VPI - Vision Programming Interface

2.0 Release - Developer Preview

An abstract representation of a 2D image pyramid. More...

Data Structures

struct  VPIPyramidData
 Stores the pyramid contents. More...
 

Macros

#define VPI_MAX_PYRAMID_LEVEL_COUNT   (10)
 Maximum number of pyramid levels.
 

Typedefs

typedef struct VPIPyramidImpl * VPIPyramid
 A handle to an image pyramid.
 

Functions

VPIStatus vpiPyramidCreate (int32_t width, int32_t height, VPIImageFormat fmt, int32_t numLevels, float scale, uint64_t flags, VPIPyramid *pyr)
 Create an empty image pyramid instance with the specified flags. More...
 
void vpiPyramidDestroy (VPIPyramid pyr)
 Destroy an image pyramid instance as well as all resources it owns. More...
 
VPIStatus vpiPyramidGetFlags (VPIPyramid pyr, uint64_t *flags)
 Returns the flags associated with the pyramid. More...
 
VPIStatus vpiPyramidGetFormat (VPIPyramid pyr, VPIImageFormat *fmt)
 Returns the image format of the pyramid levels. More...
 
VPIStatus vpiPyramidGetNumLevels (VPIPyramid pyr, int32_t *numLevels)
 Get the image pyramid level count. More...
 
VPIStatus vpiPyramidGetSize (VPIPyramid pyr, int32_t outSize, int32_t *outWidth, int32_t *outHeight)
 Get the image width and height in pixels (for all levels at once). More...
 
VPIStatus vpiPyramidGetScale (VPIPyramid pyr, float *scale)
 Returns the scale factor of the pyramid levels. More...
 
VPIStatus vpiPyramidLock (VPIPyramid pyr, VPILockMode lock)
 Acquires the lock on an pyramid object. More...
 
VPIStatus vpiPyramidLockData (VPIPyramid pyr, VPILockMode lock, VPIImageBufferType bufType, VPIPyramidData *out)
 Acquires the lock on a pyramid object and returns host-accessible pointers to each level of the pyramid. More...
 
VPIStatus vpiPyramidUnlock (VPIPyramid pyr)
 Releases the lock on a image pyramid object. More...
 
VPIStatus vpiImageCreateWrapperPyramidLevel (VPIPyramid pyr, int32_t level, VPIImage *img)
 Creates an image that wraps one pyramid level. More...
 

Detailed Description

An abstract representation of a 2D image pyramid.

2D image pyramid containers are created by calling vpiPyramidCreate to allocate and initialize an empty (zeroed) VPIPyramid object. The memory for the image pyramid data is allocated and managed by VPI.

Image formats match the ones supported by image container. The pyramid is not necessarily dyadic. The scale between levels is defined in the constructor.

Parameters such as levels, scale, width, height and image format are immutable and specified at the construction time. The internal memory layout is also backend-specific. More importantly, efficient exchange of image pyramid data between different hardware blocks might force the implementation to allocate the memory in multiple memory pools (e.g. dGPU and system DRAM). In some scenarios (to optimize performance and memory use), it might be beneficial to constrain the internal allocation policy to support only a particular set of backends.

The set of vpiPyramidLockData / vpiPyramidUnlock calls allows the user to read from/write to the image data from the host. These functions are non-blocking and oblivious to the device command queue, so it's up to the user to make sure that all pending operations using this image pyramid as input or output are finished. Also, depending on the enabled backends lock/unlock operation might be time-consuming and, for example, involve copying data over PCIe bus for dGPUs.


Data Structure Documentation

◆ VPIPyramidData

struct VPIPyramidData

Stores the pyramid contents.

Each level is represented by an entire VPIImageData. There are numLevels levels, and they can be accessed from levels[0] to levels[numLevels-1].

Definition at line 111 of file Pyramid.h.

+ Collaboration diagram for VPIPyramidData:
Data Fields
VPIImageData levels[VPI_MAX_PYRAMID_LEVEL_COUNT] Contents of every pyramid level.

Only the first numLevels levels has valid data.

int32_t numLevels Number of levels (i.e.

height) of the pyramid.

float scale Scale factor of resolution between two adjecent levels.

Function Documentation

◆ vpiImageCreateWrapperPyramidLevel()

VPIStatus vpiImageCreateWrapperPyramidLevel ( VPIPyramid  pyr,
int32_t  level,
VPIImage img 
)

#include <vpi/Pyramid.h>

Creates an image that wraps one pyramid level.

The created image doesn't own its contents. Destroying the pyramid while there are images wrapping its levels leads to undefined behavior. If image wraps the base pyramid level, locking the pyramid will also lock the image. Once the image isn't needed anymore, call vpiImageDestroy to free resources.

The created image inherits the flags of the wrapped pyramid, including the enabled backends.

Parameters
[in]pyrThe pyramid whose level will be wrapped.
  • Mandatory, it can't be NULL.
[in]levelPyramid level to wrap.
  • Must be >= 0.
[out]imgPointer to an image handle that will hold the created image.
  • Mandatory, it can't be NULL.
Return values
VPI_ERROR_INVALID_ARGUMENTOutput img is NULL.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL.
VPI_ERROR_INVALID_ARGUMENTlevel outside valid range.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_ERROR_INVALID_OPERATIONWrapped image is not created in current context.
VPI_ERROR_INVALID_CONTEXTCurrent context was destroyed.
VPI_ERROR_OUT_OF_MEMORYNot enough resources to create image.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidCreate()

VPIStatus vpiPyramidCreate ( int32_t  width,
int32_t  height,
VPIImageFormat  fmt,
int32_t  numLevels,
float  scale,
uint64_t  flags,
VPIPyramid pyr 
)

#include <vpi/Pyramid.h>

Create an empty image pyramid instance with the specified flags.

Pyramid data is zeroed.

Parameters
[in]width,heightDimensions of the finest pyramid level.
  • Width and height must be > 0.
[in]numLevelsNumber of levels.
[in]scaleScale factor from one level and the next.
  • Must be > 0 and <= 1.
[in]fmtImage format of each level.
  • Accepts non-YUV or YUV 4:4:4 formats (no chroma subsampling allowed)
  • CPU and CUDA backends only support pitch-linear formats.
  • Can't be VPI_IMAGE_FORMAT_INVALID.
[in]flagsBit field specifying the desired characteristics of the pyramid.
  • The field must be a combination of zero or more of the following flags:
    • VPIBackend flags. This pyramid can be used in algorithms running in these backends. If no backend flags are given and VPI_REQUIRE_BACKENDS is not set, it'll consider all backends supported by the active VPIContext, but disable the backends that are incompatible with the given image parameters.
    • Common object flags
  • If flag VPI_REQUIRE_BACKENDS is given, user must pass at least one valid backend that is enabled in current context AND is compatible with the given image parameters.
[out]pyrPointer to memory that will receive the created pyramid handle.
Return values
VPI_ERROR_INVALID_ARGUMENTOutput pyr is NULL.
VPI_ERROR_INVALID_ARGUMENTnumLevels outside valid range.
VPI_ERROR_INVALID_ARGUMENTwidth or height outside valid range.
VPI_ERROR_INVALID_ARGUMENTscale outside valid range.
VPI_ERROR_INVALID_ARGUMENTNo backend were given and VPI_REQUIRE_BACKENDS is set.
VPI_ERROR_INVALID_IMAGE_FORMATfmt is not accepted.
VPI_ERROR_INVALID_ARGUMENTInvalid flags.
VPI_ERROR_OUT_OF_MEMORYNot enough resources to create image.
VPI_ERROR_INVALID_CONTEXTCurrent context it destroyed.
VPI_ERROR_INVALID_OPERATIONRequested backend isn't enabled in current context.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidDestroy()

void vpiPyramidDestroy ( VPIPyramid  pyr)

#include <vpi/Pyramid.h>

Destroy an image pyramid instance as well as all resources it owns.

Parameters
[in]pyrPyramid handle. Passing NULL is allowed, to which the function simply does nothing.
  • Pyramid must not be in use by any stream, or else undefined behavior will ensue.

◆ vpiPyramidGetFlags()

VPIStatus vpiPyramidGetFlags ( VPIPyramid  pyr,
uint64_t *  flags 
)

#include <vpi/Pyramid.h>

Returns the flags associated with the pyramid.

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
[out]flagsPointer to where the flags will be written.
  • Mandatory, it can't be NULL.
Return values
VPI_ERROR_INVALID_ARGUMENTOutput flags pointer is NULL.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidGetFormat()

VPIStatus vpiPyramidGetFormat ( VPIPyramid  pyr,
VPIImageFormat fmt 
)

#include <vpi/Pyramid.h>

Returns the image format of the pyramid levels.

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
[out]fmtPointer to where the image format will be written.
  • Mandatory, it can't be NULL.
Return values
VPI_ERROR_INVALID_ARGUMENTOutput fmt is NULL.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidGetNumLevels()

VPIStatus vpiPyramidGetNumLevels ( VPIPyramid  pyr,
int32_t *  numLevels 
)

#include <vpi/Pyramid.h>

Get the image pyramid level count.

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
[out]numLevelsA pointer to a variable which will be set to the number of levels of the image pyramid.
  • Mandatory, it can't be NULL.
Return values
VPI_ERROR_INVALID_ARGUMENTOutput numLevels pointer is NULL.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidGetScale()

VPIStatus vpiPyramidGetScale ( VPIPyramid  pyr,
float *  scale 
)

#include <vpi/Pyramid.h>

Returns the scale factor of the pyramid levels.

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
[out]scalePointer to where the scale will be written.
  • Mandatory, it can't be NULL.
Return values
VPI_ERROR_INVALID_ARGUMENTOutput scale pointer is NULL.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidGetSize()

VPIStatus vpiPyramidGetSize ( VPIPyramid  pyr,
int32_t  outSize,
int32_t *  outWidth,
int32_t *  outHeight 
)

#include <vpi/Pyramid.h>

Get the image width and height in pixels (for all levels at once).

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
[in]outSizeSize of the output arrays, in elements.
  • Must be >= 1.
[out]outWidth,outHeightPointers to an array which will be filled with widths and heights (respectively) of all image pyramid levels. If any of them is NULL, the corresponding data isn't returned.
Return values
VPI_ERROR_INVALID_ARGUMENToutSize outside valid range.
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_ERROR_INVALID_ARGUMENToutWidth and outHeight can't be NULL.
VPI_SUCCESSOperation executed successfully.

◆ vpiPyramidLock()

VPIStatus vpiPyramidLock ( VPIPyramid  pyr,
VPILockMode  lock 
)

#include <vpi/Pyramid.h>

Acquires the lock on an pyramid object.

As long as the lock is held, any attempt of VPI to access the image in a mode not compatible with the lock mode will result in asynchronous stream errors, VPI_ERROR_BUFFER_LOCKED.

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
  • Pyramid must not be locked in a mode that is incompatible with given mode.
[in]lockLock mode.
Return values
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_ERROR_BUFFER_LOCKEDPyramid is already locked by either a stream or the user.
VPI_ERROR_INVALID_ARGUMENTout is NULL.
VPI_SUCCESSOperation executed successfully

◆ vpiPyramidLockData()

VPIStatus vpiPyramidLockData ( VPIPyramid  pyr,
VPILockMode  lock,
VPIImageBufferType  bufType,
VPIPyramidData out 
)

#include <vpi/Pyramid.h>

Acquires the lock on a pyramid object and returns host-accessible pointers to each level of the pyramid.

Depending on the internal image representation, as well as the actual location in memory, this function might have a significant performance overhead (format conversion, layout conversion, device-to-host memory copy).

Parameters
[in]pyrPyramid handle.
[in]lockLock mode.
[in]bufTypeThe type of buffer returned in data. It defines how the image contents can be accessed by the caller. Valid types are:
[out]outA pointer to a structure that will receive the pyramid data to be accessed from host. Pass NULL if you're only interested in making sure that the wrapped image is updated with the most recent contents from VPI. The image will still be locked.
  • The buffers it points to are valid until the pyramid is unlocked.
Return values
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_ERROR_INVALID_OPERATIONimg doesn't have required backends enabled.
VPI_ERROR_INVALID_ARGUMENTout is NULL.
VPI_ERROR_BUFFER_LOCKEDPyramid is already locked by either a stream or the user.
VPI_SUCCESSOperation executed successfully

◆ vpiPyramidUnlock()

VPIStatus vpiPyramidUnlock ( VPIPyramid  pyr)

#include <vpi/Pyramid.h>

Releases the lock on a image pyramid object.

This function might have a significant performance overhead (format conversion, layout conversion, host-to-device memory copy).

Parameters
[in]pyrPyramid handle.
  • Mandatory, it can't be NULL.
Return values
VPI_ERROR_INVALID_ARGUMENTpyr is NULL or doesn't represent a VPIPyramid instance.
VPI_ERROR_INVALID_OPERATIONpyr doesn't have CPU backend enabled.
VPI_ERROR_INVALID_OPERATIONpyr isn't locked.
VPI_SUCCESSOperation executed successfully.