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 #else /* FFT_FIXED_32 */
57 #define FFT_NAME(x) x ## _fixed
59 typedef int16_t FFTSample;
61 #endif /* FFT_FIXED_32 */
63 typedef struct FFTComplex {
67 typedef int FFTDouble;
68 typedef struct FFTContext FFTContext;
70 #endif /* FFT_FLOAT */
72 typedef struct FFTDComplex {
78 enum fft_permutation_type {
80 FF_FFT_PERM_SWAP_LSBS,
84 enum mdct_permutation_type {
86 FF_MDCT_PERM_INTERLEAVE,
94 int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
95 int mdct_bits; /* n = 2^nbits */
96 /* pre/post rotation tables */
100 * Do the permutation needed BEFORE calling fft_calc().
102 void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
104 * Do a complex FFT with the parameters defined in ff_fft_init(). The
105 * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
107 void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
108 void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
109 void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
110 void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
111 void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input);
112 enum fft_permutation_type fft_permutation;
113 enum mdct_permutation_type mdct_permutation;
117 #if CONFIG_HARDCODED_TABLES
118 #define COSTABLE_CONST const
120 #define COSTABLE_CONST
123 #define COSTABLE(size) \
124 COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
129 extern COSTABLE(128);
130 extern COSTABLE(256);
131 extern COSTABLE(512);
132 extern COSTABLE(1024);
133 extern COSTABLE(2048);
134 extern COSTABLE(4096);
135 extern COSTABLE(8192);
136 extern COSTABLE(16384);
137 extern COSTABLE(32768);
138 extern COSTABLE(65536);
139 extern COSTABLE(131072);
140 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[18];
142 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
145 * Initialize the cosine table in ff_cos_tabs[index]
146 * @param index index in ff_cos_tabs array of the table to initialize
148 void ff_init_ff_cos_tabs(int index);
150 #define ff_fft_init FFT_NAME(ff_fft_init)
151 #define ff_fft_end FFT_NAME(ff_fft_end)
154 * Set up a complex FFT.
155 * @param nbits log2 of the length of the input array
156 * @param inverse if 0 perform the forward transform, if 1 perform the inverse
158 int ff_fft_init(FFTContext *s, int nbits, int inverse);
160 void ff_fft_init_aarch64(FFTContext *s);
161 void ff_fft_init_x86(FFTContext *s);
162 void ff_fft_init_arm(FFTContext *s);
163 void ff_fft_init_mips(FFTContext *s);
164 void ff_fft_init_ppc(FFTContext *s);
166 void ff_fft_fixed_init_arm(FFTContext *s);
168 void ff_fft_end(FFTContext *s);
170 #define ff_mdct_init FFT_NAME(ff_mdct_init)
171 #define ff_mdct_end FFT_NAME(ff_mdct_end)
173 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
174 void ff_mdct_end(FFTContext *s);
176 #endif /* AVCODEC_FFT_H */