FFT/IFFT transforms. More...

#include <stdlib.h>
#include <string.h>
#include "libavutil/mathematics.h"
#include "fft.h"
#include "fft-internal.h"

Include dependency graph for fft.c:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Macros
#define	BUTTERFLIES(a0, a1, a2, a3)

#define	BUTTERFLIES_BIG(a0, a1, a2, a3)

#define	TRANSFORM(a0, a1, a2, a3, wre, wim)

#define	TRANSFORM_ZERO(a0, a1, a2, a3)

#define	PASS(name)

#define	BUTTERFLIES BUTTERFLIES_BIG

#define	DECL_FFT(n, n2, n4)

#define	pass pass_big

Functions
	COSTABLE (16)

	COSTABLE (32)

	COSTABLE (64)

	COSTABLE (128)

	COSTABLE (256)

	COSTABLE (512)

	COSTABLE (1024)

	COSTABLE (2048)

	COSTABLE (4096)

	COSTABLE (8192)

	COSTABLE (16384)

	COSTABLE (32768)

	COSTABLE (65536)

COSTABLE_CONST FFTSample *const	FFT_NAME (ff_cos_tabs)[]

static void	ff_fft_permute_c (FFTContext s, FFTComplex z)

static void	ff_fft_calc_c (FFTContext s, FFTComplex z)

static int	split_radix_permutation (int i, int n, int inverse)

av_cold void	ff_init_ff_cos_tabs (int index)
	Initialize the cosine table in ff_cos_tabs[index]. More...

static int	is_second_half_of_fft32 (int i, int n)

static av_cold void	fft_perm_avx (FFTContext *s)

av_cold int	ff_fft_init (FFTContext *s, int nbits, int inverse)
	Set up a complex FFT. More...

av_cold void	ff_fft_end (FFTContext *s)

static void	fft4 (FFTComplex *z)

static void	fft8 (FFTComplex *z)

static void	fft16 (FFTComplex *z)

Variables
static const int	avx_tab []

static void(*const	fft_dispatch [])(FFTComplex *)

Detailed Description

FFT/IFFT transforms.

Definition in file fft.c.

Macro Definition Documentation

#define BUTTERFLIES	(	a0,
		a1,
		a2,
		a3
	)

Value:

{\
    BF(t3, t5, t5, t1);\
    BF(a2.re, a0.re, a0.re, t5);\
    BF(a3.im, a1.im, a1.im, t3);\
    BF(t4, t6, t2, t6);\
    BF(a3.re, a1.re, a1.re, t4);\
    BF(a2.im, a0.im, a0.im, t6);\
}

Definition at line 269 of file fft.c.

Referenced by fft8().

#define BUTTERFLIES BUTTERFLIES_BIG

Definition at line 269 of file fft.c.

#define BUTTERFLIES_BIG	(	a0,
		a1,
		a2,
		a3
	)

Value:

{\
    FFTSample r0=a0.re, i0=a0.im, r1=a1.re, i1=a1.im;\
    BF(t3, t5, t5, t1);\
    BF(a2.re, a0.re, r0, t5);\
    BF(a3.im, a1.im, i1, t3);\
    BF(t4, t6, t2, t6);\
    BF(a3.re, a1.re, r1, t4);\
    BF(a2.im, a0.im, i0, t6);\
}

Definition at line 221 of file fft.c.

#define DECL_FFT	(	n,
		n2,
		n4
	)

Value:

static void fft##n(FFTComplex *z)\
{\
    fft##n2(z);\
    fft##n4(z+n4*2);\
    fft##n4(z+n4*3);\
    pass(z,FFT_NAME(ff_cos_##n),n4/2);\
}

Definition at line 272 of file fft.c.

Referenced by fft16().

#define PASS ( name )

Value:

static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
{\
    FFTDouble t1, t2, t3, t4, t5, t6;\
    int o1 = 2*n;\
    int o2 = 4*n;\
    int o3 = 6*n;\
    const FFTSample *wim = wre+o1;\
    n--;\
\
    TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3]);\
    TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\
    do {\
        z += 2;\
        wre += 2;\
        wim -= 2;\
        TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0]);\
        TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\
    } while(--n);\
}

Definition at line 246 of file fft.c.

#define pass pass_big

Definition at line 335 of file fft.c.

Referenced by decode_nal_units(), encode_frame(), ff_lpc_calc_coefs(), ff_pca(), ff_png_pass_row_size(), generate_transition(), gif_read_image(), guess_mv(), h264_handle_packet(), iterative_me(), new_video_stream(), png_get_interlaced_row(), residue_encode(), and vorbis_residue_decode_internal().

#define TRANSFORM	(	a0,
		a1,
		a2,
		a3,
		wre,
		wim
	)

Value:

{\
    CMUL(t1, t2, a2.re, a2.im, wre, -wim);\
    CMUL(t5, t6, a3.re, a3.im, wre,  wim);\
    BUTTERFLIES(a0,a1,a2,a3)\
}

Definition at line 231 of file fft.c.

Referenced by fft16(), and fft8().

#define TRANSFORM_ZERO	(	a0,
		a1,
		a2,
		a3
	)

Value:

{\
    t1 = a2.re;\
    t2 = a2.im;\
    t5 = a3.re;\
    t6 = a3.im;\
    BUTTERFLIES(a0,a1,a2,a3)\
}

Definition at line 237 of file fft.c.

Referenced by fft16().

Function Documentation

COSTABLE ( 16 )

COSTABLE ( 32 )

COSTABLE ( 64 )

COSTABLE ( 128 )

COSTABLE ( 256 )

COSTABLE ( 512 )

COSTABLE ( 1024 )

COSTABLE ( 2048 )

COSTABLE ( 4096 )

COSTABLE ( 8192 )

COSTABLE ( 16384 )

COSTABLE ( 32768 )

COSTABLE ( 65536 )

static void ff_fft_calc_c	(	FFTContext *	s,
		FFTComplex *	z
	)

static

Definition at line 350 of file fft.c.

Referenced by ff_fft_init().

av_cold void ff_fft_end ( FFTContext * s )

Definition at line 203 of file fft.c.

av_cold int ff_fft_init	(	FFTContext *	s,
		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

Definition at line 134 of file fft.c.

static void ff_fft_permute_c	(	FFTContext *	s,
		FFTComplex *	z
	)

static

Definition at line 193 of file fft.c.

Referenced by ff_fft_init().

av_cold void ff_init_ff_cos_tabs ( int index )

Initialize the cosine table in ff_cos_tabs[index].

Parameters

index index in ff_cos_tabs array of the table to initialize

Definition at line 82 of file fft.c.

Referenced by ff_fft_init().

static void fft16 ( FFTComplex * z )

static

Definition at line 311 of file fft.c.

static void fft4 ( FFTComplex * z )

static

Definition at line 281 of file fft.c.

Referenced by fft16(), and fft8().

static void fft8 ( FFTComplex * z )

static

Definition at line 295 of file fft.c.

Referenced by fft16().

COSTABLE_CONST FFTSample* const FFT_NAME ( ff_cos_tabs )

Referenced by ff_init_ff_cos_tabs(), and fft16().

static av_cold void fft_perm_avx ( FFTContext * s )

static

Definition at line 112 of file fft.c.

Referenced by ff_fft_init().

static int is_second_half_of_fft32	(	int	i,
		int	n
	)

static

Definition at line 100 of file fft.c.

Referenced by fft_perm_avx().

static int split_radix_permutation	(	int	i,
		int	n,
		int	inverse
	)

static

Definition at line 71 of file fft.c.

Referenced by ff_fft_init(), and fft_perm_avx().

Variable Documentation

const int avx_tab[]

static

Initial value:

= {
    0, 4, 1, 5, 8, 12, 9, 13, 2, 6, 3, 7, 10, 14, 11, 15
}

Definition at line 96 of file fft.c.

Referenced by fft_perm_avx().

void(* const fft_dispatch[])(FFTComplex *)

static

Initial value:

= {
    fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024,
    fft2048, fft4096, fft8192, fft16384, fft32768, fft65536,
}

Definition at line 345 of file fft.c.

Referenced by ff_fft_calc_c().

Paris Hackday Code

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation