2 * Copyright (C) 2016 Robin Gareus <robin@gareus.org>
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
23 #include "ardour/dB.h"
24 #include "ardour/buffer.h"
25 #include "ardour/dsp_filter.h"
29 #define isfinite_local(val) (bool)_finite((double)val)
31 #define isfinite_local std::isfinite
35 #define M_PI 3.14159265358979323846
38 using namespace ARDOUR::DSP;
41 ARDOUR::DSP::memset (float *data, const float val, const uint32_t n_samples) {
42 for (uint32_t i = 0; i < n_samples; ++i) {
48 ARDOUR::DSP::mmult (float *data, float *mult, const uint32_t n_samples) {
49 for (uint32_t i = 0; i < n_samples; ++i) {
55 ARDOUR::DSP::log_meter (float power) {
56 // compare to libs/ardour/log_meter.h
57 static const float lower_db = -192.f;
58 static const float upper_db = 0.f;
59 static const float non_linearity = 8.0;
60 return (power < lower_db ? 0.0 : powf ((power - lower_db) / (upper_db - lower_db), non_linearity));
64 ARDOUR::DSP::log_meter_coeff (float coeff) {
65 if (coeff <= 0) return 0;
66 return log_meter (fast_coefficient_to_dB (coeff));
70 ARDOUR::DSP::peaks (const float *data, float &min, float &max, uint32_t n_samples) {
71 for (uint32_t i = 0; i < n_samples; ++i) {
72 if (data[i] < min) min = data[i];
73 if (data[i] > max) max = data[i];
78 ARDOUR::DSP::process_map (BufferSet* bufs, const ChanMapping& in, const ChanMapping& out, pframes_t nframes, samplecnt_t offset, const DataType& dt)
80 const ChanMapping::Mappings& im (in.mappings());
81 const ChanMapping::Mappings& om (out.mappings());
83 for (ChanMapping::Mappings::const_iterator tm = im.begin(); tm != im.end(); ++tm) {
84 if (tm->first != dt) { continue; }
85 for (ChanMapping::TypeMapping::const_iterator i = tm->second.begin(); i != tm->second.end(); ++i) {
87 const uint32_t idx = out.get (dt, i->second, &valid);
88 if (valid && idx != i->first) {
89 bufs->get (dt, idx).read_from (bufs->get (dt, i->first), nframes, offset, offset);
93 for (ChanMapping::Mappings::const_iterator tm = im.begin(); tm != im.end(); ++tm) {
94 if (tm->first != dt) { continue; }
95 for (ChanMapping::TypeMapping::const_iterator i = tm->second.begin(); i != tm->second.end(); ++i) {
97 in.get_src (dt, i->first, &valid);
99 bufs->get (dt, i->second).silence (nframes, offset);
106 LowPass::LowPass (double samplerate, float freq)
114 LowPass::set_cutoff (float freq)
116 _a = 1.f - expf (-2.f * M_PI * freq / _rate);
120 LowPass::proc (float *data, const uint32_t n_samples)
122 // localize variables
125 for (uint32_t i = 0; i < n_samples; ++i) {
126 data[i] += a * (data[i] - z);
130 if (!isfinite_local (_z)) { _z = 0; }
134 LowPass::ctrl (float *data, const float val, const uint32_t n_samples)
136 // localize variables
139 for (uint32_t i = 0; i < n_samples; ++i) {
140 data[i] += a * (val - z);
146 ///////////////////////////////////////////////////////////////////////////////
148 Biquad::Biquad (double samplerate)
160 Biquad::Biquad (const Biquad &other)
161 : _rate (other._rate)
173 Biquad::run (float *data, const uint32_t n_samples)
175 for (uint32_t i = 0; i < n_samples; ++i) {
176 const float xn = data[i];
177 const float z = _b0 * xn + _z1;
178 _z1 = _b1 * xn - _a1 * z + _z2;
179 _z2 = _b2 * xn - _a2 * z;
183 if (!isfinite_local (_z1)) { _z1 = 0; }
184 if (!isfinite_local (_z2)) { _z2 = 0; }
188 Biquad::configure (double a1, double a2, double b0, double b1, double b2)
198 Biquad::compute (Type type, double freq, double Q, double gain)
200 if (Q <= .001) { Q = 0.001; }
201 if (freq <= 1.) { freq = 1.; }
202 if (freq >= 0.4998 * _rate) { freq = 0.4998 * _rate; }
204 /* Compute biquad filter settings.
205 * Based on 'Cookbook formulae for audio EQ biquad filter coefficents'
206 * by Robert Bristow-Johnson
208 const double A = pow (10.0, (gain / 40.0));
209 const double W0 = (2.0 * M_PI * freq) / _rate;
210 const double sinW0 = sin (W0);
211 const double cosW0 = cos (W0);
212 const double alpha = sinW0 / (2.0 * Q);
213 const double beta = sqrt (A) / Q;
219 _b0 = (1.0 - cosW0) / 2.0;
221 _b2 = (1.0 - cosW0) / 2.0;
228 _b0 = (1.0 + cosW0) / 2.0;
229 _b1 = -(1.0 + cosW0);
230 _b2 = (1.0 + cosW0) / 2.0;
236 case BandPassSkirt: /* Constant skirt gain, peak gain = Q */
245 case BandPass0dB: /* Constant 0 dB peak gain */
273 _b0 = 1.0 + (alpha * A);
275 _b2 = 1.0 - (alpha * A);
276 _a0 = 1.0 + (alpha / A);
278 _a2 = 1.0 - (alpha / A);
282 _b0 = A * ((A + 1) - ((A - 1) * cosW0) + (beta * sinW0));
283 _b1 = (2.0 * A) * ((A - 1) - ((A + 1) * cosW0));
284 _b2 = A * ((A + 1) - ((A - 1) * cosW0) - (beta * sinW0));
285 _a0 = (A + 1) + ((A - 1) * cosW0) + (beta * sinW0);
286 _a1 = -2.0 * ((A - 1) + ((A + 1) * cosW0));
287 _a2 = (A + 1) + ((A - 1) * cosW0) - (beta * sinW0);
291 _b0 = A * ((A + 1) + ((A - 1) * cosW0) + (beta * sinW0));
292 _b1 = -(2.0 * A) * ((A - 1) + ((A + 1) * cosW0));
293 _b2 = A * ((A + 1) + ((A - 1) * cosW0) - (beta * sinW0));
294 _a0 = (A + 1) - ((A - 1) * cosW0) + (beta * sinW0);
295 _a1 = 2.0 * ((A - 1) - ((A + 1) * cosW0));
296 _a2 = (A + 1) - ((A - 1) * cosW0) - (beta * sinW0);
299 abort(); /*NOTREACHED*/
311 Biquad::dB_at_freq (float freq) const
313 const double W0 = (2.0 * M_PI * freq) / _rate;
314 const float c1 = cosf (W0);
315 const float s1 = sinf (W0);
317 const float A = _b0 + _b2;
318 const float B = _b0 - _b2;
319 const float C = 1.0 + _a2;
320 const float D = 1.0 - _a2;
322 const float a = A * c1 + _b1;
323 const float b = B * s1;
324 const float c = C * c1 + _a1;
325 const float d = D * s1;
327 #define SQUARE(x) ( (x) * (x) )
328 float rv = 20.f * log10f (sqrtf ((SQUARE(a) + SQUARE(b)) * (SQUARE(c) + SQUARE(d))) / (SQUARE(c) + SQUARE(d)));
329 if (!isfinite_local (rv)) { rv = 0; }
330 return std::min (120.f, std::max(-120.f, rv));
334 Glib::Threads::Mutex FFTSpectrum::fft_planner_lock;
336 FFTSpectrum::FFTSpectrum (uint32_t window_size, double rate)
339 init (window_size, rate);
342 FFTSpectrum::~FFTSpectrum ()
345 Glib::Threads::Mutex::Lock lk (fft_planner_lock);
346 fftwf_destroy_plan (_fftplan);
348 fftwf_free (_fft_data_in);
349 fftwf_free (_fft_data_out);
355 FFTSpectrum::init (uint32_t window_size, double rate)
357 assert (window_size > 0);
358 Glib::Threads::Mutex::Lock lk (fft_planner_lock);
360 _fft_window_size = window_size;
361 _fft_data_size = window_size / 2;
362 _fft_freq_per_bin = rate / _fft_data_size / 2.f;
364 _fft_data_in = (float *) fftwf_malloc (sizeof(float) * _fft_window_size);
365 _fft_data_out = (float *) fftwf_malloc (sizeof(float) * _fft_window_size);
366 _fft_power = (float *) malloc (sizeof(float) * _fft_data_size);
370 _fftplan = fftwf_plan_r2r_1d (_fft_window_size, _fft_data_in, _fft_data_out, FFTW_R2HC, FFTW_MEASURE);
372 hann_window = (float *) malloc(sizeof(float) * window_size);
375 for (uint32_t i = 0; i < window_size; ++i) {
376 hann_window[i] = 0.5f - (0.5f * (float) cos (2.0f * M_PI * (float)i / (float)(window_size)));
377 sum += hann_window[i];
379 const double isum = 2.0 / sum;
380 for (uint32_t i = 0; i < window_size; ++i) {
381 hann_window[i] *= isum;
386 FFTSpectrum::reset ()
388 for (uint32_t i = 0; i < _fft_data_size; ++i) {
391 for (uint32_t i = 0; i < _fft_window_size; ++i) {
392 _fft_data_out[i] = 0;
397 FFTSpectrum::set_data_hann (float const * const data, uint32_t n_samples, uint32_t offset)
399 assert(n_samples + offset <= _fft_window_size);
400 for (uint32_t i = 0; i < n_samples; ++i) {
401 _fft_data_in[i + offset] = data[i] * hann_window[i + offset];
406 FFTSpectrum::execute ()
408 fftwf_execute (_fftplan);
410 _fft_power[0] = _fft_data_out[0] * _fft_data_out[0];
412 #define FRe (_fft_data_out[i])
413 #define FIm (_fft_data_out[_fft_window_size - i])
414 for (uint32_t i = 1; i < _fft_data_size - 1; ++i) {
415 _fft_power[i] = (FRe * FRe) + (FIm * FIm);
416 //_fft_phase[i] = atan2f (FIm, FRe);
423 FFTSpectrum::power_at_bin (const uint32_t b, const float norm) const {
424 assert (b < _fft_data_size);
425 const float a = _fft_power[b] * norm;
426 return a > 1e-12 ? 10.0 * fast_log10 (a) : -INFINITY;