An Introduction to Digital Media

Tony Feldman

• Publisher: Routledge
• Year: 2003
• Print ISBN: 9780415154239
• eBook ISBN: 9781134734962
• Topic: Social Sciences
• Subtopic: Media Studies
• Index: Social Sciences

In this clear and highly accessible book, Tony Feldman provides an account of the evolution and application of digital media. Clarifying its underlying technologies, he identifies its immense commercial and human potential. Using as a starting point a simplification which considers new media in two distinct sectors; packaged 'off-line' media such as CD-ROMs; and the world of transmitted media which includes digital broadcasting and interactive online services, Feldman provides a comprehensive overview of the digital media landscape. Focusing on multimedia and the entertainment media he describes and analyses the spectacular rise of CD-based information and the equally revolutionary development of the Internet and online services. Set within a commercial context, readers can identify the potential to generate revenue and profit from the new media. An Introduction to Digital Media concludes with a strategic assessment of the implications of going digital for individuals, companies and corporations.

CHAPTER 1
WHAT DIGITAL REVOLUTION?

We have already dispatched the idea of revolution and settled for seeing the move to digital media as a process of evolution with potentially revolutionary impact on our lives. But the word ‘revolution’ remains on all our lips. Leaving the semantics aside, what we are really expressing with the use of the word is not an analysis of whether digitisation is the result of a discontinuity in technological development but a less rigorous, general sense that something truly remarkable is taking place which is likely to transform all our lives and—perhaps, more profoundly—the lives of our children. The idea of digital revolution is implicitly an image of humankind stepping through a doorway into an unknown and fundamentally changed future. And it is a one-way journey, a doorway through which we can never step back to return to the comfortable media certainties of the past.

However, we need to begin any inquiry about the future impacts of digital media by understanding the starting point of the whole process. It can be summed up in a very few words. The digital revolution is being forged by an accelerating move from a world familiar with analogue media to a world that will be increasingly dominated by digital media. This, then, is the key—a shift from analogue to digital. To make sense of that simple statement, however, we need to know what analogue and digital mean and, most important, why they are different. After all, the revolution is in the difference.

ANALOGUE AND DIGITAL INFORMATION

A good way of getting a sense of what analogue information and digital information are is to imagine ‘analogue’ as an expression of our experience of the real world while ‘digital’ expresses a world belonging exclusively to computers.

Whether we know it or not, therefore, we are all familiar with analogue information. Typical examples of it are the continuously varying intensities of natural light, the meanders in an audio record’s groove, the variations in an electrical current and the mechanical fluctuations in the air which we interpret as sound. The information embedded in an analogue signal therefore is always built into some continuously varying value which can be measured. By measuring it and responding to its continuous variation, we extract the information it contains. When we listen to music, for example, our eardrums vibrate with the rhythm of changing air pressure. This creates a signal in the auditory nerves which is interpreted by our brain as the pleasing notes of an orchestra. Vision is a response to changing values in the intensity and wavelengths of light on the retina of our eye and transmitted to our brain by our optic nerves for decoding and interpretation.

Another familiar example is an old-fashioned wristwatch. When we glance down at its face we see hands sweeping across the dial at various speeds. They move continuously, covering every part of the dial at some stage of their journey. We judge the time of day by the relative positions of the hands against the scale of hours, minutes and seconds printed on the watch face. This kind of information display is analogue. We read the message of our watch by looking at a constantly changing display. There are no gaps in the information. It is a continuous flow. This is the fundamental nature of the analogue world.

Digital information is different. Its character is essentially discontinuous. Far from reflecting continuously varying values, digital information is based on just two distinct states. In the digital world, things are there or not there, ‘on’ or ‘off’. There are no in-betweens. Digital computers talk in a language called binary code. It consists of just two symbols, the digits 0 and 1. Everything a computer does, it does in this starkly simple language. Significance in the information is created by placing the symbols in different orders. In other words, the sequence 00011000 means something different from 00010100. A rich and powerful language is built up in this way. In computer jargon, each of these binary symbols, either 0 or 1, is known as a bit (a contraction of ‘binary digit’). A character of computer information—the smallest information element carrying significance in itself—usually consists of eight bits arranged in a characteristic sequence. The overall sequence is called a byte.

To contrast analogue and digital information further, we can return to our wristwatch parallel. You can always tell when people are using a digital watch. Ask them the time and they will invariably say something like, ‘It’s 4.41’. How often do you really need to know the time to the exact minute? An analogue watch user will just glance at the timepiece and say, ‘It’s about a quarter to five’. In digital timekeeping it is always one time or another. It is never ‘about’ anything. However, there is an instant when a digital watch is speechless. When the display flashes from one second to the next there is a tiny gap in the information. So, although the watch seems to supply a constant and exact reading of time, it is in fact a discontinuous display sampling individual moments of time and displaying them.

It is worth noting that although today we take for granted that computers are entirely digital, it was not always so. The earliest electronic computers were actually based on the measurement of analogue quantities. For example, an analogue computer would do its sums by passing an electrical current of a known value across a wire which would put up a known amount of resistance to the passage of the current. Because a basic law of physics tells us that voltage is always the result of multiplying the size of a current by the resistance of its carrier, we can effectively perform a simple multiplication just measuring the voltage across the wire in the computer. This simple idea of measuring related analogue quantities was the basis of analogue computing and it worked. But it worked slowly and laboriously. Digital computers are vastly more efficient. They work by just measuring whether electronic switches or ‘gates’ inside them are either open or closed. The condition of either being ‘open’ or ‘closed’ creates the two distinct states needed for binary code language. Adding up numbers in this way—which is all computers really do—is dramatically faster than stitching together calculations by trying to measure currents, resistances and voltages thousands of times every second. Indeed, today’s most powerful machines can process millions of instructions every second to carry out the behest of their programmers. In other words, digital computers are not merely fast. They are faster than we can possibly imagine.

So—although it was not always true—today when we go digital, we are speaking the exclusive language of computers.

SPEAKING THE LANGUAGE OF COMPUTERS

Why is the distinction between analogue and digital information so important in digital media technology? The answer lies in what you can do easily with digital information that you cannot readily do with its analogue counterpart. In other words, the digital revolution is founded on the distinctive characteristics of digital information that set it apart from the real world of analogue experience. The unique features of digital information are the key to its commercialisation and, ultimately, to its potential impact on our lives. What, then, is uniquely special about digital information? There are five key factors.

• Digital information is manipulable
• Digital information is networkable
• Digital information is dense
• Digital information is compressible
• Digital information is impartial

DlGITAL INFORMATION IS MANIPULABLE

By taking information out of the analogue world—the ‘real’ world, comprehensible and palpable to human beings—and translating it into the digital world, we make it infinitely changeable. In the analogue world, the reshaping of a page of information or a physical object requires some exercise of brute force. Usually, however careful we are, the change inflicted causes damage. The process is difficult, slow and untidy. More important, if we take something apart in the real world it is often difficult, if not impossible, to put it back together again.

If we translate analogue information into a digital form, however, we translate it into a medium which is infinitely and easily manipulable. We are able at a stroke to reshape the information freely—whatever it represents in the real world—in almost any way we wish and we can do it quickly, simply and perfectly. Then, when we are ready, we can reconstitute and display it as new information which human beings can once again perceive and comprehend.

An important point here is not merely the inherent manipulability of digital information in itself but the fact that digital information has this manipulability at all stages: from the moment it is created or captured in digital form to the moment it is delivered to its user and beyond. In particular, consider the significance of media being manipulable at the point of delivery because it suggests nothing less than an unprecedented new paradigm for publishing and media distribution.

The fact that media are manipulable at their point of delivery means something quite extraordinary: users of the media can shape their own experience of it. This means that manipulable information can be interactive information. We will examine the notion of interactivity in more detail later (pp. 13–17) but for now it is enough to understand it as a means of providing a dynamic experience, one which is controllable and influenced by its user’s own preferences. Potentially, for example, a new generation of interactive products will offer users a way of finding their own path through material or of tackling it at a pace that suits them or of retrieving what they want quickly by making cross-referenced searches or important correlations. This is a dramatic contrast to the traditional passive, linear experience of media that characterises the analogue world. And it suggests a powerful new model for publishing and media distribution. To understand why, consider our past experience of media products.

Until the arrival of digital media, publishers and distributors of information, education and entertainment have enjoyed a single great privilege. They have been able to dictate what customers will view or read with only a modicum of selectivity left to the customer’s discretion. Television scheduling has created the notion of ‘channels’ and ensured (give or take the intervention of video recorders) that certain programmes will be viewed and at certain preordained times. The same is true of radio. More fundamentally, both the television and film industry are founded—very successfully—on linear storytelling models. In other words, their products are created to be viewed in a particular sequence, usually embodying a beginning, middle and an end. Whether or not it would make sense to do so, viewers have had no way to re-order the sequence of programming—rather like mixing up the chapters of a book—or to select prime bits from it.

In the world of book and periodical publishing, customers buy the whole product even if all they want—and actually use—is one small part of it. In the old analogue world, customers had no freedom to say: ‘We like your book but we really only want chapters 3, 8, and 10. May we have —and pay—for just those please?’ The publishing model has always been one of benign tyranny. Publishers tell their customers not only that they must buy the entire contents of a printed work but also that they must have it paginated, designed, illustrated and bound exactly in the manner the publisher decides.

This dictatorial model is so firmly established in our experience of media products, it is unquestioningly and uncomplainingly accepted. In the digital age, while old models are unlikely to be swept away totally, new models will emerge which will alter our expectations for ever. Increasingly, users of media will find the power to control media experiences shifting in their direction. While, of course, originators and publishers will continue to determine the constraints within which this new found freedom is experienced, there is no doubt that the old model will ultimately come under pressure from the new.

A good example of how this process is already happening is the creation by McGraw-Hill in the United States of a customised, on-demand publishing service called Primis. Essentially it allows teachers to select in ‘mix and match’ style material from a wide range of existing McGraw-Hill publications plus other third-party materials and order a bespoke textbook made up of parts of those materials. Chapters from one book can be mingled with chapters from another and additional commentary and analysis can be supplied through articles extracted from journals or other publications. Teachers can even inject some of their own original work to be combined with the already published material. The result is a highly customised new text suited to an individual teacher’s needs. This remarkable new approach to educational publishing was not the result of a radical vision on the part of McGraw-Hill. It was an approach effectively forced upon them by an establishment of educators which was taking increasing exception to the high price of educational textbooks. This culminated in the emergence of a fast-copying business in New York which began to supply photocopied, bespoke collections of proprietary published texts to teachers tired of paying heavily for material only partially relevant to their needs. McGraw-Hill took the photocopiers to court for breach of copyright. The result was a technical victory for McGraw-Hill but a storm of bad publicity. In response to establishment pressure, McGraw-Hill determined to build a legitimate publishing operation—using digital technologies—that attempted to meet the expressed needs of its customers. In doing this, it demonstrated its understanding that in the changing world, media companies— whether they like it or not—must listen and be responsive to the wants of their customers.

Whatever the future prospects of Primis or its immediate derivatives, the new model of customer primacy is established and—as interactive technology makes it an increasingly practical proposition— responsiveness to individual customer requirements will become a vital issue for media companies of all kinds to grasp.

DlGITAL INFORMATION IS NETWORKABLE

This means that information in digital form can be shared and exchanged by large numbers of users simultaneously. And because networks can be global in scope, the individuals doing the sharing and exchanging can be geographically dispersed. We will look at network developments in more detail in chapter 5 but it is worth noting some important, immediate implications.

Simultaneous access to networked information means distributing the same underlying content product many times over without the difficulties and costs implied by shifting physical products through a supply chain. In other works, networks transform the economics of media distribution. Networks can also offer the capacity for users not only to communicate simultaneously with a body of information but also to communicate among themselves. This means that networks are good distribution conduits but are also a means of creating a new form of electronic community, a grouping of people whose geographic location is irrelevant and who are instead drawn together by the common thread of the network they all use.

DlGITAL INFORMATION IS DENSE

We can squeeze a lot of information in digital form into a small physical space. Much depends, of course, on the particular storage technology used —some offer greater storage density and capacity than others—but there is little doubt that immense practical convenience can be gained from the compactness of the digital format. The most obvious example is the portability of a compact disc—a technology we will examine in detail in chapter 3. If we use a print-on-paper analogy, we can encode the contents of a small library on a compact disc and mail it around the world for the cost of a postage stamp. More specifically, not only text but also digital images and video can be squeezed on the disc. Until networks emerge routinely able to handle such big files quickly, the discs will be the easiest way of transporting multimedia from one physical location to another.

DlGITAL INFORMATION IS COMPRESSIBLE

If digital information—dense as it is—is not dense enough, it can be compressed to get even more into the same physical space. As we will see when we examine digital video technology in more detail, the single most important ingredient in making it possible to handle video in digital environments is our ability to compress the digital files involved and then decompress them when needed.

The technology of digital compression is a complex, technically challenging field but it is one of the single most crucial technologies driving the transition from analogue to digital media. What it does is to effectively make narrow information pipes fat. We are not talking here about physical pipes necessarily but any kind of conduit for carrying information from one place to another. The electromagnetic spectrum, for example, is a pipe that has long been used by radio and television broadcasters to deliver their content to customers. Although the spectrum is not a physical channel of distribution it has one of the general characteristics of a pipe: it has a limited capacity for allowing information to flow through it. This analogy with pipes and their physical capacity is merely a means of making concrete a key notion in digital media. The fatness or thinness of our pipes for carrying information define a quantity called bandwidth and bandwidth itself is the real determinant of how much information we can convey to people and how fast we can send it. In other words, if our pipe is narrow it has limited bandwidth—we would call it a narrowband transmission or distribution channel—and we would struggle to send large quantities of information through it at any kind of pace that makes sense to its users at the other end. If our pipe is fat, it has much greater bandwidth—a broadband channel—and we would be able to transmit a great deal of information very quickly.

Before the digital age and the emergence of digital compression technologies, we were largely stuck with the various pipes we had, whether those pipes were wires or cables in the ground—or in electrical equipment—or vibrations of electric and magnetic fields shimmering across a spectrum of wavelengths. All had different bandwidths but were what they were—narrow or broad. Digital compression changes all that. Instead of fiddling with the pipes to find more capacity, we can for moreor less the first time fiddle instead with the information we propose to send through the pipes. So, by compressing digital information, we can effectively render thin pipes fat and fat pipes fatter. That is the miracle of compression and it has transformed our ability to handle large bodies of digital information over transmission systems such as broadcast and one-to- one networks and around the insides of computers. In particular, it has single-handedly made it possible to include video information—a medium which requires the processing and transfer of huge files of data— within complex digital environments. This single fact has transformed our experience of computing, reshaped the capabilities of computer networks and is soon going to rewrite the future of the entertainment industries.

DlGITAL INFORMATION IS IMPARTIAL

Computer systems do not care very much about what bits and bytes—the building blocks of digital information—actually represent. They care even less who they belong to. As far as a computer system is concerned, a bit is a bit and a byte is a byte and so long as the zeros and ones which underpin binary code add up to something comprehensible to the computer, it will do what it is told with them. While this is a deliberate simplification of the complex rules wh...

Table of contents

• COVER PAGE
• TITLE PAGE
• COPYRIGHT PAGE
• FOREWORD
• ABBREVIATIONS
• CHAPTER 1 WHAT DIGITAL REVOLUTION?
• CHAPTER 2 MULTIMEDIA
• CHAPTER 3 THE COMPACT DISC ARRIVES
• CHAPTER 4 MYTH AND REALITY ON THE SUPERHIGHWAY
• CHAPTER 5 ONLINE NETWORKS
• CHAPTER 6 WEB COMMERCE
• CHAPTER 7 WHAT DOES IT ALL MEAN?