xref: /aosp_15_r20/external/webrtc/modules/third_party/fft/fft.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1*d9f75844SAndroid Build Coastguard Worker /*
2*d9f75844SAndroid Build Coastguard Worker  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3*d9f75844SAndroid Build Coastguard Worker  *
4*d9f75844SAndroid Build Coastguard Worker  *  Use of this source code is governed by a BSD-style license
5*d9f75844SAndroid Build Coastguard Worker  *  that can be found in the ../../../LICENSE file in the root of the source
6*d9f75844SAndroid Build Coastguard Worker  *  tree. An additional intellectual property rights grant can be found
7*d9f75844SAndroid Build Coastguard Worker  *  in the file PATENTS.  All contributing project authors may
8*d9f75844SAndroid Build Coastguard Worker  *  be found in the AUTHORS file in the root of the source tree.
9*d9f75844SAndroid Build Coastguard Worker  */
10*d9f75844SAndroid Build Coastguard Worker 
11*d9f75844SAndroid Build Coastguard Worker /*--------------------------------*-C-*---------------------------------*
12*d9f75844SAndroid Build Coastguard Worker  * File:
13*d9f75844SAndroid Build Coastguard Worker  *       fftn.h
14*d9f75844SAndroid Build Coastguard Worker  * ---------------------------------------------------------------------*
15*d9f75844SAndroid Build Coastguard Worker  * Re[]:        real value array
16*d9f75844SAndroid Build Coastguard Worker  * Im[]:        imaginary value array
17*d9f75844SAndroid Build Coastguard Worker  * nTotal:      total number of complex values
18*d9f75844SAndroid Build Coastguard Worker  * nPass:       number of elements involved in this pass of transform
19*d9f75844SAndroid Build Coastguard Worker  * nSpan:       nspan/nPass = number of bytes to increment pointer
20*d9f75844SAndroid Build Coastguard Worker  *              in Re[] and Im[]
21*d9f75844SAndroid Build Coastguard Worker  * isign: exponent: +1 = forward  -1 = reverse
22*d9f75844SAndroid Build Coastguard Worker  * scaling: normalizing constant by which the final result is *divided*
23*d9f75844SAndroid Build Coastguard Worker  * scaling == -1, normalize by total dimension of the transform
24*d9f75844SAndroid Build Coastguard Worker  * scaling <  -1, normalize by the square-root of the total dimension
25*d9f75844SAndroid Build Coastguard Worker  *
26*d9f75844SAndroid Build Coastguard Worker  * ----------------------------------------------------------------------
27*d9f75844SAndroid Build Coastguard Worker  * See the comments in the code for correct usage!
28*d9f75844SAndroid Build Coastguard Worker  */
29*d9f75844SAndroid Build Coastguard Worker 
30*d9f75844SAndroid Build Coastguard Worker #ifndef MODULES_THIRD_PARTY_FFT_FFT_H_
31*d9f75844SAndroid Build Coastguard Worker #define MODULES_THIRD_PARTY_FFT_FFT_H_
32*d9f75844SAndroid Build Coastguard Worker 
33*d9f75844SAndroid Build Coastguard Worker #define FFT_MAXFFTSIZE 2048
34*d9f75844SAndroid Build Coastguard Worker #define FFT_NFACTOR 11
35*d9f75844SAndroid Build Coastguard Worker 
36*d9f75844SAndroid Build Coastguard Worker typedef struct {
37*d9f75844SAndroid Build Coastguard Worker   unsigned int SpaceAlloced;
38*d9f75844SAndroid Build Coastguard Worker   unsigned int MaxPermAlloced;
39*d9f75844SAndroid Build Coastguard Worker   double Tmp0[FFT_MAXFFTSIZE];
40*d9f75844SAndroid Build Coastguard Worker   double Tmp1[FFT_MAXFFTSIZE];
41*d9f75844SAndroid Build Coastguard Worker   double Tmp2[FFT_MAXFFTSIZE];
42*d9f75844SAndroid Build Coastguard Worker   double Tmp3[FFT_MAXFFTSIZE];
43*d9f75844SAndroid Build Coastguard Worker   int Perm[FFT_MAXFFTSIZE];
44*d9f75844SAndroid Build Coastguard Worker   int factor[FFT_NFACTOR];
45*d9f75844SAndroid Build Coastguard Worker 
46*d9f75844SAndroid Build Coastguard Worker } FFTstr;
47*d9f75844SAndroid Build Coastguard Worker 
48*d9f75844SAndroid Build Coastguard Worker /* double precision routine */
49*d9f75844SAndroid Build Coastguard Worker 
50*d9f75844SAndroid Build Coastguard Worker int WebRtcIsac_Fftns(unsigned int ndim,
51*d9f75844SAndroid Build Coastguard Worker                      const int dims[],
52*d9f75844SAndroid Build Coastguard Worker                      double Re[],
53*d9f75844SAndroid Build Coastguard Worker                      double Im[],
54*d9f75844SAndroid Build Coastguard Worker                      int isign,
55*d9f75844SAndroid Build Coastguard Worker                      double scaling,
56*d9f75844SAndroid Build Coastguard Worker                      FFTstr* fftstate);
57*d9f75844SAndroid Build Coastguard Worker 
58*d9f75844SAndroid Build Coastguard Worker #endif /* MODULES_THIRD_PARTY_FFT_FFT_H_ */
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