Mac Dev Center Mac OS X Reference Library Apple Applications: Final Cut Pro/Final Cut Express FxPlug Reference

Introduction

Defines the functions the application provides to retrieve parameter values.

Methods

-getGradientSamples:numSamples:depth:fromParm:atTime:

Gets the Gradient parameter settings.

-getHistogramBlackIn:BlackOut:WhiteIn:WhiteOut:Gamma:forChannel:fromParm:atTime:

Gets the Histogram parameter settings.

Gets the Gradient parameter settings.

- (BOOL)getGradientSamples:(void *)samples numSamples:(UInt32)numSamples depth:(UInt32)sampleDepth fromParm:(UInt32)parmId atTime:(double)time; 

Parameters

samples

Pointer to a buffer of size (4 * numSamples * sampleDepth). It is populated with samples of RGBA values across the gradient. The number of samples is set by numSamples.

numSamples

Number of samples from the gradient. More samples provide a more accurate representation, but require more time.

sampleDepth

Number of bytes per channel (1 = 8 bit, 2 = 16 bit float, 4 = 32 bit float).

parmId

Parameter identifier assigned upon creation.

time

Specified time, expressed in canonical frames, to retrieve the parameter values.

Return Value

Returns YES if the value is successfully retrieved; NO otherwise.

Discussion

Depending on the host application, the time value may be relative to the start of the timeline or to the start of the clip. See the header file FxPlug/FxHostCapabilities.h.

Gets the Histogram parameter settings.

- (BOOL)getHistogramBlackIn:(double *)blackIn BlackOut:(double *)blackOut WhiteIn:(double *)whiteIn WhiteOut:(double *)whiteOut Gamma:(double *)gamma forChannel:(int)channel fromParm:(UInt32)parmId atTime:(double)time;

Parameters

blackIn

Pointer for the parameter black in level value.

blackOut

Pointer for the parameter black out level value.

whiteIn

Pointer for the parameter white in level value.

whiteOut

Pointer for the parameter white out level value.

gamma

Pointer for the parameter gamma level value.

channel

Specified channel for the histogram information (RGB: 0, Red: 1, Green: 2, Blue: 3, Alpha: 4).

parmId

Parameter identifier assigned upon creation.

time

Specified time, expressed in canonical frames, to retrieve the parameter values.

Return Value

Returns YES if the value is successfully retrieved; NO otherwise.

Discussion

Depending on the host application, the time value may be relative to the start of the timeline or to the start of the clip. See the header file FxPlug/FxHostCapabilities.h.