Operating systems may have the task of handling different types of data, including multimedia. In recent years, technology has seen an increase in the use of multimedia data within computer systems. Multimedia data includes continuous media in the form of audio or video files and conventional files. Continuous media data differs from conventional data, requiring specific time restrictions to deliver files such as video, images, or audio frames.
What is Multimedia?
Multimedia refers to a wide range of applications that are commonly used nowadays. This term encompasses a broad category that includes audio and video files such as MP3 audio files, movies, short video clips, and flash/animation files of movie previews or news stories downloaded via the Internet.
In addition, multimedia also includes live webcasting (i.e., broadcasting over the World Wide Web) of various events or sports. A multimedia application does not necessarily need to be audio or video; it can include a mixture of both.
What is Media Delivery?
Multimedia data is stored in the file system just like any other data. The main difference between a regular file and a multimedia file is that multimedia files need to be accessed at a specific rate while accessing a standard file does not require any particular timing. A video usually comprises a sequence of images, known as frames, displayed rapidly. The faster the frames are displayed to users, the smoother the video looks. Typically, a rate of 24 to 30 frames per second is necessary for the video to appear smooth to the human eye.
When data is delivered from the local file system, it is called 'local playback.' Multimedia files can also be stored on a remote server and delivered to a client across a network using a technique called streaming.
There are two types of streaming techniques:
- Progressive download.
- Real-time streaming.
There are two options for downloading audio and video media files: progressive download and real-time streaming. The media file is downloaded and stored on the user's local file system with progressive download. On the other hand, real-time streaming allows the media file to be streamed to the client but not stored or downloaded by the client.
Real-time streaming is preferred for media files that are too large to store on the client system, such as long videos and Internet radio or TV broadcasts. Since the media file is not stored on the client system, real-time streaming is a better option for those who want to conserve space on their devices.
Characteristics of Multimedia Systems
The demands of multimedia systems differ significantly from those of conventional applications. Multimedia systems can have the following characteristics:
- Multimedia files can be relatively large. For example, a 100-minute MPEG-1 video file uses roughly 1.125 GB of storage, and 100 minutes of high-definition television needs approximately 15 GB of storage.
- Continuous media might need very high data rates. Think of a digital video wherein a frame of color is displayed at a resolution of 800 x 600.
- Multimedia applications are pretty sensitive to time delays at some point in playback.
