Quicktime File Format (2012-08-14).pdf

Glossarytween track A modifier track that performs aspecific kind of tweening, such as path-to-matrixrotation.tweening A process interpolating new databetween given values in conformance to analgorithm. It is an efficient way to expand or smootha movie’s presentation between its actual frames.twos-complement encoding A system for digitallyencoding sound that stores the amplitude values asa signed number—silence is represented by asample with a value of 0. For example, with 8-bitsound samples, twos-complement values wouldrange from –128 to 127, with 0 meaning silence. TheAudio Interchange File Format (AIFF) stores samplesin twos-complement form. Compare offset-binaryencoding.URL The address of a website.user data Auxiliary data that your application canstore in a QuickTime movie, track, or media structure.The user data is stored in a user data list; items inthe list are referred to as user data items. Examplesof user data include a copyright, date of creation,name of a movie’s director, and special hardwareand software requirements. See also user data list,user data itemuser data item A single element in a user data list,such as a modification date or copyright notice.user data list The collection of user data for aQuickTime movie, track, or media. Each element inthe user data list is called a user data item.VR (virtual reality) See QuickTime VR.Wired Sprite A sprite such as a clickable buttonthat has wired actions associated with it.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.445