FFT functions

Files
file	avfft.h

Data Structures
struct	FFTComplex

Typedefs
typedef float	FFTSample
typedef struct FFTContext	FFTContext
typedef struct RDFTContext	RDFTContext
typedef struct DCTContext	DCTContext

Enumerations
enum	RDFTransformType { DFT_R2C, IDFT_C2R, IDFT_R2C, DFT_C2R }
enum	DCTTransformType { DCT_II = 0, DCT_III, DCT_I, DST_I }

Functions
attribute_deprecated FFTContext *	av_fft_init (int nbits, int inverse)
	Set up a complex FFT. More...
attribute_deprecated void	av_fft_permute (FFTContext *s, FFTComplex *z)
	Do the permutation needed BEFORE calling ff_fft_calc(). More...
attribute_deprecated void	av_fft_calc (FFTContext *s, FFTComplex *z)
	Do a complex FFT with the parameters defined in av_fft_init(). More...
attribute_deprecated void	av_fft_end (FFTContext *s)
attribute_deprecated FFTContext *	av_mdct_init (int nbits, int inverse, double scale)
attribute_deprecated void	av_imdct_calc (FFTContext *s, FFTSample *output, const FFTSample *input)
attribute_deprecated void	av_imdct_half (FFTContext *s, FFTSample *output, const FFTSample *input)
attribute_deprecated void	av_mdct_calc (FFTContext *s, FFTSample *output, const FFTSample *input)
attribute_deprecated void	av_mdct_end (FFTContext *s)
attribute_deprecated RDFTContext *	av_rdft_init (int nbits, enum RDFTransformType trans)
	Set up a real FFT. More...
attribute_deprecated void	av_rdft_calc (RDFTContext *s, FFTSample *data)
attribute_deprecated void	av_rdft_end (RDFTContext *s)
attribute_deprecated DCTContext *	av_dct_init (int nbits, enum DCTTransformType type)
	Set up DCT. More...
attribute_deprecated void	av_dct_calc (DCTContext *s, FFTSample *data)
attribute_deprecated void	av_dct_end (DCTContext *s)

Detailed Description

Typedef Documentation

FFTSample

typedef float FFTSample

Definition at line 39 of file avfft.h.

FFTContext

typedef struct FFTContext FFTContext

Definition at line 45 of file avfft.h.

RDFTContext

typedef struct RDFTContext RDFTContext

Definition at line 98 of file avfft.h.

DCTContext

typedef struct DCTContext DCTContext

Definition at line 116 of file avfft.h.

Enumeration Type Documentation

RDFTransformType

enum RDFTransformType

Enumerator
DFT_R2C
IDFT_C2R
IDFT_R2C
DFT_C2R

Definition at line 91 of file avfft.h.

DCTTransformType

enum DCTTransformType

Enumerator
DCT_II
DCT_III
DCT_I
DST_I

Definition at line 118 of file avfft.h.

Function Documentation

av_fft_init()

attribute_deprecated FFTContext* av_fft_init	(	int	nbits,
		int	inverse
	)

Set up a complex FFT.

Parameters

nbits	log2 of the length of the input array
inverse	if 0 perform the forward transform, if 1 perform the inverse

Deprecated:

use av_tx_init from libavutil/tx.h with a type of AV_TX_FLOAT_FFT

Definition at line 45 of file avfft.c.

av_fft_permute()

attribute_deprecated void av_fft_permute	(	FFTContext *	s,
		FFTComplex *	z
	)

Do the permutation needed BEFORE calling ff_fft_calc().

Deprecated:

without replacement

Definition at line 63 of file avfft.c.

av_fft_calc()

attribute_deprecated void av_fft_calc	(	FFTContext *	s,
		FFTComplex *	z
	)

Do a complex FFT with the parameters defined in av_fft_init().

The input data must be permuted before. No 1.0/sqrt(n) normalization is done.

Deprecated:

use the av_tx_fn value returned by av_tx_init, which also does permutation

Definition at line 68 of file avfft.c.

av_fft_end()

attribute_deprecated void av_fft_end

(

FFTContext *

s

)

Definition at line 74 of file avfft.c.

av_mdct_init()

attribute_deprecated FFTContext* av_mdct_init	(	int	nbits,
		int	inverse,
		double	scale
	)

Deprecated:

use av_tx_init from libavutil/tx.h with a type of AV_TX_FLOAT_MDCT, with a flag of AV_TX_FULL_IMDCT for a replacement to av_imdct_calc.

Definition at line 84 of file avfft.c.

av_imdct_calc()

attribute_deprecated void av_imdct_calc	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)

Definition at line 111 of file avfft.c.

av_imdct_half()

attribute_deprecated void av_imdct_half	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)

Definition at line 117 of file avfft.c.

av_mdct_calc()

attribute_deprecated void av_mdct_calc	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)

Definition at line 123 of file avfft.c.

av_mdct_end()

attribute_deprecated void av_mdct_end

(

FFTContext *

s

)

Definition at line 129 of file avfft.c.

av_rdft_init()

attribute_deprecated RDFTContext* av_rdft_init	(	int	nbits,
		enum RDFTransformType	trans
	)

Set up a real FFT.

Parameters

nbits	log2 of the length of the input array
trans	the type of transform

Deprecated:

use av_tx_init from libavutil/tx.h with a type of AV_TX_FLOAT_RDFT

Definition at line 139 of file avfft.c.

av_rdft_calc()

attribute_deprecated void av_rdft_calc	(	RDFTContext *	s,
		FFTSample *	data
	)

Definition at line 175 of file avfft.c.

av_rdft_end()

attribute_deprecated void av_rdft_end

(

RDFTContext *

s

)

Definition at line 196 of file avfft.c.

av_dct_init()

attribute_deprecated DCTContext* av_dct_init	(	int	nbits,
		enum DCTTransformType	type
	)

Set up DCT.

Parameters

nbits	size of the input array: (1 << nbits) for DCT-II, DCT-III and DST-I (1 << nbits) + 1 for DCT-I
type	the type of transform

Note

the first element of the input of DST-I is ignored

Deprecated:

use av_tx_init from libavutil/tx.h with an appropriate type of AV_TX_FLOAT_DCT

Definition at line 206 of file avfft.c.

av_dct_calc()

attribute_deprecated void av_dct_calc	(	DCTContext *	s,
		FFTSample *	data
	)

Definition at line 249 of file avfft.c.

av_dct_end()

attribute_deprecated void av_dct_end

(

DCTContext *

s

)

Definition at line 260 of file avfft.c.