diff options
Diffstat (limited to 'libs/ardour/pi_controller.cc')
| -rw-r--r-- | libs/ardour/pi_controller.cc | 46 |
1 files changed, 23 insertions, 23 deletions
diff --git a/libs/ardour/pi_controller.cc b/libs/ardour/pi_controller.cc index 2ecfe730d8..a165aa9e40 100644 --- a/libs/ardour/pi_controller.cc +++ b/libs/ardour/pi_controller.cc @@ -1,11 +1,11 @@ /* Copyright (C) 2008 Torben Hohn - + 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 2 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 @@ -25,8 +25,8 @@ static inline double hann(double x) { return 0.5 * (1.0 - cos(2 * M_PI * x)); } - -PIController::PIController (double resample_factor, int fir_size) + +PIController::PIController (double resample_factor, int fir_size) { resample_mean = resample_factor; static_resample_factor = resample_factor; @@ -35,12 +35,12 @@ PIController::PIController (double resample_factor, int fir_size) offset_differential_index = 0; offset_integral = 0.0; smooth_size = fir_size; - + for (int i = 0; i < fir_size; i++) { offset_array[i] = 0.0; window_array[i] = hann(double(i) / (double(fir_size) - 1.0)); } - + // These values could be configurable catch_factor = 20000; catch_factor2 = 4000; @@ -62,7 +62,7 @@ PIController::get_ratio (int fill_level, int period_size) double this_catch_factor = catch_factor; double this_catch_factor2 = catch_factor2 * 4096.0/(double)period_size; - + // Save offset. if( fir_empty ) { for (int i = 0; i < smooth_size; i++) { @@ -72,50 +72,50 @@ PIController::get_ratio (int fill_level, int period_size) } else { offset_array[(offset_differential_index++) % smooth_size] = offset; } - + // Build the mean of the windowed offset array basically fir lowpassing. smooth_offset = 0.0; for (int i = 0; i < smooth_size; i++) { smooth_offset += offset_array[(i + offset_differential_index - 1) % smooth_size] * window_array[i]; } smooth_offset /= double(smooth_size); - + // This is the integral of the smoothed_offset offset_integral += smooth_offset; std::cerr << smooth_offset << " "; - + // Clamp offset : the smooth offset still contains unwanted noise which would go straigth onto the resample coeff. // It only used in the P component and the I component is used for the fine tuning anyways. - + if (fabs(smooth_offset) < pclamp) smooth_offset = 0.0; - + smooth_offset += (static_resample_factor - resample_mean) * this_catch_factor; - - // Ok, now this is the PI controller. + + // Ok, now this is the PI controller. // u(t) = K * (e(t) + 1/T \int e(t') dt') - // Kp = 1/catch_factor and T = catch_factor2 Ki = Kp/T - current_resample_factor + // Kp = 1/catch_factor and T = catch_factor2 Ki = Kp/T + current_resample_factor = static_resample_factor - smooth_offset / this_catch_factor - offset_integral / this_catch_factor / this_catch_factor2; - + // Now quantize this value around resample_mean, so that the noise which is in the integral component doesnt hurt. current_resample_factor = floor((current_resample_factor - resample_mean) * controlquant + 0.5) / controlquant + resample_mean; - + // Calculate resample_mean so we can init ourselves to saner values. // resample_mean = 0.9999 * resample_mean + 0.0001 * current_resample_factor; resample_mean = (1.0-0.01) * resample_mean + 0.01 * current_resample_factor; std::cerr << fill_level << " " << smooth_offset << " " << offset_integral << " " << current_resample_factor << " " << resample_mean << "\n"; return current_resample_factor; } - -void + +void PIController::out_of_bounds() { int i; // Set the resample_rate... we need to adjust the offset integral, to do this. // first look at the PI controller, this code is just a special case, which should never execute once - // everything is swung in. + // everything is swung in. offset_integral = - (resample_mean - static_resample_factor) * catch_factor * catch_factor2; // Also clear the array. we are beginning a new control cycle. for (i = 0; i < smooth_size; i++) { @@ -157,7 +157,7 @@ PIChaser::get_ratio(framepos_t chasetime_measured, framepos_t chasetime, framepo feed_estimator( chasetime_measured, chasetime ); std::cerr << (double)chasetime_measured/48000.0 << " " << chasetime << " " << slavetime << " "; double crude = get_estimate(); - double fine; + double fine; framepos_t massaged_chasetime = chasetime + (framepos_t)( (double)(slavetime_measured - chasetime_measured) * crude ); fine = pic->get_ratio (slavetime - massaged_chasetime, period_size); @@ -183,7 +183,7 @@ PIChaser::get_ratio(framepos_t chasetime_measured, framepos_t chasetime, framepo speed = crude; pic->reset( crude ); } - + return speed; } |