xref: /aosp_15_r20/external/speex/libspeexdsp/smallft.h (revision 28e138c64d234588b5cd2a8a403b584bd3036e4e)
1*28e138c6SAndroid Build Coastguard Worker /********************************************************************
2*28e138c6SAndroid Build Coastguard Worker  *                                                                  *
3*28e138c6SAndroid Build Coastguard Worker  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
4*28e138c6SAndroid Build Coastguard Worker  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
5*28e138c6SAndroid Build Coastguard Worker  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6*28e138c6SAndroid Build Coastguard Worker  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
7*28e138c6SAndroid Build Coastguard Worker  *                                                                  *
8*28e138c6SAndroid Build Coastguard Worker  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2001             *
9*28e138c6SAndroid Build Coastguard Worker  * by the XIPHOPHORUS Company http://www.xiph.org/                  *
10*28e138c6SAndroid Build Coastguard Worker  *                                                                  *
11*28e138c6SAndroid Build Coastguard Worker  ********************************************************************
12*28e138c6SAndroid Build Coastguard Worker 
13*28e138c6SAndroid Build Coastguard Worker  function: fft transform
14*28e138c6SAndroid Build Coastguard Worker  last mod: $Id: smallft.h,v 1.3 2003/09/16 18:35:45 jm Exp $
15*28e138c6SAndroid Build Coastguard Worker 
16*28e138c6SAndroid Build Coastguard Worker  ********************************************************************/
17*28e138c6SAndroid Build Coastguard Worker /**
18*28e138c6SAndroid Build Coastguard Worker    @file smallft.h
19*28e138c6SAndroid Build Coastguard Worker    @brief Discrete Rotational Fourier Transform (DRFT)
20*28e138c6SAndroid Build Coastguard Worker */
21*28e138c6SAndroid Build Coastguard Worker 
22*28e138c6SAndroid Build Coastguard Worker #ifndef _V_SMFT_H_
23*28e138c6SAndroid Build Coastguard Worker #define _V_SMFT_H_
24*28e138c6SAndroid Build Coastguard Worker 
25*28e138c6SAndroid Build Coastguard Worker 
26*28e138c6SAndroid Build Coastguard Worker #ifdef __cplusplus
27*28e138c6SAndroid Build Coastguard Worker extern "C" {
28*28e138c6SAndroid Build Coastguard Worker #endif
29*28e138c6SAndroid Build Coastguard Worker 
30*28e138c6SAndroid Build Coastguard Worker /** Discrete Rotational Fourier Transform lookup */
31*28e138c6SAndroid Build Coastguard Worker struct drft_lookup{
32*28e138c6SAndroid Build Coastguard Worker   int n;
33*28e138c6SAndroid Build Coastguard Worker   float *trigcache;
34*28e138c6SAndroid Build Coastguard Worker   int *splitcache;
35*28e138c6SAndroid Build Coastguard Worker };
36*28e138c6SAndroid Build Coastguard Worker 
37*28e138c6SAndroid Build Coastguard Worker extern void spx_drft_forward(struct drft_lookup *l,float *data);
38*28e138c6SAndroid Build Coastguard Worker extern void spx_drft_backward(struct drft_lookup *l,float *data);
39*28e138c6SAndroid Build Coastguard Worker extern void spx_drft_init(struct drft_lookup *l,int n);
40*28e138c6SAndroid Build Coastguard Worker extern void spx_drft_clear(struct drft_lookup *l);
41*28e138c6SAndroid Build Coastguard Worker 
42*28e138c6SAndroid Build Coastguard Worker #ifdef __cplusplus
43*28e138c6SAndroid Build Coastguard Worker }
44*28e138c6SAndroid Build Coastguard Worker #endif
45*28e138c6SAndroid Build Coastguard Worker 
46*28e138c6SAndroid Build Coastguard Worker #endif
47