The QTPlgEffectDesc class provides you with properties and methods that let you deal with effect settings.
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The QTPlgEffectDesc class constructors are called when you create a new instance of the class, while the ˜QTPlgEffectDesc class destructor, is called automatically when the class is no more in use. Also, you can invoke the class destructor by setting the instance of the class to nil.
Once a new class instance is returned, it is good practice to check the class property to be sure that the new object can be used. A QTPlgEffectDesc class instance is valid if it has obtained access to the appropriate sample description structure to be used (that is the value of the property is not 0) and the atom container structure used internally to store effect parameters has been allocated. As, when creating an instance of this class by using the , the atom container has not been yet allocated, then the class property will be false; this being the case, it is lecit to continue to use the class. The class turns out to be valid as soon as an effect decompressor has been selected using the property
The class provides you with the following initializer methods:
()
This is the default constructor. Use this constructor to create a completely new data descriptor container in memory.
The property is intialized to
–1
(other as QTPlgEffectDesc)
This is the copy constructor. The properties of the object to be copied will be used to initialize the
new class instance properties
(component as )
The new class instance will try to open a connection to the effect decompressor component specified by the
component parameter;
you can obtain a list of all of the currently installed effect decompressors by using the
method of the
module passing the appropriate
to it.
If the connection succeeds, the properties of the class will be initialized to the default settings of the selected
effect decompressor
(effectType as string)
The new class instance will try to open a connection to the effect decompressor component identified by its
(the effectType parameter); if the connection succeeds, the properties of the class
will be initialized to the default settings of the selected effect decompressor
specifies a four characters string describing the
of
the effect decompressor in use. You can obtain a list of all of the currently installed effect decompressors
by using the
method of the module specifying the appropriate
indicates if the effect will execute as quickly as frames can be sent to it for rendering
specifies the number of data source required for the effect to work. This property can return one of the following values:
- 0: the effect does not require a source; this is a free–standing special effect (examples of this type of effect are the fire or cloud QuickTime built–in effect)
- 1: the effect requires a source; this type of effect is a filter (i.e the QuickTime built–in blur effect)
- 2: the effect requires two sources; such a effect is known as transition (i.e the QuickTime built–in wipe effect)
indicates the speed of the effect, expressed in frames per second. The value returned should not be treated as an
absolute measurement of effect performance. In particular, most effects only return one value, regardless of
parameter settings and hardware. This value is an estimate of execution speed on a reference hardware platform.
Actual performance will vary depending on hardware, configuration and parameter options