TABLE OF CONTENTS Level: 2
Definition: A means of compressing digital audio signals that relies on perceptual coding schemes (the removal of data related to audio signals that are not perceptible by the human ear), AAC is widely regarded as a more efficient and effective means of audio compression compared to the long-used MP3 format. AAC provides improved audio quality at relatively low bit rates, and supports multichannel audio in that it provides up to 48 full-frequency channels. Because of its improved quality and its use with the increasingly popular iTunes online music service run by Apple, AAC has emerged as a significant challenger to MP3 and other audio compression formats. (See also Compression, MPEG, and MP3.)
Level: 3
Definition: Used for video editing projects, AAF is a widely used industry standard for saving and exchanging information related to video editing works in progress (such as transitions, edit history, and so on). AAF is used to improve compatibility among various vendor products and provides significant support for workflow management and archiving.
Level: 2
Definition: In telephone T-1 line transmissions, some of the capacity of the line has to be dedicated to internal signaling (call setup). A&B signaling is the process of taking one digital bit of information at a constant interval from each of the 24 subchannels on the T-1 line in order to let the system know that an active call is still in...
