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QuickTime for Java: A Developer's Notebook by Chris Adamson

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Creating Zero-Source Effects

QuickTime comes with an extensive collection of video effects, which you use by making movies with effects tracks—i.e., a track whose media defines a video effect.

These effects are grouped based on how many sources they operate on.

Zero-source effects

These effects are meant to be seen just by themselves. Apple includes a few of these, like fire, clouds, and water “ripples.”

One-source effects (or filters)

These effects are applied to a single source. Examples of this kind of effect include color correction or tinting, edge detection, lens flare, etc.

Two-source effects (or transitions)

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.

How do I do that?

An effects track is really just a video track (literally, a track with 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 AtomContainer s: tree-structures in which each "atom” can contain children or data, but not both. Each atom has a size and a FOUR_CHAR_CODE type, and can be accessed by index and/or type (i.e., you can get the nth atom of type m from a parent). ...

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