Compression (video)

Process which reduces the number of bytes required to store/transmit digital video . Typical schemes involve comparing frames and coding-out, or eliminating, inter-frame and intra-frame redundancies. The compression may be done by software, hardware or a combination of the two. On playback, the data is decompressed. See CODEC . Why compress video data? To reduce storage space and to playback faster. A full-screen (640 x 480 pixels ) image with 16.4 million colors takes up 1 Mb of memory. For full-motion, the computer needs to display 30 pictures/frames per second, thus requiring it to "shuffle" 30 Mb of data every second. Storing 10 seconds of video would require 300 Mb. Jan Ozer, President of Doceo Publishing , is the foremost authority on digital video/CODEC's.