ffmpeg/libavcodec/fft.h

   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 };
 114
 115 #if CONFIG_HARDCODED_TABLES
 116 #define COSTABLE_CONST const
 117 #else
 118 #define COSTABLE_CONST
 119 #endif
 120
 121 #define COSTABLE(size) \
 122     COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
 123
 124 extern COSTABLE(16);
 125 extern COSTABLE(32);
 126 extern COSTABLE(64);
 127 extern COSTABLE(128);
 128 extern COSTABLE(256);
 129 extern COSTABLE(512);
 130 extern COSTABLE(1024);
 131 extern COSTABLE(2048);
 132 extern COSTABLE(4096);
 133 extern COSTABLE(8192);
 134 extern COSTABLE(16384);
 135 extern COSTABLE(32768);
 136 extern COSTABLE(65536);
 137 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[17];
 138
 139 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
 140
 141 /**
 142  * Initialize the cosine table in ff_cos_tabs[index]
 143  * @param index index in ff_cos_tabs array of the table to initialize
 144  */
 145 void ff_init_ff_cos_tabs(int index);
 146
 147 #define ff_fft_init FFT_NAME(ff_fft_init)
 148 #define ff_fft_end  FFT_NAME(ff_fft_end)
 149
 150 /**
 151  * Set up a complex FFT.
 152  * @param nbits           log2 of the length of the input array
 153  * @param inverse         if 0 perform the forward transform, if 1 perform the inverse
 154  */
 155 int ff_fft_init(FFTContext *s, int nbits, int inverse);
 156
 157 void ff_fft_init_aarch64(FFTContext *s);
 158 void ff_fft_init_x86(FFTContext *s);
 159 void ff_fft_init_arm(FFTContext *s);
 160 void ff_fft_init_mips(FFTContext *s);
 161 void ff_fft_init_ppc(FFTContext *s);
 162
 163 void ff_fft_fixed_init_arm(FFTContext *s);
 164
 165 void ff_fft_end(FFTContext *s);
 166
 167 #define ff_mdct_init FFT_NAME(ff_mdct_init)
 168 #define ff_mdct_end  FFT_NAME(ff_mdct_end)
 169
 170 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
 171 void ff_mdct_end(FFTContext *s);
 172
 173 #endif /* AVCODEC_FFT_H */