---------------------------------------------------------------------------- The Florida SunFlash Multimedia: Key Concepts (3 of 6) SunFLASH Vol 40 #27 April 1992 ---------------------------------------------------------------------------- 3 Key Multimedia Concepts Before reading about the more technical aspects of multimedia, you should be familiar with some of the key concepts that apply to multimedia technology. --------------------------------------------------------------------------- Key Processes --------------------------------------------------------------------------- Authoring Authoring is the process of using multimedia applications to create multimedia materials for others to view. Multimedia authoring utilizes a wide variety of tools, from the more familiar text editor or desktop publishing application, to tools for capturing and manipulating video images or editing audio files. Authors might include specialized creators of training, sales, or corporate applications such as insurance claims processing. Or, they might be creators of everyday business communications like voice-annotated email. Over time, everyone involved in business communications will probably have some level of multimedia authoring capability. Playback Playback is the process of viewing multimedia materials created by an author. Playback can include a range of activities, from viewing a single video clip to participating in a series of interactive multimedia training modules. Some playback applications (for example many training and presentation applications) are sold separately from their authoring applications. However, many developers are selling authoring and playback capabilities in a single product. Collaboration Collaboration involves two or more people working together in real-time, or in a "store-and-forward" mode (defined in the next section). Applications in development will enable a group of people to collaborate in real-time over the network using shared screens, shared whiteboards, and video conferencing. Collaboration can range from two people reviewing a slide set on-line to a conference of doctors at different locations sharing patient files and discussing treatment options. Editing Editing is the familiar process of changing the content of files to achieve more effective communication by cutting, pasting, cropping, resizing, or copying. Multimedia editing can be done on all types of media: voice annotations, music, still images, motion video, graphics and text. Tools for editing vary from simple tools for email voice annotations to more sophisticated tools for video manipulation. --------------------------------------------------------------------------- Key Concepts --------------------------------------------------------------------------- Real-Time Operating in real-time means that there is little time delay in the communication of information. You make a change to a screen display, and your colleagues at different workstations see the change almost immediately. This is in contrast to the concept of "store-and-forward". Store-and-Forward The concept of store-and-forward means a time delay between the creation and receipt of multimedia materials. This is the process that most people currently use. It does not accommodate live interaction between people. The information is created at one point in time, and received at another. An example of this is today's electronic mail. Synchronization Synchronization is very precise real-time processing, down to the milli-second. Some forms of multimedia, such as audio and video, are time-critical. Time delays that might not be noticeable in text or graphics delivery are unacceptable for audio and video. Workstations and networks must be capable of transmitting this kind of data in a synchronized manner. Where audio and video are combined, they must be time-stamped so that they can both play back at the same time. One-way Communication One-way communication goes from an author to a playback user, but not the other way around. Examples of one-way communication include training and documentation materials, and presentations. The material is authored specifically for playback by the end user and not for a collaborative work effort. One-way communication materials remain unchanged until the master is updated by the author. Multi-way Communication Multi-way communication goes between two people, or between groups of people in all directions. Multi-way communication can be in real-time, or in store-and-forward mode. Examples of multi-way communication include a video conference, where one individual is giving a presentation to a group of people who listen and ask questions from their workstations; and group conferencing, where several people collaborate, supported by audio, video, and graphics on their workstation screens. Compound Documents A compound document is one that enables incorporation of different kinds of media - audio, video, images, text, and graphics. --------------------------------------------------------------------------- Key Applications --------------------------------------------------------------------------- Videoconferencing Videoconferencing is communication with others using video and audio applications to see and hear each other. Audio can be provided through specialized videoconferencing equipment, through the telephone, or through the computer. Videoconferencing has traditionally been done with dedicated equipment. The use of computers for conferencing is very recent. Synchronized, real-time audio and video is required. Shared Screens Shared screen applications enable two or more workstations to display the same screen simultaneously. For example, two users sharing a screen can work on the same spreadsheet. Changes made by one user can be seen by the other as they are made. Shared screens can be implemented in two ways. One way enables people to view each other's screen while one person makes changes. The other way enables people to run the same application on both screens so that both users can make changes simultaneously. Shared Whiteboards Shared whiteboards enable you to "mark-up" a screen using a mouse or stylus input device and have the results show on other screens. The concept is similar to a traditional whiteboard mark-up process where everyone has a different color marking pen to circle, write, or cross out items. The background board can be a window from the workstation such as a spreadsheet, image, or blank canvas, or it can be the entire workstation screen. The shared whiteboard can be used for either real-time or store-and-forward collaboration. In the store- and-forward scenario, the mark-ups can be implemented in a time-delayed fashion so everyone can follow the entire step-by-step process. Software-only Video Playback Video software playback displays a stream of video without any specialized chips or boards. The playback is done through a software application. The video is usually compressed to minimize the storage space required. Hypermedia Hypermedia is a type of authoring and playback software through which you can access multiple layers of multimedia information related to a specific topic. The information can be in the form of text, graphics, images, audio, or video. For example, suppose you received a hypermedia document about the Sun file system. You could click on a hotspot (such as the words file system) and then read a description. You could then click an icon to see an illustration of a file structure, and then click the file icon to see and hear more information in a video explaining the file system. Runtime A runtime environment is the software that plays back multimedia materials. The runtime material is created by the author. Examples of runtime applications are presentations and training, where the material cannot be edited but only viewed. The runtime software could be a slide show viewer, a software-only video playback application, or a hypermedia runtime document. Device Control Device control enables you to control different media devices over the network through software. The media devices include VCRs, laser disc players, video cameras, CD players, and so on. Control capabilities are available on the workstation through a graphical user interface. They are similar to the controls on the device itself, such as play, record, reverse, eject, and fast forward. Device control is important because it enables you to control video and audio remotely - without requiring physical access. Telephony Telephony refers to the integration of the telephone into the workstation. For instance, making or forwarding a call will be as easy as pointing to an address book entry. Caller identification (if available from the telephone company) could be used to automatically start an application or bring up a database file. Voicemail and incoming faxes can be integrated with email. Users can have all the features of today's telephones accessible through their workstations, plus the added benefits provided by integrating the telephone with other desktop functions. Titles When an author sells what he or she has created, it is called a title. For instance, the various encyclopedias, dictionaries, musical works, and games available on CD are all "titles". Someone authors the material, and sells it to users who can play it back but not change the content.