1 /*
2  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the ../../../LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 /*--------------------------------*-C-*---------------------------------*
12  * File:
13  *       fftn.h
14  * ---------------------------------------------------------------------*
15  * Re[]:        real value array
16  * Im[]:        imaginary value array
17  * nTotal:      total number of complex values
18  * nPass:       number of elements involved in this pass of transform
19  * nSpan:       nspan/nPass = number of bytes to increment pointer
20  *              in Re[] and Im[]
21  * isign: exponent: +1 = forward  -1 = reverse
22  * scaling: normalizing constant by which the final result is *divided*
23  * scaling == -1, normalize by total dimension of the transform
24  * scaling <  -1, normalize by the square-root of the total dimension
25  *
26  * ----------------------------------------------------------------------
27  * See the comments in the code for correct usage!
28  */
29 
30 #ifndef MODULES_THIRD_PARTY_FFT_FFT_H_
31 #define MODULES_THIRD_PARTY_FFT_FFT_H_
32 
33 #define FFT_MAXFFTSIZE 2048
34 #define FFT_NFACTOR 11
35 
36 typedef struct {
37   unsigned int SpaceAlloced;
38   unsigned int MaxPermAlloced;
39   double Tmp0[FFT_MAXFFTSIZE];
40   double Tmp1[FFT_MAXFFTSIZE];
41   double Tmp2[FFT_MAXFFTSIZE];
42   double Tmp3[FFT_MAXFFTSIZE];
43   int Perm[FFT_MAXFFTSIZE];
44   int factor[FFT_NFACTOR];
45 
46 } FFTstr;
47 
48 /* double precision routine */
49 
50 int WebRtcIsac_Fftns(unsigned int ndim,
51                      const int dims[],
52                      double Re[],
53                      double Im[],
54                      int isign,
55                      double scaling,
56                      FFTstr* fftstate);
57 
58 #endif /* MODULES_THIRD_PARTY_FFT_FFT_H_ */
59