The Get Regions Of Interest Action

The Get Regions Of Interest Action
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	#include "ofxImageEffect.h"
	#define kOfxImageEffectActionGetRegionsOfInterest         "OfxImageEffectActionGetRegionsOfInterest"

Arguments

handle handle to the instance, cast to an OfxImageEffectHandle ,
inArgs has the following properties...
- kOfxPropTime the effect time for which a region of definition is being requested,
- kOfxImageEffectPropRenderScale the render scale that should be used in any calculations in this action,
- kOfxImageEffectPropRegionOfInterest the region to be rendered in the output image, in Canonical Coordinates.
outArgs has a set of 4 dimensional double properties, one for each of the input clips to the effect. The properties are each named "OfxImageClipPropRoI_" with the clip name post pended, for example "OfxImageClipPropRoI_Source". These are initialised to the default RoI.

Description

This action allows a host to ask an effect, given a region I want to render, what region do you need from each of your input clips. In that way, depending on the host architecture, a host can fetch the minimal amount of the image needed as input. Note that there is a region of interest to be set in outArgs for each input clip that exists on the effect. Form more details see Image Effect Architectures .

Return Values

kOfxStatOK, the action was trapped and at least one RoI was set in the outArgs property set
kOfxStatReplyDefault, the action was not trapped and the host should use the default values
kOfxStatErrMemory, in which case the action may be called again after a memory purge
kOfxStatFailed, something wrong, but no error code appropriate, plugin to post message
kOfxStatErrFatal

Default Action

The default RoI is simply the value passed in on the kOfxImageEffectPropRegionOfInterest inArgs property set. All the RoIs in the outArgs property set must initialised to this value before the action is called.

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The Get Region of Definition Action	Home	The Get Frames Needed Action