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: smallft.h,v 1.3 2003/09/16 18:35:45 jm Exp $
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
47