Task One - Hardware for Multimedia

Multimedia Hardware

Key Terms: PC or IBM compatible, SPA, CPU, Risc, Ram, digitize, scanner, graphics tablet, midi, hard disk, optical disk, CD, DVD, SCSI, Firewire, USB

What is multimedia? Let's break the word down. Multi- means many and -Media means showing information. So, put them together and multimedia is showing information, using many different methods to get across those ideas.

Many people think, "Oh, that's a Powerpoint presentation, right?" Well, it could be, but there are many other programs that let you create multimedia shows. True, Powerpoint is the most widely used, but once you learn how to use one type of multimedia presentation software, you should be able to use those skills on other, similar software.

A few years ago, purchasing a multimedia computer was quite complicated, but because of the tremendous growth of multimedia applications, most computers that you buy today are already designed to run multimedia applications. If you are interested in developing multimedia applications, however, you should consider a more powerful computer. If your computer is too slow, productivity will be lost; and in today's fast-paced technological society, you need a fast computer to keep up.

Effectively developing and delivering multimedia applications requires a more powerful personal computer than one used to write a letter, prepare a budget, or answer e-mail. Because personal computers are becoming more and more powerful, most of those purchased today have built-in multimedia capabilities that allow you to deliver and display multimedia applications. However, if creation of high-end multimedia applications is your goal, you will definitely want to consider certain specifications that have been established specifically for multimedia.


With the right adapters, software, and hardware, camcorders and digital video cameras can be used to capture full-motion images. Although regular camcorders store video on film, digital video cameras store images as digital data. This enables the digital images to be transferred directly into the product being created. Digital video cameras range in price from under a hundred dollars for small desktop cameras like the Connectix QuickCam, to thousands of dollars for higher-end equipment.

Digital video cameras offer an inexpensive means of getting images into your computer, however, you should be aware that the resolution is often quite low and the color is sometimes questionable.


Digital cameras allow you to take pictures just as you would with a regular camera, but without film developing and processing. Unlike regular cameras, photographs are not stored on film but are instead stored in a digital format on magnetic disk or internal memory. The photographs can be immediately recognized by the computer and added to any multimedia product.


Scanners digitize already developed images including photographs, drawings, pages of text. By converting these images to a digital format, they can be interpreted and recognized by the microprocessor of the computer. A better way of scanning larger images is to use a page or flatbed scanner. These scanners look like small photocopiers. Page scanners are either gray-scale scanners that work well with black-and-white photographs or color scanners that can record millions of colors.

A graphics tablet is similar to a digitizing tablet, however, it contains additional characters and commands. Like the digitizing tablet, each location on the graphics tablet corresponds to a specific location on the screen.


As is true with most equipment, all microphones are not created equal. If you are planning to use a microphone for input, you will want to purchase a superior, high-quality microphone because your recordings will depend on its quality.

Next to the original sound, the microphone is the most important factor in any sound system. The microphone is designed to pick up and amplify incoming acoustic waves or harmonics precisely and correctly and convert them to electrical signals. Depending on its sensitivity, the microphone will pick up the sound of someone's voice, sound from a musical instrument, and any other sound that comes to it. Regardless of the quality of the other audio-system components, the true attributes of the original sound are forever lost if the microphone does not capture them,

Macintosh computers come with a built-in microphone, and more and more PCs that include Sound Blaster sound cards also include a microphone. These microphones are generally adequate for medium-quality sound recording of voiceover's and narration. These microphones are not adequate for recording music


MIDI (Musical Instrument Digital Interface) is a standard that was agreed upon by the major manufacturers of musical instruments. The MIDI standard was established so musical instruments could be hooked together and could thereby communicate with one another.

To communicate, MIDI instruments have an "in" port and an "out" port that enables them to be connected to one another. Some MIDI instruments also have a "through" port that allows several MIDI instruments to be daisy chained together.


Multimedia products require much greater storage capacity than text-based data. All multimedia authors soon learn that huge drives are essential for the enormous files used in multimedia and audiovisual creation. Floppy diskettes really aren't useful for storing multimedia products. Even small presentations will quickly consume the 1.44 MB of storage allotted to a high-density diskette.

In addition to a hefty storage capacity, a fast drive is also important. This is because large files, even if they are compressed, take a long time to load and a long time to save and back up. Consequently, if the drive is slow, frustration and lost productivity will undoubtedly follow. When purchasing a storage medium, consider the speed of the device-how fast it can retrieve and save large files as well as the size of its storage capacity.


Optical storage offers much higher storage capacity than magnetic storage. This makes it a much better medium for storing and distributing multimedia products that are full of graphics, audio, and video files. In addition, reading data with lasers is more precise. Therefore, when working with multimedia, optical storage media such as Magneto-Optical Disks (MO) and CD-ROM (CD) is more common than magnetic media. Digital Versatile Disk (DVD), a newer optical storage medium with even greater storage capacity than a CD, will probably take the place of these other optical media within the next few years.


CD-ROM stands for compact disk read only memory. A CD-ROM can hold about 650MB of data. Because CDs provide so much storage capacity, they are ideal for storing large data files, graphics, sound, and video. Entire references such as encyclopedias complete with text and graphics, as well as audio and video to further enhance the information, can be stored on one CD-ROM. In addition, interactive components that enable the user to respond to and control the medium ensure that the user will be even more attentive and likely to retain information. For these reasons, CDs have been the medium of choice for publishing multimedia applications.

Because a CD-ROM is the most common type of optical disk, computers sold today include a CD-ROM drive as standard equipment. In fact, in order to have a multimedia personal computer based on the standards set by the MPC, you must have a CD-ROM drive. Therefore, when considering the purchase of a multimedia computer, the important consideration in regard to the CD-ROM drive is the speed of transfer.

CD-ROM speed is measured in kilobytes (KB) per second. This refers to the speed at which data is transferred from the CD to the computer processor or monitor. Double speed (2x) CD-ROM drives can transfer data at a rate of 300 KB per second, quadruple speed (4x) can transfer data at a rate of 600 KB per second, and so on up to 24x and higher.


DVD, which in some places stands for Digital Versatile Disk, but really doesn't stand for anything, is the newest and most promising multimedia storage and distribution technology. DVD technology offers the greatest potential to multimedia because its storage capacity is extensive.

DVD's are the same size as CDs, but they offer much more storage capacity. DVD's are either single or double sided. A double-sided DVD is actually two single DVD's glued together. By using more densely packed data pits together with more closely spaced tracks, DVD's can store tremendous amounts of data. DVD disk types and capacities include the following four:

  • DVD-5: one layer, one side-max. capacity about 4.7GB.
  • DVD-9: one layer, dual sided-max. capacity about 8.5GB.
  • DVD-10: two layers, one side-max. capacity about 9GB.
  • DVD-18: two layers, dual sided-max. capacity about 17GB.


A bus is any line that transmits data between memory and input/output devices or between memory and the CPU. Parallel bus structures transmit eight bits of data at one time while a serial bus transmits one bit of data at one time. The following are the common bus structures.


FireWire or IEEE-1394 is a Sony-backed standard that was developed by Apple Computer. It appears on Sony's latest digital video cameras. The goals of FireWire are to reduce network bottlenecks and sluggish file transfers. FireWire can connect up to 63 devices always accessible at full speed. FireWire has already been adopted as the transmission standard for digital video. Therefore, it will probably be used as an audio and video interconnect with multimedia applications, but its future beyond that is uncertain.


Universal Serial Bus (USB) is a low-cost, low-speed interconnect designed to PCs to keyboards, mice, joysticks, telephones, and low-end scanners daisy chain configuration. Due to its low speed, its storage use will be limited to midrange CD-ROM drives.


The image displayed on the computer monitor depends on the quality of the monitor and software, as well as the capability of the video adapter card. For multimedia applications, it is critical that all of these elements work together to create high quality graphic images. However,

because all display systems are not the same, you will have very little control over how your images appear on other people's systems. Consequently, it is a good idea to test your projects on different display systems to see how your digital images appear.

When purchasing a computer monitor to be used with multimedia applications, you will want to consider purchasing a larger screen. Screen sizes are measured along the diagonal and range in size from eight to more than 50 inches. You will probably want at least a 17-inch monitor. Though this larger monitor will cost you a bit more, it will prove well worth it if you intend to spend any time at all either designing or otherwise working with multimedia applications. In fact, after you have spent some time working with multimedia applications, you may even want to consider purchasing two monitors if you are using a Macintosh or PC setup that will support two monitors.

The number of colors that the monitor can display is also important. The number colors is dependent on the amount of memory installed on the video board as well as the monitor itself. The number of colors a monitor can ay varies as listed below:

4-bit system will display 16 different colors

8-bit system will display 256 different colors

16-bit system will display 65,636 different colors

A 24-bit system will display more than 16 million different colors.

Most monitors can display at least 256 colors (8-bit), which is probably adequate for multimedia presentations, particularly if the presentation is delivered via the Web, but it may not be adequate for video. Eight-bit images are the most compatible across multiple platforms and they also take up very little disk space. Computer monitors capable of displaying thousands of colors (16-bit) are quickly becoming the multimedia standard. Images on these displays not only look better, they also display much faster.

Using Graphics

Key Terms: still image, digital image, resolution, compression, bit map graphics, pixel, vector graphics, TIFF, BMP, PICT, GIF, JPG, clip art, digital video

Still images are vital to multimedia applications. We are a very visual society. With the advent of technology, we have become even more visual. This is because our society is fast-paced and in many circumstances, a picture really is worth a thousand words. One table, chart, graphic, or photograph can illustrate what might take many pages of narrative text to communicate. In the end, the image may still do a better job of creating a lasting impression. In societies such as ours where communicating information quickly is crucial, the importance of graphic elements in multimedia applications cannot be overstated.

Graphics can be used in multimedia applications as backgrounds, buttons, icons, navigational items, colors, maps, and charts; illustrations to explain concepts, information, and moods; and logos to communicate corporate image.

In addition, once images are in a digital format, image-editing software such as Adobe Photoshop can be used to edit and manipulate them even further. Using image-editing software, multimedia developers can combine text and images to create almost any work of art they can imagine.

Because still images are so vital to a multimedia project, care and time in creating just the right image is important. When searching for the right image for your multimedia application, you should first create a list description of the images you need for your project. Once you know what an choose to create the images yourself, obtain the images from age provider, or hire a graphic designer to create them for you.

In order to be used in a multimedia application, images must be in a digital format. Digitizing is the process of converting images into a format that the computer can recognize and manipulate. In other words, the image is converted into a series of binary data or 1's and O's. There are many different sources of preexisting digitized images, or you can digitize images that are currently photographs, slides, or line art.

When deciding upon an appropriate resolution for your image, keep in mind that a higher resolution will display a superior image, but it will also result in a larger file size. This means the file will require more storage space and it will take longer to display. In other words, there is a trade-off for higher resolution images. For example, when creating images for Web pages, we must be willing to give up some quality in order to ensure that the graphic file sizes are small enough to download quickly at 500K to IOOOK. Because graphic files take up a lot more storage space than text, it is quite easy to run out of disk space or to spend a significant amount of time waiting for graphic files to transfer or download. For these reasons, you may find it necessary to compress your image files. Compression is simply an algorithm that is used to create smaller file sizes. There are two types of compression: lossy and lossless.

Graphics editors can be classified as one of two types. Bitmap graphics editors or paint programs allow you to create bitmap graphics. Vector graphics editors or draw programs allow you to create vector graphics. Let's look at the fundamental differences between these two types of graphics and graphics editors.

Paint Programs and Bitmapped Graphics

When you use a paint program the image you create is considered a bitmapped image. Bitmapped images are stored in memory as pixels. Pixels are picture elements. To illustrate, imagine that each piece of a graphic image is broken down into small squares. Each small square represents one pixel. This pixel records the screen location and color value on a bit map in memory. A bit map is a grid similar to graph paper from which each small square will be directly mapped back onto the computer screen as a pixel.

Bitmapped graphics editors or paint programs are the only programs that allow you to edit images at the pixel level. This means they are the only type of program that can be used to accomplish effects like touching up photographs. In addition, paint programs are typically easier to learn and use than draw programs. Though bitmap-based paint programs are easier to use than vector-based draw programs, the resulting bitmapped images are not as flexible as vector graphics.

Because bitmapped images are pixel-based, when you enlarge these images the squares simply get bigger. In other words, because bitmapped images have a specific resolution or number of pixels per inch, if the image is enlarged without

Draw Programs and Vector Graphics

Drawing programs excel as art production and illustration tools for creating original artwork. When you use a draw program, the resulting graphic is vector based. Unlike bitmapped graphics, vector graphics are created and recreated from mathematical models. These models actually create the image as a series of mathmatical formulas that connect vectors or simple geometric shapes like lines s that ultimately become circles and boxes. based graphics can be resized or contorted without losing the quality image. Vector-based graphics are smoother and more precise than bitmapped graphics. They also require a lot less memory. Because vector graphics are more versatile and more precise than bitmapped images, professionals in drafting often use them. In addition to draw programs, most 3D graphics s and Computer Aided Drafting (CAD) programs also produce vector S. of the more common draw programs used today include CorelDRAW, Blustrator, MacDraw, Claris Works, and Macrornedia FreeHand. By at some of the features found in Adobe Illustrator, you should get a feel ing programs and how they differ from paint programs.

File Formats

Graphic images may be stored in a wide variety of file formats. In choosing a format, you should consider how and where the image will be used. This is because the application must support the file format you select. Some formats are proprietary while others have become universally supported by the graphics industry. Though proprietary formats may function perfectly in their own environment, their lack of compatibility with other systems can create problems.

In the Macintosh environment, the PICT format, a vector-based file format, is the image format supported by almost all Macintosh applications. Recently, the Windows environment has standardized on the BMP file format. Prior to this, there were multiple file formats under DOS that made it difficult to transfer graphic files from one application to another. The most common file formats are described below.


The TIFF file format is probably the most widely used bitmapped file format. Image-editing applications, scanning software, illustration programs, page-layout programs, and even word processing programs support TIFF files. The TIFF format works for all types of images and supports bit depths from 1 to 32 bits. In addition, TIFF is cross platform. Versions are available for the Mac, PC, and UNIX systems. The TIFF file format is often used when the output is printed.

The BMP format has been adopted as the standard bitmapped format on the Windows platform. It is a very basic format supported by most Windows applications. It is also the most efficient format to use with Windows.

CompuServe created this format. Consequently, you may see it listed as CompuServe GIF. It is one of two standard formats used on the Web without plug-ins. It is the method of storing bitmaps on the Web. The GIF format only supports up to 256 colors.

These are formats for the Macintosh. They are generally used only for screen display. Some Mac programs can only import images saved as either PICT or EPS. Unlike the EPS format, PICT does not provide information for separations, which means graphics saved with this file format will be smaller than EPS files. PICT2 added additional levels of color to the PICT format.

This format creates a very compact file. Because of its small file size, it is easy to transmit across networks. Consequently, it is one of only two graphic file formats supported by the World Wide Web without plug-ins. Do keep in mind that in order to make the file so small, lossy compression is used when a file is saved or converted to this format. This means pixels will be removed from the image. JPEG files are bitmapped images.

This is Kodak's Photo CD graphics file format. It is a bitmapped format that contains different image sizes for each photograph.

This is only a small sample of all of the different graphic file formats available. There are also many proprietary formats. If you plan to transfer files from application to application, consider using the most common file format supported by all of your applications. If you get stuck because an application does not support a graphics file format, graphic conversion software is available to help you change the file format so that you can import and export graphic images from almost any application to another.

Keep in mind, that in most situations, commercial image providers are only selling the rights to use the image, they are not selling the image itself. In other words, they may sell you the right to use the image in one multimedia application, but the image does not become your property. If you want to use it again in a different multimedia application, you may very well have to pay another royalty. The agreements vary depending on the image, the original artist, and the commercial image provider. Take caution and read the licensing agreement carefully before you include an image from a CD or the Web in a multimedia application. Just because you purchased the CD or were given access to the image on the Web, that doesn't necessarily mean you own it.




If in doubt, assume an image is copyright protected. The 1976 Federal Copyright Act stipulates that copyrighted images are property of the creator from the time they are created to 50 years beyond his or her life. If the creator is a corporation or business, the image is property of the creator up to 75 years after publication or 100 years following creation, whichever is shorter.

After the copyright period has expired, the image becomes public domain. Public domain images can be manipulated and used without permission from the artist and without having to pay the artist any royalties for using them.

When images or other copyright protected works are used strictly for instruction and research in an educational setting, copyright permission may not be necessary. This exclusion is referred to as a fair use policy. There are many factors that determine when this exception applies and when it does not. If you are uncertain as to whether or not an image is copyright protected, don't take chances; assume that it is copyright protected and seek the advice of a legal expert.

Using Sound

Key Terms: amplitude, decibel, frequency, Hz, kHz, ambient sound, downloaded, streamed, rate, resolution, mono, stereo, analog, digital, WAV, AIFF, MPEG, MIDI

We acquire a great deal of knowledge through our ears. Unfortunately, other than in the entertainment industry, many multimedia developers don't take advantage of this sense by incorporating sound into their multimedia products. Sound enhances a multimedia application by supplementing presentations, images, animation, and video. In the past, only those who could afford expensive soundrecording equipment and facilities could produce high-quality, digital sound. Today, computers and synthesizers make it possible for the average person to produce comparable sound and music.

A sound is a waveform.
The amplitude
is the distance between the valley and the peak of a waveform. The amplitude of a waveform determines its volume, which is measured in decibels. A decibel is the smallest variation in amplitude that can be detected by the human ear.

The frequency is the number of peaks that occur in one second. Frequency is measured in Hertz (Hz) or Kilohertz (kHz), which represent thousands of cycles per second. The frequency of a waveform determines its pitch.

In multimedia applications, sounds are either content sounds or ambient sounds.

Content sounds furnish information. Narration and dialog are content sounds. Music and other sounds can also be considered content sounds if they are part of the topic itself. For example, the sound of a motor would be content sound if it were used to distinguish between different engine problems.

Ambient sounds include background sounds and special effects
. Ambient sounds reinforce messages and set the mood. Music is a universal language that most people enjoy and appreciate. Classical music might be used in the background to set the mood for a multimedia application on literature and the arts while new age rhythms would be better for a multimedia application on the healing power of crystals.

Special sound effects can reinforce or enliven a message. Different types of laughter could be incorporated into a multimedia application that included comic relief such as knock-knock jokes. As bullets enter the presentation screen in Microsoft PowerPoint, special sounds draw attention to and reinforce the bulleted item.

In multimedia applications, audio can either be synched with the occurrence of other objects in the production, or it can serve as a trigger to the user. As a trigger, it becomes a form of hypermedia called hyperaudio. In this format, users are given control. They can click on the sound object when they are ready to listen to the clip.

Like every other multimedia element, if you decide to incorporate sound into a multimedia application, you should have a reason for doing so. In other words, you shouldn't use soundjust because you can. Along the same lines, don't assume that more is better. Using too much sound is rarely a problem because most people fail to add it where it could truly enhance an application, but do keep in mind that balance is important.

Sound adds another dimension to a multimedia application, If used well, it is an extremely powerful element that can stimulate emotional responses that would never be activated from text and graphics alone. Sound should be used selectively and appropriately whenever and wherever it will help convey the intended message or complement the purpose of the multimedia application. Sound can be used to get attention, to entertain, to give directions, to personalize an interface, or to convey an educational or persuasive message.

Audio on the Web can either be
downloaded or streamed. Downloadable sound files are stored on your computer before they are played. Streaming is a more advanced process that allows the sound to be played as it is downloading. These two processes will be discussed in greater depth in Chapter 8.

The rate is the number of waveform samples per second. The sampling rate is usually measured in kilohertz with 22 KHz and 44 KHz being the most common sampling rates. A higher sampling rate produces a higher quality sound.

The disadvantage of using a higher sampling rate is that sound files with higher sampling rates require greater storage capacity.

Resolution is the number of binary bits processed for each sound wave. Like all digital data, sound that has been recorded by a multimedia computer is represented in bits. Bits represent the vibrations in the sound wave. As the number of bits used to sample the sound increases, the range and the quality of the sound also improves. When more bits are processed, the recording is smoother and purer, thus the sound is more realistic. Because 16-bit recordings contain much more information than 8-bit recordings, they are higher quality. In addition, 16-bit recordings offer a dynamic range of 98dB (decibels). This makes them superior to 8-bit recordings, which only offer 50dB. According to MPC standards, MPC1 requires 8-bit sound although MPC2 and MPC3 require a higher quality 16-bit sound. Once again, there is a trade-off in recording sound with a higher resolution. A sound file with a higher resolution requires much greater storage capacity.

Mono versus Stereo Sound
Mono sounds are flat and unrealistic compared to stereo sounds, which are much more dynamic and lifelike. However, stereo sound files require twice the storage capacity of mono sound files. Therefore, if storage and transfer are concerns, mono sound files may be the more appropriate choice.

Analog vs Digital


There are two types of sound: analog and digital. Analog sound is a continuous stream of sound waves. To be understood by the computer, these sound waves must be converted to numbers. The process of converting analog sounds into numbers is called digitizing or sound sampling. Analog sounds that have been converted to numbers are digital sounds. When we are working with digital sound, we call it audio. Therefore, sound that has been converted from analog to digital is often called digital audio. sounds. Non-destructive sound processing methods maintain the original file. A copy of the original file can be manipulated by playing it louder or softer, combining it with other sounds on other tracks, or modifying it in other ways. Using non-destructive processing, the original file remains untouched in case it is needed at a later time.

Once a sound has been recorded, digitized, processed, and incorporated into a multimedia application, it is ready to be delivered. So that you can hear it through your speakers, the digital sound is sent through a
digital-to-analog converter (DAC).

The delivery system will vary as the intended audience of the multimedia application changes. When considering the delivery of sound, you should consider the number of different sounds that will be delivered, how they will be delivered, where they will be delivered, and to whom they will be delivered. In other words, the application may include one voice and some background music designed for one user in front of a desktop computer or it may be a presentation with various different types of music, narration, and special effects designed for a larger audience to be presented in an auditorium. Regardless, a high quality delivery system will help ensure that the sounds you've worked hard to create make the right impression.

There are many different types of digital audio file formats that have resulted from working with different computer platforms and software. Some of the betterknown formats include:

WAV is the Waveform format. It is the most commonly used and supported format on the Windows platform. Developed by Microsoft, the Wave format is a subset of RIFE RIFF is capable of sampling rates of 8 and 16 bits. With Wave, there are several different encoding methods to choose from including Wave or PCM format. Therefore, when developing sound for the Internet, it is important to make sure you use the encoding method that the player you're recommending supports.

AU is the Sun Audio format. It was developed by Sun Microsystems to be used on UNIX, NeXT & Sun Sparc workstations. It is a 16-bit compressed audio format that is fairly prevalent on the Web. This is probably because it plays on the widest number of platforms.

RA is Progressive Networks RealAudio format. It is very popular for streaming audio on the Internet because it offers good compression up to a factor of 18. Streaming technology enables a sound file to begin playing before the entire file has been downloaded.

AIFF or AEF is Apple's Audio Interchange For -mat. This is the Macintosh waveform format. It is also supported on IBM compatibles and Silicon Graphics machines. The AIFF format supports a large number of sampling rates up to 32 bits.

MPEG and MPEG2 are the Motion Picture Experts Group formats. They are a compressed audio and video format. Some Web sites use these formats for their audio because their compression capabilities offer up to a factor of at least 14: 1. These formats will probably become quite widespread as the price of hardwarebased MPEG decoders continues to go down and as software decoders and faster processors become more mainstream. In addition, MPEG is a standard format.

MIDI (MID, MDI, MFF) is an internationally accepted file format used to store Musical Instrument Digital Interface (MIDI) data. It is a format used to represent electronic music produced by a MIDI device (such as a synthesizer or electronic keyboard). This format provides instructions on how to replay music, but it does not actually record the waveform. For this reason, MIDI files are small and efficient, which is why they are often found used on the Web. On a PC, MIDI files will have a mid extension.

SND is the Sound file format developed by Apple. It is limited to a sampling rate of 8 bits, and is used primarily within the operating system.

If you want your multimedia application to work on Macs as well as PCs, you will probably want to save your files using either the Audio Interchange File Format (AIFF) or the Musical Instrument Digital Interface (MIDI) file format. Though Macromedia Director and most authoring programs support many different sound file formats, if you plan to include sound in your multimedia application (and of course you should), consider using the AIFF format. Not only is it a cross-platform format, it can also reside outside the multimedia application. This means the multimedia file will be smaller and will therefore play faster. In addition, the AIFF format can be used if you plan to bum the multimedia application onto a CD.

With the right equipment you can create your own sound:

Top Of Page