apps/codecs/libspeex/smallft.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2001             *
   9  * by the XIPHOPHORUS Company http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: fft transform
  14  last mod: $Id$
  15
  16  ********************************************************************/
  17 /**
  18    @file smallft.h
  19    @brief Discrete Rotational Fourier Transform (DRFT)
  20 */
  21
  22 #ifndef _V_SMFT_H_
  23 #define _V_SMFT_H_
  24
  25
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 /** Discrete Rotational Fourier Transform lookup */
  31 struct drft_lookup{
  32   int n;
  33   float *trigcache;
  34   int *splitcache;
  35 };
  36
  37 extern void spx_drft_forward(struct drft_lookup *l,float *data);
  38 extern void spx_drft_backward(struct drft_lookup *l,float *data);
  39 extern void spx_drft_init(struct drft_lookup *l,int n);
  40 extern void spx_drft_clear(struct drft_lookup *l);
  41
  42 #ifdef __cplusplus
  43 }
  44 #endif
  45
  46 #endif