/* * This file is part of libsidplayfp, a SID player engine. * * Copyright 2012-2013 Leandro Nini * Copyright 2007-2010 Antti Lankila * * 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 * 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, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include #include #include #include "siddefs-fp.h" #include "Resampler.h" #include "TwoPassSincResampler.h" /** * Simple sin waveform in, power output measurement function. * It would be far better to use FFT. */ int main(int argc, const char* argv[]) { const double RATE = 985248.4; const int RINGSIZE = 2048; std::auto_ptr r(reSIDfp::TwoPassSincResampler::create(RATE, 48000.0, 20000.0)); std::map results; clock_t start = clock(); for (double freq = 1000.; freq < RATE / 2.; freq *= 1.01) { /* prefill resampler buffer */ int k = 0; double omega = 2 * M_PI * freq / RATE; for (int j = 0; j < RINGSIZE; j ++) { int signal = static_cast(32768.0 * sin(k++ * omega) * sqrt(2)); r->input(signal); } int n = 0; float pwr = 0; /* Now, during measurement stage, put 100 cycles of waveform through filter. */ for (int j = 0; j < 100000; j ++) { int signal = static_cast(32768.0 * sin(k++ * omega) * sqrt(2)); if (r->input(signal)) { float out = r->output(); pwr += out * out; n += 1; } } results.insert(std::make_pair(freq, 10 * log10(pwr / n))); } clock_t end = clock(); for (std::map::iterator it = results.begin(); it != results.end(); ++it) { std::cout << std::fixed << std::setprecision(0) << std::setw(6) << (*it).first << " Hz " << (*it).second << " dB" << std::endl; } std::cout << "Filtering time " << (end - start) * 1000. / CLOCKS_PER_SEC << " ms" << std::endl; }