Matrices
QuickTime files use matrices to describe spatial information about many objects, such as tracks within a movie.
Overview
A transformation matrix defines how to map points from one coordinate space into another coordinate space. By modifying the contents of a transformation matrix, you can perform several standard graphics display operations, including translation, rotation, and scaling. The matrix used to accomplish two-dimensional transformations is described mathematically by a 3-by-3 matrix.
All values in the matrix are 32-bit fixed-point numbers divided as 16.16, except for the {u, v, w} column, which contains 32-bit fixed-point numbers divided as 2.30. The following figure illustrates the matrix formula QuickTime uses to transform displayed objects.
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When you specify a matrix in a movie header atom for a movie atom, QuickTime applies the transformation from the matrix to the atoms included in the movie atom, such as a clipping atom, one or more track atoms, a user data atom, and a color table atom.