comes with an extensive collection of
video effects, which you use by making movies with
track whose media defines a video effect.
These effects are grouped based on how many sources they operate on.
These effects are meant to be seen just by themselves. Apple includes a few of these, like fire, clouds, and water “ripples.”
These effects are applied to a single source. Examples of this kind of effect include color correction or tinting, edge detection, lens flare, etc.
These are effects that apply to two sources at once. Typically, they’re used to visually change the display from one video source to another. Examples of these include dissolves and wipes.
The simplest of these are the zero-source effects, because they don’t require wiring up the effect to sources. Instead, you just put an appropriate effects sample into a video track and you’re done.
An effects track is really just a video track (literally, a track
VideoMedia), whose samples are descriptions
of effects: the ID of the effect and any parameters it might take. In
QuickTime, these are passed in the form of
tree-structures in which each
can contain children or data, but not both. Each atom has a size and
type, and can be accessed by index and/or type (i.e., you can get the
nth atom of type
m from a parent). ...