Fast Fourier Transform

Operations that applies the Fast Fourier Transform and its inverse to 2D images. More...

Functions
VPIStatus	vpiCreateFFT (VPIBackend backend, uint32_t inputWidth, uint32_t inputHeight, const VPIImageFormat inFormat, const VPIImageFormat outFormat, VPIPayload *payload)
	Creates payload for direct Fast Fourier Transform algorithm. More...
VPIStatus	vpiSubmitFFT (VPIStream stream, VPIPayload payload, VPIImage input, VPIImage output, uint32_t flags)
	Runs the direct Fast Fourier Transform on single image. More...
VPIStatus	vpiCreateIFFT (VPIBackend backend, uint32_t outputWidth, uint32_t outputHeight, const VPIImageFormat inFormat, const VPIImageFormat outFormat, VPIPayload *payload)
	Creates payload for inverse Fast Fourier Transform algorithm. More...
VPIStatus	vpiSubmitIFFT (VPIStream stream, VPIPayload payload, VPIImage input, VPIImage output, uint32_t flags)
	Runs the inverse Fast Fourier Transform on single image. More...

Inverse FFT flags. Valid flags to be used in \ref vpiSubmitIFFT. They
can be or-ed together.
#define	VPI_IFFT_DENORMALIZED   (1u)
	Do not normalize the output. More...

Detailed Description

Operations that applies the Fast Fourier Transform and its inverse to 2D images.

Both FFT and inverse FFT need a payload created during application initialization phase, where image dimensions, input and output types are defined. The payload then can be used to submit operations on different images, as long as their dimensions and types match what was defined during payload creation.

Macro Definition Documentation

VPI_IFFT_DENORMALIZED

#define VPI_IFFT_DENORMALIZED   (1u)

#include <vpi/algo/FFT.h>

Do not normalize the output.

This leads to faster execution as normalization isn't usually needed. Absense of this flag will scale the output, dividing it by the total pixel count. This makes the output the exact inverse of direct Fast Fourier Transform.

Definition at line 144 of file FFT.h.

Function Documentation

vpiCreateFFT()

VPIStatus vpiCreateFFT	(	VPIBackend	backend,
		uint32_t	inputWidth,
		uint32_t	inputHeight,
		const VPIImageFormat	inFormat,
		const VPIImageFormat	outFormat,
		VPIPayload *	payload
	)

#include <vpi/algo/FFT.h>

Creates payload for direct Fast Fourier Transform algorithm.

The created payload can then be used with vpiSubmitFFT.

Parameters

[in]	backend	VPI backend that will execute the algorithm.
[in]	inputWidth,inputHeight	Dimensions of the input/output images to be used.
[in]	inFormat	Input image format.
[in]	outFormat	Output image format.
[out]	payload	Pointer to memory where the created payload handle will be written to.

Returns

an error code on failure else VPI_SUCCESS.

vpiCreateIFFT()

VPIStatus vpiCreateIFFT	(	VPIBackend	backend,
		uint32_t	outputWidth,
		uint32_t	outputHeight,
		const VPIImageFormat	inFormat,
		const VPIImageFormat	outFormat,
		VPIPayload *	payload
	)

#include <vpi/algo/FFT.h>

Creates payload for inverse Fast Fourier Transform algorithm.

The created payload can then be used with vpiSubmitIFFT.

Parameters

[in]	backend	VPI backend that will execute the algorithm.
[in]	outputWidth,outputHeight	Output image dimensions.
[in]	inFormat	Input image format.
[in]	outFormat	Output image format.
[out]	payload	Pointer to memory where the created payload handle will be written to.

Returns

an error code on failure else VPI_SUCCESS

vpiSubmitFFT()

VPIStatus vpiSubmitFFT	(	VPIStream	stream,
		VPIPayload	payload,
		VPIImage	input,
		VPIImage	output,
		uint32_t	flags
	)

#include <vpi/algo/FFT.h>

Runs the direct Fast Fourier Transform on single image.

Parameters

[in]	stream	The stream where the operation will be queued in.
[in]	payload	Payload created with vpiCreateFFT
[in]	input	Input image in space domain.
[out]	output	Image where the result in frequency domain will be written to.
[in]	flags	Control flags, currently it must be set to 0.

Returns

an error code on failure else VPI_SUCCESS

vpiSubmitIFFT()

VPIStatus vpiSubmitIFFT	(	VPIStream	stream,
		VPIPayload	payload,
		VPIImage	input,
		VPIImage	output,
		uint32_t	flags
	)

#include <vpi/algo/FFT.h>

Runs the inverse Fast Fourier Transform on single image.

Parameters

[in]	stream	A stream handle where the operation will be queued in.
[in]	payload	Payload created with vpiCreateIFFT
[in]	input	Input image in frequency domain.
[out]	output	Image where the result in space domain will be written to.
[in]	flags	Control flags, 0 for default processing, where output scaled.

Returns

an error code on failure else VPI_SUCCESS