Multimedia Dictionary

1. Multimedia Dictionary • Compiled by Lucy Raymond11 August 09

2. Multimedia DictionaryA B CD E F G H I J K L M N O P Q R S T U V W X Y Z

3. Compression • Compression first eliminates redundant data from a file and then removes less important data to shrink file size still further. This process is achieved using algorithms, or “codecs” (short for compressors- decompressors), that handle the media compression and the decompression when it is played.

4. Criteria and Metrics • Criteria and associated metrics are important for evaluation in a variety of everyday circumstances. In broad terms, criteria identify the characteristics which are considered important for some purpose. Metrics provide a basis for measuring and comparing individual performances or properties relative to the criteria.

5. Digital audio • Digital audio is the method of representing audio in digital form. Digital audio has emerged because of its usefulness in the recording, manipulation, mass-production, and distribution of sound. An analog signal is converted to a digital signal at a given sampling rate and bit resolution; it may contain multiple channels (2 channels for stereo or more for surround sound). Generally speaking: the higher the sampling rate and bit resolution the more fidelity, as well as increase the amount of digital data.

6. Downloading • Downloadable media is stored on the client machine in memory or on the viewer’s hard drive. Most downloadable media is progressive, which means that the information necessary for playback is stored at the beginning of the file. Progressive download allows the viewer to start watching the video before the entire file has downloaded. As long as the download speed stays above the data rate of the movie, playback will be uninterrupted. • The quality of downloadable media is generally higher than that of streaming media. • The main drawback of downloadable media is the storage demand it places on the viewer’s computer, another it doesn’t allow random access.

7. Downsampling • Downsampling (or "subsampling") is the process of reducing the sampling rate of a signal. This is usually done to reduce the data rate or the size of the data. (Wikipedia)

8. Hypermedia • Hypermedia (probably the best known example is the World Wide Web) goes beyond linear sequences of screens and provides more complex interlinking of content.

9. Linear and non-linear multimedia • Linear multimedia start and continue till the end without any navigation control for the user. • Non-Linear Multimedia offer interactivity to the end user.

10. Plug-ins • Plugins are small programs which extend the ability of a web browser to display different forms of multimedia content.

11. Peripherals • Peripherals are components that are not part of the central processor but may be connected to it and are most often used for input or output of data.

12. Streaming • Streaming technology sends data to the desktop continuously but does not download the entire file. In the optimal scenario, the content is stored on a streaming media server, which maintains a constant conversation with the client to determine how much data the user can support. Based on this information, the server adjusts the data stream accordingly and sends just enough data to the client. Streaming media plays directly to the display; it is not stored in memory or on the user’s hard drive.