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

Media Data Atom TypesTween MediakTweenRegionDataContains the data for a QuickDraw region. Used only by a kTweenTypeQDRegion atom.Its parent atom is a kTweenEntry atom.A kTweenEntry atom can contain only one kTweenRegionData or kTweenPictureData atom. TheID of this atom is always 1. The index of this atom is always 1.This atom is a leaf atom. The data type of its data is Region.Either a kTweenPictureData or kTweenRegionData atom is required for a kTweenTypeQDRegiontween.Sequence Tween AtomskTweenSequenceElementSpecifies an entry in a tween sequence.Its parent is the tween QT atom container (which you specify with the constantkParentAtomIsContainer).The ID of a kTweenSequenceElement atom must be unique among the kTweenSequenceElementatoms in the same QT atom container. The index of a kTweenSequenceElement atom specifies its orderin the sequence; the first entry in the sequence has the index 1, the second 2, and so on.This atom is a leaf atom. The data type of its data is TweenSequenceEntryRecord, a data structure thatcontains the following fields:endPercentA value of type Fixed that specifies the point in the duration of the tween media sample at whichthe sequence entry ends. This is expressed as a percentage; for example, if the value is 75.0, thesequence entry ends after three-quarters of the total duration of the tween media sample haveelapsed. The sequence entry begins after the end of the previous sequence entry or, for the firstentry in the sequence, at the beginning of the tween media sample.tweenAtomIDA value of type QTAtomID that specifies the kTweenEntry atom containing the tween for thesequence element. The kTweenEntry atom and the kTweenSequenceElement atom mustboth be a child atoms of the same tween QT atom container.dataAtomIDA value of type QTAtomID that specifies the kTweenData atom containing the data for the tween.This atom must be a child atom of the atom specified by the tweenAtomID field.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.246