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 #ifndef FFT_FLOAT 26 #define FFT_FLOAT 1 27 #endif 28 29 #ifndef FFT_FIXED_32 30 #define FFT_FIXED_32 0 31 #endif 32 33 #include <stdint.h> 34 #include "config.h" 35 #include "libavutil/mem.h" 36 37 #if FFT_FLOAT 38 39 #include "avfft.h" 40 41 #define FFT_NAME(x) x 42 43 typedef float FFTDouble; 44 45 #else 46 47 #if FFT_FIXED_32 48 49 #define Q31(x) (int)((x)*2147483648.0 + 0.5) 50 #define FFT_NAME(x) x ## _fixed_32 51 52 typedef int32_t FFTSample; 53 54 #else /* FFT_FIXED_32 */ 55 56 #define FFT_NAME(x) x ## _fixed 57 58 typedef int16_t FFTSample; 59 60 #endif /* FFT_FIXED_32 */ 61 62 typedef struct FFTComplex { 63 FFTSample re, im; 64 } FFTComplex; 65 66 typedef int FFTDouble; 67 typedef struct FFTContext FFTContext; 68 69 #endif /* FFT_FLOAT */ 70 71 typedef struct FFTDComplex { 72 FFTDouble re, im; 73 } FFTDComplex; 74 75 /* FFT computation */ 76 77 enum fft_permutation_type { 78 FF_FFT_PERM_DEFAULT, 79 FF_FFT_PERM_SWAP_LSBS, 80 FF_FFT_PERM_AVX, 81 }; 82 83 enum mdct_permutation_type { 84 FF_MDCT_PERM_NONE, 85 FF_MDCT_PERM_INTERLEAVE, 86 }; 87 88 struct FFTContext { 89 int nbits; 90 int inverse; 91 uint16_t *revtab; 92 FFTComplex *tmp_buf; 93 int mdct_size; /* size of MDCT (i.e. number of input data * 2) */ 94 int mdct_bits; /* n = 2^nbits */ 95 /* pre/post rotation tables */ 96 FFTSample *tcos; 97 FFTSample *tsin; 98 /** 99 * Do the permutation needed BEFORE calling fft_calc(). 100 */ 101 void (*fft_permute)(struct FFTContext *s, FFTComplex *z); 102 /** 103 * Do a complex FFT with the parameters defined in ff_fft_init(). The 104 * input data must be permuted before. No 1.0/sqrt(n) normalization is done. 105 */ 106 void (*fft_calc)(struct FFTContext *s, FFTComplex *z); 107 void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input); 108 void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input); 109 void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input); 110 void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input); 111 enum fft_permutation_type fft_permutation; 112 enum mdct_permutation_type mdct_permutation; 113 uint32_t *revtab32; 114 }; 115 116 #if CONFIG_HARDCODED_TABLES 117 #define COSTABLE_CONST const 118 #else 119 #define COSTABLE_CONST 120 #endif 121 122 #define COSTABLE(size) \ 123 COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2] 124 125 extern COSTABLE(16); 126 extern COSTABLE(32); 127 extern COSTABLE(64); 128 extern COSTABLE(128); 129 extern COSTABLE(256); 130 extern COSTABLE(512); 131 extern COSTABLE(1024); 132 extern COSTABLE(2048); 133 extern COSTABLE(4096); 134 extern COSTABLE(8192); 135 extern COSTABLE(16384); 136 extern COSTABLE(32768); 137 extern COSTABLE(65536); 138 extern COSTABLE(131072); 139 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[18]; 140 141 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs) 142 143 /** 144 * Initialize the cosine table in ff_cos_tabs[index] 145 * @param index index in ff_cos_tabs array of the table to initialize 146 */ 147 void ff_init_ff_cos_tabs(int index); 148 149 #define ff_fft_init FFT_NAME(ff_fft_init) 150 #define ff_fft_end FFT_NAME(ff_fft_end) 151 152 /** 153 * Set up a complex FFT. 154 * @param nbits log2 of the length of the input array 155 * @param inverse if 0 perform the forward transform, if 1 perform the inverse 156 */ 157 int ff_fft_init(FFTContext *s, int nbits, int inverse); 158 159 void ff_fft_init_aarch64(FFTContext *s); 160 void ff_fft_init_x86(FFTContext *s); 161 void ff_fft_init_arm(FFTContext *s); 162 void ff_fft_init_mips(FFTContext *s); 163 void ff_fft_init_ppc(FFTContext *s); 164 165 void ff_fft_fixed_init_arm(FFTContext *s); 166 167 void ff_fft_end(FFTContext *s); 168 169 #define ff_mdct_init FFT_NAME(ff_mdct_init) 170 #define ff_mdct_end FFT_NAME(ff_mdct_end) 171 172 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale); 173 void ff_mdct_end(FFTContext *s); 174 175 #endif /* AVCODEC_FFT_H */ 176