FFmpeg
fft.h
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1 /*
2  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVCODEC_FFT_H
23 #define AVCODEC_FFT_H
24 
25 #ifndef FFT_FLOAT
26 #define FFT_FLOAT 1
27 #endif
28 
29 #ifndef FFT_FIXED_32
30 #define FFT_FIXED_32 0
31 #endif
32 
33 #include <stdint.h>
34 #include "config.h"
35 
36 #include "libavutil/mem_internal.h"
37 
38 #if FFT_FLOAT
39 
40 #include "avfft.h"
41 
42 #define FFT_NAME(x) x
43 
44 typedef float FFTDouble;
45 
46 #else
47 
48 #if FFT_FIXED_32
49 
50 #define Q31(x) (int)((x)*2147483648.0 + 0.5)
51 #define FFT_NAME(x) x ## _fixed_32
52 
53 typedef int32_t FFTSample;
54 
55 #endif /* FFT_FIXED_32 */
56 
57 typedef struct FFTComplex {
58  FFTSample re, im;
59 } FFTComplex;
60 
61 typedef int FFTDouble;
62 typedef struct FFTContext FFTContext;
63 
64 #endif /* FFT_FLOAT */
65 
66 typedef struct FFTDComplex {
68 } FFTDComplex;
69 
70 /* FFT computation */
71 
76 };
77 
81 };
82 
83 struct FFTContext {
84  int nbits;
85  int inverse;
86  uint16_t *revtab;
88  int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
89  int mdct_bits; /* n = 2^nbits */
90  /* pre/post rotation tables */
93  /**
94  * Do the permutation needed BEFORE calling fft_calc().
95  */
96  void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
97  /**
98  * Do a complex FFT with the parameters defined in ff_fft_init(). The
99  * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
100  */
101  void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
102  void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
103  void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
104  void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
107  uint32_t *revtab32;
108 };
109 
110 #if CONFIG_HARDCODED_TABLES
111 #define COSTABLE_CONST const
112 #define ff_init_ff_cos_tabs(index)
113 #else
114 #define COSTABLE_CONST
115 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
116 
117 /**
118  * Initialize the cosine table in ff_cos_tabs[index]
119  * @param index index in ff_cos_tabs array of the table to initialize
120  */
121 void ff_init_ff_cos_tabs(int index);
122 #endif
123 
124 #define COSTABLE(size) \
125  COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
126 
127 extern COSTABLE(16);
128 extern COSTABLE(32);
129 extern COSTABLE(64);
130 extern COSTABLE(128);
131 extern COSTABLE(256);
132 extern COSTABLE(512);
133 extern COSTABLE(1024);
134 extern COSTABLE(2048);
135 extern COSTABLE(4096);
136 extern COSTABLE(8192);
137 extern COSTABLE(16384);
138 extern COSTABLE(32768);
139 extern COSTABLE(65536);
140 extern COSTABLE(131072);
141 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[18];
142 
143 #define ff_fft_init FFT_NAME(ff_fft_init)
144 #define ff_fft_end FFT_NAME(ff_fft_end)
145 
146 /**
147  * Set up a complex FFT.
148  * @param nbits log2 of the length of the input array
149  * @param inverse if 0 perform the forward transform, if 1 perform the inverse
150  */
151 int ff_fft_init(FFTContext *s, int nbits, int inverse);
152 
158 
159 void ff_fft_end(FFTContext *s);
160 
161 #define ff_mdct_init FFT_NAME(ff_mdct_init)
162 #define ff_mdct_end FFT_NAME(ff_mdct_end)
163 
164 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
165 void ff_mdct_end(FFTContext *s);
166 
167 #endif /* AVCODEC_FFT_H */
FFTContext::revtab
uint16_t * revtab
Definition: fft.h:86
ff_fft_init
#define ff_fft_init
Definition: fft.h:143
ff_fft_init_ppc
void ff_fft_init_ppc(FFTContext *s)
Definition: fft_init.c:152
ff_init_ff_cos_tabs
#define ff_init_ff_cos_tabs
Definition: fft.h:115
FFTContext::tcos
FFTSample * tcos
Definition: fft.h:91
mem_internal.h
output
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce output
Definition: filter_design.txt:225
FFTContext::mdct_calc
void(* mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:104
index
fg index
Definition: ffmpeg_filter.c:170
FFTDComplex
Definition: fft.h:66
ff_mdct_init
#define ff_mdct_init
Definition: fft.h:161
FFTContext::inverse
int inverse
Definition: fft.h:85
FF_FFT_PERM_SWAP_LSBS
@ FF_FFT_PERM_SWAP_LSBS
Definition: fft.h:74
FF_FFT_PERM_DEFAULT
@ FF_FFT_PERM_DEFAULT
Definition: fft.h:73
FFTContext::tmp_buf
FFTComplex * tmp_buf
Definition: fft.h:87
FFT_NAME
#define FFT_NAME(x)
Definition: fft.h:42
FFTContext::revtab32
uint32_t * revtab32
Definition: fft.h:107
s
#define s(width, name)
Definition: cbs_vp9.c:257
ff_fft_init_x86
void ff_fft_init_x86(FFTContext *s)
Definition: fft_init.c:27
FFTContext::fft_permutation
enum fft_permutation_type fft_permutation
Definition: fft.h:105
mdct_permutation_type
mdct_permutation_type
Definition: fft.h:78
ff_fft_end
#define ff_fft_end
Definition: fft.h:144
int32_t
int32_t
Definition: audio_convert.c:194
FFTContext::mdct_permutation
enum mdct_permutation_type mdct_permutation
Definition: fft.h:106
COSTABLE_CONST
#define COSTABLE_CONST
Definition: fft.h:114
FFTDComplex::re
FFTDouble re
Definition: fft.h:67
FFTSample
float FFTSample
Definition: avfft.h:35
avfft.h
FFTComplex
void FFTComplex
Definition: tx_priv.h:46
FFTContext::imdct_half
void(* imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:103
FFTContext::imdct_calc
void(* imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:102
FFTContext::nbits
int nbits
Definition: fft.h:84
COSTABLE
#define COSTABLE(size)
Definition: fft.h:124
ff_mdct_end
#define ff_mdct_end
Definition: fft.h:162
FFTContext::fft_permute
void(* fft_permute)(struct FFTContext *s, FFTComplex *z)
Do the permutation needed BEFORE calling fft_calc().
Definition: fft.h:96
FFTComplex::im
FFTSample im
Definition: avfft.h:38
ff_fft_init_mips
void ff_fft_init_mips(FFTContext *s)
FFT transform.
Definition: fft_mips.c:502
FFTComplex::re
FFTSample re
Definition: avfft.h:38
FFTDouble
float FFTDouble
Definition: fft.h:44
FFTContext::fft_calc
void(* fft_calc)(struct FFTContext *s, FFTComplex *z)
Do a complex FFT with the parameters defined in ff_fft_init().
Definition: fft.h:101
input
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some input
Definition: filter_design.txt:172
FFTContext::mdct_size
int mdct_size
Definition: fft.h:88
FFTContext
Definition: fft.h:83
FF_MDCT_PERM_INTERLEAVE
@ FF_MDCT_PERM_INTERLEAVE
Definition: fft.h:80
ff_fft_init_arm
void ff_fft_init_arm(FFTContext *s)
Definition: fft_init_arm.c:38
fft_permutation_type
fft_permutation_type
Definition: fft.h:72
FFTContext::tsin
FFTSample * tsin
Definition: fft.h:92
ff_fft_init_aarch64
void ff_fft_init_aarch64(FFTContext *s)
Definition: fft_init_aarch64.c:36
FF_MDCT_PERM_NONE
@ FF_MDCT_PERM_NONE
Definition: fft.h:79
FFTContext::mdct_bits
int mdct_bits
Definition: fft.h:89
inverse
static uint32_t inverse(uint32_t v)
find multiplicative inverse modulo 2 ^ 32
Definition: asfcrypt.c:35
FFTDComplex::im
FFTDouble im
Definition: fft.h:67
FF_FFT_PERM_AVX
@ FF_FFT_PERM_AVX
Definition: fft.h:75
FFTComplex
Definition: avfft.h:37