rockbox/apps/eq.h
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

49 lines
1.9 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006-2007 Thom Johansen
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _EQ_H
#define _EQ_H
#include <inttypes.h>
/* These depend on the fixed point formats used by the different filter types
and need to be changed when they change.
*/
#define FILTER_BISHELF_SHIFT 5
#define EQ_PEAK_SHIFT 4
#define EQ_SHELF_SHIFT 6
struct eqfilter {
int32_t coefs[5]; /* Order is b0, b1, b2, a1, a2 */
int32_t history[2][4];
};
void filter_shelf_coefs(unsigned long cutoff, long A, bool low, int32_t *c);
void filter_bishelf_coefs(unsigned long cutoff_low, unsigned long cutoff_high,
long A_low, long A_high, long A, int32_t *c);
void eq_pk_coefs(unsigned long cutoff, unsigned long Q, long db, int32_t *c);
void eq_ls_coefs(unsigned long cutoff, unsigned long Q, long db, int32_t *c);
void eq_hs_coefs(unsigned long cutoff, unsigned long Q, long db, int32_t *c);
void eq_filter(int32_t **x, struct eqfilter *f, unsigned num,
unsigned channels, unsigned shift);
#endif