fft_template.c File Reference

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

Go to the source code of this file.

Data Structures
struct	CosTabsInitOnce

Macros
#define	INIT_FF_COS_TABS_FUNC(index, size)
#define	PROCESS_FFT_PERM_SWAP_LSBS(num)
#define	PROCESS_FFT_PERM_DEFAULT(num)
#define	SPLIT_RADIX_PERMUTATION(num)
#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 (131072)
static av_cold void	init_ff_cos_tabs (int index)
av_cold void	ff_init_ff_cos_tabs (int index)
	Initialize the cosine table in ff_cos_tabs[index]. More...
COSTABLE_CONST FFTSample *const	FFT_NAME (ff_cos_tabs)[]
static void	fft_permute_c (FFTContext *s, FFTComplex *z)
static void	fft_calc_c (FFTContext *s, FFTComplex *z)
static int	split_radix_permutation (int i, int n, int inverse)
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 CosTabsInitOnce	cos_tabs_init_once []
static const int	avx_tab []
static void(*const	fft_dispatch [])(FFTComplex *)

Detailed Description

FFT/IFFT transforms.

Definition in file fft_template.c.

Macro Definition Documentation

INIT_FF_COS_TABS_FUNC

#define INIT_FF_COS_TABS_FUNC	(		index,
			size
	)

Value:

static av_cold void init_ff_cos_tabs_ ## size (void)\
{                                                   \
    init_ff_cos_tabs(index);                        \
}

Definition at line 74 of file fft_template.c.

PROCESS_FFT_PERM_SWAP_LSBS

#define PROCESS_FFT_PERM_SWAP_LSBS

(

num

)

Value:

    do {\
    for(i = 0; i < n; i++) {\
        int k;\
        j = i;\
        j = (j & ~3) | ((j >> 1) & 1) | ((j << 1) & 2);\
        k = -split_radix_permutation(i, n, s->inverse) & (n - 1);\
        s->revtab##num[k] = j;\
    } \
} while(0);

PROCESS_FFT_PERM_DEFAULT

#define PROCESS_FFT_PERM_DEFAULT

(

num

)

Value:

    do {\
    for(i = 0; i < n; i++) {\
        int k;\
        j = i;\
        k = -split_radix_permutation(i, n, s->inverse) & (n - 1);\
        s->revtab##num[k] = j;\
    } \
} while(0);

SPLIT_RADIX_PERMUTATION

#define SPLIT_RADIX_PERMUTATION

(

num

)

Value:

    do { \
    if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS) {\
        PROCESS_FFT_PERM_SWAP_LSBS(num) \
    } else {\
        PROCESS_FFT_PERM_DEFAULT(num) \
    }\
} while(0);

BUTTERFLIES [1/2]

#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 541 of file fft_template.c.

BUTTERFLIES_BIG

#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 492 of file fft_template.c.

TRANSFORM

#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 502 of file fft_template.c.

TRANSFORM_ZERO

#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 508 of file fft_template.c.

PASS

#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 517 of file fft_template.c.

BUTTERFLIES [2/2]

#define BUTTERFLIES   BUTTERFLIES_BIG

Definition at line 541 of file fft_template.c.

DECL_FFT

#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 545 of file fft_template.c.

pass

#define pass   pass_big

Definition at line 608 of file fft_template.c.

Function Documentation

COSTABLE() [1/14]

COSTABLE

(

16

)

COSTABLE() [2/14]

COSTABLE

(

32

)

COSTABLE() [3/14]

COSTABLE

(

64

)

COSTABLE() [4/14]

COSTABLE

(

128

)

COSTABLE() [5/14]

COSTABLE

(

256

)

COSTABLE() [6/14]

COSTABLE

(

512

)

COSTABLE() [7/14]

COSTABLE

(

1024

)

COSTABLE() [8/14]

COSTABLE

(

2048

)

COSTABLE() [9/14]

COSTABLE

(

4096

)

COSTABLE() [10/14]

COSTABLE

(

8192

)

COSTABLE() [11/14]

COSTABLE

(

16384

)

COSTABLE() [12/14]

COSTABLE

(

32768

)

COSTABLE() [13/14]

COSTABLE

(

65536

)

COSTABLE() [14/14]

COSTABLE

(

131072

)

init_ff_cos_tabs()

static av_cold void init_ff_cos_tabs ( int  index )

static

Definition at line 57 of file fft_template.c.

ff_init_ff_cos_tabs()

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 116 of file fft_template.c.

Referenced by ff_fft_init().

FFT_NAME()

COSTABLE_CONST FFTSample* const FFT_NAME

(

ff_cos_tabs

)

Referenced by fft16(), and init_ff_cos_tabs().

fft_permute_c()

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

static

Definition at line 298 of file fft_template.c.

Referenced by ff_fft_init().

fft_calc_c()

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

static

Definition at line 624 of file fft_template.c.

Referenced by ff_fft_init().

split_radix_permutation()

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

static

Definition at line 144 of file fft_template.c.

Referenced by fft_perm_avx().

is_second_half_of_fft32()

static int is_second_half_of_fft32 ( int  i, int  n  )

static

Definition at line 160 of file fft_template.c.

Referenced by fft_perm_avx().

fft_perm_avx()

static av_cold void fft_perm_avx ( FFTContext *  s )

static

Definition at line 172 of file fft_template.c.

Referenced by ff_fft_init().

ff_fft_init()

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 194 of file fft_template.c.

ff_fft_end()

av_cold void ff_fft_end

(

FFTContext *

s

)

Definition at line 313 of file fft_template.c.

fft4()

static void fft4 ( FFTComplex *  z )

static

Definition at line 554 of file fft_template.c.

Referenced by fft16(), and fft8().

fft8()

static void fft8 ( FFTComplex *  z )

static

Definition at line 568 of file fft_template.c.

Referenced by fft16().

fft16()

static void fft16 ( FFTComplex *  z )

static

Definition at line 584 of file fft_template.c.

Variable Documentation

cos_tabs_init_once

CosTabsInitOnce cos_tabs_init_once[]

static

Initial value:

= {
    { NULL },
    { NULL },
    { NULL },
    { NULL },
    { init_ff_cos_tabs_16, AV_ONCE_INIT },
    { init_ff_cos_tabs_32, AV_ONCE_INIT },
    { init_ff_cos_tabs_64, AV_ONCE_INIT },
    { init_ff_cos_tabs_128, AV_ONCE_INIT },
    { init_ff_cos_tabs_256, AV_ONCE_INIT },
    { init_ff_cos_tabs_512, AV_ONCE_INIT },
    { init_ff_cos_tabs_1024, AV_ONCE_INIT },
    { init_ff_cos_tabs_2048, AV_ONCE_INIT },
    { init_ff_cos_tabs_4096, AV_ONCE_INIT },
    { init_ff_cos_tabs_8192, AV_ONCE_INIT },
    { init_ff_cos_tabs_16384, AV_ONCE_INIT },
    { init_ff_cos_tabs_32768, AV_ONCE_INIT },
    { init_ff_cos_tabs_65536, AV_ONCE_INIT },
    { init_ff_cos_tabs_131072, AV_ONCE_INIT },
}

Definition at line 95 of file fft_template.c.

Referenced by ff_init_ff_cos_tabs().

avx_tab

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 156 of file fft_template.c.

Referenced by fft_perm_avx().

fft_dispatch

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

static

Initial value:

= {
    fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024,
    fft2048, fft4096, fft8192, fft16384, fft32768, fft65536, fft131072
}

Definition at line 619 of file fft_template.c.

Referenced by fft_calc_c().