v1/util_xforms.h

   1 /*----------------------------------------------------------------------------
   2     ChucK Concurrent, On-the-fly Audio Programming Language
   3       Compiler and Virtual Machine
   4
   5     Copyright (c) 2004 Ge Wang and Perry R. Cook.  All rights reserved.
   6       http://chuck.cs.princeton.edu/
   7       http://soundlab.cs.princeton.edu/
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17     GNU General Public License for more details.
  18
  19     You should have received a copy of the GNU General Public License
  20     along with this program; if not, write to the Free Software
  21     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22     U.S.A.
  23 -----------------------------------------------------------------------------*/
  24
  25 //-----------------------------------------------------------------------------
  26 // name: util_xform.h
  27 // desc: transforms
  28 //
  29 // authors: Ge Wang (gewang@cs.princeton.edu)
  30 //          Perry R. Cook (prc@cs.princeton.edu)
  31 //          FFT - from CARL distribution
  32 // date: 11.27.2003
  33 //-----------------------------------------------------------------------------
  34 #ifndef __UTIL_XFORM_H__
  35 #define __UTIL_XFORM_H__
  36
  37 #include <math.h>
  38
  39
  40 // complex type
  41 typedef struct { float re ; float im ; } complex;
  42 // polar type
  43 typedef struct { float modulus ; float phase ; } polar;
  44
  45 // complex absolute value
  46 #define cmp_abs(x) ( sqrt( (x).re * (x).re + (x).im * (x).im ) )
  47 #define __modulus(x) cmp_abs(x)
  48 #define __phase(x) ( atan2((double)(x).re, (double)(x).im) )
  49
  50 #define FFT_FORWARD 1
  51 #define FFT_INVERSE 0
  52 #define make_window hanning
  53
  54 // c linkage
  55 #if ( defined( __cplusplus ) || defined( _cplusplus ) )
  56   extern "C" {
  57 #endif
  58
  59 // make the window
  60 void hanning( float * window, unsigned long length );
  61 void hamming( float * window, unsigned long length );
  62 void blackman( float * window, unsigned long length );
  63 // apply the window
  64 void apply_window( float * data, float * window, unsigned long length );
  65
  66 // real fft, N must be power of 2
  67 void rfft( float * x, long N, unsigned int forward );
  68 // complex fft, NC must be power of 2
  69 void cfft( float * x, long NC, unsigned int forward );
  70
  71 // c linkage
  72 #if ( defined( __cplusplus ) || defined( _cplusplus ) )
  73   }
  74 #endif
  75
  76 #endif