Brickworks > API documentation > bw_comp
Feedforward compressor/limiter with independent sidechain input.
Module type: dsp
Version: 1.1.0
Requires:
typedef struct bw_comp_coeffs bw_comp_coeffs;
Coefficients and related.
typedef struct bw_comp_state bw_comp_state;
Internal state and related.
static inline void bw_comp_init(
bw_comp_coeffs * BW_RESTRICT coeffs);
Initializes input parameter values in coeffs.
static inline void bw_comp_set_sample_rate(
bw_comp_coeffs * BW_RESTRICT coeffs,
float sample_rate);
Sets the sample_rate (Hz) value in coeffs.
static inline void bw_comp_reset_coeffs(
bw_comp_coeffs * BW_RESTRICT coeffs);
Resets coefficients in coeffs to assume their target values.
static inline float bw_comp_reset_state(
const bw_comp_coeffs * BW_RESTRICT coeffs,
bw_comp_state * BW_RESTRICT state,
float x_0,
float x_sc_0);
Resets the given state to its initial values using the given coeffs and the initial input value x_0 and sidechain input value x_sc_0.
Returns the corresponding initial output value.
static inline void bw_comp_reset_state_multi(
const bw_comp_coeffs * BW_RESTRICT coeffs,
bw_comp_state * BW_RESTRICT const * BW_RESTRICT state,
const float * x_0,
const float * x_sc_0,
float * y_0,
size_t n_channels);
Resets each of the n_channels states to its initial values using the given coeffs and the corresponding initial input value in the x_0 array and sidechain input value in the x_sc_0 array.
The corresponding initial output values are written into the y_0 array, if not BW_NULL.
If x_sc_0 is BW_NULL the initial sidechain input values are assumed to be 0.f.
static inline void bw_comp_update_coeffs_ctrl(
bw_comp_coeffs * BW_RESTRICT coeffs);
Triggers control-rate update of coefficients in coeffs.
static inline void bw_comp_update_coeffs_audio(
bw_comp_coeffs * BW_RESTRICT coeffs);
Triggers audio-rate update of coefficients in coeffs.
static inline float bw_comp_process1(
const bw_comp_coeffs * BW_RESTRICT coeffs,
bw_comp_state * BW_RESTRICT state,
float x,
float x_sc);
Processes one input sample x and the corresponding sidechain input sample x_sc using coeffs, while using and updating state. Returns the corresponding output sample.
static inline void bw_comp_process(
bw_comp_coeffs * BW_RESTRICT coeffs,
bw_comp_state * BW_RESTRICT state,
const float * x,
const float * x_sc,
float * y,
size_t n_samples);
Processes the first n_samples of the input buffer x and the first n_samples of the sidechain input buffer x_sc, and fills the first n_samples of the output buffer y, while using and updating both coeffs and state (control and audio rate).
If x_sc is BW_NULL it behaves as if a zero-filled buffer was passed instead.
static inline void bw_comp_process_multi(
bw_comp_coeffs * BW_RESTRICT coeffs,
bw_comp_state * BW_RESTRICT const * BW_RESTRICT state,
const float * const * x,
const float * const * x_sc,
float * const * y,
size_t n_channels,
size_t n_samples);
Processes the first n_samples of the n_channels input buffers x and the first n_samples of the n_channels sidechain input buffers x_sc, 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 states (control and audio rate).
If x_sc is BW_NULL it behaves as if zero-filled buffers were passed instead.
static inline void bw_comp_set_thresh_lin(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the threshold value (linear) in coeffs.
Valid range: [1e-20f, 1e20f].
Default value: 1.f.
static inline void bw_comp_set_thresh_dBFS(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the threshold value (dBFS) in coeffs.
Valid range: [-400.f, 400.f].
Default value: 0.f.
static inline void bw_comp_set_ratio(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the compression ratio value in coeffs.
value is actually the slope of the gain curve above the threshold, hence 1.f means no compression and 0.f is a hard limit.
Valid range: [0.f, 1.f].
Default value: 1.f.
static inline void bw_comp_set_attack_tau(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the attack time constant value (s) in coeffs.
value must be non-negative.
Default value: 0.f.
static inline void bw_comp_set_release_tau(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the release time constant value (s) in coeffs.
value must be non-negative.
Default value: 0.f.
static inline void bw_comp_set_gain_lin(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the output makeup gain value (linear ratio) in coeffs.
value must be finite.
Default value: 1.f.
static inline void bw_comp_set_gain_dB(
bw_comp_coeffs * BW_RESTRICT coeffs,
float value);
Sets the output makeup gain value (dB) in coeffs.
value must be less than or equal to 770.630f.
Default value: 0.f.
static inline char bw_comp_coeffs_is_valid(
const bw_comp_coeffs * BW_RESTRICT coeffs);
Tries to determine whether coeffs is valid and returns non-0 if it seems to be the case and 0 if it is certainly not. False positives are possible, false negatives are not.
coeffs must at least point to a readable memory block of size greater than or equal to that of bw_comp_coeffs.
static inline char bw_comp_state_is_valid(
const bw_comp_coeffs * BW_RESTRICT coeffs,
const bw_comp_state * BW_RESTRICT state);
Tries to determine whether state is valid and returns non-0 if it seems to be the case and 0 if it is certainly not. False positives are possible, false negatives are not.
If coeffs is not BW_NULL extra cross-checks might be performed (state is supposed to be associated to coeffs).
state must at least point to a readable memory block of size greater than or equal to that of bw_comp_state.
template<size_t N_CHANNELS>
class Comp {
public:
Comp();
void setSampleRate(
float sampleRate);
void reset(
float x0 = 0.f,
float xSc0 = 0.f,
float * BW_RESTRICT y0 = nullptr);
#ifndef BW_CXX_NO_ARRAY
void reset(
float x0,
float xSc0,
std::array<float, N_CHANNELS> * BW_RESTRICT y0);
#endif
void reset(
const float * x0,
const float * xSc0,
float * y0 = nullptr);
#ifndef BW_CXX_NO_ARRAY
void reset(
std::array<float, N_CHANNELS> x0,
std::array<float, N_CHANNELS> xSc0,
std::array<float, N_CHANNELS> * BW_RESTRICT y0 = nullptr);
#endif
void process(
const float * const * x,
const float * const * xSc,
float * const * y,
size_t nSamples);
#ifndef BW_CXX_NO_ARRAY
void process(
std::array<const float *, N_CHANNELS> x,
std::array<const float *, N_CHANNELS> xSc,
std::array<float *, N_CHANNELS> y,
size_t nSamples);
#endif
// >> the following 2 methods only exist because of a typo, don't use
void setTreshLin(
float value);
void setTreshDBFS(
float value);
// <<
void setThreshLin(
float value);
void setThreshDBFS(
float value);
void setRatio(
float value);
void setAttackTau(
float value);
void setReleaseTau(
float value);
void setGainLin(
float value);
void setGainDB(
float value);
...
}
bw_comp_reset_state_multi, bw_comp_process, and bw_comp_process_multi APIs to accept BW_NULL as sidechain inputs.BW_NULL and BW_CXX_NO_ARRAY.setThreshLin() and setThreshDB() methods to fix a typo in method names without breaking the API.bw_comp_reset_state().bw_comp_reset_state_multi() and updated C++ API in this regard.bw_comp_reset_state() returns the initial output value.reset() functions taking arrays as arguments.bw_comp_process() and bw_comp_process_multi() now use size_t to count samples and channels.const and BW_RESTRICT specifiers to input arguments and implementation.process() function taking C-style arrays as arguments.bw_comp_reset_coeffs().bw_comp_process_multi().bw_comp_set_ratio() documentation.