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# kTweenDuration

An atom that specifies the duration of a tween operation.

## Overview

When a QuickTime movie includes a tween track, the time units for the duration are those of the tween track. If a tween component is used outside of a movie, the application using the tween data determines how the duration value and values returned by the component are interpreted.

Its parent atom is a `kTweenEntry` atom.

A `kTweenEntry` atom can contain only one `kTweenDuration` 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 `TimeValue`.

This atom is optional. If it is not included, the duration of the tween operation is the duration of the media sample that contains it.

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