线传输模块、音视频同步模块、音视频播放/显示模块和回音消除模块,并通过Linux多线程编程技术实现了各个模块的代码化,论文给出了各个模块实现的关键技术和算法流程。
最后的实验结果表明,媒体流能在整个系统中得到平稳、实时、同步地处理。本课题所研究的基于嵌入式Linux的无线多媒体系统可广泛应用于视频监控、信息家电、智能小区、远程抄表等领域,具有很强的实用价值,同时也对未来嵌入式系统研究和无线多媒体技术研究起到一定的参考作用。
With the progress of the multimedia and networking technology in recent years, multimedia communications have become the theme of this age and being concerned by more and more people. Meanwhile, as the computer technology has gradually gotten onto the so-called "post-PC era", wireless multimedia system is encountering to the corresponding small, embedded development. It will become a hotspot in recent years for its outstanding performance and a broad application prospects in many fields.
With the project of "Real-Time Digital Transmission System based on the DSP Application" which is supported by Zhejiang Science& Technology Department, via research to related key point of standards and theories, this thesis complete the design and implementation of the system and analyzes and tests the system performance finally.
Firstly, through studying and comparison towards some kinds of audio and video codec, the simplified codec algorithm is introduced to meet the needs of the resource-limited system.
Secondly, a total block diagram of a wireless video system is been put forward and the system based on the ARM9 (S3C2410) processor as hardware, the Embedded Linux as software and WLAN as transmission medium is been describes and built on, including how to make choice, cross-compile environment building, Bootloader, Linux kernel, file system compiling, configuring and downloading.
Subsequently, the five parts: AV capture block, RTP protocol wireless transmission block, AV synchronization block, AV display block and echo-elimination block are well modularized and their functions are realized by utilizing the multi-thread technology provided by Linux. The thesis gives the key issues and flow chart of every module.
Finally, the test result shows the whole system successfully managed the media stream in a smooth, real-time and synchronous way. It can be widely applied on video controlling, information household appliances, intellectual district, remote meter reading etc. and it can provide reference for the future research of Embedded system and wireless multimedia.
引文
铩颷1]陈廷标.多媒体通信[M].北京:北京邮电大学出版社,1997.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[2]顾琰,无线多媒体通信中网络通信协议的研究[D].东南大学硕士学位论文,2000.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[3]钟锡昌.应该大力发展嵌入式软件[DB/OL].http://www.ednc.com.cn,2000:-12-30Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[4]华恒科技公司.嵌入式Linux简介[DB/OL].http://www.hhcn.org/jianjie.htmlQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[5]孙天泽.嵌入式设计及Linux驱动开发指南[M].北京:电子工业出版社,2004.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[6]杜春雷.ARM体系结构与编程[M].北京:清华大学出版社,2001.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[7]田泽.ARM9嵌入式Linux开发实验与实践[M].北京:北京航空航天大学出版社,2002.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[8]鲍长春.低比特率数字语音编码基础[M].北京:北京工业大学出版社,2001.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[9]杨行俊,迟惠生等.语音信号数字处理[M].北京:电子工业出版社,1995.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[10]Speech Coding Algorithms:Foundtion and Evolution of Standardized Coder[S],2003.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[11]ITU-T Recommendation G.711:Pulse Code Modulation(PCM)of Voice Frequency[S],2003.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[12]ITU-T Recommendation G.726:40,32,24,16kbit/s Adaptive Differential Pulse Code ModulationQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
(ADPCM)[S],1990.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[13]ITU-T Recommendation G.723.1:Dual Rate Speech Coder for Multimedia CommunicationsQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Transmitting at 5.3 and 6.3 kbit/s[S],1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[14]ITU-T Recommendation G.728:Coding of Speech at 16 kbit/s using Low-Delay Code Excited LinearQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Prediction[S],1992.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[15]ITU-T Recommendation G.729:Coding of Speech at 8 kbit/s using Conjugate-Structure Algebraic-Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Code-Excited Linear-Predictions(CS-ACELP),1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[16]ITU-T Recommendation G.729 Annex B:A Silence Compression Scheme for G.729 OptimisedQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
forTerminal Conforming to ITU-T v.70[S],1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[17]ITU-T Recommendation G.723.1 Annex A:Dual Rate Speech Coder for Multimedia CommunicationsQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Transmitting at 5.3 and 6.3 kbit/s[S].Annex A:Silence Compression Scheme,1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[18]O.Hersent,D.Gurle and J.Petit.IP Telephony:Packet-Based Multimedia Communications System[S],Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
2000.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[19]ETSI GSM 06.10:Digital Cellular telecommunications system(phase 2+):Full rate speechQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
transcoding[S],1994.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[20]ETSI GSM 06.20 v5.1.0:Digital cellular telecommunications system(phase 2+):Half rate speechQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
transcoding[S],1997.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[21]ETSI GSM 06.60 v4.1.0:Enhanced full speech transcoding[S],1998.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[22]W.Gardner,P.Jacobs,and C.Lee.QCELP:A Variable Rate Speech Coder for CDMA Digital Cellular.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Speech and Audio Coding for Wireless Networks[S].MA:Kluwer,1993.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[23]I.Gerson and M.A.Jasiuk.Vector Sum Excited Linear Prediction(VSELP)Speech Coding at 8 kbit/s[S].Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[24]ITU-T Recommendation H.263:Video Coding for Low Bit Rate Communication[S],version 1,1995,Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
version2,1998.
[25]T.Sikora.The MPEG-4 video standard verification model[J].IEEE Transaction on Circuits and Systems for Video Technology,Special issue on MPEG-4,7(1):19-31,1997.
[26]A.Puri and T.Chen.Multimedia Systems,Standards,and Networks[M].New York:Marcel Dekker,2000.
[27]ITU-T H.263 recommendation:Video coding for low bit rate communication[S],version 2,1998.
[28]Heiko Schwarz,Thomas Wiegand.The emerging JVT/H.26x Video Coding Standardavailable[DB/OL].http://bs.hhi.de/-Wiegand
[29]Joint video team(JVT)of ITU-T VCEG and ISO/IEC MPEG Final draft international standard of joint video specification(ITU-T Rec.H.264/ISO/IEC 14496-10)[J].JVTG050,05.2003.
[30]Zheng Li-ming,Zhang Hui-ting,Liu Wei-ping,et al.Research and implement of the video-sound synchronous technology of the distributed IP videoconferencing system[J].Computer Engineering and Aplication,2002,11:227-229.
[31]泰乐公司.增强无线网络话音质量的技术建议.电信工程技术与标准化[J],2005.7:82-83.
[32]刘启诚.奥泰矽,回音消除设备的最佳解决方案提供者.通信世界[J],2005.6:34-36.
[33]郑国惠.基于嵌入式Linux的无线视频传输终端的设计与实现[D].浙江工业大学论文,2006:30-31.
[34]鲍长春.数字语音编码原理[M].西安:西安电子科技大学出版社,2007.
[35]RTP:A Transport Protocol for Real-time Applications[S],RFC 1889-1996.
[36]曹宁,胡建荣,马银松.IP视频会议系统中音视频同步的研究[J].中国图象图形学报,Vol.10,No.2,255-259.
[37]Samsung Electronics.S3C2410X user's manual[Z],2003.
[38]Yaghmour.K.构建嵌入式Linux系统[M].北京:中国电力出版社,2004.
[39]尤盈盈.基于嵌入式系统的无线多媒体传输系统终端的研究[D].浙江工业大学论文,2005:30-34.
[40]Daniel P.Bovet and Marco Cesati.深入理解Linux内核[M].北京:中国电力出版社,2004.
[41]嵌入式系统bootloader内幕[DB/OL].http://www-900.ibm.com/developerWorks/cn/linux/l-btloader/index.html
[42]广州斯道信息技术有限公司.怎样使用斯道s3c2410普及版Ⅱ的bootloader[Z],2005.
[43]李善平,刘文峰,王焕龙.Linux与嵌入式系统[M].北京:清华大学出版社,2003.
[44]MIZI Linux SDK for S3C2410[DB/OL].http://www.mizi.com/developer/s3c2410x/index.html
[45]广州斯道信息技术有限公司.广州斯道s3c2410普及版Ⅱ技术手册[Z],2005.
[46]Omni Vision Technologies,Inc,OV7620 Product Specifications-rev.1.3[EB/OL].http://home.pacific.net.hk/~comedia/ov7620.pdf
[47]OmniVision Technologies,Inc,OV511 Advanced Camera to USB Bridge[EB/OL].http://mxhaard.free.fr/spca50x/Doc/Omnivision/ds 511P.pdf
[48]魏洪兴,胡亮,区学楼.嵌入式系统设计与实例开发试验教材Ⅱ[M].北京:清华大学出版社,2005.
[49]李侃,廖启征.基于S3C2410平台与嵌入式Linux的图像采集应用[J].ARM开发与应用,2006.3(2):126-128.
[50]张雄,叶念渝,田俊.基于S3C2410的网络视频采集[J].兵工自动化,2006,25(5):71-73.
[51]张永强,赵永勇,李崇德.嵌入式远程视频采集系统的设计与实现[J].现代电子技术, 2006.4:75-77.
[52]陈俊宏.嵌入式系统原理与实务[M].北京:中国铁道出版社,2004.3.
[53]无线USB网卡MA111产品介绍[DB/OL].http://www.netgear.com.cn/product/details/ma111.htm
[54]张崙.32位嵌入式系统硬件设计与调试[M].北京:机械工业出版社,2005.5.
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[2]顾琰,无线多媒体通信中网络通信协议的研究[D].东南大学硕士学位论文,2000.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[3]钟锡昌.应该大力发展嵌入式软件[DB/OL].http://www.ednc.com.cn,2000:-12-30Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[4]华恒科技公司.嵌入式Linux简介[DB/OL].http://www.hhcn.org/jianjie.htmlQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[5]孙天泽.嵌入式设计及Linux驱动开发指南[M].北京:电子工业出版社,2004.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[6]杜春雷.ARM体系结构与编程[M].北京:清华大学出版社,2001.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[7]田泽.ARM9嵌入式Linux开发实验与实践[M].北京:北京航空航天大学出版社,2002.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[8]鲍长春.低比特率数字语音编码基础[M].北京:北京工业大学出版社,2001.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[9]杨行俊,迟惠生等.语音信号数字处理[M].北京:电子工业出版社,1995.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[10]Speech Coding Algorithms:Foundtion and Evolution of Standardized Coder[S],2003.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[11]ITU-T Recommendation G.711:Pulse Code Modulation(PCM)of Voice Frequency[S],2003.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[12]ITU-T Recommendation G.726:40,32,24,16kbit/s Adaptive Differential Pulse Code ModulationQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
(ADPCM)[S],1990.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[13]ITU-T Recommendation G.723.1:Dual Rate Speech Coder for Multimedia CommunicationsQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Transmitting at 5.3 and 6.3 kbit/s[S],1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[14]ITU-T Recommendation G.728:Coding of Speech at 16 kbit/s using Low-Delay Code Excited LinearQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Prediction[S],1992.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[15]ITU-T Recommendation G.729:Coding of Speech at 8 kbit/s using Conjugate-Structure Algebraic-Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Code-Excited Linear-Predictions(CS-ACELP),1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[16]ITU-T Recommendation G.729 Annex B:A Silence Compression Scheme for G.729 OptimisedQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
forTerminal Conforming to ITU-T v.70[S],1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[17]ITU-T Recommendation G.723.1 Annex A:Dual Rate Speech Coder for Multimedia CommunicationsQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Transmitting at 5.3 and 6.3 kbit/s[S].Annex A:Silence Compression Scheme,1996.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[18]O.Hersent,D.Gurle and J.Petit.IP Telephony:Packet-Based Multimedia Communications System[S],Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
2000.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[19]ETSI GSM 06.10:Digital Cellular telecommunications system(phase 2+):Full rate speechQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
transcoding[S],1994.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[20]ETSI GSM 06.20 v5.1.0:Digital cellular telecommunications system(phase 2+):Half rate speechQuery =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
transcoding[S],1997.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[21]ETSI GSM 06.60 v4.1.0:Enhanced full speech transcoding[S],1998.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[22]W.Gardner,P.Jacobs,and C.Lee.QCELP:A Variable Rate Speech Coder for CDMA Digital Cellular.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
Speech and Audio Coding for Wireless Networks[S].MA:Kluwer,1993.Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[23]I.Gerson and M.A.Jasiuk.Vector Sum Excited Linear Prediction(VSELP)Speech Coding at 8 kbit/s[S].Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
[24]ITU-T Recommendation H.263:Video Coding for Low Bit Rate Communication[S],version 1,1995,Query =
CADORecordset Error
Code = 80040e31
Code meaning = IDispatch error #3121
Source = Microsoft OLE DB Provider for SQL Server
Description = 超时已过期
version2,1998.
[25]T.Sikora.The MPEG-4 video standard verification model[J].IEEE Transaction on Circuits and Systems for Video Technology,Special issue on MPEG-4,7(1):19-31,1997.
[26]A.Puri and T.Chen.Multimedia Systems,Standards,and Networks[M].New York:Marcel Dekker,2000.
[27]ITU-T H.263 recommendation:Video coding for low bit rate communication[S],version 2,1998.
[28]Heiko Schwarz,Thomas Wiegand.The emerging JVT/H.26x Video Coding Standardavailable[DB/OL].http://bs.hhi.de/-Wiegand
[29]Joint video team(JVT)of ITU-T VCEG and ISO/IEC MPEG Final draft international standard of joint video specification(ITU-T Rec.H.264/ISO/IEC 14496-10)[J].JVTG050,05.2003.
[30]Zheng Li-ming,Zhang Hui-ting,Liu Wei-ping,et al.Research and implement of the video-sound synchronous technology of the distributed IP videoconferencing system[J].Computer Engineering and Aplication,2002,11:227-229.
[31]泰乐公司.增强无线网络话音质量的技术建议.电信工程技术与标准化[J],2005.7:82-83.
[32]刘启诚.奥泰矽,回音消除设备的最佳解决方案提供者.通信世界[J],2005.6:34-36.
[33]郑国惠.基于嵌入式Linux的无线视频传输终端的设计与实现[D].浙江工业大学论文,2006:30-31.
[34]鲍长春.数字语音编码原理[M].西安:西安电子科技大学出版社,2007.
[35]RTP:A Transport Protocol for Real-time Applications[S],RFC 1889-1996.
[36]曹宁,胡建荣,马银松.IP视频会议系统中音视频同步的研究[J].中国图象图形学报,Vol.10,No.2,255-259.
[37]Samsung Electronics.S3C2410X user's manual[Z],2003.
[38]Yaghmour.K.构建嵌入式Linux系统[M].北京:中国电力出版社,2004.
[39]尤盈盈.基于嵌入式系统的无线多媒体传输系统终端的研究[D].浙江工业大学论文,2005:30-34.
[40]Daniel P.Bovet and Marco Cesati.深入理解Linux内核[M].北京:中国电力出版社,2004.
[41]嵌入式系统bootloader内幕[DB/OL].http://www-900.ibm.com/developerWorks/cn/linux/l-btloader/index.html
[42]广州斯道信息技术有限公司.怎样使用斯道s3c2410普及版Ⅱ的bootloader[Z],2005.
[43]李善平,刘文峰,王焕龙.Linux与嵌入式系统[M].北京:清华大学出版社,2003.
[44]MIZI Linux SDK for S3C2410[DB/OL].http://www.mizi.com/developer/s3c2410x/index.html
[45]广州斯道信息技术有限公司.广州斯道s3c2410普及版Ⅱ技术手册[Z],2005.
[46]Omni Vision Technologies,Inc,OV7620 Product Specifications-rev.1.3[EB/OL].http://home.pacific.net.hk/~comedia/ov7620.pdf
[47]OmniVision Technologies,Inc,OV511 Advanced Camera to USB Bridge[EB/OL].http://mxhaard.free.fr/spca50x/Doc/Omnivision/ds 511P.pdf
[48]魏洪兴,胡亮,区学楼.嵌入式系统设计与实例开发试验教材Ⅱ[M].北京:清华大学出版社,2005.
[49]李侃,廖启征.基于S3C2410平台与嵌入式Linux的图像采集应用[J].ARM开发与应用,2006.3(2):126-128.
[50]张雄,叶念渝,田俊.基于S3C2410的网络视频采集[J].兵工自动化,2006,25(5):71-73.
[51]张永强,赵永勇,李崇德.嵌入式远程视频采集系统的设计与实现[J].现代电子技术, 2006.4:75-77.
[52]陈俊宏.嵌入式系统原理与实务[M].北京:中国铁道出版社,2004.3.
[53]无线USB网卡MA111产品介绍[DB/OL].http://www.netgear.com.cn/product/details/ma111.htm
[54]张崙.32位嵌入式系统硬件设计与调试[M].北京:机械工业出版社,2005.5.
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