brickworks/include/bw_peak.h

357 lines
12 KiB
C

/*
* Brickworks
*
* Copyright (C) 2023 Orastron Srl unipersonale
*
* Brickworks 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, version 3 of the License.
*
* Brickworks 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 General Public License
* along with Brickworks. If not, see <http://www.gnu.org/licenses/>.
*
* File author: Stefano D'Angelo
*/
/*!
* module_type {{{ dsp }}}
* version {{{ 1.0.0 }}}
* requires {{{ bw_common bw_gain bw_math bw_mm2 bw_one_pole bw_svf }}}
* description {{{
* Second-order peak filter with unitary gain at DC and asymptotically
* as frequency increases.
*
* The quality factor of the underlying bandpass filter can be either
* directly controlled via the Q parameter or indirectly through the
* bandwidth parameter, which designates the distance in octaves between
* midpoint gain frequencies, i.e., frequencies with gain = peak gain / 2 in
* dB terms. The use_bandiwdth parameter allows you to choose which
* parameterization to use.
* }}}
* changelog {{{
* <ul>
* <li>Version <strong>1.0.0</strong>:
* <ul>
* <li>Now using <code>size_t</code> instead of
* <code>BW_SIZE_T</code>.</li>
* </ul>
* </li>
* <li>Version <strong>0.6.0</strong>:
* <ul>
* <li>Removed dependency on bw_config.</li>
* </ul>
* </li>
* <li>Version <strong>0.5.0</strong>:
* <ul>
* <li>Added <code>bw_peak_process_multi()</code>.</li>
* <li>Fixed documentation for <code>bw_peak_set_peak_gain_lin()</code>
* and <code>bw_peak_set_gain_dB()</code>.</li>
* <li>Added C++ wrapper.</li>
* </ul>
* </li>
* <li>Version <strong>0.4.0</strong>:
* <ul>
* <li>Added initial input value to
* <code>bw_peak_reset_state()</code>.</li>
* </ul>
* </li>
* <li>Version <strong>0.3.0</strong>:
* <ul>
* <li>First release.</li>
* </ul>
* </li>
* </ul>
* }}}
*/
#ifndef _BW_PEAK_H
#define _BW_PEAK_H
#ifdef __cplusplus
extern "C" {
#endif
#include <bw_common.h>
/*! api {{{
* #### bw_peak_coeffs
* ```>>> */
typedef struct _bw_peak_coeffs bw_peak_coeffs;
/*! <<<```
* Coefficients and related.
*
* #### bw_peak_state
* ```>>> */
typedef struct _bw_peak_state bw_peak_state;
/*! <<<```
* Internal state and related.
*
* #### bw_peak_init()
* ```>>> */
static inline void bw_peak_init(bw_peak_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Initializes input parameter values in `coeffs`.
*
* #### bw_peak_set_sample_rate()
* ```>>> */
static inline void bw_peak_set_sample_rate(bw_peak_coeffs *BW_RESTRICT coeffs, float sample_rate);
/*! <<<```
* Sets the `sample_rate` (Hz) value in `coeffs`.
*
* #### bw_peak_reset_coeffs()
* ```>>> */
static inline void bw_peak_reset_coeffs(bw_peak_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Resets coefficients in `coeffs` to assume their target values.
*
* #### bw_peak_reset_state()
* ```>>> */
static inline void bw_peak_reset_state(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x0);
/*! <<<```
* Resets the given `state` to its initial values using the given `coeffs`
* and the quiescent/initial input value `x0`.
*
* #### bw_peak_update_coeffs_ctrl()
* ```>>> */
static inline void bw_peak_update_coeffs_ctrl(bw_peak_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Triggers control-rate update of coefficients in `coeffs`.
*
* #### bw_peak_update_coeffs_audio()
* ```>>> */
static inline void bw_peak_update_coeffs_audio(bw_peak_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Triggers audio-rate update of coefficients in `coeffs`.
*
* #### bw_peak_process1()
* ```>>> */
static inline float bw_peak_process1(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x);
/*! <<<```
* Processes one input sample `x` using `coeffs`, while using and updating
* `state`. Returns the corresponding output sample.
*
* #### bw_peak_process()
* ```>>> */
static inline void bw_peak_process(bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, const float *x, float *y, int n_samples);
/*! <<<```
* Processes the first `n_samples` of the input buffer `x` and fills the
* first `n_samples` of the output buffer `y`, while using and updating both
* `coeffs` and `state` (control and audio rate).
*
* #### bw_peak_process_multi()
* ```>>> */
static inline void bw_peak_process_multi(bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state **BW_RESTRICT state, const float **x, float **y, int n_channels, int n_samples);
/*! <<<```
* Processes the first `n_samples` of the `n_channels` input buffers `x` and
* fills the first `n_samples` of the `n_channels` output buffers `y`, while
* using and updating both the common `coeffs` and each of the `n_channels`
* `state`s (control and audio rate).
*
* #### bw_peak_set_cutoff()
* ```>>> */
static inline void bw_peak_set_cutoff(bw_peak_coeffs *BW_RESTRICT coeffs, float value);
/*! <<<```
* Sets the cutoff frequency `value` (Hz) in `coeffs`.
*
* Default value: `1e3f`.
*
* #### bw_peak_set_Q()
* ```>>> */
static inline void bw_peak_set_Q(bw_peak_coeffs *BW_RESTRICT coeffs, float value);
/*! <<<```
* Sets the quality factor to the given `value` in `coeffs`.
*
* `value` must be equal or bigger than `0.5f`.
*
* Default value: `0.5f`.
*
* #### bw_peak_set_peak_gain_lin()
* ```>>> */
static inline void bw_peak_set_peak_gain_lin(bw_peak_coeffs *BW_RESTRICT coeffs, float value);
/*! <<<```
* Sets the peak gain parameter to the given `value` (linear gain) in
* `coeffs`.
*
* Default value: `0.f`.
*
* #### bw_peak_set_peak_gain_dB()
* ```>>> */
static inline void bw_peak_set_peak_gain_dB(bw_peak_coeffs *BW_RESTRICT coeffs, float value);
/*! <<<```
* Sets the peak gain parameter to the given `value` (dB) in `coeffs`.
*
* Default value: `-INFINITY`.
*
* #### bw_peak_set_bandiwdth()
* ```>>> */
static inline void bw_peak_set_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, float value);
/*! <<<```
* Sets the bandwidth `value` (octaves) in `coeffs`.
*
* Default value: `0.5f`.
*
* #### bw_peak_set_use_bandwidth()
* ```>>> */
static inline void bw_peak_set_use_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, char value);
/*! <<<```
* Sets whether the quality factor should be controlled via the bandwidth
* parameter (`value` non-`0`) or via the Q parameter (`0`).
*
* Default value: non-`0` (use bandwidth parameter).
* }}} */
/*** Implementation ***/
/* WARNING: This part of the file is not part of the public API. Its content may
* change at any time in future versions. Please, do not use it directly. */
#include <bw_mm2.h>
#include <bw_math.h>
struct _bw_peak_coeffs {
// Sub-components
bw_mm2_coeffs mm2_coeffs;
// Coefficients
float bw_k;
// Parameters
float peak_gain;
float Q;
float bandwidth;
char use_bandwidth;
int param_changed;
};
struct _bw_peak_state {
bw_mm2_state mm2_state;
};
#define _BW_PEAK_PARAM_PEAK_GAIN 1
#define _BW_PEAK_PARAM_Q (1<<1)
#define _BW_PEAK_PARAM_BANDWIDTH (1<<2)
static inline void bw_peak_init(bw_peak_coeffs *BW_RESTRICT coeffs) {
bw_mm2_init(&coeffs->mm2_coeffs);
coeffs->peak_gain = 1.f;
coeffs->Q = 0.5f;
coeffs->bandwidth = 2.543106606327224f;
coeffs->use_bandwidth = 1;
}
static inline void bw_peak_set_sample_rate(bw_peak_coeffs *BW_RESTRICT coeffs, float sample_rate) {
bw_mm2_set_sample_rate(&coeffs->mm2_coeffs, sample_rate);
}
static inline void _bw_peak_update_mm2_params(bw_peak_coeffs *BW_RESTRICT coeffs) {
if (coeffs->param_changed) {
if (coeffs->use_bandwidth) {
if (coeffs->param_changed & (_BW_PEAK_PARAM_PEAK_GAIN | _BW_PEAK_PARAM_BANDWIDTH)) {
if (coeffs->param_changed & _BW_PEAK_PARAM_BANDWIDTH)
coeffs->bw_k = bw_pow2f(coeffs->bandwidth);
const float Q = bw_sqrtf(coeffs->bw_k * coeffs->peak_gain) * bw_rcpf(coeffs->bw_k - 1.f);
bw_mm2_set_Q(&coeffs->mm2_coeffs, Q);
bw_mm2_set_coeff_bp(&coeffs->mm2_coeffs, (coeffs->peak_gain - 1.f) * bw_rcpf(Q));
}
} else {
if (coeffs->param_changed & (_BW_PEAK_PARAM_PEAK_GAIN | _BW_PEAK_PARAM_Q)) {
if (coeffs->param_changed & _BW_PEAK_PARAM_Q)
bw_mm2_set_Q(&coeffs->mm2_coeffs, coeffs->Q);
bw_mm2_set_coeff_bp(&coeffs->mm2_coeffs, (coeffs->peak_gain - 1.f) * bw_rcpf(coeffs->Q));
}
}
coeffs->param_changed = 0;
}
}
static inline void bw_peak_reset_coeffs(bw_peak_coeffs *BW_RESTRICT coeffs) {
coeffs->param_changed = ~0;
_bw_peak_update_mm2_params(coeffs);
bw_mm2_reset_coeffs(&coeffs->mm2_coeffs);
}
static inline void bw_peak_reset_state(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x0) {
bw_mm2_reset_state(&coeffs->mm2_coeffs, &state->mm2_state, x0);
}
static inline void bw_peak_update_coeffs_ctrl(bw_peak_coeffs *BW_RESTRICT coeffs) {
_bw_peak_update_mm2_params(coeffs);
bw_mm2_update_coeffs_ctrl(&coeffs->mm2_coeffs);
}
static inline void bw_peak_update_coeffs_audio(bw_peak_coeffs *BW_RESTRICT coeffs) {
bw_mm2_update_coeffs_audio(&coeffs->mm2_coeffs);
}
static inline float bw_peak_process1(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x) {
return bw_mm2_process1(&coeffs->mm2_coeffs, &state->mm2_state, x);
}
static inline void bw_peak_process(bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, const float *x, float *y, int n_samples) {
bw_peak_update_coeffs_ctrl(coeffs);
for (int i = 0; i < n_samples; i++) {
bw_peak_update_coeffs_audio(coeffs);
y[i] = bw_peak_process1(coeffs, state, x[i]);
}
}
static inline void bw_peak_process_multi(bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state **BW_RESTRICT state, const float **x, float **y, int n_channels, int n_samples) {
bw_peak_update_coeffs_ctrl(coeffs);
for (int i = 0; i < n_samples; i++) {
bw_peak_update_coeffs_audio(coeffs);
for (int j = 0; j < n_channels; j++)
y[j][i] = bw_peak_process1(coeffs, state[j], x[j][i]);
}
}
static inline void bw_peak_set_cutoff(bw_peak_coeffs *BW_RESTRICT coeffs, float value) {
bw_mm2_set_cutoff(&coeffs->mm2_coeffs, value);
}
static inline void bw_peak_set_Q(bw_peak_coeffs *BW_RESTRICT coeffs, float value) {
if (coeffs->Q != value) {
coeffs->Q = value;
coeffs->param_changed |= _BW_PEAK_PARAM_Q;
}
}
static inline void bw_peak_set_peak_gain_lin(bw_peak_coeffs *BW_RESTRICT coeffs, float value) {
if (coeffs->peak_gain != value) {
coeffs->peak_gain = value;
coeffs->param_changed |= _BW_PEAK_PARAM_PEAK_GAIN;
}
}
static inline void bw_peak_set_peak_gain_dB(bw_peak_coeffs *BW_RESTRICT coeffs, float value) {
bw_peak_set_peak_gain_lin(coeffs, bw_dB2linf(value));
}
static inline void bw_peak_set_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, float value) {
if (coeffs->bandwidth != value) {
coeffs->bandwidth = value;
coeffs->param_changed |= _BW_PEAK_PARAM_BANDWIDTH;
}
}
static inline void bw_peak_set_use_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, char value) {
if ((coeffs->use_bandwidth && !value) || (!coeffs->use_bandwidth && value)) {
coeffs->use_bandwidth = value;
coeffs->param_changed |= _BW_PEAK_PARAM_Q | _BW_PEAK_PARAM_BANDWIDTH;
}
}
#undef _BW_PEAK_PARAM_PEAK_GAIN
#undef _BW_PEAK_PARAM_Q
#undef _BW_PEAK_PARAM_BANDWIDTH
#ifdef __cplusplus
}
#endif
#endif