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 WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_MAIN_SOURCE_FFT_H_
31 #define WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_MAIN_SOURCE_FFT_H_
32 
33 
34 #include "structs.h"
35 
36 
37 /* double precision routine */
38 
39 
40 int WebRtcIsac_Fftns (unsigned int ndim, const int dims[], double Re[], double Im[],
41                      int isign, double scaling, FFTstr *fftstate);
42 
43 
44 
45 #endif /* WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_MAIN_SOURCE_FFT_H_ */
46