OfxImageEffectSuiteV1

struct OfxImageEffectSuiteV1

The OFX suite for image effects.

This suite provides the functions needed by a plugin to defined and use an image effect plugin.

Public Members

OfxStatus (*getPropertySet)(OfxImageEffectHandle imageEffect, OfxPropertySetHandle *propHandle)

Retrieves the property set for the given image effect.

  • imageEffect image effect to get the property set for
  • propHandle pointer to a the property set pointer, value is returned here
The property handle is for the duration of the image effect handle.

Return

OfxStatus (*getParamSet)(OfxImageEffectHandle imageEffect, OfxParamSetHandle *paramSet)

Retrieves the parameter set for the given image effect.

  • imageEffect image effect to get the property set for
  • paramSet pointer to a the parameter set, value is returned here
The param set handle is valid for the lifetime of the image effect handle.

Return

OfxStatus (*clipDefine)(OfxImageEffectHandle imageEffect, const char *name, OfxPropertySetHandle *propertySet)

Define a clip to the effect.

  • pluginHandle - the handle passed into ‘describeInContext’ action
  • name - unique name of the clip to define
  • propertySet - a property handle for the clip descriptor will be returned here
This function defines a clip to a host, the returned property set is used to describe various aspects of the clip to the host. Note that this does not create a clip instance.

Pre
  • we are inside the describe in context action.
Return

OfxStatus (*clipGetHandle)(OfxImageEffectHandle imageEffect, const char *name, OfxImageClipHandle *clip, OfxPropertySetHandle *propertySet)

Get the propery handle of the named input clip in the given instance.

  • imageEffect - an instance handle to the plugin
  • name - name of the clip, previously used in a clip define call
  • clip - where to return the clip
  • propertySet if not null, the descriptor handle for a parameter’s property set will be placed here.
The propertySet will have the same value as would be returned by OfxImageEffectSuiteV1::clipGetPropertySet
This return a clip handle for the given instance, note that this will \em not be the same as the
clip handle returned by clipDefine and will be distanct to clip handles in any other instance
of the plugin.

Not a valid call in any of the describe actions.

Pre
  • create instance action called,
  • name passed to clipDefine for this context,
  • not inside describe or describe in context actions.
Post
  • handle will be valid for the life time of the instance.

OfxStatus (*clipGetPropertySet)(OfxImageClipHandle clip, OfxPropertySetHandle *propHandle)

Retrieves the property set for a given clip.

  • clip clip effect to get the property set for
  • propHandle pointer to a the property set handle, value is returedn her
The property handle is valid for the lifetime of the clip, which is generally the lifetime of the instance.

Return

OfxStatus (*clipGetImage)(OfxImageClipHandle clip, OfxTime time, const OfxRectD *region, OfxPropertySetHandle *imageHandle)

Get a handle for an image in a clip at the indicated time and indicated region.

  • clip - the clip to extract the image from
  • time - time to fetch the image at
  • region - region to fetch the image from (optional, set to NULL to get a ‘default’ region) this is in the CanonicalCoordinates.
  • imageHandle - property set containing the image’s data
An image is fetched from a clip at the indicated time for the given region and returned in the imageHandle.

If the region parameter is not set to NULL, then it will be clipped to the clip’s Region of Definition for the given time. The returned image will be at least as big as this region. If the region parameter is not set, then the region fetched will be at least the Region of Interest the effect has previously specified, clipped the clip’s Region of Definition.

If clipGetImage is called twice with the same parameters, then two separate image handles will be returned, each of which must be release. The underlying implementation could share image data pointers and use reference counting to maintain them.

Pre
  • clip was returned by clipGetHandle
Post
  • image handle is only valid for the duration of the action clipGetImage is called in
  • image handle to be disposed of by clipReleaseImage before the action returns
Return
  • kOfxStatOK - the image was successfully fetched and returned in the handle,
  • kOfxStatFailed - the image could not be fetched because it does not exist in the clip at the indicated time and/or region, the plugin should continue operation, but assume the image was black and transparent.
  • kOfxStatErrBadHandle - the clip handle was invalid,
  • kOfxStatErrMemory - the host had not enough memory to complete the operation, plugin should abort whatever it was doing.

OfxStatus (*clipReleaseImage)(OfxPropertySetHandle imageHandle)

Releases the image handle previously returned by clipGetImage.

Pre
  • imageHandle was returned by clipGetImage
Post
  • all operations on imageHandle will be invalid
Return

OfxStatus (*clipGetRegionOfDefinition)(OfxImageClipHandle clip, OfxTime time, OfxRectD *bounds)

Returns the spatial region of definition of the clip at the given time.

  • clipHandle - the clip to extract the image from
  • time - time to fetch the image at
  • region - region to fetch the image from (optional, set to NULL to get a ‘default’ region) this is in the CanonicalCoordinates.
  • imageHandle - handle where the image is returned
An image is fetched from a clip at the indicated time for the given region and returned in the imageHandle.

If the region parameter is not set to NULL, then it will be clipped to the clip’s Region of Definition for the given time. The returned image will be at least as big as this region. If the region parameter is not set, then the region fetched will be at least the Region of Interest the effect has previously specified, clipped the clip’s Region of Definition.

Pre
  • clipHandle was returned by clipGetHandle
Post
  • bounds will be filled the RoD of the clip at the indicated time
Return
  • kOfxStatOK - the image was successfully fetched and returned in the handle,
  • kOfxStatFailed - the image could not be fetched because it does not exist in the clip at the indicated time, the plugin should continue operation, but assume the image was black and transparent.
  • kOfxStatErrBadHandle - the clip handle was invalid,
  • kOfxStatErrMemory - the host had not enough memory to complete the operation, plugin should abort whatever it was doing.

int (*abort)(OfxImageEffectHandle imageEffect)

Returns whether to abort processing or not.

  • imageEffect - instance of the image effect
A host may want to signal to a plugin that it should stop whatever rendering it is doing and start again. Generally this is done in interactive threads in response to users tweaking some parameter.

This function indicates whether a plugin should stop whatever processing it is doing.

Return
  • 0 if the effect should continue whatever processing it is doing
  • 1 if the effect should abort whatever processing it is doing

OfxStatus (*imageMemoryAlloc)(OfxImageEffectHandle instanceHandle, size_t nBytes, OfxImageMemoryHandle *memoryHandle)

Allocate memory from the host’s image memory pool.

  • instanceHandle - effect instance to associate with this memory allocation, may be NULL.
  • nBytes - the number of bytes to allocate
  • memoryHandle - pointer to the memory handle where a return value is placed
Memory handles allocated by this should be freed by OfxImageEffectSuiteV1::imageMemoryFree. To access the memory behind the handle you need to call OfxImageEffectSuiteV1::imageMemoryLock.

See ImageEffectsMemoryAllocation.

Return
  • kOfxStatOK if all went well, a valid memory handle is placed in memoryHandle
  • kOfxStatErrBadHandle if instanceHandle is not valid, memoryHandle is set to NULL
  • kOfxStatErrMemory if there was not enough memory to satisfy the call, memoryHandle is set to NULL

OfxStatus (*imageMemoryFree)(OfxImageMemoryHandle memoryHandle)

Frees a memory handle and associated memory.

  • memoryHandle - memory handle returned by imageMemoryAlloc
This function frees a memory handle and associated memory that was previously allocated via OfxImageEffectSuiteV1::imageMemoryAlloc

If there are outstanding locks, these are ignored and the handle and memory are freed anyway.

See ImageEffectsMemoryAllocation.

Return

OfxStatus (*imageMemoryLock)(OfxImageMemoryHandle memoryHandle, void **returnedPtr)

Lock the memory associated with a memory handle and make it available for use.

  • memoryHandle - memory handle returned by imageMemoryAlloc
  • returnedPtr - where to the pointer to the locked memory
This function locks them memory associated with a memory handle and returns a pointer to it. The memory will be 16 byte aligned, to allow use of vector operations.

Note that memory locks and unlocks nest.

After the first lock call, the contents of the memory pointer to by returnedPtr is undefined. All subsequent calls to lock will return memory with the same contents as the previous call.

Also, if unlocked, then relocked, the memory associated with a memory handle may be at a different address.

See also OfxImageEffectSuiteV1::imageMemoryUnlock and ImageEffectsMemoryAllocation.

Return
  • kOfxStatOK if the memory was locked, a pointer is placed in returnedPtr
  • kOfxStatErrBadHandle if the value of memoryHandle was not a valid pointer returned by OfxImageEffectSuiteV1::imageMemoryAlloc, null is placed in *returnedPtr
  • kOfxStatErrMemory if there was not enough memory to satisfy the call, *returnedPtr is set to NULL

OfxStatus (*imageMemoryUnlock)(OfxImageMemoryHandle memoryHandle)

Unlock allocated image data.

  • allocatedData - pointer to memory previously returned by OfxImageEffectSuiteV1::imageAlloc
This function unlocks a previously locked memory handle. Once completely unlocked, memory associated with a memoryHandle is no longer available for use. Attempting to use it results in undefined behaviour.

Note that locks and unlocks nest, and to fully unlock memory you need to match the count of locks placed upon it.

Also note, if you unlock a completely unlocked handle, it has no effect (ie: the lock count can’t be negative).

If unlocked, then relocked, the memory associated with a memory handle may be at a different address, however the contents will remain the same.

See also OfxImageEffectSuiteV1::imageMemoryLock and ImageEffectsMemoryAllocation.

Return
  • kOfxStatOK if the memory was unlocked cleanly,
  • kOfxStatErrBadHandle if the value of memoryHandle was not a valid pointer returned by OfxImageEffectSuiteV1::imageMemoryAlloc, null is placed in *returnedPtr