Wired Movies and Sprites

Sprite Image Registration

Sprite images have a default registration point of 0, 0. To specify a different point, you add an atom of type kSpriteImageRegistrationAtomType as a child atom of the kSpriteImageAtomType and set its leaf data to a FixedPoint value with the desired registration point.

The format of an override sample is identical to that of a key frame sample with the following exceptions:

An override sample does not contain images, which means it does not contain an atom of type kSpriteImagesContainerAtomType or any of its children.
In an override sample, all of the sprite atoms and sprite property atoms are optional.

For example, to define an override sample that modifies the location of the third sprite defined by the previous key frame sample, you would create a QT atom container and add the following atoms to it (assuming that the sprite track format is of type kKeyFrameAndSingleOverride ):

Figure 4 An example of an override sample atom container