/* * Brickworks * * Copyright (C) 2022, 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 . * * File author: Stefano D'Angelo */ /*! * module_type {{{ dsp }}} * version {{{ 1.0.0 }}} * requires {{{ bw_common bw_math bw_one_pole bw_svf }}} * description {{{ * Second-order notch filter with unitary gain at DC and asymptotically as * frequency increases, and null gain at cutoff frequency. * }}} * changelog {{{ * * }}} */ #ifndef BW_NOTCH_H #define BW_NOTCH_H #include #ifdef __cplusplus extern "C" { #endif /*! api {{{ * #### bw_notch_coeffs * ```>>> */ typedef struct bw_notch_coeffs bw_notch_coeffs; /*! <<<``` * Coefficients and related. * * #### bw_notch_state * ```>>> */ typedef struct bw_notch_state bw_notch_state; /*! <<<``` * Internal state and related. * * #### bw_notch_init() * ```>>> */ static inline void bw_notch_init(bw_notch_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Initializes input parameter values in `coeffs`. * * #### bw_notch_set_sample_rate() * ```>>> */ static inline void bw_notch_set_sample_rate(bw_notch_coeffs *BW_RESTRICT coeffs, float sample_rate); /*! <<<``` * Sets the `sample_rate` (Hz) value in `coeffs`. * * #### bw_notch_reset_coeffs() * ```>>> */ static inline void bw_notch_reset_coeffs(bw_notch_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Resets coefficients in `coeffs` to assume their target values. * * #### bw_notch_reset_state() * ```>>> */ static inline void bw_notch_reset_state(const bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT state, float x_0); /*! <<<``` * Resets the given `state` to its initial values using the given `coeffs` * and the quiescent/initial input value `x_0`. * * #### bw_notch_update_coeffs_ctrl() * ```>>> */ static inline void bw_notch_update_coeffs_ctrl(bw_notch_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Triggers control-rate update of coefficients in `coeffs`. * * #### bw_notch_update_coeffs_audio() * ```>>> */ static inline void bw_notch_update_coeffs_audio(bw_notch_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Triggers audio-rate update of coefficients in `coeffs`. * * #### bw_notch_process1() * ```>>> */ static inline float bw_notch_process1(const bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT state, float x); /*! <<<``` * Processes one input sample `x` using `coeffs`, while using and updating * `state`. Returns the corresponding output sample. * * #### bw_notch_process() * ```>>> */ static inline void bw_notch_process(bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT state, const float *x, float *y, size_t 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_notch_process_multi() * ```>>> */ static inline void bw_notch_process_multi(bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT const *BW_RESTRICT state, const float * const *x, float * const *y, size_t n_channels, size_t 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_notch_set_cutoff() * ```>>> */ static inline void bw_notch_set_cutoff(bw_notch_coeffs *BW_RESTRICT coeffs, float value); /*! <<<``` * Sets the cutoff frequency `value` (Hz) in `coeffs`. * * Default value: `1e3f`. * * #### bw_notch_set_Q() * ```>>> */ static inline void bw_notch_set_Q(bw_notch_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`. * }}} */ #ifdef __cplusplus } #endif /*** 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 #ifdef __cplusplus extern "C" { #endif struct bw_notch_coeffs { // Sub-components bw_svf_coeffs svf_coeffs; }; struct bw_notch_state { bw_svf_state svf_state; }; static inline void bw_notch_init(bw_notch_coeffs *BW_RESTRICT coeffs) { bw_svf_init(&coeffs->svf_coeffs); } static inline void bw_notch_set_sample_rate(bw_notch_coeffs *BW_RESTRICT coeffs, float sample_rate) { bw_svf_set_sample_rate(&coeffs->svf_coeffs, sample_rate); } static inline void bw_notch_reset_coeffs(bw_notch_coeffs *BW_RESTRICT coeffs) { bw_svf_reset_coeffs(&coeffs->svf_coeffs); } static inline void bw_notch_reset_state(const bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT state, float x_0) { bw_svf_reset_state(&coeffs->svf_coeffs, &state->svf_state, x_0); } static inline void bw_notch_update_coeffs_ctrl(bw_notch_coeffs *BW_RESTRICT coeffs) { bw_svf_update_coeffs_ctrl(&coeffs->svf_coeffs); } static inline void bw_notch_update_coeffs_audio(bw_notch_coeffs *BW_RESTRICT coeffs) { bw_svf_update_coeffs_audio(&coeffs->svf_coeffs); } static inline float bw_notch_process1(const bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT state, float x) { float lp, bp, hp; bw_svf_process1(&coeffs->svf_coeffs, &state->svf_state, x, &lp, &bp, &hp); return lp + hp; } static inline void bw_notch_process(bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT state, const float *x, float *y, size_t n_samples) { bw_notch_update_coeffs_ctrl(coeffs); for (size_t i = 0; i < n_samples; i++) { bw_notch_update_coeffs_audio(coeffs); y[i] = bw_notch_process1(coeffs, state, x[i]); } } static inline void bw_notch_process_multi(bw_notch_coeffs *BW_RESTRICT coeffs, bw_notch_state *BW_RESTRICT const *BW_RESTRICT state, const float * const *x, float * const *y, size_t n_channels, size_t n_samples) { bw_notch_update_coeffs_ctrl(coeffs); for (size_t i = 0; i < n_samples; i++) { bw_notch_update_coeffs_audio(coeffs); for (size_t j = 0; j < n_channels; j++) y[j][i] = bw_notch_process1(coeffs, state[j], x[j][i]); } } static inline void bw_notch_set_cutoff(bw_notch_coeffs *BW_RESTRICT coeffs, float value) { bw_svf_set_cutoff(&coeffs->svf_coeffs, value); } static inline void bw_notch_set_Q(bw_notch_coeffs *BW_RESTRICT coeffs, float value) { bw_svf_set_Q(&coeffs->svf_coeffs, value); } #ifdef __cplusplus } #include namespace Brickworks { /*** Public C++ API ***/ /*! api_cpp {{{ * ##### Brickworks::Notch * ```>>> */ template class Notch { public: Notch(); void setSampleRate(float sampleRate); void reset(float x_0 = 0.f); void process( const float * const *x, float * const *y, size_t nSamples); void process( std::array x, std::array y, size_t nSamples); void setCutoff(float value); void setQ(float value); /*! <<<... * } * ``` * }}} */ /*** 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. */ private: bw_notch_coeffs coeffs; bw_notch_state states[N_CHANNELS]; bw_notch_state *BW_RESTRICT statesP[N_CHANNELS]; }; template inline Notch::Notch() { bw_notch_init(&coeffs); for (size_t i = 0; i < N_CHANNELS; i++) statesP[i] = states + i; } template inline void Notch::setSampleRate(float sampleRate) { bw_notch_set_sample_rate(&coeffs, sampleRate); } template inline void Notch::reset(float x_0) { bw_notch_reset_coeffs(&coeffs); for (size_t i = 0; i < N_CHANNELS; i++) bw_notch_reset_state(&coeffs, states + i, x_0); } template inline void Notch::process( const float * const *x, float * const *y, size_t nSamples) { bw_notch_process_multi(&coeffs, statesP, x, y, N_CHANNELS, nSamples); } template inline void Notch::process( std::array x, std::array y, size_t nSamples) { process(x.data(), y.data(), nSamples); } template inline void Notch::setCutoff(float value) { bw_notch_set_cutoff(&coeffs, value); } template inline void Notch::setQ(float value) { bw_notch_set_Q(&coeffs, value); } } #endif #endif