fft_template.c File Reference

FFT/IFFT transforms. More...

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

Go to the source code of this file.

Macros
#define	PROCESS_FFT_PERM_SWAP_LSBS(num)
#define	PROCESS_FFT_PERM_DEFAULT(num)
#define	SPLIT_RADIX_PERMUTATION(num)

Functions
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)

Variables
static const int	avx_tab []

Detailed Description

FFT/IFFT transforms.

Definition in file fft_template.c.

Macro Definition Documentation

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);

Function Documentation

fft_permute_c()

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

static

Definition at line 293 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 317 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 ff_tx_gen_ptwo_revtab(), and 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 308 of file fft_template.c.

Variable Documentation

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().