1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/*
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_FFT_H
#define AVCODEC_FFT_H
#include <stdint.h>
#include "../config.h"
#include "libavutil/mem.h"
#include "avfft.h"
/* FFT computation */
struct FFTContext {
int nbits;
int inverse;
uint16_t *revtab;
FFTComplex *tmp_buf;
int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
int mdct_bits; /* n = 2^nbits */
/* pre/post rotation tables */
FFTSample *tcos;
FFTSample *tsin;
void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
int permutation;
#define FF_MDCT_PERM_NONE 0
#define FF_MDCT_PERM_INTERLEAVE 1
};
#if CONFIG_HARDCODED_TABLES
#define COSTABLE_CONST const
#define SINTABLE_CONST const
#define SINETABLE_CONST const
#else
#define COSTABLE_CONST
#define SINTABLE_CONST
#define SINETABLE_CONST
#endif
#define COSTABLE(size) \
COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
#define SINTABLE(size) \
SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
#define SINETABLE(size) \
SINETABLE_CONST DECLARE_ALIGNED(16, float, ff_sine_##size)[size]
extern COSTABLE(16);
extern COSTABLE(32);
extern COSTABLE(64);
extern COSTABLE(128);
extern COSTABLE(256);
extern COSTABLE(512);
extern COSTABLE(1024);
extern COSTABLE(2048);
extern COSTABLE(4096);
extern COSTABLE(8192);
extern COSTABLE(16384);
extern COSTABLE(32768);
extern COSTABLE(65536);
extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
/**
* Initialize the cosine table in ff_cos_tabs[index]
* \param index index in ff_cos_tabs array of the table to initialize
*/
void ff_init_ff_cos_tabs(int index);
extern SINTABLE(16);
extern SINTABLE(32);
extern SINTABLE(64);
extern SINTABLE(128);
extern SINTABLE(256);
extern SINTABLE(512);
extern SINTABLE(1024);
extern SINTABLE(2048);
extern SINTABLE(4096);
extern SINTABLE(8192);
extern SINTABLE(16384);
extern SINTABLE(32768);
extern SINTABLE(65536);
/**
* Set up a complex FFT.
* @param nbits log2 of the length of the input array
* @param inverse if 0 perform the forward transform, if 1 perform the inverse
*/
int ff_fft_init(FFTContext *s, int nbits, int inverse);
void ff_fft_permute_c(FFTContext *s, FFTComplex *z);
void ff_fft_calc_c(FFTContext *s, FFTComplex *z);
void ff_fft_init_altivec(FFTContext *s);
void ff_fft_init_mmx(FFTContext *s);
void ff_fft_init_arm(FFTContext *s);
void ff_dct_init_mmx(DCTContext *s);
/**
* Do the permutation needed BEFORE calling ff_fft_calc().
*/
static inline void ff_fft_permute(FFTContext *s, FFTComplex *z)
{
s->fft_permute(s, z);
}
/**
* Do a complex FFT with the parameters defined in ff_fft_init(). The
* input data must be permuted before. No 1.0/sqrt(n) normalization is done.
*/
static inline void ff_fft_calc(FFTContext *s, FFTComplex *z)
{
s->fft_calc(s, z);
}
void ff_fft_end(FFTContext *s);
/* MDCT computation */
static inline void ff_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input)
{
s->imdct_calc(s, output, input);
}
static inline void ff_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input)
{
s->imdct_half(s, output, input);
}
static inline void ff_mdct_calc(FFTContext *s, FFTSample *output,
const FFTSample *input)
{
s->mdct_calc(s, output, input);
}
/**
* Maximum window size for ff_kbd_window_init.
*/
#define FF_KBD_WINDOW_MAX 1024
/**
* Generate a Kaiser-Bessel Derived Window.
* @param window pointer to half window
* @param alpha determines window shape
* @param n size of half window, max FF_KBD_WINDOW_MAX
*/
void ff_kbd_window_init(float *window, float alpha, int n);
/**
* Generate a sine window.
* @param window pointer to half window
* @param n size of half window
*/
void ff_sine_window_init(float *window, int n);
/**
* initialize the specified entry of ff_sine_windows
*/
void ff_init_ff_sine_windows(int index);
extern SINETABLE( 32);
extern SINETABLE( 64);
extern SINETABLE( 128);
extern SINETABLE( 256);
extern SINETABLE( 512);
extern SINETABLE(1024);
extern SINETABLE(2048);
extern SINETABLE(4096);
extern SINETABLE_CONST float * const ff_sine_windows[13];
int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
void ff_mdct_end(FFTContext *s);
/* Real Discrete Fourier Transform */
struct RDFTContext {
int nbits;
int inverse;
int sign_convention;
/* pre/post rotation tables */
const FFTSample *tcos;
SINTABLE_CONST FFTSample *tsin;
FFTContext fft;
void (*rdft_calc)(struct RDFTContext *s, FFTSample *z);
};
/**
* Set up a real FFT.
* @param nbits log2 of the length of the input array
* @param trans the type of transform
*/
int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);
void ff_rdft_end(RDFTContext *s);
void ff_rdft_init_arm(RDFTContext *s);
static av_always_inline void ff_rdft_calc(RDFTContext *s, FFTSample *data)
{
s->rdft_calc(s, data);
}
/* Discrete Cosine Transform */
struct DCTContext {
int nbits;
int inverse;
RDFTContext rdft;
const float *costab;
FFTSample *csc2;
void (*dct_calc)(struct DCTContext *s, FFTSample *data);
void (*dct32)(FFTSample *out, const FFTSample *in);
};
/**
* Set up DCT.
* @param nbits size of the input array:
* (1 << nbits) for DCT-II, DCT-III and DST-I
* (1 << nbits) + 1 for DCT-I
*
* @note the first element of the input of DST-I is ignored
*/
int ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType type);
void ff_dct_calc(DCTContext *s, FFTSample *data);
void ff_dct_end (DCTContext *s);
#endif /* AVCODEC_FFT_H */
|
