apps/eq.h

   1 /***************************************************************************
   2  *             __________               __   ___.
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   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 Thom Johansen
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #ifndef _EQ_H
  21 #define _EQ_H
  22
  23 #include <inttypes.h>
  24
  25 /* These depend on the fixed point formats used by the different filter types
  26    and need to be changed when they change.
  27  */
  28 #define EQ_PEAK_SHIFT 4
  29 #define EQ_SHELF_SHIFT 8
  30
  31 struct eqfilter {
  32     int32_t coefs[5];        /* Order is b0, b1, b2, a1, a2 */
  33     int32_t history[2][4];
  34 };
  35
  36 void eq_pk_coefs(unsigned long cutoff, unsigned long Q, long db, long *c);
  37 void eq_ls_coefs(unsigned long cutoff, unsigned long Q, long db, long *c);
  38 void eq_hs_coefs(unsigned long cutoff, unsigned long Q, long db, long *c);
  39 void eq_filter(int32_t **x, struct eqfilter *f, unsigned num,
  40                unsigned channels, unsigned shift);
  41
  42 #endif
  43