十八单元电子信息类专业英语第18单元B译文

1、Passage B Characteristics 特点Multimedia is one of the most innovative ways of using a telecommunications network to achieve effective communications(1)between people and(2)for access to information. This chapter describes the essential ingredients of multimedia and gives a wide variety of examples of

2、 applications in a wide range of industrial settings. 多媒体是一种使用电信网络实现人们之间的有效通信和获取信息最创新的方式。这一章描述了多媒体的基本成分,而且举出各种各样的在广泛的工业设置应用的例子。Four Key Ingredients四个关键要素Multimedia communications is defined here as the combination of four key ingredients:多媒体通信在这里被定义为四个关键成分的组合: Two or more of the five media of commun

3、ication (audio, data, fax, image, and video);两个或两个以上的五个沟通的媒体(音频、数据、传真、图像和视频); Interactive capabilities between the communicating parties;通信各方之间的互动功能; Communications with Human Users. Multimedia systems involve communications with human users as senders or receivers of information, or both. By contra

4、st, single medium systems, such as data and fax, can involve inter-machine communications with no human user present while the communication is underway. It is the human element that benefits from more than one medium of communication, and also from the interactive capabilities of multimedia systems

5、.1 与人类用户通信。多媒体系统涉及与人类用户发送方或接收方的信息或两者兼而有之的通信。相比之下,单一的媒介系统,如数据和传真,可以涉及跨机器通信而且没有人类用户在场反而沟通正在进行。这是人类受益于多个通信媒介,以及多媒体互动功能的元素。1 Synchronization. Multimedia systems require two types of synchronization between the different media. Continuous synchronization is required for audio/video, for instance, to coor

6、dinate lip movement with speech. Synthetic synchronization is required by the designer of the system to organize the presentation of material in the desires manner (e.g., the sequencing of video clips with data and graphics).同步。多媒体系统需要两种类型的不同媒体之间的同步。对于音频/视频来说，连续同步被需要,例如,嘴唇运动配合演讲。合成同步系统的设计要求系统设计者用渴求的

7、方式组织物质的呈现(如,用数据和图形对视频片段进行测序)。Videoconferencing is a typical example of multimedia, combining two media (audio and video), interaction, human users, and synchronization. By contrast, broadcast television allows no backward channel for the information receiver to interact with the information provider

8、, and it is therefore not regarded as a multimedia communication. 多媒体视频会议是一个典型的例子,结合两种媒体(音频和视频),相互作用,人类用户和同步。相比之下,广播电视不允许针对信息接收器的反向通道影响信息提供者,因此它不被视为一个多媒体通信。The types of interaction in multimedia systems are as follows:互动多媒体系统的类型如下: Search and browse. These correspond to database access functions for

9、 extracting the required multimedia information from storage.搜索和浏览。这些对应于数据库访问功能即从存储中提取所需要的多媒体信息。 Interactive “buttons”. A frame of information (i.e., a screen or portion of a screen) may contain buttons that can be selected(e.g. , using a cursor)to control the presentation of information, and to pas

10、s on to another frame. Examples of “buttons” are lists of options, menu selections, and portions of the displayed information that can be selected to obtain additional information on that subject.互动“按钮”。即一帧信息（屏幕或屏幕的一部分）可能包含可以选择的按钮,(如,使用游标)来控制信息的展示,并传递到另一个框架。“按钮”的例子是列表的选项,菜单选择,和部分陈列的信息,可以选择它来获取额外的关于这

11、个话题的信息。 Windowing. One frame of information overlaps a background frame, and the size of frames can be changed by the user so as to view portions of several frames simultaneously. 窗口。一帧的信息重叠一背景帧,用户可以改变帧的大小目的在于同时查看多个框架各部分。 Fast Forward, rewind, pause, and skip. “Tape recorder” commands to control the

12、 sequence and speed of presentation of information can be used, not just with audio and video information but also to control a sequence of frames of data, fax, and image.2快进,快退、暂停、跳过。“录音机”命令用来控制可以被使用的信息的显示顺序和速度,这不仅伴随音频和视频信息而且用来控制数据帧序列,传真,和图像。2 Conversational interaction. When a human user is presen

13、t at each end of the communication channel, a wide range of conversational interactions are possible, including audio discussion, displaying data and images in shared screens, and pointing to, editing and annotating the contents of the shared screen.会话交互。当人类用户存在于通信通道的两端时,一个广泛的对话交互是可能的,包括音频讨论,显示数据和在共

14、享屏幕中的图像,以及指向,编辑和注释的共享屏幕的内容。Enabling Technologies支持技术Multimedia communications has come about as a result of the development of a number of technological capabilities. These capabilities are described in the following subsections.多媒体通信是作为许多技术能力的发展的结果。下面的分段将描述这些功能。 Fast-Packet Networks. The high bandw

15、idth, burst nature of multimedia communications makes it particularly suited to fast-packet telecommunication capabilities such as those provided by ATM and DQDB. Until these networks are widely deployed, multimedia communications can be based on circuit capabilities at a range of bandwidths and low

16、er bandwidth packet capabilities. such as X.25 and frame relay.3Fast-Packet网络。带宽高,多媒体通信爆发的特性使它特别适合fast-packet电信提供的ATM和DQDB等功能。直到这些网络被广泛部署,多媒体通信在一定范围的带宽和低带宽数据包的能力内建立在电路上。如X.25和帧中继。3 High Capacity Storage Systems. The predominance of storage intensive media, such as audio, video, and high resolution i

17、mage in multimedia communications requires high capacity storage systems, such as optical disks.大容量存储系统。存储密集的媒体的优势,如音频、视频、和高分辨率图像在多媒体通信需要大容量存储系统,如光碟。 Powerful Processing Capability. The encoding/decoding of a variety of media plus the synchronization of their presentation to the user require powerfu

18、l processors.强大的处理能力。各种媒体的编码/解码加上他们呈现给用户的需要强大的处理器的同步性。 Compression Coding. The development of coding techniques for audio, image, and video has enabled multimedia communications to be compressed into available bandwidth. This enabled many multimedia systems to be developed before the availability of

19、 broadband networks. Broadband communications results in improved quality and lower end-to-end delay.压缩编码。音频、图像和视频编码技术的发展,使得多媒体通信成为被压缩的可用带宽。这能够使许多多媒体系统在宽带网络的可用性之前被开发。宽带通信导致更高的质量和更低的端到端的延迟。 Hypertext. Hypertext is a precursor to multimedia that was developed several years before the technology necess

20、ary for multimedia became available.4 Using only one mediumimageit provided many of the interactive capabilities of multimedia systems and served to prime the market for the true multimedia that is becoming available today.超文本。超文本是多媒体的先驱，它是先于多媒体技术被应用之前所开发的。4只使用一种多媒体影像，它提供许多多媒体系统互动功能,而且对于真正的多媒体的主要市场今

21、天变得可用。 Windowing. Windowing software gives an interface in which the user can interact with several files or software processes using a single screen. It was originally developed in a single medium situationnamely, imageand was rapidly extended to cater for motion video. It greatly enhances the inte

22、ractive capabilities of many multimedia systems today.窗口。窗口软件提供一个接口,用户可以使用一个屏幕对多个文件或软件操控。它最初是用一个单一的媒介状态来开发,换句话说，即图像，并且它被迅速扩展到满足移动视频的需要。今天它大大提高了许多多媒体系统的互动功能。Business Advantages of Multimedia Communications多媒体通信的业务优势There is a strong latent demand for multimedia communications as evidenced by:这儿有一种为多媒

23、体通信强烈的潜在需求的证明: the use of videoconferencing to display a technical drawing or other object of discussion as well as the head and shoulders of the discussant. This is essentially the use of motion video to provide a still-image capability.视频会议的使用用来显示技术图纸或其他对象的讨论以及讨论者的头和肩膀。本质上这就是移动视频为提供一个静态影像的用途。 the

24、use of fax and data communication equipment during the course of a videoconferencing;在视频会议过程中传真和数据通信设备的使用;the use of modems that allow voice and data communications over one voice-grade line.调制解调器的使用允许语音和数据通信在一个声音等级。These examples imply a demand for interactive combinations of all five communication

25、s media: audio, data, image, fax, and video.这些例子暗示对于交互式的所有五个传播媒体组合:音频、数据、图像、传真和视频的一种要求。The business effectiveness of multimedia communications can be estimated from the effectiveness of earlier forms of computer mediated communications (CMC) in which users exchange data, sometimes as an accompanimen

26、t to a telephone conversation. Business experience of CMC, and research into its benefits, is more established than for multimedia since it has been used since the mid-1970s. The effectiveness of CMC has been analyzed in business group decision-making situations and in educational settings as an instructional tool.多媒体通信的业务有效性可以从早期CMC形式的有效性进行估测，用户可以交换其中的数据，有时可以作为电话交谈的一种陪伴。由于CMC自1970年代中期被使用，CMC的商业经历和利益相关的研究比多媒体更多地被建立。CMC的有效性已经分析了在商业团体决策的情况而且在教育设置中作为一种指导工具。Group Decision Making群体决策Studies have shown that there are advantages to CMC in group decision-making situations