What Is Multimedia

Reading: Identify multimedia software and file types

Identify multimedia software and file types

Inside this reading:

What is multimedia? 2

Interactive multimedia 2

Developing multimedia 3

Standards and specifications 5

Multimedia—text 7

Multimedia—graphics 8

Multimedia—video 12

Multimedia—audio 15

Multimedia—animation 18

Multimedia design specifications 19

Multimedia editing software 20

Summary 22

What is multimedia?

In the era of convergence, multimedia seems to be everywhere around us. It is generally described as any combination of text, graphics, video, animation and sound. It is a broad area and has always been difficult to easily define.

Examples of multimedia applications might include:

· learning from an educational CDROM played on a PC

· navigating through an online tutorial that explains science concepts using animation

· participating in video conferencing

· watching a training DVD

· listening to a streamed broadcast of an overseas radio network

…to name just a few!

Interactive multimedia

Interactive multimedia describes media where the viewer or user has control of the elements, allowing them to decide what occurs, where, how and when.

The principle of interactivity has been one of the successful ideals behind the operation and use of Internet. However, as we all know, one of the problems with the web can be too much content. Even while content is valid, relevant and true, materials are often not edited or collated, and we can spend a lot of time filtering through a mass.

The role of the multimedia developer, then, is to collect relevant material on a specific subject and then author a tool that allows users to focus on materials specific to their interests. To do this successfully will increase access and save the user time.

The major growth areas of multimedia today are online and in telecommunication tools, such as third generation (3G) mobile phones, Blackberries and Palm pilots. (A good way to keep up-to-date with developments in telecommunication tools is to simply search for a term such as ‘PDA technology’, using your favourite search engine.)

Developing multimedia

The three main stages in developing a multimedia product are planning, production, and review.

Planning

There are a number of important aspects to consider in the planning phase.

Stakeholders

First, you’ll need to identify and establish the roles of the stakeholders. The stakeholders are the client, project manager, navigation designer, instructional designers, programmers—anyone with a stake, interest or investment in the project.

Documentation

The documentation of your project is crucial. You’ll need to make sure the purpose, objectives and brief of the project are specified, as well as its scope. Many projects end up in troubled waters because the stakeholders have different expectations of what will be achieved—so clarifying this at the start is extremely important.

Product specifications

Storyboards, interaction flowcharts, templates and style sheets, all contribute to the overall design specifications for a project. Such specifications need to be determined and confirmed with stakeholders.

Multimedia elements

Appropriate multimedia elements need to be identified for inclusion: text, graphics, animation, video, and audio. The format and scope of these elements needs to be confirmed with stakeholders, together with the relevant standards that will apply.

Hardware and software

Appropriate hardware and software need to be identified and selected for the development and delivery of the product.

Hardware considerations will include:

· CPU speed

· memory size

· output devices

· input devices.

Software that needs to be considered includes:

· the authoring software itself

· software required for development of the various multimedia elements

· delivery platform considerations

· interpretation of scripts

· run-time modules and executables.

Production and review

Production involves using an authoring tool to produce a working prototype, preparing the various media elements, and using the authoring tool to integrate them. Stakeholders need to then review the prototype using appropriate hardware and software.

To be reviewed the product needs to be tested against the storyboards and flowcharts specified in the design phase. Additional tests are also needed to test the product against design specifications—these include load tests and functional tests. Acceptance tests must also be run with stakeholders.

Pre-installation testing will include extensive ‘walk throughs’ (simulations of use). On completion of all these tests, a final product will be developed, with any identified defects corrected and all the media integrated. The product will then be installed on the final delivery platform.

Where might multimedia products go wrong?

Multimedia authoring takes a great deal of planning. If the groundwork is not completed thoroughly, the end product will often not meet its goal.

You must consider technical perspectives, business perspectives and human dimensions, if a multimedia project is to be successful. Let’s consider past experience to look at common mistakes in these areas.

The technical perspective

Multimedia products often work perfectly in the development environment but not on the end user’s PC. The product may not function particularly well, for instance, when it is delivered via a slower medium such as the web, or alternatively, operates on a PC that has different settings (such as a different operating system, alternate security settings, different directory structures or missing the necessary plug-ins).

The business perspective

A CDROM multimedia product may have information that was correct when content was developed but is incorrect at the time of release. The discrepancy could well be due to a business decision made outside of the multimedia project. This is common in companies or organisations that have dynamic and changing environments.

The human dimension

Be wary of designing a system that assumes competence in PC use. The system may be technically excellent, but if many of the participants have had no PC experience, then they may not be able to navigate through it.

In conclusion, such simple things seem absolutely obvious—however errors of this kind are regularly made. It can’t be reinforced enough; the developer must observe the project from all three aspects (the technical perspective, the business perspective and the human dimension). If one area is overlooked, then the whole project risks failure.

Importantly, the role of a multimedia author is to consider all the key elements and ensure that the end product is technically functional, informative, and easy to navigate, while also able to motivate end-users.

Standards and specifications

Why are standards and specifications important?

Specifications and standards are the starting point and the foundation of a good project. In many ways, standards define the quality of the end product and the ease with which the product will be maintained and supported. Editing and re-editing are important aspects in all of this. If there are consistent standards, editing can occur in a fast and uniform process (for example, batch processing of graphics is easier when all graphics have similar standards, sizes, formats and naming conventions).

Specifications

You need a framework of features and requirements on which to base your design. To record specifications for elements you will need to systematically list all the components of everything you will require in order to develop the product. You do not necessarily need to specify how the individual features will work—that will happen during the design phase.

Multimedia standards

Standards are important in the exchange and transport of content. Agreed ways of exchanging content make business investment and the development of technology possible. Well-known examples of such standards are those in television, such as phase alternation by line (PAL) and the analog television system, NTSC (named for the standards body who created it, National Television Systems Committee). It is important to be aware of current issues and trends with respect to standards, and to apply them wisely.

Sometimes the dominance of a standard results from costly industrial or marketing wars. An example is Video Home System or VHS, the industrial standard for consumer videotape players-recorders, introduced in 1976 by the JVC corporation. VHS won the battle over Sony corporation’s Betamax format and Sanyo’s Betacord version, released a year earlier. Many say the ‘Beta’ standards were actually superior to VHS.

Standards for multimedia are also quite complex and constantly developing. This is a fast moving and ever-changing area. Some standards, despite heavy investment and promotion still don’t get fully accepted. However, multimedia can be applied to a wide range of situations, and varying relevant standards for each of these situations can apply.

Here are just a few briefly described examples of standards that relate to a multimedia setting:

· Graphics and video standards include JPEG (named for the Joint Photographic Experts Group) and MPEG (named for the Joint Photographic Experts Group)

· Internet standards include IP Multicast, MIME (Multipurpose Internet Mail Extensions), RTP (Real-time Transport Protocol) and RFC (Request for Comments—one of a series of numbered Internet informational documents and standards)

· World Wide Web Consortium or W3C standards include GIF (Graphics Interchange Format), QuickTime (developed by Apple Computer), DVI (Digital Visual Interface) and MIDI (Musical Instrument Digital Interface).

There are literally hundreds of standards—the above list is just the beginning.

Reflect: Learning multimedia standards

Where do you think you might go to learn about multimedia standards? The web, of course—you’ll find some suggested sites to visit in the Practice section.

Multimedia—text

Text is the simplest multimedia element to create and edit. Many of us have several years experience with word processing, so manipulating text is often considered quite easy. However, there are important things to remember when creating, incorporating and formatting text into a multimedia production.

Here is a list of suggestions for the use of text in multimedia.

· Select appropriate fonts. It is generally wise to use common standards such as Arial and Times New Roman, as these fonts are supported on most computers and common browsers.

· Be concise. Remember, a picture conveys a thousand words!

· Make sure that important text is always readable. Be aware of small font sizes that may be displayed differently on various resolutions and browser settings. A common error occurs when ‘text-size’ settings in browsers such as Internet Explorer are set to high or low. Always check this, and if in doubt use default.

· Attempt to control the location of text, instructions and navigation to make it easy for the user to find what they need.

· On the web, attempt to use a font set, a template or CCS (Cascading Style Sheets) to control how the page and text will appear.

· Many developers prefer to work with text within a word-processing package then import it into the multimedia application.

· Some developers display their text as graphics, but this practice can be problematic if there is major editing to do at later point.

· If there is a large amount of text to include, provide hyperlinks to it so that a user can selectively focus on what they do and don’t want.

· Be aware that some applications that are text intensive also use Optical Character Resolution (OCR) scans to display text.

Of course, this is just a short list. You should use some of the suggestions in the Resources section to investigate the use of text in multimedia projects.

Multimedia—graphics

Graphic files can add emphasis, illustrate concepts and provide background meaning. They are generally considered to be an essential element of a multimedia product.

You need to be aware of the main factors that allow the best graphic display for the end user. One of the main problems, particularly online, is that graphic files can be very large and difficult to work with, especially when compared with text files.

The better the quality of a graphic, the larger its file size will be. Larger file sizes can have a whole range of negative effects, including longer transfer and download times, larger storage space needs and greater cost.

Dealing with large file sizes

Let’s consider the size of unprocessed digital image and video files. One character of text usually requires one byte of storage space. A whole text page might require a couple of hundred bytes. However, a colour image the size of a small standard Video Graphics Array (VGA) screen occupies (in principle) 640x480x3 bytes. This is the number of pixels multiplied by the number of bytes per pixel—one for each of the R, G, and B channels. That’s a lot of bytes! As you can see it is extremely important to reduce the size of graphics for the purposes of storage and transmission.

Compression techniques

Various compression techniques and formats have been developed to address the problem of large files. One technique is to code the image in a compressed way at one end, and decode it to an uncompressed form at the other. For this to work both parties must be able to apply the same standard. Use of compression techniques and formats often brings fidelity trade-offs, and it can be challenging for a developer to produce the best quality for the user with the smallest loss of quality.

When developing multimedia, a standard way of compressing graphics should be documented to make sure that the end product is always usable and acceptable to stakeholders.

Reflect: Thinking about file sizes

Do a couple of simple tests to help you to think about file sizes. Open a text document and copy the text into a text editor (not a word processor). Save the file and notice the amount of space taken up by the text alone. If you can, take a photograph with a low-end digital still camera, and compare the file sizes. You’ll see that even a low-end photographic image is much bigger than a page of text.

Factors affecting the use of graphics

Here’s a summary of the main issues contributing to the selection and use of graphics:

· What screen resolution should be used? 1024x768 will display a better image than 640x480.

· What image sizes are to be used? Image size refers to the number of pixels or picture elements that make up the image. Often, one of the main tasks for developers is physically resizing graphics to a specification such as 200 x 200 pixels.

· What colour depth will be used? 16 bit? Millions of colours? Obviously, the higher the number, the better the quality.

· What file size or range is acceptable? Most graphics for web delivery should be no more than 15 Kb, with larger sizes acceptable for CD-ROM.

· What format should be used: JPEG, PNG (Portable Network Graphics), GIF (Graphics Interchange Format) or TIFF (Tagged Image File Format).

Types of graphics: Bitmap and Vector

Bitmap files (also called raster files) contain graphics information described as an array of dots (pixels). Colour information, called colour depth, is recorded for each pixel. Bitmaps are often used to store and display photographic images, as they can detail subtle gradients in colour. However they do lose visual quality and become distorted when resized. Commercially available programs for creating bitmap graphics include Paint Shop Pro and Adobe Photoshop.