Tween media

Overview

Tween media is used to store pairs of values to be interpolated between in QuickTime movies. These interpolated values modify the playback of other media types by using track references and track input maps. For example, a tween media could generate gradually changing volume levels to cause a sound track to fade out. It has a media type of 'twen'.

Every tween operation is based on a collection of one or more values from which a range of output values can be algorithmically derived. Each tween is assigned a time duration, and an output value can be generated for any time value within the duration. In the simplest kind of tween operation, a pair of values is provided as input and values between the two values are generated as output.

A tween track is a special track in a movie that is used exclusively as a modifier track. The data it contains, known as tween data, is used to generate values that modify the playback of other tracks, usually by interpolating values. The tween media handler sends these values to other media handlers; it never presents data.

Topics

Storing tween media

• Tween sample description
• Tween sample data
• Tween type categories
• Tween QT atom container

See Also

Media data atom types

• Sprite media
• Sprite track properties
• Sprite track media format
• Sprite media atom and data types
• Sprite button behaviors
• QT atom container description key
• Sprite media handler track properties QT atom container format
• Sprite media handler sample QT atom container formats
• Wired action grammar
• 3D media
• VR media
• Node parent atom
• Node location atom structure ('nloc')
• Custom cursor atom
• Node information atom container