• smallft.h
  • /********************************************************************
     *                                                                  *
     * 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 1994-2007             *
     * by the Xiph.Org Foundation https://xiph.org/                     *
     *                                                                  *
     ********************************************************************
    
     function: fft transform
    
     ********************************************************************/
    
    #ifndef _V_SMFT_H_
    #define _V_SMFT_H_
    
    #include "vorbis/codec.h"
    
    typedef struct {
      int n;
      float *trigcache;
      int *splitcache;
    } drft_lookup;
    
    extern void drft_forward(drft_lookup *l,float *data);
    extern void drft_backward(drft_lookup *l,float *data);
    extern void drft_init(drft_lookup *l,int n);
    extern void drft_clear(drft_lookup *l);
    
    #endif