The Public Context API. More...

Macros
#define	VX_MAX_IMPLEMENTATION_NAME (64)
	Defines the length of the implementation name string, including the trailing zero.

Typedefs
typedef struct Context *	vx_context
	An opaque reference to the implementation context.

Enumerations
enum	vx_context_attribute_e { VX_CONTEXT_VENDOR_ID = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x0 , VX_CONTEXT_VERSION = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x1 , VX_CONTEXT_UNIQUE_KERNELS = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x2 , VX_CONTEXT_MODULES = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x3 , VX_CONTEXT_REFERENCES = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x4 , VX_CONTEXT_IMPLEMENTATION = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x5 , VX_CONTEXT_EXTENSIONS_SIZE = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x6 , VX_CONTEXT_EXTENSIONS = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x7 , VX_CONTEXT_CONVOLUTION_MAX_DIMENSION = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x8 , VX_CONTEXT_OPTICAL_FLOW_MAX_WINDOW_DIMENSION = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0x9 , VX_CONTEXT_IMMEDIATE_BORDER = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0xA , VX_CONTEXT_UNIQUE_KERNEL_TABLE = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0xB , VX_CONTEXT_IMMEDIATE_BORDER_POLICY = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0xC , VX_CONTEXT_NONLINEAR_MAX_DIMENSION = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0xd , VX_CONTEXT_MAX_TENSOR_DIMS = VX_ATTRIBUTE_BASE(VX_ID_KHRONOS, VX_TYPE_CONTEXT) + 0xE }
	A list of context attributes. More...

enum	vx_memory_type_e { VX_MEMORY_TYPE_NONE = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_MEMORY_TYPE) + 0x0 , VX_MEMORY_TYPE_HOST = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_MEMORY_TYPE) + 0x1 }
	An enumeration of memory import types. More...

enum	vx_termination_criteria_e { VX_TERM_CRITERIA_ITERATIONS = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_TERM_CRITERIA) + 0x0 , VX_TERM_CRITERIA_EPSILON = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_TERM_CRITERIA) + 0x1 , VX_TERM_CRITERIA_BOTH = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_TERM_CRITERIA) + 0x2 }
	The termination criteria list. More...

enum	vx_accessor_e { VX_READ_ONLY = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_ACCESSOR) + 0x1 , VX_WRITE_ONLY = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_ACCESSOR) + 0x2 , VX_READ_AND_WRITE = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_ACCESSOR) + 0x3 }
	The memory accessor hint flags. These enumeration values are used to indicate desired system behavior, not the User intent. For example: these can be interpretted as hints to the system about cache operations or marshalling operations. More...

enum	vx_round_policy_e { VX_ROUND_POLICY_TO_ZERO = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_ROUND_POLICY) + 0x1 , VX_ROUND_POLICY_TO_NEAREST_EVEN = VX_ENUM_BASE(VX_ID_KHRONOS, VX_ENUM_ROUND_POLICY) + 0x2 }
	The Round Policy Enumeration. More...

Functions
VX_API_ENTRY vx_context VX_API_CALL	vxCreateContext (void)
	Creates a `vx_context`.

VX_API_ENTRY vx_status VX_API_CALL	vxReleaseContext (vx_context *context)
	Releases the OpenVX object context.

VX_API_ENTRY vx_context VX_API_CALL	vxGetContext (vx_reference reference)
	Retrieves the context from any reference from within a context.

VX_API_ENTRY vx_status VX_API_CALL	vxQueryContext (vx_context context, vx_enum attribute, void *ptr, vx_size size)
	Queries the context for some specific information.

VX_API_ENTRY vx_status VX_API_CALL	vxSetContextAttribute (vx_context context, vx_enum attribute, const void *ptr, vx_size size)
	Sets an attribute on the context.

VX_API_ENTRY vx_status VX_API_CALL	vxSetImmediateModeTarget (vx_context context, vx_enum target_enum, const char *target_string)
	Sets the default target of the immediate mode. Upon successful execution of this function any future execution of immediate mode function is attempted on the new default target of the context.

Detailed Description

The Public Context API.

Macro Definition Documentation

◆ VX_MAX_IMPLEMENTATION_NAME

#define VX_MAX_IMPLEMENTATION_NAME (64)

#include <vx.h>

Defines the length of the implementation name string, including the trailing zero.

Typedef Documentation

◆ vx_context

typedef struct Context* vx_context

#include <vx_types.h>

An opaque reference to the implementation context.

See also: vxCreateContext

Enumeration Type Documentation

◆ vx_accessor_e

enum vx_accessor_e

#include <vx_types.h>

The memory accessor hint flags. These enumeration values are used to indicate desired system behavior, not the User intent. For example: these can be interpretted as hints to the system about cache operations or marshalling operations.

Enumerator
VX_READ_ONLY	The memory shall be treated by the system as if it were read-only. If the User writes to this memory, the results are implementation defined.
VX_WRITE_ONLY	The memory shall be treated by the system as if it were write-only. If the User reads from this memory, the results are implementation defined.
VX_READ_AND_WRITE	The memory shall be treated by the system as if it were readable and writeable.

◆ vx_context_attribute_e

enum vx_context_attribute_e

#include <vx_types.h>

A list of context attributes.

Enumerator
VX_CONTEXT_VENDOR_ID	Queries the unique vendor ID. Read-only. Use a `vx_uint16`.
VX_CONTEXT_VERSION	Queries the OpenVX Version Number. Read-only. Use a `vx_uint16`
VX_CONTEXT_UNIQUE_KERNELS	Queries the context for the number of unique kernels. Read-only. Use a `vx_uint32` parameter.
VX_CONTEXT_MODULES	Queries the context for the number of active modules. Read-only. Use a `vx_uint32` parameter.
VX_CONTEXT_REFERENCES	Queries the context for the number of active references. Read-only. Use a `vx_uint32` parameter.
VX_CONTEXT_IMPLEMENTATION	Queries the context for it's implementation name. Read-only. Use a `vx_char`[`VX_MAX_IMPLEMENTATION_NAME`] array.
VX_CONTEXT_EXTENSIONS_SIZE	Queries the number of bytes in the extensions string. Read-only. Use a `vx_size` parameter.
VX_CONTEXT_EXTENSIONS	Retrieves the extensions string. Read-only. This is a space-separated string of extension names. Each OpenVX official extension has a unique identifier, comprised of capital letters, numbers and the underscore character, prefixed with "KHR_", for example "KHR_NEW_FEATURE". Use a `vx_char` pointer allocated to the size returned from `VX_CONTEXT_EXTENSIONS_SIZE`.
VX_CONTEXT_CONVOLUTION_MAX_DIMENSION	The maximum width or height of a convolution matrix. Read-only. Use a `vx_size` parameter. Each vendor must support centered kernels of size w X h, where both w and h are odd numbers, 3 <= w <= n and 3 <= h <= n, where n is the value of the `VX_CONTEXT_CONVOLUTION_MAX_DIMENSION` attribute. n is an odd number that should not be smaller than 9. w and h may or may not be equal to each other. All combinations of w and h meeting the conditions above must be supported. The behavior of `vxCreateConvolution` is undefined for values larger than the value returned by this attribute.
VX_CONTEXT_OPTICAL_FLOW_MAX_WINDOW_DIMENSION	The maximum window dimension of the OpticalFlowPyrLK kernel. The value of this attribute shall be equal to or greater than '9'. See also `VX_KERNEL_OPTICAL_FLOW_PYR_LK`. Read-only. Use a `vx_size` parameter.
VX_CONTEXT_IMMEDIATE_BORDER	The border mode for immediate mode functions. Graph mode functions are unaffected by this attribute. Read-write. Use a pointer to a `vx_border_t` structure as parameter. Note The assumed default value for immediate mode functions is `VX_BORDER_UNDEFINED`.
VX_CONTEXT_UNIQUE_KERNEL_TABLE	Returns the table of all unique the kernels that exist in the context. Read-only. Use a `vx_kernel_info_t` array. Precondition You must call `vxQueryContext` with `VX_CONTEXT_UNIQUE_KERNELS` to compute the necessary size of the array.
VX_CONTEXT_IMMEDIATE_BORDER_POLICY	The unsupported border mode policy for immediate mode functions. Read-Write. Graph mode functions are unaffected by this attribute. Use a `vx_enum` as parameter. Will contain a `vx_border_policy_e`. Note The assumed default value for immediate mode functions is `VX_BORDER_POLICY_DEFAULT_TO_UNDEFINED`. Users should refer to the documentation of their implementation to determine what border modes are supported by each kernel.
VX_CONTEXT_NONLINEAR_MAX_DIMENSION	The dimension of the largest nonlinear filter supported. See `vxNonLinearFilterNode`. The implementation must support all dimensions (height or width, not necessarily the same) up to the value of this attribute. The lowest value that must be supported for this attribute is 9. Read-only. Use a `vx_size` parameter.
VX_CONTEXT_MAX_TENSOR_DIMS	tensor Data maximal number of dimensions supported by the implementation.

◆ vx_memory_type_e

enum vx_memory_type_e

#include <vx_types.h>

An enumeration of memory import types.

Enumerator
VX_MEMORY_TYPE_NONE	For memory allocated through OpenVX, this is the import type.
VX_MEMORY_TYPE_HOST	The default memory type to import from the Host.

◆ vx_round_policy_e

enum vx_round_policy_e

#include <vx_types.h>

The Round Policy Enumeration.

Enumerator
VX_ROUND_POLICY_TO_ZERO	When scaling, this truncates the least significant values that are lost in operations.
VX_ROUND_POLICY_TO_NEAREST_EVEN	When scaling, this rounds to nearest even output value.

◆ vx_termination_criteria_e

enum vx_termination_criteria_e

#include <vx_types.h>

The termination criteria list.

See also: Kernel: Optical Flow PyrLK

Enumerator
VX_TERM_CRITERIA_ITERATIONS	Indicates a termination after a set number of iterations.
VX_TERM_CRITERIA_EPSILON	Indicates a termination after matching against the value of eplison provided to the function.
VX_TERM_CRITERIA_BOTH	Indicates that both an iterations and eplison method are employed. Whichever one matches first causes the termination.

Function Documentation

◆ vxCreateContext()

VX_API_ENTRY vx_context VX_API_CALL vxCreateContext ( void )

#include <vx_api.h>

Creates a vx_context.

This creates a top-level object context for OpenVX.

Note: This is required to do anything else.

Returns: The reference to the implementation context vx_context. Any possible errors preventing a successful creation should be checked using vxGetStatus.

Postcondition: vxReleaseContext

Examples: bubble_pop.cpp, canny.cpp, optical_flow.cpp, orb.cpp, and skinToneDetector.cpp.

◆ vxGetContext()

VX_API_ENTRY vx_context VX_API_CALL vxGetContext ( vx_reference reference )

#include <vx_api.h>

Retrieves the context from any reference from within a context.

Parameters

[in] reference The reference from which to extract the context.

Returns: The overall context that created the particular reference. Any possible errors preventing a successful completion of this function should be checked using vxGetStatus.

◆ vxQueryContext()

VX_API_ENTRY vx_status VX_API_CALL vxQueryContext	(	vx_context	context,
		vx_enum	attribute,
		void *	ptr,
		vx_size	size )

#include <vx_api.h>

Queries the context for some specific information.

Parameters

[in]	context	The reference to the context.
[in]	attribute	The attribute to query. Use a `vx_context_attribute_e`.
[out]	ptr	The location at which to store the resulting value.
[in]	size	The size in bytes of the container to which ptr points.

Returns: A vx_status_e enumeration.

Return values

VX_SUCCESS	No errors; any other value indicates failure.
VX_ERROR_INVALID_REFERENCE	context is not a valid `vx_context` reference.
VX_ERROR_INVALID_PARAMETERS	If any of the other parameters are incorrect.
VX_ERROR_NOT_SUPPORTED	If the attribute is not supported on this implementation.

◆ vxReleaseContext()

VX_API_ENTRY vx_status VX_API_CALL vxReleaseContext ( vx_context * context )

#include <vx_api.h>

Releases the OpenVX object context.

All reference counted objects are garbage-collected by the return of this call. No calls are possible using the parameter context after the context has been released until a new reference from vxCreateContext is returned. All outstanding references to OpenVX objects from this context are invalid after this call.

Parameters

[in] context The pointer to the reference to the context.

Postcondition: After returning from this function the reference is zeroed.

Returns: A vx_status_e enumeration.

Return values

VX_SUCCESS	No errors; any other value indicates failure.
VX_ERROR_INVALID_REFERENCE	context is not a valid `vx_context` reference.

Precondition: vxCreateContext

Examples: bubble_pop.cpp, canny.cpp, optical_flow.cpp, orb.cpp, and skinToneDetector.cpp.

◆ vxSetContextAttribute()

VX_API_ENTRY vx_status VX_API_CALL vxSetContextAttribute	(	vx_context	context,
		vx_enum	attribute,
		const void *	ptr,
		vx_size	size )

#include <vx_api.h>

Sets an attribute on the context.

Parameters

[in]	context	The handle to the overall context.
[in]	attribute	The attribute to set from `vx_context_attribute_e`.
[in]	ptr	The pointer to the data to which to set the attribute.
[in]	size	The size in bytes of the data to which ptr points.

Returns: A vx_status_e enumeration.

Return values

VX_SUCCESS	No errors; any other value indicates failure.
VX_ERROR_INVALID_REFERENCE	context is not a valid `vx_context` reference.
VX_ERROR_INVALID_PARAMETERS	If any of the other parameters are incorrect.
VX_ERROR_NOT_SUPPORTED	If the attribute is not settable.

◆ vxSetImmediateModeTarget()

VX_API_ENTRY vx_status VX_API_CALL vxSetImmediateModeTarget	(	vx_context	context,
		vx_enum	target_enum,
		const char *	target_string )

#include <vx_api.h>

Sets the default target of the immediate mode. Upon successful execution of this function any future execution of immediate mode function is attempted on the new default target of the context.

Parameters

[in]	context	The reference to the implementation context.
[in]	target_enum	The default immediate mode target enum to be set to the `vx_context` object. Use a `vx_target_e`.
[in]	target_string	The target name ASCII string. This contains a valid value when target_enum is set to `VX_TARGET_STRING`, otherwise it is ignored.

Returns: A vx_status_e enumeration.

Return values

VX_SUCCESS	Default target set; any other value indicates failure.
VX_ERROR_INVALID_REFERENCE	If the context is not a valid `vx_context` reference.
VX_ERROR_NOT_SUPPORTED	If the specified target is not supported in this context.

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ VX_MAX_IMPLEMENTATION_NAME

Typedef Documentation

◆ vx_context

Enumeration Type Documentation

◆ vx_accessor_e

◆ vx_context_attribute_e

◆ vx_memory_type_e

◆ vx_round_policy_e

◆ vx_termination_criteria_e

Function Documentation

◆ vxCreateContext()

◆ vxGetContext()

◆ vxQueryContext()

◆ vxReleaseContext()

◆ vxSetContextAttribute()

◆ vxSetImmediateModeTarget()