GNU Radio 3.6.4.1 C++ API
lpc.h
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1 /*---------------------------------------------------------------------------*\
2 
3  FILE........: lpc.h
4  AUTHOR......: David Rowe
5  DATE CREATED: 24/8/09
6 
7  Linear Prediction functions written in C.
8 
9 \*---------------------------------------------------------------------------*/
10 
11 /*
12  Copyright (C) 2009 David Rowe
13 
14  All rights reserved.
15 
16  This program is free software; you can redistribute it and/or modify
17  it under the terms of the GNU Lesser General Public License version 2.1, as
18  published by the Free Software Foundation. This program is
19  distributed in the hope that it will be useful, but WITHOUT ANY
20  WARRANTY; without even the implied warranty of MERCHANTABILITY or
21  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
22  License for more details.
23 
24  You should have received a copy of the GNU Lesser General Public License
25  along with this program; if not, see <http://www.gnu.org/licenses/>.
26 */
27 
28 #ifndef __LPC__
29 #define __LPC__
30 
31 #define LPC_MAX_ORDER 20
32 
33 void hanning_window(float Sn[], float Wn[], int Nsam);
34 void autocorrelate(float Sn[], float Rn[], int Nsam, int order);
35 void autocorrelate_freq(float Pw[], float w[], float R[], int Nsam, int order);
36 void levinson_durbin(float R[], float lpcs[], int order);
37 void inverse_filter(float Sn[], float a[], int Nsam, float res[], int order);
38 void synthesis_filter(float res[], float a[], int Nsam, int order, float Sn_[]);
39 void find_aks(float Sn[], float a[], int Nsam, int order, float *E);
40 void weight(float ak[], float gamma, int order, float akw[]);
41 
42 #endif