The Is Identity Action

	#include "ofxImageEffect.h"
	#define kOfxImageEffectActionIsIdentity            "OfxImageEffectActionIsIdentity"

  • handle handle to the instance, cast to an OfxImageEffectHandle ,
  • inArgs has the following properties...
  • outArgs has the following properties which the plugin can set...
    • kOfxPropName this to the name of the clip that should be used if the effect is an identity transform, defaults to the empty string
    • kOfxPropTime the time to use from the indicated source clip as an identity image (allowing time slips to happen), defaults to the value in kOfxPropTime in inArgs


Sometimes an effect can pass through an input uprocessed, for example a blur effect with a blur size of 0. This action can be called by a host before it attempts to render an effect to determine if it can simply copy input directly to output without having to call the render action on the effect.

If the effect does not need to process any pixels, it should set the value of the kOfxPropName to the clip that the host should us as the output instead, and the kOfxPropTime property on outArgs to be the time at which the frame should be fetched from a clip.

Return Values

  • kOfxStatOK, the action was trapped and the effect should not have its render action called, the values in outArgs indicate what frame from which clip to use instead
  • kOfxStatReplyDefault, the action was not trapped and the host should call the render action
  • 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 action is to call the render action on the effect.