Chris@366: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@366: 
Chris@366: #include "dsp/Resampler.h"
Chris@366: 
Chris@366: #include "dsp/Window.h"
Chris@366: #include "dsp/FFT.h"
Chris@366: 
Chris@366: #include <iostream>
Chris@366: 
Chris@366: #include <cmath>
Chris@366: 
Chris@366: #define BOOST_TEST_DYN_LINK
Chris@366: #define BOOST_TEST_MAIN
Chris@366: 
Chris@366: #include <boost/test/unit_test.hpp>
Chris@366: 
Chris@366: BOOST_AUTO_TEST_SUITE(TestResampler)
Chris@366: 
Chris@366: using std::cout;
Chris@366: using std::endl;
Chris@366: using std::vector;
Chris@366: 
Chris@366: void
Chris@366: testResamplerOneShot(int sourceRate,
Chris@366: 		     int targetRate,
Chris@366: 		     int n,
Chris@366: 		     double *in,
Chris@366: 		     int m,
Chris@366: 		     double *expected,
Chris@366: 		     int skip)
Chris@366: {
Chris@366:     vector<double> resampled = Resampler::resample(sourceRate, targetRate,
Chris@366: 						   in, n);
Chris@366:     if (skip == 0) {
Chris@366: 	BOOST_CHECK_EQUAL(resampled.size(), m);
Chris@366:     }
Chris@366:     for (int i = 0; i < m; ++i) {
Chris@366: 	BOOST_CHECK_SMALL(resampled[i + skip] - expected[i], 1e-6);
Chris@366:     }
Chris@366: }
Chris@366: 
Chris@366: void
Chris@366: testResampler(int sourceRate,
Chris@366: 	      int targetRate,
Chris@366: 	      int n,
Chris@366: 	      double *in,
Chris@366: 	      int m,
Chris@366: 	      double *expected)
Chris@366: {
Chris@366:     // Here we provide the input in chunks (of varying size)
Chris@366: 
Chris@366:     Resampler r(sourceRate, targetRate);
Chris@366:     int latency = r.getLatency();
Chris@366: 
Chris@366:     int m1 = m + latency;
Chris@366:     int n1 = int((m1 * sourceRate) / targetRate);
Chris@366: 
Chris@366:     double *inPadded = new double[n1];
Chris@366:     double *outPadded = new double[m1];
Chris@366: 
Chris@366:     for (int i = 0; i < n1; ++i) {
Chris@366: 	if (i < n) inPadded[i] = in[i];
Chris@366: 	else inPadded[i] = 0.0;
Chris@366:     }
Chris@366:     
Chris@366:     for (int i = 0; i < m1; ++i) {
Chris@366: 	outPadded[i] = -999.0;
Chris@366:     }
Chris@366: 
Chris@366:     int chunkSize = 1;
Chris@366:     int got = 0;
Chris@366:     int i = 0;
Chris@366: 
Chris@366:     while (true) {
Chris@366: 	got += r.process(inPadded + i, outPadded + got, chunkSize);
Chris@366: 	i = i + chunkSize;
Chris@366: 	chunkSize = chunkSize + 1;
Chris@366: 	if (i >= n1) {
Chris@366: 	    break;
Chris@366: 	} else if (i + chunkSize >= n1) {
Chris@366: 	    chunkSize = n1 - i;
Chris@366: 	} else if (chunkSize > 15) {
Chris@366: 	    chunkSize = 1;
Chris@366: 	}
Chris@366:     }
Chris@366: 
Chris@366:     BOOST_CHECK_EQUAL(got, m1);
Chris@366: 
Chris@366:     for (int i = latency; i < m1; ++i) {
Chris@366: 	BOOST_CHECK_SMALL(outPadded[i] - expected[i-latency], 1e-8);
Chris@366:     }
Chris@366: 
Chris@366:     delete[] outPadded;
Chris@366:     delete[] inPadded;
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(sameRateOneShot)
Chris@366: {
Chris@366:     double d[] = { 0, 0.1, -0.3, -0.4, -0.3, 0, 0.5, 0.2, 0.8, -0.1 };
Chris@366:     testResamplerOneShot(4, 4, 10, d, 10, d, 0);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(sameRate)
Chris@366: {
Chris@366:     double d[] = { 0, 0.1, -0.3, -0.4, -0.3, 0, 0.5, 0.2, 0.8, -0.1 };
Chris@366:     testResampler(4, 4, 10, d, 10, d);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(interpolatedMisc)
Chris@366: {
Chris@366:     // Interpolating any signal by N should give a signal in which
Chris@366:     // every Nth sample is the original signal
Chris@366:     double in[] = { 0, 0.1, -0.3, -0.4, -0.3, 0, 0.5, 0.2, 0.8, -0.1 };
Chris@366:     int n = sizeof(in)/sizeof(in[0]);
Chris@366:     for (int factor = 2; factor < 10; ++factor) {
Chris@366: 	vector<double> out = Resampler::resample(6, 6 * factor, in, n);
Chris@366: 	for (int i = 0; i < n; ++i) {
Chris@366: 	    BOOST_CHECK_SMALL(out[i * factor] - in[i], 1e-5);
Chris@366: 	}
Chris@366:     }
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(interpolatedSine)
Chris@366: {
Chris@366:     // Interpolating a sinusoid should give us a sinusoid, once we've
Chris@366:     // dropped the first few samples
Chris@366:     double in[1000];
Chris@366:     double out[2000];
Chris@366:     for (int i = 0; i < 1000; ++i) {
Chris@366: 	in[i] = sin(i * M_PI / 2.0);
Chris@366:     }
Chris@366:     for (int i = 0; i < 2000; ++i) {
Chris@366: 	out[i] = sin(i * M_PI / 4.0);
Chris@366:     }
Chris@366:     testResamplerOneShot(8, 16, 1000, in, 200, out, 512);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(decimatedSine)
Chris@366: {
Chris@366:     // Decimating a sinusoid should give us a sinusoid, once we've
Chris@366:     // dropped the first few samples
Chris@366:     double in[2000];
Chris@366:     double out[1000];
Chris@366:     for (int i = 0; i < 2000; ++i) {
Chris@366: 	in[i] = sin(i * M_PI / 8.0);
Chris@366:     }
Chris@366:     for (int i = 0; i < 1000; ++i) {
Chris@366: 	out[i] = sin(i * M_PI / 4.0);
Chris@366:     }
Chris@366:     testResamplerOneShot(16, 8, 2000, in, 200, out, 256);
Chris@366: }
Chris@366: 
Chris@366: double
Chris@366: measureSinFreq(const vector<double> &v, int rate, int countCycles)
Chris@366: {
Chris@366:     int n = v.size();
Chris@366:     int firstPeak = -1;
Chris@366:     int lastPeak = -1;
Chris@366:     int nPeaks = 0;
Chris@366:     // count +ve peaks
Chris@366:     for (int i = v.size()/4; i + 1 < n; ++i) {
Chris@366:         // allow some fuzz
Chris@366:         int x0 = int(10000 * v[i-1]);
Chris@366:         int x1 = int(10000 * v[i]);
Chris@366:         int x2 = int(10000 * v[i+1]);
Chris@366:         if (x1 > 0 && x1 > x0 && x1 >= x2) {
Chris@366:             if (firstPeak < 0) firstPeak = i;
Chris@366:             lastPeak = i;
Chris@366:             ++nPeaks;
Chris@366:             if (nPeaks == countCycles) break;
Chris@366:         }
Chris@366:     }
Chris@366:     int nCycles = nPeaks - 1;
Chris@366:     if (nCycles <= 0) return 0.0;
Chris@366:     double cycle = double(lastPeak - firstPeak) / nCycles;
Chris@366: //    cout << "lastPeak = " << lastPeak << ", firstPeak = " << firstPeak << ", dist = " << lastPeak - firstPeak << ", nCycles = " << nCycles << ", cycle = " << cycle << endl;
Chris@366:     return rate / cycle;
Chris@366: }
Chris@366: 
Chris@366: void
Chris@366: testSinFrequency(int freq,
Chris@366:                  int sourceRate,
Chris@366:                  int targetRate)
Chris@366: {
Chris@366:     // Resampling a sinusoid and then resampling back should give us a
Chris@366:     // sinusoid of the same frequency as we started with
Chris@366: 
Chris@366:     int nCycles = 500;
Chris@366: 
Chris@366:     int duration = int(nCycles * float(sourceRate) / float(freq));
Chris@366: //    cout << "freq = " << freq << ", sourceRate = " << sourceRate << ", targetRate = " << targetRate << ", duration = " << duration << endl;
Chris@366: 
Chris@366:     vector<double> in(duration, 0);
Chris@366:     for (int i = 0; i < duration; ++i) {
Chris@366:         in[i] = sin(i * M_PI * 2.0 * freq / sourceRate);
Chris@366:     }
Chris@366: 
Chris@366:     vector<double> out = Resampler::resample(sourceRate, targetRate,
Chris@366:                                              in.data(), in.size());
Chris@366: 
Chris@366:     vector<double> back = Resampler::resample(targetRate, sourceRate,
Chris@366:                                               out.data(), out.size());
Chris@366: 
Chris@366:     BOOST_CHECK_EQUAL(in.size(), back.size());
Chris@366: 
Chris@366:     double inFreq = measureSinFreq(in, sourceRate, nCycles / 2);
Chris@366:     double backFreq = measureSinFreq(back, sourceRate, nCycles / 2);
Chris@366:     
Chris@366:     BOOST_CHECK_SMALL(inFreq - backFreq, 1e-8);
Chris@366: }
Chris@366: 
Chris@366: // In each of the following we use a frequency that has an exact cycle
Chris@366: // length in samples at the lowest sample rate, so that we can easily
Chris@366: // rule out errors in measuring the cycle length after resampling. If
Chris@366: // the resampler gets its input or output rate wrong, that will show
Chris@366: // up no matter what the test signal's initial frequency is.
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(downUp2)
Chris@366: {
Chris@366:     testSinFrequency(441, 44100, 22050);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(downUp5)
Chris@366: {
Chris@366:     testSinFrequency(300, 15000, 3000);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(downUp16)
Chris@366: {
Chris@366:     testSinFrequency(300, 48000, 3000);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(upDown2)
Chris@366: {
Chris@366:     testSinFrequency(441, 44100, 88200);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(upDown5)
Chris@366: {
Chris@366:     testSinFrequency(300, 3000, 15000);
Chris@366: }
Chris@366: 
Chris@366: BOOST_AUTO_TEST_CASE(upDown16)
Chris@366: {
Chris@366:     testSinFrequency(300, 3000, 48000);
Chris@366: }
Chris@366: 
Chris@366: vector<double>
Chris@366: squareWave(int rate, double freq, int n)
Chris@366: {
Chris@366:     //!!! todo: hoist, test
Chris@366:     vector<double> v(n, 0.0);
Chris@366:     for (int h = 0; h < (rate/4)/freq; ++h) {
Chris@366: 	double m = h * 2 + 1;
Chris@366: 	double scale = 1.0 / m;
Chris@366: 	for (int i = 0; i < n; ++i) {
Chris@366: 	    double s = scale * sin((i * 2.0 * M_PI * m * freq) / rate);
Chris@366: 	    v[i] += s;
Chris@366: 	}
Chris@366:     }
Chris@366:     return v;
Chris@366: }
Chris@366: 
Chris@366: void
Chris@366: testSpectrum(int inrate, int outrate)
Chris@366: {
Chris@366:     // One second of a square wave
Chris@366:     int freq = 500;
Chris@366: 
Chris@366:     vector<double> square =
Chris@366: 	squareWave(inrate, freq, inrate);
Chris@366: 
Chris@366:     vector<double> maybeSquare = 
Chris@366: 	Resampler::resample(inrate, outrate, square.data(), square.size());
Chris@366: 
Chris@366:     BOOST_CHECK_EQUAL(maybeSquare.size(), outrate);
Chris@366: 
Chris@366:     Window<double>(HanningWindow, inrate).cut(square.data());
Chris@366:     Window<double>(HanningWindow, outrate).cut(maybeSquare.data());
Chris@366: 
Chris@366:     // forward magnitude with size inrate, outrate
Chris@366: 
Chris@366:     vector<double> inSpectrum(inrate, 0.0);
Chris@366:     FFTReal(inrate).forwardMagnitude(square.data(), inSpectrum.data());
Chris@366:     for (int i = 0; i < (int)inSpectrum.size(); ++i) {
Chris@366: 	inSpectrum[i] /= inrate;
Chris@366:     }
Chris@366: 
Chris@366:     vector<double> outSpectrum(outrate, 0.0);
Chris@366:     FFTReal(outrate).forwardMagnitude(maybeSquare.data(), outSpectrum.data());
Chris@366:     for (int i = 0; i < (int)outSpectrum.size(); ++i) {
Chris@366: 	outSpectrum[i] /= outrate;
Chris@366:     }
Chris@366: 
Chris@366:     // Don't compare bins any higher than 96% of Nyquist freq of lower sr
Chris@366:     int lengthOfInterest = (inrate < outrate ? inrate : outrate) / 2;
Chris@366:     lengthOfInterest = lengthOfInterest - (lengthOfInterest / 25);
Chris@366: 
Chris@366:     for (int i = 0; i < lengthOfInterest; ++i) {
Chris@366: 	BOOST_CHECK_SMALL(inSpectrum[i] - outSpectrum[i], 1e-7);
Chris@366:     }
Chris@366: }
Chris@366: /*
Chris@366: BOOST_AUTO_TEST_CASE(spectrum)
Chris@366: {
Chris@366:     int rates[] = { 8000, 22050, 44100, 48000 };
Chris@366:     for (int i = 0; i < (int)(sizeof(rates)/sizeof(rates[0])); ++i) {
Chris@366: 	    for (int j = 0; j < (int)(sizeof(rates)/sizeof(rates[0])); ++j) {
Chris@366: 	    testSpectrum(rates[i], rates[j]);
Chris@366: 	}
Chris@366:     }
Chris@366: }
Chris@366: */
Chris@366: BOOST_AUTO_TEST_SUITE_END()
Chris@366: