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libavcodec/fft.h

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00001 /*
00002  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
00003  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #ifndef AVCODEC_FFT_H
00023 #define AVCODEC_FFT_H
00024 
00025 #include <stdint.h>
00026 #include "config.h"
00027 #include "libavutil/mem.h"
00028 #include "avfft.h"
00029 
00030 /* FFT computation */
00031 
00032 struct FFTContext {
00033     int nbits;
00034     int inverse;
00035     uint16_t *revtab;
00036     FFTComplex *exptab;
00037     FFTComplex *exptab1; /* only used by SSE code */
00038     FFTComplex *tmp_buf;
00039     int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
00040     int mdct_bits; /* n = 2^nbits */
00041     /* pre/post rotation tables */
00042     FFTSample *tcos;
00043     FFTSample *tsin;
00044     void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
00045     void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
00046     void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
00047     void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
00048     void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
00049     int split_radix;
00050     int permutation;
00051 #define FF_MDCT_PERM_NONE       0
00052 #define FF_MDCT_PERM_INTERLEAVE 1
00053 };
00054 
00055 #if CONFIG_HARDCODED_TABLES
00056 #define COSTABLE_CONST const
00057 #define SINTABLE_CONST const
00058 #define SINETABLE_CONST const
00059 #else
00060 #define COSTABLE_CONST
00061 #define SINTABLE_CONST
00062 #define SINETABLE_CONST
00063 #endif
00064 
00065 #define COSTABLE(size) \
00066     COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
00067 #define SINTABLE(size) \
00068     SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
00069 #define SINETABLE(size) \
00070     SINETABLE_CONST DECLARE_ALIGNED(16, float, ff_sine_##size)[size]
00071 extern COSTABLE(16);
00072 extern COSTABLE(32);
00073 extern COSTABLE(64);
00074 extern COSTABLE(128);
00075 extern COSTABLE(256);
00076 extern COSTABLE(512);
00077 extern COSTABLE(1024);
00078 extern COSTABLE(2048);
00079 extern COSTABLE(4096);
00080 extern COSTABLE(8192);
00081 extern COSTABLE(16384);
00082 extern COSTABLE(32768);
00083 extern COSTABLE(65536);
00084 extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
00085 
00090 void ff_init_ff_cos_tabs(int index);
00091 
00092 extern SINTABLE(16);
00093 extern SINTABLE(32);
00094 extern SINTABLE(64);
00095 extern SINTABLE(128);
00096 extern SINTABLE(256);
00097 extern SINTABLE(512);
00098 extern SINTABLE(1024);
00099 extern SINTABLE(2048);
00100 extern SINTABLE(4096);
00101 extern SINTABLE(8192);
00102 extern SINTABLE(16384);
00103 extern SINTABLE(32768);
00104 extern SINTABLE(65536);
00105 
00111 int ff_fft_init(FFTContext *s, int nbits, int inverse);
00112 void ff_fft_permute_c(FFTContext *s, FFTComplex *z);
00113 void ff_fft_calc_c(FFTContext *s, FFTComplex *z);
00114 
00115 void ff_fft_init_altivec(FFTContext *s);
00116 void ff_fft_init_mmx(FFTContext *s);
00117 void ff_fft_init_arm(FFTContext *s);
00118 
00122 static inline void ff_fft_permute(FFTContext *s, FFTComplex *z)
00123 {
00124     s->fft_permute(s, z);
00125 }
00130 static inline void ff_fft_calc(FFTContext *s, FFTComplex *z)
00131 {
00132     s->fft_calc(s, z);
00133 }
00134 void ff_fft_end(FFTContext *s);
00135 
00136 /* MDCT computation */
00137 
00138 static inline void ff_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input)
00139 {
00140     s->imdct_calc(s, output, input);
00141 }
00142 static inline void ff_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input)
00143 {
00144     s->imdct_half(s, output, input);
00145 }
00146 
00147 static inline void ff_mdct_calc(FFTContext *s, FFTSample *output,
00148                                 const FFTSample *input)
00149 {
00150     s->mdct_calc(s, output, input);
00151 }
00152 
00159 void ff_kbd_window_init(float *window, float alpha, int n);
00160 
00166 void ff_sine_window_init(float *window, int n);
00167 
00171 void ff_init_ff_sine_windows(int index);
00172 extern SINETABLE(  32);
00173 extern SINETABLE(  64);
00174 extern SINETABLE( 128);
00175 extern SINETABLE( 256);
00176 extern SINETABLE( 512);
00177 extern SINETABLE(1024);
00178 extern SINETABLE(2048);
00179 extern SINETABLE(4096);
00180 extern SINETABLE_CONST float * const ff_sine_windows[13];
00181 
00182 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
00183 void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
00184 void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
00185 void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
00186 void ff_mdct_end(FFTContext *s);
00187 
00188 /* Real Discrete Fourier Transform */
00189 
00190 struct RDFTContext {
00191     int nbits;
00192     int inverse;
00193     int sign_convention;
00194 
00195     /* pre/post rotation tables */
00196     const FFTSample *tcos;
00197     SINTABLE_CONST FFTSample *tsin;
00198     FFTContext fft;
00199     void (*rdft_calc)(struct RDFTContext *s, FFTSample *z);
00200 };
00201 
00207 int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);
00208 void ff_rdft_end(RDFTContext *s);
00209 
00210 void ff_rdft_init_arm(RDFTContext *s);
00211 
00212 static av_always_inline void ff_rdft_calc(RDFTContext *s, FFTSample *data)
00213 {
00214     s->rdft_calc(s, data);
00215 }
00216 
00217 /* Discrete Cosine Transform */
00218 
00219 struct DCTContext {
00220     int nbits;
00221     int inverse;
00222     RDFTContext rdft;
00223     const float *costab;
00224     FFTSample *csc2;
00225     void (*dct_calc)(struct DCTContext *s, FFTSample *data);
00226 };
00227 
00236 int  ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType type);
00237 void ff_dct_calc(DCTContext *s, FFTSample *data);
00238 void ff_dct_end (DCTContext *s);
00239 
00240 #endif /* AVCODEC_FFT_H */

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