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
35 #include "libavutil/mem.h"
43 typedef float FFTDouble;
49 #define Q31(x) (int)((x)*2147483648.0 + 0.5)
50 #define FFT_NAME(x) x ## _fixed_32
52 typedef int32_t FFTSample;
54 #else /* FFT_FIXED_32 */
56 #define FFT_NAME(x) x ## _fixed
58 typedef int16_t FFTSample;
60 #endif /* FFT_FIXED_32 */
62 typedef struct FFTComplex {
66 typedef int FFTDouble;
67 typedef struct FFTContext FFTContext;
69 #endif /* FFT_FLOAT */
71 typedef struct FFTDComplex {
82 int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
83 int mdct_bits; /* n = 2^nbits */
84 /* pre/post rotation tables */
88 * Do the permutation needed BEFORE calling fft_calc().
90 void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
92 * Do a complex FFT with the parameters defined in ff_fft_init(). The
93 * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
95 void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
96 void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
97 void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
98 void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
99 void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input);
101 #define FF_FFT_PERM_DEFAULT 0
102 #define FF_FFT_PERM_SWAP_LSBS 1
103 #define FF_FFT_PERM_AVX 2
104 int mdct_permutation;
105 #define FF_MDCT_PERM_NONE 0
106 #define FF_MDCT_PERM_INTERLEAVE 1
109 #if CONFIG_HARDCODED_TABLES
110 #define COSTABLE_CONST const
112 #define COSTABLE_CONST
115 #define COSTABLE(size) \
116 COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
121 extern COSTABLE(128);
122 extern COSTABLE(256);
123 extern COSTABLE(512);
124 extern COSTABLE(1024);
125 extern COSTABLE(2048);
126 extern COSTABLE(4096);
127 extern COSTABLE(8192);
128 extern COSTABLE(16384);
129 extern COSTABLE(32768);
130 extern COSTABLE(65536);
131 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[17];
133 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
136 * Initialize the cosine table in ff_cos_tabs[index]
137 * @param index index in ff_cos_tabs array of the table to initialize
139 void ff_init_ff_cos_tabs(int index);
141 #define ff_fft_init FFT_NAME(ff_fft_init)
142 #define ff_fft_end FFT_NAME(ff_fft_end)
145 * Set up a complex FFT.
146 * @param nbits log2 of the length of the input array
147 * @param inverse if 0 perform the forward transform, if 1 perform the inverse
149 int ff_fft_init(FFTContext *s, int nbits, int inverse);
151 void ff_fft_init_x86(FFTContext *s);
152 void ff_fft_init_arm(FFTContext *s);
153 void ff_fft_init_mips(FFTContext *s);
154 void ff_fft_init_ppc(FFTContext *s);
156 void ff_fft_fixed_init_arm(FFTContext *s);
158 void ff_fft_end(FFTContext *s);
160 #define ff_mdct_init FFT_NAME(ff_mdct_init)
161 #define ff_mdct_end FFT_NAME(ff_mdct_end)
163 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
164 void ff_mdct_end(FFTContext *s);
166 #endif /* AVCODEC_FFT_H */