2 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31 #include "libavutil/mem.h"
39 typedef float FFTDouble;
43 #define FFT_NAME(x) x ## _fixed
45 typedef int16_t FFTSample;
46 typedef int FFTDouble;
48 typedef struct FFTComplex {
52 typedef struct FFTContext FFTContext;
54 #endif /* FFT_FLOAT */
56 typedef struct FFTDComplex {
62 enum fft_permutation_type {
64 FF_FFT_PERM_SWAP_LSBS,
68 enum mdct_permutation_type {
70 FF_MDCT_PERM_INTERLEAVE,
78 int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
79 int mdct_bits; /* n = 2^nbits */
80 /* pre/post rotation tables */
84 * Do the permutation needed BEFORE calling fft_calc().
86 void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
88 * Do a complex FFT with the parameters defined in ff_fft_init(). The
89 * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
91 void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
92 void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
93 void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
94 void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
95 void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input);
96 enum fft_permutation_type fft_permutation;
97 enum mdct_permutation_type mdct_permutation;
100 #if CONFIG_HARDCODED_TABLES
101 #define COSTABLE_CONST const
103 #define COSTABLE_CONST
106 #define COSTABLE(size) \
107 COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
112 extern COSTABLE(128);
113 extern COSTABLE(256);
114 extern COSTABLE(512);
115 extern COSTABLE(1024);
116 extern COSTABLE(2048);
117 extern COSTABLE(4096);
118 extern COSTABLE(8192);
119 extern COSTABLE(16384);
120 extern COSTABLE(32768);
121 extern COSTABLE(65536);
122 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[17];
124 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
127 * Initialize the cosine table in ff_cos_tabs[index]
128 * @param index index in ff_cos_tabs array of the table to initialize
130 void ff_init_ff_cos_tabs(int index);
132 #define ff_fft_init FFT_NAME(ff_fft_init)
133 #define ff_fft_end FFT_NAME(ff_fft_end)
136 * Set up a complex FFT.
137 * @param nbits log2 of the length of the input array
138 * @param inverse if 0 perform the forward transform, if 1 perform the inverse
140 int ff_fft_init(FFTContext *s, int nbits, int inverse);
142 void ff_fft_init_aarch64(FFTContext *s);
143 void ff_fft_init_x86(FFTContext *s);
144 void ff_fft_init_arm(FFTContext *s);
145 void ff_fft_init_ppc(FFTContext *s);
147 void ff_fft_fixed_init_arm(FFTContext *s);
149 void ff_fft_end(FFTContext *s);
151 #define ff_mdct_init FFT_NAME(ff_mdct_init)
152 #define ff_mdct_end FFT_NAME(ff_mdct_end)
154 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
155 void ff_mdct_end(FFTContext *s);
157 #endif /* AVCODEC_FFT_H */