rockbox/lib/rbcodec/dsp/tone_controls.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 Thom Johansen
* Copyright (C) 2012 Michael Sevakis
*
* 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.
*
****************************************************************************/
#include "rbcodecconfig.h"
#include "platform.h"
#include "fixedpoint.h"
#include "dsp_proc_entry.h"
#include "dsp_filter.h"
#include "tone_controls.h"
#include "dsp_misc.h"
/* These apply to all DSP streams to remain as consistant as possible with
* the behavior of hardware tone controls */
/* Cutoffs in HZ - not adjustable for now */
static const unsigned int tone_bass_cutoff = 200;
static const unsigned int tone_treble_cutoff = 3500;
/* Current bass and treble gain values */
static int tone_bass = 0;
static int tone_treble = 0;
/* Current prescaler setting */
static int tone_prescale = 0;
/* Data for each DSP */
static struct dsp_filter tone_filters[DSP_COUNT] IBSS_ATTR;
static void update_filter(int id, unsigned int fout)
{
filter_bishelf_coefs(fp_div(tone_bass_cutoff, fout, 32),
fp_div(tone_treble_cutoff, fout, 32),
tone_bass, tone_treble, -tone_prescale,
&tone_filters[id]);
}
/* Update the filters' coefficients based upon the bass/treble settings */
void tone_set_prescale(int prescale)
{
int bass = tone_bass;
int treble = tone_treble;
tone_prescale = prescale;
struct dsp_config *dsp;
for (int i = 0; (dsp = dsp_get_config(i)); i++)
{
update_filter(i, dsp_get_output_frequency(dsp));
bool enable = bass != 0 || treble != 0;
dsp_proc_enable(dsp, DSP_PROC_TONE_CONTROLS, enable);
if (enable && !dsp_proc_active(dsp, DSP_PROC_TONE_CONTROLS))
{
filter_flush(&tone_filters[i]); /* Going online */
dsp_proc_activate(dsp, DSP_PROC_TONE_CONTROLS, true);
}
}
}
/* Prescaler is always set after setting bass/treble, so we wait with
* calculating coefs until such time. */
/* Change the bass setting */
void tone_set_bass(int bass)
{
tone_bass = bass;
}
/* Change the treble setting */
void tone_set_treble(int treble)
{
tone_treble = treble;
}
/* Apply the tone control filter in-place */
static void tone_process(struct dsp_proc_entry *this,
struct dsp_buffer **buf_p)
{
struct dsp_buffer *buf = *buf_p;
filter_process((struct dsp_filter *)this->data, buf->p32, buf->remcount,
buf->format.num_channels);
}
/* DSP message hook */
static intptr_t tone_configure(struct dsp_proc_entry *this,
struct dsp_config *dsp,
unsigned int setting,
intptr_t value)
{
switch (setting)
{
case DSP_PROC_INIT:
if (value != 0)
break; /* Already enabled */
this->data = (intptr_t)&tone_filters[dsp_get_id(dsp)];
this->process = tone_process;
/* Fall-through */
case DSP_FLUSH:
filter_flush((struct dsp_filter *)this->data);
break;
case DSP_SET_OUT_FREQUENCY:
update_filter(dsp_get_id(dsp), value);
break;
}
return 0;
}
/* Database entry */
DSP_PROC_DB_ENTRY(TONE_CONTROLS,
tone_configure);