2 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of FFmpeg.
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.
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.
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
30 #define FFT_FIXED_32 0
36 #include "libavutil/mem_internal.h"
44 typedef float FFTDouble;
50 #define Q31(x) (int)((x)*2147483648.0 + 0.5)
51 #define FFT_NAME(x) x ## _fixed_32
53 typedef int32_t FFTSample;
55 #endif /* FFT_FIXED_32 */
57 typedef struct FFTComplex {
61 typedef int FFTDouble;
62 typedef struct FFTContext FFTContext;
64 #endif /* FFT_FLOAT */
66 typedef struct FFTDComplex {
72 enum fft_permutation_type {
74 FF_FFT_PERM_SWAP_LSBS,
78 enum mdct_permutation_type {
80 FF_MDCT_PERM_INTERLEAVE,
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 */
94 * Do the permutation needed BEFORE calling fft_calc().
96 void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
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.
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);
105 enum fft_permutation_type fft_permutation;
106 enum mdct_permutation_type mdct_permutation;
110 #if CONFIG_HARDCODED_TABLES
111 #define COSTABLE_CONST const
112 #define ff_init_ff_cos_tabs(index)
114 #define COSTABLE_CONST
115 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
118 * Initialize the cosine table in ff_cos_tabs[index]
119 * @param index index in ff_cos_tabs array of the table to initialize
121 void ff_init_ff_cos_tabs(int index);
124 #define COSTABLE(size) \
125 COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
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];
143 #define ff_fft_init FFT_NAME(ff_fft_init)
144 #define ff_fft_end FFT_NAME(ff_fft_end)
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
151 int ff_fft_init(FFTContext *s, int nbits, int inverse);
153 void ff_fft_init_aarch64(FFTContext *s);
154 void ff_fft_init_x86(FFTContext *s);
155 void ff_fft_init_arm(FFTContext *s);
156 void ff_fft_init_mips(FFTContext *s);
157 void ff_fft_init_ppc(FFTContext *s);
159 void ff_fft_end(FFTContext *s);
161 #define ff_mdct_init FFT_NAME(ff_mdct_init)
162 #define ff_mdct_end FFT_NAME(ff_mdct_end)
164 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
165 void ff_mdct_end(FFTContext *s);
167 #endif /* AVCODEC_FFT_H */