Object: Delay

Detailed Description

Defines the Delay Object interface.

A Delay is an opaque object that contains a manually-controlled, temporally-delayed list of objects. A Delay cannot be an output of a kernel. Also, aging of a Delay (see vxAgeDelay) cannot be performed during graph execution. Supported delay object types include:

• VX_TYPE_ARRAY,
• VX_TYPE_IMAGE,
• VX_TYPE_PYRAMID,
• VX_TYPE_MATRIX,
• VX_TYPE_CONVOLUTION,
• VX_TYPE_DISTRIBUTION,
• VX_TYPE_REMAP,
• VX_TYPE_LUT,
• VX_TYPE_THRESHOLD,
• VX_TYPE_SCALAR

Modules
	Delay Attribute Constants
	The delay attribute list.

Typedefs
typedef struct _vx_delay *	vx_delay
	The delay object. This is like a ring buffer of objects that is maintained by the OpenVX implementation. More...

Functions
vx_status VX_API_CALL	vxAgeDelay (vx_delay delay)
	Shifts the internal delay ring by one. More...
vx_delay VX_API_CALL	vxCreateDelay (vx_context context, vx_reference exemplar, vx_size num_slots)
	Creates a Delay object [R00882]. More...
vx_reference VX_API_CALL	vxGetReferenceFromDelay (vx_delay delay, vx_int32 index)
	Retrieves a reference to a delay slot object [R00903]. More...
vx_status VX_API_CALL	vxQueryDelay (vx_delay delay, vx_enum attribute, void *ptr, vx_size size)
	Queries a vx_delay object attribute [R00872]. More...
vx_status VX_API_CALL	vxReleaseDelay (vx_delay *delay)
	Releases a reference to a delay object [R00878]. The object may not be garbage collected until its total reference count is zero. More...

Typedef Documentation

vx_delay

typedef struct _vx_delay* vx_delay

The delay object. This is like a ring buffer of objects that is maintained by the OpenVX implementation.

See also

vxCreateDelay

Definition at line 234 of file vx_types.h.

Function Documentation

vxQueryDelay()

vx_status VX_API_CALL vxQueryDelay	(	vx_delay	delay,
		vx_enum	attribute,
		void *	ptr,
		vx_size	size
	)

Queries a vx_delay object attribute [R00872].

Parameters

[in]	delay	The reference to a delay object [R00873].
[in]	attribute	The attribute to query, use a Delay Attribute Constants value [R00874].
[out]	ptr	The location at which to store the resulting value [R00875].
[in]	size	The size of the container to which ptr points [R00876].

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00877].
VX_ERROR_INVALID_REFERENCE	delay is not a valid vx_delay reference.

vxReleaseDelay()

vx_status VX_API_CALL vxReleaseDelay

(

vx_delay *

delay

)

Releases a reference to a delay object [R00878]. The object may not be garbage collected until its total reference count is zero.

Parameters

[in]

delay

The pointer to the delay object reference to release [R00879].

Postcondition

After returning from this function the reference is zeroed [R00880].

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00881].
VX_ERROR_INVALID_REFERENCE	delay is not a valid vx_delay reference.

vxCreateDelay()

vx_delay VX_API_CALL vxCreateDelay	(	vx_context	context,
		vx_reference	exemplar,
		vx_size	num_slots
	)

Creates a Delay object [R00882].

This function creates a delay object with num_slots slots [R00883]. Each slot contains a clone of the exemplar [R00884]. The clones only inherit the metadata of the exemplar [R00885]. The data content of the exemplar is ignored and the clones have their data is implementation-dependent at delay creation time. The function does not alter the exemplar [R00886]. Also, it doesn't retain or release the reference to the exemplar [R00887].

Note

For the definition of metadata attributes see vxSetMetaFormatAttribute.

Parameters

[in]	context	The reference to the context [R00888].
[in]	exemplar	The exemplar object. Supported exemplar object types are: VX_TYPE_ARRAY [R00889] VX_TYPE_CONVOLUTION [R00890] VX_TYPE_DISTRIBUTION [R00891] VX_TYPE_IMAGE [R00892] VX_TYPE_LUT [R00893] VX_TYPE_MATRIX [R00894] VX_TYPE_OBJECT_ARRAY [R00895] VX_TYPE_PYRAMID [R00896] VX_TYPE_REMAP [R00897] VX_TYPE_SCALAR [R00898] VX_TYPE_THRESHOLD [R00899]
[in]	num_slots	The number of objects in the delay [R00900].

Returns

A delay reference vx_delay [R00901]. Any possible errors preventing a successful creation should be checked using vxGetStatus [R00902].

vxGetReferenceFromDelay()

vx_reference VX_API_CALL vxGetReferenceFromDelay	(	vx_delay	delay,
		vx_int32	index
	)

Retrieves a reference to a delay slot object [R00903].

Parameters

[in]	delay	The reference to the delay object [R00904].
[in]	index	The index of the delay slot from which to extract the object reference [R00905].

Returns

vx_reference. Any possible errors preventing a successful completion of the function should be checked using vxGetStatus [R00906].

Note

The delay index is in the range \( [-count+1,0] \) [R00907]. 0 is always the current object.

A reference retrieved with this function must not be given to its associated release API (e.g. vxReleaseImage) unless vxRetainReference is used.

vxAgeDelay()

vx_status VX_API_CALL vxAgeDelay

(

vx_delay

delay

)

Shifts the internal delay ring by one.

This function performs a shift of the internal delay ring by one. This means that, the data originally at index 0 move to index -1 and so forth until index \( -count+1 \) [R00908]. The data originally at index \( -count+1 \) move to index 0 [R00909]. Here \( count \) is the number of slots in delay ring. When a delay is aged, any graph making use of this delay (delay object itself or data objects in delay slots) gets its data automatically updated accordingly [R00910].

Parameters

[in]

delay

[R00911]

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	Delay was aged; any other value indicates failure [R00912].
VX_ERROR_INVALID_REFERENCE	delay is not a valid vx_delay reference.