/*
  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef AVCODEC_FFT_H
 #define AVCODEC_FFT_H
 

 #ifndef FFT_FLOAT
 #define FFT_FLOAT 1

 #endif
 

 #ifndef FFT_FIXED_32
 #define FFT_FIXED_32 0

 #endif
 

 #include <stdint.h>
 #include "config.h"
 #include "libavutil/mem.h"

 #if FFT_FLOAT

 #include "avfft.h"

 #define FFT_NAME(x) x
 
 typedef float FFTDouble;
 
 #else
 

 #if FFT_FIXED_32

 
 #define Q31(x) (int)((x)*2147483648.0 + 0.5)
 #define FFT_NAME(x) x ## _fixed_32
 
 typedef int32_t FFTSample;
 

 #else /* FFT_FIXED_32 */

 #define FFT_NAME(x) x ## _fixed
 
 typedef int16_t FFTSample;

 #endif /* FFT_FIXED_32 */

 
 typedef struct FFTComplex {

     FFTSample re, im;

 } FFTComplex;
 

 typedef int    FFTDouble;

 typedef struct FFTContext FFTContext;
 

 #endif /* FFT_FLOAT */

 typedef struct FFTDComplex {
     FFTDouble re, im;
 } FFTDComplex;
 

 /* FFT computation */
 

 struct FFTContext {

     int nbits;
     int inverse;
     uint16_t *revtab;
     FFTComplex *tmp_buf;
     int mdct_size; /* size of MDCT (i.e. number of input data * 2) */

     int mdct_bits; /* n = 2^nbits */

     /* pre/post rotation tables */
     FFTSample *tcos;
     FFTSample *tsin;

     /**
      * Do the permutation needed BEFORE calling fft_calc().
      */

     void (*fft_permute)(struct FFTContext *s, FFTComplex *z);

     /**
      * Do a complex FFT with the parameters defined in ff_fft_init(). The
      * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
      */

     void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
     void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
     void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
     void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);

     void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input);

     int fft_permutation;
 #define FF_FFT_PERM_DEFAULT   0
 #define FF_FFT_PERM_SWAP_LSBS 1

 #define FF_FFT_PERM_AVX       2

     int mdct_permutation;

 #define FF_MDCT_PERM_NONE       0
 #define FF_MDCT_PERM_INTERLEAVE 1

 };

 
 #if CONFIG_HARDCODED_TABLES
 #define COSTABLE_CONST const
 #else
 #define COSTABLE_CONST
 #endif
 
 #define COSTABLE(size) \

     COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]

 extern COSTABLE(16);
 extern COSTABLE(32);
 extern COSTABLE(64);
 extern COSTABLE(128);
 extern COSTABLE(256);
 extern COSTABLE(512);
 extern COSTABLE(1024);
 extern COSTABLE(2048);
 extern COSTABLE(4096);
 extern COSTABLE(8192);
 extern COSTABLE(16384);
 extern COSTABLE(32768);
 extern COSTABLE(65536);

 extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[17];
 
 #define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)

 
 /**

  * Initialize the cosine table in ff_cos_tabs[index]

  * @param index index in ff_cos_tabs array of the table to initialize

  */
 void ff_init_ff_cos_tabs(int index);
 

 #define ff_fft_init FFT_NAME(ff_fft_init)
 #define ff_fft_end  FFT_NAME(ff_fft_end)
 

 /**

  * Set up a complex FFT.

  * @param nbits           log2 of the length of the input array
  * @param inverse         if 0 perform the forward transform, if 1 perform the inverse
  */
 int ff_fft_init(FFTContext *s, int nbits, int inverse);
 

 void ff_fft_init_x86(FFTContext *s);

 void ff_fft_init_arm(FFTContext *s);

 void ff_fft_init_mips(FFTContext *s);

 void ff_fft_init_ppc(FFTContext *s);

 void ff_fft_fixed_init_arm(FFTContext *s);

 
 void ff_fft_end(FFTContext *s);
 

 #define ff_mdct_init FFT_NAME(ff_mdct_init)
 #define ff_mdct_end  FFT_NAME(ff_mdct_end)
 

 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
 void ff_mdct_end(FFTContext *s);
 
 #endif /* AVCODEC_FFT_H */