基于宽带网的DVB接收系统的软件设计及其实现
摘要
DVB体系的应用起始于直播卫星系统，后来逐渐被有线电视系统采用，由于Internet的崛起，有人开始了基于Internet的DVB系统的研究，可是Internet带宽低，错误率高，这些Internet网络固有的局限性，限制了需要大量数据的传播的DVB系统的广泛应用。采用广播电视系统的有线电视高速宽带网络，并且通过利用DVB标准中规定的各种控制信息，以PC机为客户端，实现了基于宽带的DVB接收系统。这个接收系统采用Windows平台，硬件采用专用接收卡接收DVB广播数据；驱动软件部分采用NDIS体系结构，这样的体系结构能够易于在各个Windows平台中移植；应用软件部分采用DirectShow中的过滤器结构，实现了一个SourceFilter，这样可以使用通用的控制媒体播放器MediaPlayer来播放MPEG节目，又能够控制媒体流的播放。通过测试，该DVB接收系统能够同时完成MPEG-2和MPEG-1格式的播放以及文件的下载。
本系统和以往的同类系统或机顶盒方式相比有着以下特点：
1)基于NDIS的驱动部分设计使得本系统能够在各个Windows平台上面进行方便的移植，而不需要修改太多的源代码。
2)采用多级缓存方式，解决了播放速度暂时不匹配和包重组缓存问题。系统采用核心态一级缓存和用户态二级缓存的设计方式，使得在发送数据速率和播放速率暂时不一致的情况下能够顺利播放，使得二级缓存中的缓存数据量整体保持在一个稳定的水平。
3)采用分级处理的方式使得各个模块的功能明确，便于修改和升级。比如小端口驱动只负责和接收卡的通讯和包的接收，而包的重新组合则在协议层完成，这样如果需要增加一种播放类型则不需要修改小端口层。
4)媒体播放采用Windows自带的MediaPla控件，文件下载和浏览都采用IE浏览器，这样使得所有操作都是所有Windows用户所熟悉的，也是友好的。
实现本系统就能使得以往的DVB接收由机顶盒硬件方式转变成软件方式，扩大了DVB系统的使用范围，便于数字电视的更快发展。
The application of DVB system which started with satellite living broadcast
system was adoptted by CATV gradually. By the growing up of Internet, DVB system
based on llnternet became the research object of researchers and engineers. However,
narrow band and high error rate of Internet limited the application of DVB system
which should transport lots of data on network. Nowadays high-speed broadband
network of CATV is used to realize DVB system whose client is personal computer.
We developed the client software of this DVB system which was based on windows
platform. The hardware used in client is a DVI3 receive card and the archecture of the
receive card driver is NDIS which makes the driver can be migrated in different
windows platforms easily. The application software part is based on filter structure in
Directshow and we developed a source filter through which ~ve can control the
playing back of the mediaplayer. By our test, the DVB receive system can play back
the MPEG-2 and MPEG-I vedio and download files.
The softe-vare part of the DVB receiving system has following advantages.
1) The design of driver based on NDIS make it easy that the software can be
migrated in different windows platforms without too much modification.
2) Multi-level buffer is used to resolve the problem of slow play and packet
re-assemble. The system use one buffer in kernel mode and one buffer in user
mode which makes the movie can be played frequently when there is any
speed difference between sending and receiving.
3) Multi-level software module is used which makes the system can be updated
and modified easily. For example, miniport dirver answers for the
communication to receiving card and the receiption of TS packet without
re-assembling the TS packet to PS packet. So if a new kind of media type is
demanded in this system, the miniport driver part of the system should not be
aniniended.
4) MediaPlayer and IE are the most popular software built in windows operating
system. So the software using these tools are friendly to users.
本系统和以往的同类系统或机顶盒方式相比有着以下特点：
1)基于NDIS的驱动部分设计使得本系统能够在各个Windows平台上面进行方便的移植，而不需要修改太多的源代码。
2)采用多级缓存方式，解决了播放速度暂时不匹配和包重组缓存问题。系统采用核心态一级缓存和用户态二级缓存的设计方式，使得在发送数据速率和播放速率暂时不一致的情况下能够顺利播放，使得二级缓存中的缓存数据量整体保持在一个稳定的水平。
3)采用分级处理的方式使得各个模块的功能明确，便于修改和升级。比如小端口驱动只负责和接收卡的通讯和包的接收，而包的重新组合则在协议层完成，这样如果需要增加一种播放类型则不需要修改小端口层。
4)媒体播放采用Windows自带的MediaPla控件，文件下载和浏览都采用IE浏览器，这样使得所有操作都是所有Windows用户所熟悉的，也是友好的。
实现本系统就能使得以往的DVB接收由机顶盒硬件方式转变成软件方式，扩大了DVB系统的使用范围，便于数字电视的更快发展。
The application of DVB system which started with satellite living broadcast
system was adoptted by CATV gradually. By the growing up of Internet, DVB system
based on llnternet became the research object of researchers and engineers. However,
narrow band and high error rate of Internet limited the application of DVB system
which should transport lots of data on network. Nowadays high-speed broadband
network of CATV is used to realize DVB system whose client is personal computer.
We developed the client software of this DVB system which was based on windows
platform. The hardware used in client is a DVI3 receive card and the archecture of the
receive card driver is NDIS which makes the driver can be migrated in different
windows platforms easily. The application software part is based on filter structure in
Directshow and we developed a source filter through which ~ve can control the
playing back of the mediaplayer. By our test, the DVB receive system can play back
the MPEG-2 and MPEG-I vedio and download files.
The softe-vare part of the DVB receiving system has following advantages.
1) The design of driver based on NDIS make it easy that the software can be
migrated in different windows platforms without too much modification.
2) Multi-level buffer is used to resolve the problem of slow play and packet
re-assemble. The system use one buffer in kernel mode and one buffer in user
mode which makes the movie can be played frequently when there is any
speed difference between sending and receiving.
3) Multi-level software module is used which makes the system can be updated
and modified easily. For example, miniport dirver answers for the
communication to receiving card and the receiption of TS packet without
re-assembling the TS packet to PS packet. So if a new kind of media type is
demanded in this system, the miniport driver part of the system should not be
aniniended.
4) MediaPlayer and IE are the most popular software built in windows operating
system. So the software using these tools are friendly to users.
引文
[1] ISO/TEC,"Information Technology-Generic Coding of Moving Pictures andAssociated Audio: Systems-ISO/TEC 13818-1 International Standard",Nov.1994．
[2] ETSI Standard TR 101 200,"Digital Video Broadcasting (DVB): A Guidelinefor the Use of DVB Specifications and Standards",Sep.1997．
[3] ETSI Standard EN 300 468,"Digital Video Broadcasting (DVB) :Specification for Service Information (SI) in DVB System",Feb.1998．
[4] ETSI Standard ETR 211,"Digital Video Broadcasting (DVB ) : Guidelines onImplementation and Usage of Service Information (SI) ",Aug.1997．
[5] ETSI Standard EN 300 429,"Digital Video Broadcasting (DVB) : FrameStructure,Channel Coding and Modulation for Cable Systems",Apr.1998．
[6] ETSI Standard ETR 289,"Digital Video Broadcasting (DVB): Support for useof scrambling and Conditional Access (CA) ",Mar.1997．
[7] Paul W.Lyons,"Grand Alliance Prototype Transport Stream Encoder Designand Implementation",IEEE Transaction on Consumer Electronics,Vol.41,No.3,Aug.1995．
[8] EBU Project Group B/CA,"Functional model of a conditional access system",Jun.1995．
[9] Hyun Ho Jeon,"Transmission of System Information and Additional ServiceData for Digital HDTV Broadcasting",IEEE Transaction on Broadcasting,Vol.44,No.1,Mar.1998．
[10] ETSI Standard EN 301 192,"Digital Video Broadcasting (DVB): DVBspecification for data broadcasting",Jun.1999．
[11] Jae D.Kim,Si Joong Kim and Jong-Seog Koh,"An Analysis andImplementation of Precise Synchronization Mechanism for MPEG-2 MediaObjects",SPIE,Vol.3024．
[12] ETSI Standard TS 103 197,"Digital Video Broadcasting (DVB): Head-endimplementation of DVB SimulCrypt",Jun.2000．
[13] Yu-Jen Chang and Alan T.Pan,"Design and Implementation of a Real-TimeMPEG-Ⅱ Bit Rate Measure System",IEEE Transaction on ConsumerElectronics,Vol.45,No.1,Feb.1999．
[14] G M.Drury,"DVB Channel Coding Standards for Broadcasting compressedVideo Services",Electronics & Communication Engineering Journal,
Feb. 1997.
【15】Microsoft Windows 2000 DDK Document, Network Driver
【16】Microsoft Platform SDK(Apfil 2000) Document, Graphics and Multimedia Services, DirectX
【17】G. Rossi著，马明译，“对电视广播节目的有条件访问：技术方案”，国际广播电视技术，1997年第5期。
【18】管泓著，“标准数字视盘机DVD原理与应用”，国防工业出版社。
【19】杜百川，“DVB及其标准”，国际广播电视标准，1997年第1期。
【20】潘笑梅，“DVD技术及其应用”，电视技术，1999年6月。
【21】孟凡定，“DVB的现状与前景”，电视技术，1999年7月。
【22】王建松，“数字有线电视系统综合业务接入终端”，世界广播电视，1999年10月。
【23】黎洪松，“数字视频技术及其应用”，清华大学出版社。
【24】杨品，钟玉琢，蔡莲红 译，“MPEG运动图象压缩编码标准(ISO／IEC 11172)”，机械工业出版社。
【25】钟玉琢，乔秉新，祈卫 译，“运动图象及其伴音通用编码标准——MPEG-2”，清华大学出版社
【26】Pascal Frossard, "MPEG-2 over lossy packet networks QoS Analysis and Improvement", July 1998
【27】SiegFried Dickhoven and Olaf Menzel, "Broadband DVB-based Internet and Intranets via Satellite
[2] ETSI Standard TR 101 200,"Digital Video Broadcasting (DVB): A Guidelinefor the Use of DVB Specifications and Standards",Sep.1997．
[3] ETSI Standard EN 300 468,"Digital Video Broadcasting (DVB) :Specification for Service Information (SI) in DVB System",Feb.1998．
[4] ETSI Standard ETR 211,"Digital Video Broadcasting (DVB ) : Guidelines onImplementation and Usage of Service Information (SI) ",Aug.1997．
[5] ETSI Standard EN 300 429,"Digital Video Broadcasting (DVB) : FrameStructure,Channel Coding and Modulation for Cable Systems",Apr.1998．
[6] ETSI Standard ETR 289,"Digital Video Broadcasting (DVB): Support for useof scrambling and Conditional Access (CA) ",Mar.1997．
[7] Paul W.Lyons,"Grand Alliance Prototype Transport Stream Encoder Designand Implementation",IEEE Transaction on Consumer Electronics,Vol.41,No.3,Aug.1995．
[8] EBU Project Group B/CA,"Functional model of a conditional access system",Jun.1995．
[9] Hyun Ho Jeon,"Transmission of System Information and Additional ServiceData for Digital HDTV Broadcasting",IEEE Transaction on Broadcasting,Vol.44,No.1,Mar.1998．
[10] ETSI Standard EN 301 192,"Digital Video Broadcasting (DVB): DVBspecification for data broadcasting",Jun.1999．
[11] Jae D.Kim,Si Joong Kim and Jong-Seog Koh,"An Analysis andImplementation of Precise Synchronization Mechanism for MPEG-2 MediaObjects",SPIE,Vol.3024．
[12] ETSI Standard TS 103 197,"Digital Video Broadcasting (DVB): Head-endimplementation of DVB SimulCrypt",Jun.2000．
[13] Yu-Jen Chang and Alan T.Pan,"Design and Implementation of a Real-TimeMPEG-Ⅱ Bit Rate Measure System",IEEE Transaction on ConsumerElectronics,Vol.45,No.1,Feb.1999．
[14] G M.Drury,"DVB Channel Coding Standards for Broadcasting compressedVideo Services",Electronics & Communication Engineering Journal,
Feb. 1997.
【15】Microsoft Windows 2000 DDK Document, Network Driver
【16】Microsoft Platform SDK(Apfil 2000) Document, Graphics and Multimedia Services, DirectX
【17】G. Rossi著，马明译，“对电视广播节目的有条件访问：技术方案”，国际广播电视技术，1997年第5期。
【18】管泓著，“标准数字视盘机DVD原理与应用”，国防工业出版社。
【19】杜百川，“DVB及其标准”，国际广播电视标准，1997年第1期。
【20】潘笑梅，“DVD技术及其应用”，电视技术，1999年6月。
【21】孟凡定，“DVB的现状与前景”，电视技术，1999年7月。
【22】王建松，“数字有线电视系统综合业务接入终端”，世界广播电视，1999年10月。
【23】黎洪松，“数字视频技术及其应用”，清华大学出版社。
【24】杨品，钟玉琢，蔡莲红 译，“MPEG运动图象压缩编码标准(ISO／IEC 11172)”，机械工业出版社。
【25】钟玉琢，乔秉新，祈卫 译，“运动图象及其伴音通用编码标准——MPEG-2”，清华大学出版社
【26】Pascal Frossard, "MPEG-2 over lossy packet networks QoS Analysis and Improvement", July 1998
【27】SiegFried Dickhoven and Olaf Menzel, "Broadband DVB-based Internet and Intranets via Satellite