MULTIMEDIA DATA TYPES
Video
· Video is composed of different story units such as shots, scenes and sequences arranged according to some logical structure
· Frames recorded sequentially from a shot, one or several related shots are combined in a scene, and a series of related scenes forms a sequence.
Digital Video
· Refers to the capturing manipulation and storage of video in digital format
· The CCD (Charged-Coupled Device) cameras to capture the moving images, but they store the images in a high-quality, endlessly reproducible, easily edited, digital format.
· Pixel: The individual picture elements, or “dots” of color, that are arranged in a two dimensional array to define a digital image or video frame
· Resolution: The dimensions of an image, in pixels, typically expressed as the number of horizontal pixels across and the number of vertical pixels down.
· Compress (encode): To reduce the size of audio or video data through the use of a compression scheme. .
· Decompress (decode): To process a compressed bit-stream and recover the original data (if lossless compression), or an approximation of the original (if loss compression).
Image Data
· An image is represented as a two- dimensional array of coefficients, each coefficient representing the brightness level in that point.
· The low frequency components (smooth variations) constitute the base of an image, and the high frequency components (the edges which give the detail) add upon them to refine the image, thereby giving a detailed image.
Digital Image Data
· A digital image is composed of a set of pixels
· The number of pixels across a given area (described either as dots-per-inch or as the pixel dimensions of a display device) governs the resolution of an image.
Audio Data
· The term “audio” is synonymous with sound and is used more in TV production than in motion picture production.
· Mono: Monophonic audio - a single channel of audio.
· Stereo: Two-channel audio, with left and right channels.
· Narration: A voice that explains what is happening on a video.
· Sample rate: The rate at which samples of a continuous signal, such as music or a sound, are captured into a digital representation of the original signal.
· Hz: Hertz a measurement used for audio sampling rate, as in the number of audio samples per second.
· Mic: Microphone audio input.
· Line level: An analog audio connection intended for connecting interconnecting audio equipment, and without the amplification required to connect to speakers.
Digital Audio
· Digital audio is the encoding of an audio signal as a series of symbols (or numbers) that can be processed by a computer.
· Digitization of audio data is most commonly achieved by sampling an analog signal at fixed intervals and by storing the amplitude of each sample in binary form
· A digital audio record therefore consists of a number of samples.
Hypertext
· Hypertext is a way of presenting information in which text, sounds, images, and actions are linked together in a way that allows you to move between them in whatever order you choose
· Hypertext usually refers to any text available on the World Wide Web (WWW) that contains links to other documents.
· Hypertext provides links among pieces of information (text, graphics or sound) that permit the user to “explore ideas and pursue throughout in a tree and nonlinear fashion”.
· Hypertext systems have been described as containing easier, richer, more highly featured linking of information than afforded by other types of familiar application programs available in decision support systems or reporting systems
· Hypertext has been conceptualized as existing on three levels: the informal, experimental, and the collaborative.
· Integrated, homogeneous way to describe, organize, and structure multimedia information units, and to represent their temporal relationships in a single entity
· a multimedia document is a structured collection of attributes, text, image, video, and audio data
· Multimedia document storage and retrieval should be possible through the structure, attributes, and media content of the document
