release/src/router/libvorbis/lib/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 1994-2007             *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: fft transform
  14  last mod: $Id: smallft.h 13293 2007-07-24 00:09:47Z xiphmont $
  15
  16  ********************************************************************/
  17
  18 #ifndef _V_SMFT_H_
  19 #define _V_SMFT_H_
  20
  21 #include "vorbis/codec.h"
  22
  23 typedef struct {
  24   int n;
  25   float *trigcache;
  26   int *splitcache;
  27 } drft_lookup;
  28
  29 extern void drft_forward(drft_lookup *l,float *data);
  30 extern void drft_backward(drft_lookup *l,float *data);
  31 extern void drft_init(drft_lookup *l,int n);
  32 extern void drft_clear(drft_lookup *l);
  33
  34 #endif