TECHNOLOGIES USED IN MULTIMEDIA SYSTEMS AND THEIR APPLICATIONS

Transcription

1 TECHNOLOGIES USED IN MULTIMEDIA SYSTEMS AND THEIR APPLICATIONS Prepared for Mr. John Williams English Technical Report Writing by Mohammed Al- Hajjaj Electrical Engineering Department Abstract This report discusses Multimedia Systems. Some brief background about Multimedia elements is reviewed. Then, some technologies used in these systems involving computer animation, the multicast session layer technology and a middleware system are described and exemplified. Some applications of these systems are then discussed. 2 May 2005

2 TABLE OF CONTENTS INTRODUCTION. 2 I. ELEMENTS OF MULTIMEDIA SYSTEMS... 3 II. TECHNOLOGIES USED IN MULTIMEDIA SYSTEMS... 5 A. Computer Animation B. Multi Cast Session Layer Technology C. A Middleware System III. SOME APPLICATIONS OF MULTIMEDIA SYSTEMS. 7 A. Digital Video B. Home Networking C. The Berkeley Software System CONCLUSION... 8 WORKS CITIED 9-2 -

3 INTRODUCTION This report introduces multimedia systems and their impact on the field of information exchange. The word multimedia is associated, in the minds of many people, with the concept of collecting and using different media into one application. With the huge increase of human knowledge and information, multimedia systems are urgently required. A Multimedia system means presenting or conveying information by using a combination of text, audio, graphics, animation and video. As the information can be presented in various formats, Multimedia enhances user experience and makes it easier and faster to grasp information. Presenting information is nothing new, but Multimedia generally implies presenting information in various digital formats. An educational concept can be explained or demonstrated by using text, images and sound. (3: 1) The specific purpose of this report is to discuss some technologies used in Multimedia systems and describe their impact. In addition, elements of Multimedia Systems are briefly introduced. Moreover, attention is paid to some applications and uses of Multimedia systems. The report will be of particular interest to people with interests in operating systems, networking, signal processing, graphics, databases, human computer interfaces and cognitive science. (3:1) The report starts with reviewing elements of multimedia systems. This is followed by discussing some technologies used in these systems. Finally, some of multimedia applications and uses are indicated. I. ELEMENTS OF MULTIMEDIA SYSTEMS This chapter consists of three sections. The first section introduces visual elements including vector graphics and raster graphics. The second section introduces sound elements and the third is about organizational elements which are subdivided into traditional and modern elements

4 A. Visual Elements The larger, sharper and more colorful an image is, the harder it is to present and manipulate on a screen. Photographs, drawings and other images must be converted into a format that the computer can display and manipulate. Such formats include vector graphics and raster graphics. 1. Vector Graphics Vector graphics use mathematical formulas to recreate the original images composed of a group of lines. The computer s memory stores each line as a vector. On the screen of vector graphics, an electron beam moves forth and back between the points designated by the computer and paths, emitting light and then producing lines. Therefore, a contiguous image is formed when solid shapes are created by collecting lines together. Vector graphics emerged in the mid 1960s and was used until they were replaced by raster graphics. (5:508) 2. Raster Graphics Raster graphics store, control and represent images as a matrix or individual dots (pixels). Each dot or pixel has an accurate location described by its rows and column. The frame of a picture consists of hundreds of very small horizontal rows. Each row is composed of hundreds of pixels. (5:508) B. Sound Elements Sound, like visual elements must be recorded and converted so the computer can understand and use it in presentations. The computer, having multimedia systems, can be used in composing rhythms and other musical elements. Max Vernon Mathews and his group developed a computer of synthesizing sound directly..multimedia computers can produce a wide variety of musical and audio applications. (5:509) - 4 -

5 C. Organizational Elements Multimedia elements in a presentation require a framework that encourages the user to learn and interact with the information. These interactive organizational elements can be subdivided into: conventional and modern elements. 1. Traditional Elements Traditional interactive elements include a desktop or a laptop computer, a mouse and a keyboard. These elements help the user to move from a document to another or fro a file to another. (3:6) 2. Modern Elements Conventional interactive elements are being replaced by modern elements, such as a pen, voice, gesture, touch, smell, etc.). These elements enable the user to press a button on a computer or gesture with a hand or give the commands orally. (3:6) II. SOME TECHNOLOGIES USED IN MULTIMEDIA SYSTEMS This chapter consists of three main sections. The first section introduces computer animation including software tools of animation and animation applications. The second section deals with multicast session layer technology for the internet, which is subdivided into its importance and applications. The third section briefly reviews the middleware system. A. Computer Animation Computer animation is the creation of illusion of motion by viewing a succession of computergenerated still images. Prior to the age of computers, animation was carried out by filming handdrawn or painted series on plastic or paper. Animation styles and techniques have developed greatly by the use of computers and electronic video equipment. Computer animation cannot be carried out without understanding its software tools and applications. (5:421) - 5 -

6 1. Software Tools of Computer Animation Software tools of animation consists of 3 D studio, light wave, Photoshop for images, Dream weaver for websites, Premiere for audio/ video. PowerPoint for presentations, i Movie for home movies and adobe Photoshop. All these tools help to create animation. (3:8) 2. Applications of Animation Computer animation has a variety of uses and applications. The main application of computer animation is that it makes presentation look more professional and attractive to the eye. Lawrence A Rowe states: Photoshop is an excellent tool for graphic design expert and i Movie is an excellent tool for less sophisticated tech-oriented end users. PowerPoint is also required to make the creation of formal presentation material available to every PC user. (3:8) Therefore, computer animation tools can be used to prepare material that documents a significant life event such as a birthday, wedding, or birth of a child. (3:7) B. Multicast Session Layer Technology A great deal of effort has been carried out in improving multicast technology for the internet during the past decade. Using multicast technology is very useful in delivering data to multiple destinations. Thus, a multicast session layer technology for the internet is very essential because of its applications. 1- The Importance of Multicast Session Layer Technology Some multicast protocols are used for a limited application. For example, a single source Multicast (SSM) is suitable for streaming radio or television. However, it is not general enough to carry out all other multicast applications. Therefore, a new technology, multicast session layer, is required to meet the requirements of multi applications. In other words, it is needed to provide a rich service - 6 -

7 model that can be mapped to several network- level implementation techniques. Its main advantage is that it makes the job of writing a multicast application simple. (6:1) 2. Applications of Multicast Session Layer Distribution of the same content to several simultaneous receivers is its most important application of multicast session layer. Multiparty teamwork and videoconferencing are other important applications of multicast session layer (6:4). In addition, broadcasting a continuous stream of information (e.g. sports scores, stock quotes--- etc.) to general participants.(6:3) C. A Middleware System A Middleware system and application program interface is designed to solve the problem of controlling the crossing point or interface between traditional audio/ video signals and internet streaming media. Rowe states: Infrastructure for Distributed Video and Audio, (INDIVA) is a middleware system designed to simplify the development of applications that access and control audio;/ video equipment, media streams, streaming media processing services, and conference resources. In essence, it provides high level abstractions for accessing equipment and managing the interface between production equipment and streaming media applications. (4:2) III. SOME APPLICATIONS OF MULTIMEDIA SYSTEMS This chapter consists of three main sections. The first section is about the applications of digital video. The second section discusses home networking and the third section introduces the applications of Berkeley Software decoder. A. Digital Video Digital video is the most important multimedia application. Digital cameras, DVD, camera coders and high speed, high resolution printers and scanners are tools of multimedia systems (1: 6). Digital video can be used to prepare educational material. Video tools are required for the teacher to prepare educational material including video displays to show an object. Recreation and animation - 7 -

8 are required to illustrate dynamic behaviors. Tools to set up material showing places and experiences are required by a travel agent. This material might include live interactions with people at remote places, pictures, videos and sounds. (3:7) B. Home Networking With multicast session layer, high- bandwidth home networking is a forthcoming advantage that will become real for the general population. The Home Audio Video interoperability (HAVI), architecture, addressing, versioning and management isochronous streams for consumer electronics are applications of multimedia systems. A document depicting the physical and data link layers and midlayer protocols needed for a home network is being developed by the Video Electronics Standards Association (VESA) (1:9). C. The Applications of Berkeley Software Video Decoder The Berkeley software video decoder is one of the implementations of multimedia systems which is widely used in several research systems and commercial products. Decoding video streams on a desktop computer can be carried out by using the Berkeley MPEG-1 video decoder. (2:1) CONCLUSION It is concluded that the more applications multimedia systems provide, the more technologies are generated. Although Multimedia is associated in the minds of many readers with entertainment and computer games, It has several applications in different fields. It has had an enormous impact on education, medicine and commercial applications. For example, medical schools use multimediasimulated operations that enable prospective surgeons to perform operations on a computergenerated virtual patient. Therefore, multimedia technologies have been developed greatly so that they can satisfy the needs of several people in different fields

9 WORKS CITIED 1. Liu, Peiya, et al. IEEE 1394 Changing THE Way We Do Multimedia Communications. Computer.org. Feb 2005: < Computer.org / multimedia/ articles/ firewire.htm > 2. Patel, Ketan, et al. The Berkeley Software MPEG-1 Video Decoder. Berkeley 2004: < Berkeley. edu.com/ research / publications /2004;/ 168/html > 3. Rowe, Lawrence, and Ramesh Jain. ACM SIGMM Retreat Report on Future Directions in Multimedia Research. Berkeley 2004: Berkeley. edu.com/ research / publications /2004 /168/html > 4. Rowe, Lawrence, et al. INDIVA: Distributed Streaming Media and Equipment Control Middleware. Berkeley 2002: < Berkeley. edu.com/ research / publications /2002 / 168/html > 5. Safra, Jacob, and James Goulka Animation and Computer Graphics. The New Encyclopedia Britannica 1 st and 3 rd : Swan, Andrew, and Lawrence Rowe. The Case for a Multicast Session Layer. Berkeley 2003: 1-6. < Berkeley. edu.com/ research / publications /2003 / 168/html > - 9 -