UHSDR/UHSDR-active-devel/mchf-eclipse/drivers/freedv/lpc.h
2022-11-08 16:13:55 +01:00

44 lines
1.6 KiB
C

/*---------------------------------------------------------------------------*\
FILE........: lpc.h
AUTHOR......: David Rowe
DATE CREATED: 24/8/09
Linear Prediction functions written in C.
\*---------------------------------------------------------------------------*/
/*
Copyright (C) 2009-2012 David Rowe
All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License version 2.1, as
published by the Free Software Foundation. This program is
distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __LPC__
#define __LPC__
#define LPC_MAX_ORDER 20
void pre_emp(float Sn_pre[], float Sn[], float *mem, int Nsam);
void de_emp(float Sn_se[], float Sn[], float *mem, int Nsam);
void hanning_window(float Sn[], float Wn[], int Nsam);
void autocorrelate(float Sn[], float Rn[], int Nsam, int order);
void levinson_durbin(float R[], float lpcs[], int order);
void inverse_filter(float Sn[], float a[], int Nsam, float res[], int order);
void synthesis_filter(float res[], float a[], int Nsam, int order, float Sn_[]);
void find_aks(float Sn[], float a[], int Nsam, int order, float *E);
void weight(float ak[], float gamma, int order, float akw[]);
#endif