The main characteristic of a multimedia system is the use of more than one kind of media to deliver content and functionality. Web and desktop computing programs can both involve multimedia components. As well as different media items, a multimedia application will normally involve programming code and enhanced user interaction. Multimedia items generally fall into one of five main categories and use many different techniques for digital formatting.
Image files through digital media appear in many multimedia applications. Digital photographs can display content or can form part of a user interface. Interactive elements, such as buttons, often use custom images created by the designers and developers involved in the making of the application. Digital image files use a variety of formats and file extensions. Among the most common are PNGs and JPEGs. Both of these often appear on websites, as the formats allow developers to minimize on file size while maximizing on picture quality. Software such as Photoshop allow developers to create complex visual effects with digital images.
Audio files and streams play a major role in some multimedia systems. Audio files appear as part of application content and also to aid interaction with people who may have difficulty with reading. When they appear within Web applications and sites, audio files sometimes need to be deployed using plug-in media players. Formats include MP3, WMA etc. Web services can also stream audio, so that users can begin playback before the entire file is downloaded.
Text content is by far the most common media type in computing applications, it’s usually forgotten about seeing as we use it so much. Most multimedia systems use a combination of text and other media to deliver functions. Text in multimedia systems can express specific information and can act as reinforcement for information contained in other media items. This is a common practice in applications with accessibility requirements. For example, when Web pages include image elements, they can also include a short amount of text as information about the image for the user’s browser to include as an alternative, in case the digital image item is not available.