libspeex/filters.h

/* Copyright (C) 2002 Jean-Marc Valin 
   File: filters.h
   Various analysis/synthesis filters

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.
   
   This library 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
   Lesser General Public License for more details.
   
   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef FILTERS_H
#define FILTERS_H

void print_vec(float *vec, int len, char *name);

/* Apply bandwidth expansion on LPC coef */
void bw_lpc(float gamma, float *lpc_in, float *lpc_out, int order);

/* Synthesis filter using the past of y[n] (negative indices) as memory */
void syn_filt(float *x, float *a, float *y, int N, int ord);

/* Synthesis filter using zero memory */
void syn_filt_zero(float *x, float *a, float *y, int N, int ord);

/* Synthesis filter using memory */
void syn_filt_mem(float *x, float *a, float *y, int N, int ord, float *mem);

/* Analysis (FIR) filter using the past of x[n] (negative indices) as memory */
void residue(float *x, float *a, float *y, int N, int ord);

/* Analysis (FIR) filter using zero memory */
void residue_zero(float *x, float *a, float *y, int N, int ord);

/* Analysis (FIR) filter using memory */
void residue_mem(float *x, float *a, float *y, int N, int ord, float *mem);

/* Cross correlation */
float xcorr(float *x, float *y, int len);

/* FIR filter */
void fir_mem(float *x, float *a, float *y, int N, int M, float *mem);

void syn_percep_zero(float *x, float *ak, float *awk1, float *awk2, float *y, int N, int ord);

#endif