FFmpeg
Data Structures | Macros | Functions | Variables
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"

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

#define INIT_FF_COS_TABS_FUNC (   index,
  size 
)
Value:
static av_cold void init_ff_cos_tabs_ ## size (void)\
{ \
}
#define av_cold
Definition: attributes.h:88
ptrdiff_t size
Definition: opengl_enc.c:100
int index
Definition: gxfenc.c:89
static av_cold void init_ff_cos_tabs(int index)
Definition: fft_template.c:57

Definition at line 74 of file fft_template.c.

#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);
static int split_radix_permutation(int i, int n, int inverse)
Definition: fft_template.c:144
#define s(width, name)
Definition: cbs_vp9.c:257
int
for(j=16;j >0;--j)
int i
Definition: input.c:407
#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);
static int split_radix_permutation(int i, int n, int inverse)
Definition: fft_template.c:144
#define s(width, name)
Definition: cbs_vp9.c:257
int
for(j=16;j >0;--j)
int i
Definition: input.c:407
#define SPLIT_RADIX_PERMUTATION (   num)
Value:
do { \
if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS) {\
} else {\
}\
} while(0);
#define PROCESS_FFT_PERM_DEFAULT(num)
#define s(width, name)
Definition: cbs_vp9.c:257
if(ret)
#define PROCESS_FFT_PERM_SWAP_LSBS(num)

Referenced by ff_fft_init().

#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);\
}
#define a0
Definition: regdef.h:46
#define a1
Definition: regdef.h:47
#define a3
Definition: regdef.h:49
#define t1
Definition: regdef.h:29
#define t3
Definition: regdef.h:31
#define a2
Definition: regdef.h:48
#define t5
Definition: regdef.h:33
#define t6
Definition: regdef.h:34
#define t4
Definition: regdef.h:32
#define BF(a, b, c, s)
#define t2
Definition: regdef.h:30

Definition at line 536 of file fft_template.c.

Referenced by fft8().

#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);\
}
#define a0
Definition: regdef.h:46
#define a1
Definition: regdef.h:47
#define a3
Definition: regdef.h:49
#define t1
Definition: regdef.h:29
#define t3
Definition: regdef.h:31
float FFTSample
Definition: avfft.h:35
#define a2
Definition: regdef.h:48
#define t5
Definition: regdef.h:33
#define t6
Definition: regdef.h:34
#define t4
Definition: regdef.h:32
#define BF(a, b, c, s)
#define t2
Definition: regdef.h:30

Definition at line 487 of file fft_template.c.

#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);\
}
#define BUTTERFLIES(a0, a1, a2, a3)
Definition: fft_template.c:536
#define a0
Definition: regdef.h:46
#define a1
Definition: regdef.h:47
#define a3
Definition: regdef.h:49
#define t1
Definition: regdef.h:29
#define a2
Definition: regdef.h:48
#define t5
Definition: regdef.h:33
#define t6
Definition: regdef.h:34
#define t2
Definition: regdef.h:30

Definition at line 497 of file fft_template.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;\
}
#define BUTTERFLIES(a0, a1, a2, a3)
Definition: fft_template.c:536
#define a0
Definition: regdef.h:46
#define a1
Definition: regdef.h:47
#define a3
Definition: regdef.h:49
#define t1
Definition: regdef.h:29
#define a2
Definition: regdef.h:48
#define t5
Definition: regdef.h:33
#define t6
Definition: regdef.h:34
#define t2
Definition: regdef.h:30

Definition at line 503 of file fft_template.c.

Referenced by fft16().

#define PASS (   name)
Value:
static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
{\
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);\
}
float FFTDouble
Definition: fft.h:44
#define t1
Definition: regdef.h:29
#define t3
Definition: regdef.h:31
float FFTSample
Definition: avfft.h:35
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without and describe what they do
#define t5
Definition: regdef.h:33
#define TRANSFORM(a0, a1, a2, a3, wre, wim)
Definition: fft_template.c:497
#define TRANSFORM_ZERO(a0, a1, a2, a3)
Definition: fft_template.c:503
int
#define t6
Definition: regdef.h:34
#define t4
Definition: regdef.h:32
#define t2
Definition: regdef.h:30
const char * name
Definition: opengl_enc.c:102

Definition at line 512 of file fft_template.c.

#define BUTTERFLIES   BUTTERFLIES_BIG

Definition at line 536 of file fft_template.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);\
}
#define pass
Definition: fft_template.c:603
COSTABLE_CONST FFTSample *const FFT_NAME(ff_cos_tabs)[]

Definition at line 540 of file fft_template.c.

Referenced by fft16().

#define pass   pass_big

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  )
COSTABLE ( 131072  )
static av_cold void init_ff_cos_tabs ( int  index)
static

Definition at line 57 of file fft_template.c.

av_cold void ff_init_ff_cos_tabs ( int  index)

Initialize the cosine table in ff_cos_tabs[index].

Parameters
indexindex in ff_cos_tabs array of the table to initialize

Definition at line 116 of file fft_template.c.

Referenced by ff_fft_init().

COSTABLE_CONST FFTSample* const FFT_NAME ( ff_cos_tabs  )
static void fft_permute_c ( FFTContext s,
FFTComplex z 
)
static

Definition at line 293 of file fft_template.c.

Referenced by ff_fft_init(), and ff_init_ff_cos_tabs().

static void fft_calc_c ( FFTContext s,
FFTComplex z 
)
static

Definition at line 619 of file fft_template.c.

Referenced by ff_fft_end(), ff_fft_init(), and ff_init_ff_cos_tabs().

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().

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().

static av_cold void fft_perm_avx ( FFTContext s)
static

Definition at line 172 of file fft_template.c.

Referenced by ff_fft_init().

av_cold int ff_fft_init ( FFTContext s,
int  nbits,
int  inverse 
)

Set up a complex FFT.

Parameters
nbitslog2 of the length of the input array
inverseif 0 perform the forward transform, if 1 perform the inverse

Definition at line 194 of file fft_template.c.

av_cold void ff_fft_end ( FFTContext s)

Definition at line 308 of file fft_template.c.

static void fft4 ( FFTComplex z)
static

Definition at line 549 of file fft_template.c.

Referenced by fft16(), and fft8().

static void fft8 ( FFTComplex z)
static

Definition at line 563 of file fft_template.c.

Referenced by fft16().

static void fft16 ( FFTComplex z)
static

Definition at line 579 of file fft_template.c.

Variable Documentation

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 },
}
#define NULL
Definition: coverity.c:32
#define AV_ONCE_INIT
Definition: thread.h:173

Definition at line 95 of file fft_template.c.

Referenced by ff_init_ff_cos_tabs().

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().

void(* const fft_dispatch[])(FFTComplex *)
static
Initial value:
= {
fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024,
fft2048, fft4096, fft8192, fft16384, fft32768, fft65536, fft131072
}
static void fft4(FFTComplex *z)
Definition: fft_template.c:549
static void fft8(FFTComplex *z)
Definition: fft_template.c:563
static void fft16(FFTComplex *z)
Definition: fft_template.c:579

Definition at line 614 of file fft_template.c.

Referenced by fft_calc_c().