9c2345a0bd80f29a32d2fdc1bd40862989e71f8d
[libav.git] / libavcodec / fft.h
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 #include <stdint.h>
26 #include "config.h"
27 #include "libavutil/mem.h"
28
29 /* FFT computation */
30
31 /* NOTE: soon integer code will be added, so you must use the
32 FFTSample type */
33 typedef float FFTSample;
34
35 typedef struct FFTComplex {
36 FFTSample re, im;
37 } FFTComplex;
38
39 typedef struct FFTContext {
40 int nbits;
41 int inverse;
42 uint16_t *revtab;
43 FFTComplex *exptab;
44 FFTComplex *exptab1; /* only used by SSE code */
45 FFTComplex *tmp_buf;
46 int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
47 int mdct_bits; /* n = 2^nbits */
48 /* pre/post rotation tables */
49 FFTSample *tcos;
50 FFTSample *tsin;
51 void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
52 void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
53 void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
54 void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
55 void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
56 int split_radix;
57 int permutation;
58 #define FF_MDCT_PERM_NONE 0
59 #define FF_MDCT_PERM_INTERLEAVE 1
60 } FFTContext;
61
62 #if CONFIG_HARDCODED_TABLES
63 #define COSTABLE_CONST const
64 #define SINTABLE_CONST const
65 #define SINETABLE_CONST const
66 #else
67 #define COSTABLE_CONST
68 #define SINTABLE_CONST
69 #define SINETABLE_CONST
70 #endif
71
72 #define COSTABLE(size) \
73 COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
74 #define SINTABLE(size) \
75 SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
76 #define SINETABLE(size) \
77 SINETABLE_CONST DECLARE_ALIGNED(16, float, ff_sine_##size)[size]
78 extern COSTABLE(16);
79 extern COSTABLE(32);
80 extern COSTABLE(64);
81 extern COSTABLE(128);
82 extern COSTABLE(256);
83 extern COSTABLE(512);
84 extern COSTABLE(1024);
85 extern COSTABLE(2048);
86 extern COSTABLE(4096);
87 extern COSTABLE(8192);
88 extern COSTABLE(16384);
89 extern COSTABLE(32768);
90 extern COSTABLE(65536);
91 extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
92
93 /**
94 * Initializes the cosine table in ff_cos_tabs[index]
95 * \param index index in ff_cos_tabs array of the table to initialize
96 */
97 void ff_init_ff_cos_tabs(int index);
98
99 extern SINTABLE(16);
100 extern SINTABLE(32);
101 extern SINTABLE(64);
102 extern SINTABLE(128);
103 extern SINTABLE(256);
104 extern SINTABLE(512);
105 extern SINTABLE(1024);
106 extern SINTABLE(2048);
107 extern SINTABLE(4096);
108 extern SINTABLE(8192);
109 extern SINTABLE(16384);
110 extern SINTABLE(32768);
111 extern SINTABLE(65536);
112
113 /**
114 * Sets up a complex FFT.
115 * @param nbits log2 of the length of the input array
116 * @param inverse if 0 perform the forward transform, if 1 perform the inverse
117 */
118 int ff_fft_init(FFTContext *s, int nbits, int inverse);
119 void ff_fft_permute_c(FFTContext *s, FFTComplex *z);
120 void ff_fft_calc_c(FFTContext *s, FFTComplex *z);
121
122 void ff_fft_init_altivec(FFTContext *s);
123 void ff_fft_init_mmx(FFTContext *s);
124 void ff_fft_init_arm(FFTContext *s);
125
126 /**
127 * Do the permutation needed BEFORE calling ff_fft_calc().
128 */
129 static inline void ff_fft_permute(FFTContext *s, FFTComplex *z)
130 {
131 s->fft_permute(s, z);
132 }
133 /**
134 * Do a complex FFT with the parameters defined in ff_fft_init(). The
135 * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
136 */
137 static inline void ff_fft_calc(FFTContext *s, FFTComplex *z)
138 {
139 s->fft_calc(s, z);
140 }
141 void ff_fft_end(FFTContext *s);
142
143 /* MDCT computation */
144
145 static inline void ff_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input)
146 {
147 s->imdct_calc(s, output, input);
148 }
149 static inline void ff_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input)
150 {
151 s->imdct_half(s, output, input);
152 }
153
154 static inline void ff_mdct_calc(FFTContext *s, FFTSample *output,
155 const FFTSample *input)
156 {
157 s->mdct_calc(s, output, input);
158 }
159
160 /**
161 * Generate a Kaiser-Bessel Derived Window.
162 * @param window pointer to half window
163 * @param alpha determines window shape
164 * @param n size of half window
165 */
166 void ff_kbd_window_init(float *window, float alpha, int n);
167
168 /**
169 * Generate a sine window.
170 * @param window pointer to half window
171 * @param n size of half window
172 */
173 void ff_sine_window_init(float *window, int n);
174
175 /**
176 * initialize the specified entry of ff_sine_windows
177 */
178 void ff_init_ff_sine_windows(int index);
179 extern SINETABLE( 32);
180 extern SINETABLE( 64);
181 extern SINETABLE( 128);
182 extern SINETABLE( 256);
183 extern SINETABLE( 512);
184 extern SINETABLE(1024);
185 extern SINETABLE(2048);
186 extern SINETABLE(4096);
187 extern SINETABLE_CONST float * const ff_sine_windows[13];
188
189 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
190 void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
191 void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
192 void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
193 void ff_mdct_end(FFTContext *s);
194
195 /* Real Discrete Fourier Transform */
196
197 enum RDFTransformType {
198 DFT_R2C,
199 IDFT_C2R,
200 IDFT_R2C,
201 DFT_C2R,
202 };
203
204 typedef struct {
205 int nbits;
206 int inverse;
207 int sign_convention;
208
209 /* pre/post rotation tables */
210 const FFTSample *tcos;
211 SINTABLE_CONST FFTSample *tsin;
212 FFTContext fft;
213 } RDFTContext;
214
215 /**
216 * Sets up a real FFT.
217 * @param nbits log2 of the length of the input array
218 * @param trans the type of transform
219 */
220 int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);
221 void ff_rdft_calc(RDFTContext *s, FFTSample *data);
222 void ff_rdft_end(RDFTContext *s);
223
224 /* Discrete Cosine Transform */
225
226 typedef struct {
227 int nbits;
228 int inverse;
229 FFTSample *data;
230 RDFTContext rdft;
231 const float *costab;
232 FFTSample *csc2;
233 } DCTContext;
234
235 /**
236 * Sets up (Inverse)DCT.
237 * @param nbits log2 of the length of the input array
238 * @param inverse >0 forward transform, <0 inverse transform
239 */
240 int ff_dct_init(DCTContext *s, int nbits, int inverse);
241 void ff_dct_calc(DCTContext *s, FFTSample *data);
242 void ff_dct_end (DCTContext *s);
243
244 #endif /* AVCODEC_FFT_H */