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

Media Data Atom TypesTween MediaTween TypekTweenType3dTranslateData TypeTQ3Vector3DThis atom is optional. For each tween type, the default value is the data structure that specifies an identitytransform, that is, a transform that does not alter the 3D data.Interpolation Tween AtomskTweenOutputMaxSpecifies the maximum output value of an interpolation tween atom. If a kTweenOutputMax atom isincluded for an interpolation tween, output values for the tween atom are scaled to be within the minimumand maximum values. The minimum value is either the value of the kTweenOutputMin atom or, if thereis no kTweenOutputMin atom, 0. For example, if an interpolation tween atom has values between 0 and4, and it has kTweenOutputMin and kTweenOutputMax atoms with values 1 and 2, respectively, a valueof 0 (the minimum value before scaling) is scaled to 1 (the minimum specified by the kTweenOutputMinatom), a value of 4 (the maximum value before scaling) is scaled to 2 (the maximum specified by thekTweenOutputMax atom), and a value of 3 (three-quarters of the way between the maximum andminimum values before scaling) is scaled to 1.75 (three-quarters of the way between the values of thekTweenOutputMin and kTweenOutputMax atoms).Its parent atom is a kTweenEntry atom.A kTweenEntry atom can contain only one kTweenOutputMax atom. The ID 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 Fixed.This atom is optional. If it is not included, QuickTime does not scale interpolation tween values.kTweenOutputMinSpecifies the minimum output value of an interpolation tween atom. If both kTweenOutputMin andkTweenOutputMax atoms are included for an interpolation tween atom, output values for the tweenatom are scaled to be within the minimum and maximum values. For example, if an interpolation tweenatom has values between 0 and 4, and it has kTweenOutputMin and kTweenOutputMax atoms withvalues 1 and 2, respectively, a value of 0 (the minimum value before scaling) is scaled to 1 (the minimumspecified by the kTweenOutputMin atom), a value of 4 (the maximum value before scaling) is scaled to2 (the maximum specified by the kTweenOutputMax atom), and a value of 3 (three-quarters of the way2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.244