QuickTime 4 Reference

Utility Functions

This section contains definitions of functions that are designed to be helpful when working with effects.

MakeImageDescriptionForEffect

MakeImageDescriptionForEffect returns an image description you can use to help create a sample description for an effect. To create a sample description, you create and fill out a data structure of type ImageDescription . The MakeImageDescriptionForEffect function simplifies this process.



 
OSErr MakeImageDescriptionForEffect (

                     OSType effectType,

                     ImageDescriptionHandle * idh) ;

effectType: The four-character code identifying the type of effect to make an image description for, such as `solr'.
idh: The handle of an image description. On entry, this parameter normally points to an image description whose contents are nil . On return, the image description is correctly filled-out for the selected effect type.

DISCUSSION

Only sample descriptions made with MakeImageDescriptionForEffect can be used in stacked effects, where one effect track acts as a source for another. Image descriptions built using sample code from earlier versions of QuickTime cannot be used when stacking effects.

For a code sample showing how to use MakeImageDescriptionForEffect , see "Creating a Sample Description" .