You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

398 lines
11 KiB

/*
Calf Box, an open source musical instrument.
Copyright (C) 2010 Krzysztof Foltman
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 3 of the License, or
(at your option) any later version.
This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef CBOX_BIQUAD_FLOAT_H
#define CBOX_BIQUAD_FLOAT_H
#include "config.h"
#include "dspmath.h"
struct cbox_biquadf_state
{
float x1;
float y1;
float x2;
float y2;
};
struct cbox_biquadf_coeffs
{
float a0;
float a1;
float a2;
float b1;
float b2;
};
static inline void cbox_biquadf_reset(struct cbox_biquadf_state *state)
{
state->x1 = state->y1 = state->x2 = state->y2 = 0.f;
}
static inline float cbox_biquadf_is_audible(struct cbox_biquadf_state *state, float level)
{
return fabs(state->x1) + fabs(state->x2) + fabs(state->y1) + fabs(state->y2) >= level;
}
// Based on filter coefficient equations by Robert Bristow-Johnson
static inline void cbox_biquadf_set_lp_rbj(struct cbox_biquadf_coeffs *coeffs, float fc, float q, float sr)
{
float omega=(float)(2*M_PI*fc/sr);
float sn=sin(omega);
float cs=cos(omega);
float alpha=(float)(sn/(2*q));
float inv=(float)(1.0/(1.0+alpha));
coeffs->a2 = coeffs->a0 = (float)(inv*(1 - cs)*0.5f);
coeffs->a1 = coeffs->a0 + coeffs->a0;
coeffs->b1 = (float)(-2*cs*inv);
coeffs->b2 = (float)((1 - alpha)*inv);
}
static inline void cbox_biquadf_set_lp_rbj_lookup(struct cbox_biquadf_coeffs *coeffs, const struct cbox_sincos *sincos, float q)
{
float sn=sincos->sine;
float cs=sincos->cosine;
float alpha=(float)(sn/(2*q));
float inv=(float)(1.0/(1.0+alpha));
coeffs->a2 = coeffs->a0 = (float)(inv*(1 - cs)*0.5f);
coeffs->a1 = coeffs->a0 + coeffs->a0;
coeffs->b1 = (float)(-2*cs*inv);
coeffs->b2 = (float)((1 - alpha)*inv);
}
// Based on filter coefficient equations by Robert Bristow-Johnson
static inline void cbox_biquadf_set_hp_rbj(struct cbox_biquadf_coeffs *coeffs, float fc, float q, float sr)
{
float omega=(float)(2*M_PI*fc/sr);
float sn=sin(omega);
float cs=cos(omega);
float alpha=(float)(sn/(2*q));
float inv=(float)(1.0/(1.0+alpha));
coeffs->a2 = coeffs->a0 = (float)(inv*(1 + cs)*0.5f);
coeffs->a1 = -2 * coeffs->a0;
coeffs->b1 = (float)(-2*cs*inv);
coeffs->b2 = (float)((1 - alpha)*inv);
}
static inline void cbox_biquadf_set_hp_rbj_lookup(struct cbox_biquadf_coeffs *coeffs, const struct cbox_sincos *sincos, float q)
{
float sn=sincos->sine;
float cs=sincos->cosine;
float alpha=(float)(sn/(2*q));
float inv=(float)(1.0/(1.0+alpha));
coeffs->a2 = coeffs->a0 = (float)(inv*(1 + cs)*0.5f);
coeffs->a1 = -2 * coeffs->a0;
coeffs->b1 = (float)(-2*cs*inv);
coeffs->b2 = (float)((1 - alpha)*inv);
}
// Based on filter coefficient equations by Robert Bristow-Johnson
static inline void cbox_biquadf_set_bp_rbj(struct cbox_biquadf_coeffs *coeffs, float fc, float q, float sr)
{
float omega=(float)(2*M_PI*fc/sr);
float sn=sin(omega);
float cs=cos(omega);
float alpha=(float)(sn/(2*q));
float inv=(float)(1.0/(1.0+alpha));
coeffs->a0 = (float)(inv*alpha);
coeffs->a1 = 0.f;
coeffs->a2 = -coeffs->a0;
coeffs->b1 = (float)(-2*cs*inv);
coeffs->b2 = (float)((1 - alpha)*inv);
}
static inline void cbox_biquadf_set_bp_rbj_lookup(struct cbox_biquadf_coeffs *coeffs, const struct cbox_sincos *sincos, float q)
{
float sn=sincos->sine;
float cs=sincos->cosine;
float alpha=(float)(sn/(2*q));
float inv=(float)(1.0/(1.0+alpha));
coeffs->a0 = (float)(inv*alpha);
coeffs->a1 = 0.f;
coeffs->a2 = -coeffs->a0;
coeffs->b1 = (float)(-2*cs*inv);
coeffs->b2 = (float)((1 - alpha)*inv);
}
// Based on filter coefficient equations by Robert Bristow-Johnson
static inline void cbox_biquadf_set_peakeq_rbj(struct cbox_biquadf_coeffs *coeffs, float freq, float q, float peak, float sr)
{
float A = sqrt(peak);
float w0 = freq * 2 * M_PI * (1.0 / sr);
float alpha = sin(w0) / (2 * q);
float ib0 = 1.0 / (1 + alpha/A);
coeffs->a1 = coeffs->b1 = -2*cos(w0) * ib0;
coeffs->a0 = ib0 * (1 + alpha*A);
coeffs->a2 = ib0 * (1 - alpha*A);
coeffs->b2 = ib0 * (1 - alpha/A);
}
static inline void cbox_biquadf_set_peakeq_rbj_scaled(struct cbox_biquadf_coeffs *coeffs, float freq, float q, float A, float sr)
{
float w0 = freq * 2 * M_PI * (1.0 / sr);
float alpha = sin(w0) / (2 * q);
float ib0 = 1.0 / (1 + alpha/A);
coeffs->a1 = coeffs->b1 = -2*cos(w0) * ib0;
coeffs->a0 = ib0 * (1 + alpha*A);
coeffs->a2 = ib0 * (1 - alpha*A);
coeffs->b2 = ib0 * (1 - alpha/A);
}
// This is my math, and it's rather suspect
static inline void cbox_biquadf_set_1plp(struct cbox_biquadf_coeffs *coeffs, float freq, float sr)
{
float w = hz2w(freq, sr);
float x = tan (w * 0.5f);
float q = 1 / (1 + x);
float a01 = x*q;
float b1 = a01 - q;
coeffs->a0 = a01;
coeffs->a1 = a01;
coeffs->b1 = b1;
coeffs->a2 = 0;
coeffs->b2 = 0;
}
static inline void cbox_biquadf_set_1php(struct cbox_biquadf_coeffs *coeffs, float freq, float sr)
{
float w = hz2w(freq, sr);
float x = tan (w * 0.5f);
float q = 1 / (1 + x);
float a01 = x*q;
float b1 = a01 - q;
coeffs->a0 = q;
coeffs->a1 = -q;
coeffs->b1 = b1;
coeffs->a2 = 0;
coeffs->b2 = 0;
}
static inline void cbox_biquadf_set_1p(struct cbox_biquadf_coeffs *coeffs, float a0, float a1, float b1, int two_copies)
{
if (two_copies)
{
// (a0 + a1z) * (a0 + a1z) = a0^2 + 2*a0*a1*z + a1^2*z^2
// (1 - b1z) * (1 - b1z) = 1 - 2b1*z + b1^2*z^2
coeffs->a0 = a0*a0;
coeffs->a1 = 2*a0*a1;
coeffs->b1 = 2 * b1;
coeffs->a2 = a1*a1;
coeffs->b2 = b1*b1;
}
else
{
coeffs->a0 = a0;
coeffs->a1 = a1;
coeffs->b1 = b1;
coeffs->a2 = 0;
coeffs->b2 = 0;
}
}
static inline void cbox_biquadf_set_1plp_lookup(struct cbox_biquadf_coeffs *coeffs, const struct cbox_sincos *sincos, int two_copies)
{
float x = sincos->prewarp;
float q = sincos->prewarp2;
float a01 = x*q;
float b1 = a01 - q;
cbox_biquadf_set_1p(coeffs, a01, a01, b1, two_copies);
}
static inline void cbox_biquadf_set_1php_lookup(struct cbox_biquadf_coeffs *coeffs, const struct cbox_sincos *sincos, int two_copies)
{
float x = sincos->prewarp;
float q = sincos->prewarp2;
float a01 = x*q;
float b1 = a01 - q;
cbox_biquadf_set_1p(coeffs, q, -q, b1, two_copies);
}
#if USE_NEON
#include <arm_neon.h>
static inline void cbox_biquadf_process(struct cbox_biquadf_state *state, struct cbox_biquadf_coeffs *coeffs, float *buffer)
{
int i;
float32x2_t c0 = {coeffs->a0, 0};
float32x2_t c1 = {coeffs->a1, -coeffs->b1};
float32x2_t c2 = {coeffs->a2, -coeffs->b2};
float32x2_t s1 = {state->x1, state->y1};
float32x2_t s2 = {state->x2, state->y2};
for (i = 0; i < CBOX_BLOCK_SIZE; i ++)
{
float32x2_t in12 = {buffer[i], 0.f};
float32x2_t out12 = vmla_f32(vmla_f32(vmul_f32(c1, s1), c2, s2), in12, c0); // [a1 * x1 + a2 * x2 + a0 * in, -b1 * y1 - b2 * y2 + 0]
float32x2x2_t trn = vtrn_f32(out12, in12); // [[a1 * x1 + a2 * x2 + a0 * in, in12], [-b1 * y1 - b2 * y2, 0]]
float32x2_t out120 = vadd_f32(trn.val[0], trn.val[1]);
s2 = s1;
s1 = vrev64_f32(out120);
buffer[i] = out120[0];
}
state->x1 = s1[0];
state->y1 = s1[1];
state->x2 = s2[0];
state->y2 = s2[1];
}
#else
static inline void cbox_biquadf_process(struct cbox_biquadf_state *state, struct cbox_biquadf_coeffs *coeffs, float *buffer)
{
int i;
float a0 = coeffs->a0;
float a1 = coeffs->a1;
float a2 = coeffs->a2;
float b1 = coeffs->b1;
float b2 = coeffs->b2;
double y1 = state->y1;
double y2 = state->y2;
for (i = 0; i < CBOX_BLOCK_SIZE; i++)
{
float in = buffer[i];
double out = a0 * in + a1 * state->x1 + a2 * state->x2 - b1 * y1 - b2 * y2;
buffer[i] = out;
state->x2 = state->x1;
state->x1 = in;
y2 = y1;
y1 = out;
}
state->y2 = sanef(y2);
state->y1 = sanef(y1);
}
#endif
static inline void cbox_biquadf_process_stereo(struct cbox_biquadf_state *lstate, struct cbox_biquadf_state *rstate, struct cbox_biquadf_coeffs *coeffs, float *buffer)
{
int i;
float a0 = coeffs->a0;
float a1 = coeffs->a1;
float a2 = coeffs->a2;
float b1 = coeffs->b1;
float b2 = coeffs->b2;
double ly1 = lstate->y1;
double ly2 = lstate->y2;
double ry1 = rstate->y1;
double ry2 = rstate->y2;
for (i = 0; i < 2 * CBOX_BLOCK_SIZE; i += 2)
{
float inl = buffer[i], inr = buffer[i + 1];
float outl = a0 * inl + a1 * lstate->x1 + a2 * lstate->x2 - b1 * ly1 - b2 * ly2;
float outr = a0 * inr + a1 * rstate->x1 + a2 * rstate->x2 - b1 * ry1 - b2 * ry2;
lstate->x2 = lstate->x1;
lstate->x1 = inl;
ly2 = ly1;
ly1 = outl;
buffer[i] = outl;
rstate->x2 = rstate->x1;
rstate->x1 = inr;
ry2 = ry1;
ry1 = outr;
buffer[i + 1] = outr;
}
lstate->y2 = sanef(ly2);
lstate->y1 = sanef(ly1);
rstate->y2 = sanef(ry2);
rstate->y1 = sanef(ry1);
}
static inline double cbox_biquadf_process_sample(struct cbox_biquadf_state *state, struct cbox_biquadf_coeffs *coeffs, double in)
{
double out = sanef(coeffs->a0 * sanef(in) + coeffs->a1 * state->x1 + coeffs->a2 * state->x2 - coeffs->b1 * state->y1 - coeffs->b2 * state->y2);
state->x2 = state->x1;
state->x1 = in;
state->y2 = state->y1;
state->y1 = out;
return out;
}
static inline void cbox_biquadf_process_to(struct cbox_biquadf_state *state, struct cbox_biquadf_coeffs *coeffs, float *buffer_in, float *buffer_out)
{
int i;
float a0 = coeffs->a0;
float a1 = coeffs->a1;
float a2 = coeffs->a2;
float b1 = coeffs->b1;
float b2 = coeffs->b2;
double y1 = state->y1;
double y2 = state->y2;
for (i = 0; i < CBOX_BLOCK_SIZE; i++)
{
float in = buffer_in[i];
double out = a0 * in + a1 * state->x1 + a2 * state->x2 - b1 * y1 - b2 * y2;
buffer_out[i] = out;
state->x2 = state->x1;
state->x1 = in;
y2 = y1;
y1 = out;
}
state->y2 = sanef(y2);
state->y1 = sanef(y1);
}
static inline void cbox_biquadf_process_adding(struct cbox_biquadf_state *state, struct cbox_biquadf_coeffs *coeffs, float *buffer_in, float *buffer_out)
{
int i;
float a0 = coeffs->a0;
float a1 = coeffs->a1;
float a2 = coeffs->a2;
float b1 = coeffs->b1;
float b2 = coeffs->b2;
double y1 = state->y1;
double y2 = state->y2;
for (i = 0; i < CBOX_BLOCK_SIZE; i++)
{
float in = buffer_in[i];
double out = a0 * in + a1 * state->x1 + a2 * state->x2 - b1 * y1 - b2 * y2;
buffer_out[i] += out;
state->x2 = state->x1;
state->x1 = in;
y2 = y1;
y1 = out;
}
state->y2 = sanef(y2);
state->y1 = sanef(y1);
}
#endif