173 lines
4.4 KiB
C
173 lines
4.4 KiB
C
/*
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* Brickworks
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*
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* Copyright (C) 2022 Orastron Srl unipersonale
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*
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* Brickworks is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, version 3 of the License.
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*
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* Brickworks is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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*
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* File author: Stefano D'Angelo
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*/
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/*!
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* module_type {{{ dsp }}}
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* version {{{ 0.2.0 }}}
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* requires {{{ bw_config bw_common bw_math }}}
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* description {{{
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* Slew-rate limiter with separate maximum increasing and decreasing rates.
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* }}}
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* changelog {{{
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* <ul>
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* <li>Version <strong>0.2.0</strong>:
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* <ul>
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* <li>Refactored API to avoid dynamic memory allocation.</li>
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* </ul>
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* </li>
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* <li>Version <strong>0.1.0</strong>:
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* <ul>
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* <li>First release.</li>
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* </ul>
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* </li>
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* </ul>
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* }}}
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*/
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#ifndef _BW_SLEW_LIM_H
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#define _BW_SLEW_LIM_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/*! api {{{
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* #### bw_slew_lim
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* ```>>> */
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typedef struct _bw_slew_lim bw_slew_lim;
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/*! <<<```
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* Instance object.
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* >>> */
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/*! ...
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* #### bw_slew_lim_init()
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* ```>>> */
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void bw_slew_lim_new(bw_slew_lim *instance);
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/*! <<<```
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* Initializes the `instance` object.
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* >>> */
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/*! ...
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* #### bw_slew_lim_set_sample_rate()
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* ```>>> */
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void bw_slew_lim_set_sample_rate(bw_slew_lim *instance, float sample_rate);
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/*! <<<```
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* Sets the `sample_rate` (Hz) value for the given `instance`.
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* >>> */
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/*! ...
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* #### bw_slew_lim_reset()
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* ```>>> */
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void bw_slew_lim_reset(bw_slew_lim *instance);
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/*! <<<```
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* Resets the given `instance` to its initial state.
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* >>> */
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/*! ...
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* #### bw_slew_lim_process()
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* ```>>> */
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void bw_slew_lim_process(bw_slew_lim *instance, const float* x, float* y, int n_samples);
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/*! <<<```
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* Lets the given `instance` process `n_samples` samples from the input
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* buffer `x` and fills the corresponding `n_samples` samples in the output
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* buffer `y`.
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* >>> */
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/*! ...
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* #### bw_slew_lim_set_init_val()
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* ```>>> */
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void bw_slew_lim_set_init_val(bw_slew_lim *instance, float value);
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/*! <<<```
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* Sets the initial/quiescent `value` for the given `instance`.
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*
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* In practice, when processing the first buffer after a reset, the past
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* input and output are both assumed to have virtually been constant and of
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* the specified `value`.
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*
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* Default value: `0.f`.
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* >>> */
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/*! ...
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* #### bw_slew_lim_set_max_rate()
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* ```>>> */
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void bw_slew_lim_set_max_rate(bw_slew_lim *instance, float value);
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/*! <<<```
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* Sets both the maximum increasing and decreasing variation rate to the
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* given `value` (1/s) for the given `instance`.
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*
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* `value` represents the maximum variation per second and must be
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* non-negative.
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*
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* This is equivalent to calling both `bw_slew_lim_set_max_inc_rate()` and
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* `bw_slew_lim_set_max_dec_rate()` with same `instance` and `value`.
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*
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* Default value: `INFINITY`.
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* >>> */
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/*! ...
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* #### bw_slew_lim_set_max_inc_rate()
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* ```>>> */
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void bw_slew_lim_set_max_inc_rate(bw_slew_lim *instance, float value);
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/*! <<<```
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* Sets the maximum increasing variation rate to the given `value` (1/s) for
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* the given `instance`.
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*
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* `value` represents the maximum variation per second and must be
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* non-negative.
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*
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* Default value: `INFINITY`.
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* >>> */
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/*! ...
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* #### bw_slew_lim_set_max_inc_rate()
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* ```>>> */
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void bw_slew_lim_set_max_dec_rate(bw_slew_lim *instance, float value);
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/*! <<<```
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* Sets the maximum decreasing variation rate to the given `value` (1/s) for
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* the given `instance`.
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*
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* `value` represents the maximum variation per second and must be
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* non-negative.
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*
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* Default value: `INFINITY`.
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* }}} */
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/* WARNING: the internal definition of this struct is not part of the public
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* API. Its content may change at any time in future versions. Please, do not
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* access its members directly. */
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struct _bw_slew_lim {
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// Coefficients
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float T;
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// Parameters
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float init_val;
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float max_inc_rate;
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float max_dec_rate;
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// State
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char first_run;
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float y_z1;
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};
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#ifdef __cplusplus
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}
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#endif
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#endif
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