通信及电子信息工程专业英语第8单元

1、Unit 8 MultimediaMultimediaUnit 8 Multimediav The word multimedia is being used to describe a mixture of hardware .software and applications, with a consequent confusion in peoples minds as to what it is. it is a confusion situation that could lead to a missed opportunity for industry to develop a n

2、ew marketplace. The term multimedia literally means many forms of communication and in a sense we have always been immersed in a multimedia environment because we are being that respond to sound , light, touch, and ideas. This is essentially an interactive environment.v “多媒体多媒体”这个词正在被用于描述混合的硬件，软件和应用

3、这个词正在被用于描述混合的硬件，软件和应用程序，伴随着人们心中随之而来的混乱。这是一个混乱的程序，伴随着人们心中随之而来的混乱。这是一个混乱的局面，它可能导致错过一个工业发展新市场的机会。多媒局面，它可能导致错过一个工业发展新市场的机会。多媒体这一术语字面上的意味着许多形式的交流，就某种意义体这一术语字面上的意味着许多形式的交流，就某种意义来说我们一直浸泡在多媒体的环境里。因为我们正在回应来说我们一直浸泡在多媒体的环境里。因为我们正在回应声，光，触摸和想法。这实质是一个互动的环境。声，光，触摸和想法。这实质是一个互动的环境。 Unit 8 Multimediav In the modern p

4、resentation of multimedia we now have the technology that can begin to move towards an ability ,already held by the human being ,in that by using computer technology, such as CD-ROM, not only can we bring together audio and visual images but also be interactive with other computer users.v 在现在多媒体介绍中，

5、我们现在有技术可以开始面向能力。在现在多媒体介绍中，我们现在有技术可以开始面向能力。它已经通过人类举行，利用计算机技术。如光驱，不仅能它已经通过人类举行，利用计算机技术。如光驱，不仅能为我们带来共同的音频和视觉图像组合在一起。而且也与为我们带来共同的音频和视觉图像组合在一起。而且也与其他的电脑用户互动。其他的电脑用户互动。 Unit 8 Multimediav Perhaps the biggest reason for the explosion of multimedia offerings is the enormous advances in personal desk top com

6、puter , This computer advance would appear to bring multimedia facilities within the reach of the majority of homes for about US$1 600; this system might consist of a 486 processor with 4Mbytes of RAM and 340 Mbytes of hard disc storage ,with a colour monitor ,CD-ROM, sound system ,language and lear

7、ning systems and Windows and Lotus Applications .This sort of specification is aimed at the personal ,home computer market and is probably more for games and education.v 也许最大的原因是多媒体产品爆炸是个人台式电脑的巨大进步。这台电也许最大的原因是多媒体产品爆炸是个人台式电脑的巨大进步。这台电脑事先似乎使多媒体设施达到大多数家庭的大约脑事先似乎使多媒体设施达到大多数家庭的大约1600美元。这个系统美元。这个系统可能包括一个可能

8、包括一个486处理器的处理器的4M内存和内存和340M的硬盘存储，彩色显示器，的硬盘存储，彩色显示器，光驱，音响系统，语言学习系统，光驱，音响系统，语言学习系统，Windows 和和 Lotus应用。这种规应用。这种规范是针对个人，家用电脑市场。更多的可能是为了教育和游戏。范是针对个人，家用电脑市场。更多的可能是为了教育和游戏。 Unit 8 Multimediav The first element associated with multimedia is perhaps the CD-ROM, now considered a mature technology. The CD-ROM

9、is used to store data that represents visual imagery and current units can store up to 650 Mbytes of data. The standards of multimedia can be found in what is known as the ITU White Book, which brings together various standards for CD-ROM and video compression and it is essential that these two area

10、s of standards are taken together.v第一个相关多媒体的元素可能是光驱，现在被认为是第一个相关多媒体的元素可能是光驱，现在被认为是一个成熟的技术。光驱被用来存储代表视觉图像和当一个成熟的技术。光驱被用来存储代表视觉图像和当前单元可以最多存储前单元可以最多存储650M字节的数据。多媒体标准字节的数据。多媒体标准可以被发现，从被称为国际电信联盟的白皮书中。它可以被发现，从被称为国际电信联盟的白皮书中。它汇集了各种光驱和视频压缩的标准。它至关重要的是汇集了各种光驱和视频压缩的标准。它至关重要的是这两个地区的标准联系起来。这两个地区的标准联系起来。 Unit 8 Mul

11、timediav A crucial element in the provision of multimedia is the use of compressed video .Without compression the amount of storage that would have to be provided by the CD-ROM would be immense, or you would only be able to store 15 seconds of a full motion picture. If compression is applied to the

12、motion pictures experts group(MPEG-1) standard, then a 650 Mbytes CD-ROM can hold either 72 minutes of video, or 19 hours of audio, or 7 000 still photographs.v 提供的多媒体中一个关键的因素是压缩视频的使用提供的多媒体中一个关键的因素是压缩视频的使用.无压缩无压缩存储的不得不提供巨大的光盘，否则你只可以存储一个存储的不得不提供巨大的光盘，否则你只可以存储一个15秒的完整电影。如果压缩应用于运动图像专家组秒的完整电影。如果压缩应用于运动图

13、像专家组（MPEG-1）标准。然后）标准。然后650MB的光盘可以容纳的光盘可以容纳72分分钟的视频，或钟的视频，或19小时的音频，或小时的音频，或7000 张静态照片。张静态照片。Unit 8 Multimediav The standards for moving pictures are set by MPEG as international standards. The two levels are MPEG-1, which sets the provision of consumer quality of video and audio and MPEG-2,which sets

14、 the higher standards for professional, broadcast images and also looks to define high definition television.v 移动图片的标准是由移动图片的标准是由MPEG设定作为国际标准。两个层次设定作为国际标准。两个层次的是的是MPEG-1，它设定消费者提供质量的音频和视频。，它设定消费者提供质量的音频和视频。MPEG-2设置了高标准的专业，广播图像，也定义了高清设置了高标准的专业，广播图像，也定义了高清晰的电视。晰的电视。 Unit 8 Multimediav MPEG-2 looks at m

15、ore than pictures, it looks at the associated sound, storage methods, bit rates needed, coding algorithms, etc. Modern encoders are not only used in the CD-ROM area, but also as a means of transmitting signals, they use a number of digital signal processor to form a vision encoder.v MPEG-2的清晰度看起来更多于

16、图片。它看来相关联的声的清晰度看起来更多于图片。它看来相关联的声音，存储方法，比特率需求，编码算法等。现代的编码器音，存储方法，比特率需求，编码算法等。现代的编码器不仅使用在光盘地区，而且还作为一种工具传输信号，他不仅使用在光盘地区，而且还作为一种工具传输信号，他们使用的许多数字信号处理器形成了视觉编码器。们使用的许多数字信号处理器形成了视觉编码器。v Unit 8 Multimediav he problem for the CD-ROM industry is that although they know what the data rate will be if the picture

17、 signal is encoded, they have different ways of putting the data onto a disc. As standards evolve this problem may be disappear, but in the meantime anyone looking to upgrade their multimedia systems has to look not only at the MPEG encoder but also at the PC, which must be at least a 486 standard w

18、ith a clock speed of at least 25 MHz, because anything to a lower standard will give an inferior performance regardless of where the data is stored.v 光盘行业的问题是虽然他们知道数据传输速率将像图片信号编码他们有不光盘行业的问题是虽然他们知道数据传输速率将像图片信号编码他们有不同的方式把数据刻录到光盘。作为标准的演变，这一问题可能消失。但在同的方式把数据刻录到光盘。作为标准的演变，这一问题可能消失。但在此期间，寻找提升它们多媒体系统已不单看此期间

19、，寻找提升它们多媒体系统已不单看MPEG的编码器，而且在个的编码器，而且在个人电脑。其中必须至少有一个人电脑。其中必须至少有一个486标准的时钟速率至少标准的时钟速率至少25兆赫兹。因为兆赫兹。因为任何一个较低的标准会给一个弱质的性能，无论数据存储在什么地方。任何一个较低的标准会给一个弱质的性能，无论数据存储在什么地方。 Unit 8 Multimediav If we consider the business area of multimedia applications, the provision of video is crucial and that video informati

20、on must come to user in real time and therefore be processed in real time. This means that any system must conform to the CCITT MPEG-2 standard. The technology to do this has moved on tremendously in the last few years due to the need to reduce the cost of transmitting data over the network. The enc

21、oders and decoders for video are now manufactured with a minimum of integrated circuits.v 如果我们考虑多媒体应用的业务领域，提供的视频是至关如果我们考虑多媒体应用的业务领域，提供的视频是至关重要的。视频信息必须实时面向用户。因而处理是实时的。重要的。视频信息必须实时面向用户。因而处理是实时的。这意味着任何系统必须符合这意味着任何系统必须符合CCITT（国际电话电报咨询委（国际电话电报咨询委员会）的员会）的MPEG-2标准。这样的技术已经在过去的几年由标准。这样的技术已经在过去的几年由于需要降低通过网络来传

22、输数据成本。视频的编码器和译于需要降低通过网络来传输数据成本。视频的编码器和译码器码器 是现在最低集成的电路制造。是现在最低集成的电路制造。 Unit 8 Multimediav What then are the problems for the designer? The individual elements of multimedia are already handled by a standard 486 personal computer, such things as audio, graphics and text, but the major challenge is in

23、 real time video, for this is the major business requirement and a necessityif multimedia systems are to become standard items for the desktop. v 然后然后什么是设计师的问题？个人多媒体元素已经由一个标准的什么是设计师的问题？个人多媒体元素已经由一个标准的486个人的电脑处理，诸如音频，图形和文字。但主要的挑战是实时的视个人的电脑处理，诸如音频，图形和文字。但主要的挑战是实时的视频。这是主要的业务需求和必要多媒体系统成为台式机的标准项目。频。这是主要的

24、业务需求和必要多媒体系统成为台式机的标准项目。Unit 8 Multimediav This real time processing requires a vast amount of data storage and this is a function of the amount of information contained in a colour picture, for instance a normal 640480 pixel colour picture requires well over 1 Mbyte of storage to give the required q

25、uality, though for full motion video this is increased up to 100 Mbytes of data.v 这种实时处理需要大量的数据存储。这是一个功能包含大这种实时处理需要大量的数据存储。这是一个功能包含大量信息的彩色图片。例如一个正常的量信息的彩色图片。例如一个正常的640*480像素的彩像素的彩色图片需要超过色图片需要超过1MB的存储提供所需要的质量。虽然全的存储提供所需要的质量。虽然全动态视频，这是增加到动态视频，这是增加到100MB的数据。的数据。 Unit 8 Multimediav The spread of multime

26、dia users is not just a function of technology, and it is certainly not an stoppable process. The key to its take-up is in the successful selling of video and television services, which are often gathered under the general title of video-on-demand (VOD) interactive services. A typical VOD architectu

27、re takes trunk and access networks into account. The video server is the key to on-demand services. The video server will store a large number of programs that can be instantly accessed by a large number of individual subscribers, it is stored in a compressed form to save space5.v 多媒体用户的传播不仅仅是技术的功能，这肯定不是一个阻断过程。它的多媒体用户的传播不仅仅是技术的功能，这肯定不是一个阻断过程。它的采取行动的关键是成功的视频和电视服务的销售。这是经常聚集在主标题采取行动的关键是成功的视频和电视服务的销售。这是经常聚集在主标题下的视频的需求（视频点播）互动服务。一个典型的视频点播架构需要考下的视频的需求（视频点播