D-Modem/pjproject-2.11.1/third_party/speex/libspeex/smallft.h

47 lines
1.4 KiB
C
Raw Normal View History

2021-10-30 02:41:03 +08:00
/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2001 *
* by the XIPHOPHORUS Company http://www.xiph.org/ *
* *
********************************************************************
function: fft transform
last mod: $Id$
********************************************************************/
/**
@file smallft.h
@brief Discrete Rotational Fourier Transform (DRFT)
*/
#ifndef _V_SMFT_H_
#define _V_SMFT_H_
#ifdef __cplusplus
extern "C" {
#endif
/** Discrete Rotational Fourier Transform lookup */
struct drft_lookup{
int n;
float *trigcache;
int *splitcache;
};
extern void spx_drft_forward(struct drft_lookup *l,float *data);
extern void spx_drft_backward(struct drft_lookup *l,float *data);
extern void spx_drft_init(struct drft_lookup *l,int n);
extern void spx_drft_clear(struct drft_lookup *l);
#ifdef __cplusplus
}
#endif
#endif