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authorRobin Gareus <robin@gareus.org>2016-10-06 00:51:32 +0200
committerRobin Gareus <robin@gareus.org>2016-10-06 00:58:20 +0200
commita543ae329c4a3d6af3182ee55f3c865a89db2f08 (patch)
tree6e4e4e2846407cdf2c32d285d20956da1018d500 /libs/qm-dsp/dsp
parentee2a1b7bea2010a6244c5dadf2ee02c4433c1658 (diff)
Thin out qm-dsp code: no threading
Diffstat (limited to 'libs/qm-dsp/dsp')
-rw-r--r--libs/qm-dsp/dsp/rateconversion/Resampler.cpp416
-rw-r--r--libs/qm-dsp/dsp/rateconversion/Resampler.h102
2 files changed, 0 insertions, 518 deletions
diff --git a/libs/qm-dsp/dsp/rateconversion/Resampler.cpp b/libs/qm-dsp/dsp/rateconversion/Resampler.cpp
deleted file mode 100644
index f0598cab2c..0000000000
--- a/libs/qm-dsp/dsp/rateconversion/Resampler.cpp
+++ /dev/null
@@ -1,416 +0,0 @@
-/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
-/*
- QM DSP Library
-
- Centre for Digital Music, Queen Mary, University of London.
- This file by Chris Cannam.
-
- 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. See the file
- COPYING included with this distribution for more information.
-*/
-
-#include "Resampler.h"
-
-#include "maths/MathUtilities.h"
-#include "base/KaiserWindow.h"
-#include "base/SincWindow.h"
-#include "thread/Thread.h"
-
-#include <iostream>
-#include <vector>
-#include <map>
-#include <cassert>
-
-using std::vector;
-using std::map;
-using std::cerr;
-using std::endl;
-
-//#define DEBUG_RESAMPLER 1
-//#define DEBUG_RESAMPLER_VERBOSE 1
-
-Resampler::Resampler(int sourceRate, int targetRate) :
- m_sourceRate(sourceRate),
- m_targetRate(targetRate)
-{
- initialise(100, 0.02);
-}
-
-Resampler::Resampler(int sourceRate, int targetRate,
- double snr, double bandwidth) :
- m_sourceRate(sourceRate),
- m_targetRate(targetRate)
-{
- initialise(snr, bandwidth);
-}
-
-Resampler::~Resampler()
-{
- delete[] m_phaseData;
-}
-
-// peakToPole -> length -> beta -> window
-static map<double, map<int, map<double, vector<double> > > >
-knownFilters;
-
-static Mutex
-knownFilterMutex;
-
-void
-Resampler::initialise(double snr, double bandwidth)
-{
- int higher = std::max(m_sourceRate, m_targetRate);
- int lower = std::min(m_sourceRate, m_targetRate);
-
- m_gcd = MathUtilities::gcd(lower, higher);
- m_peakToPole = higher / m_gcd;
-
- if (m_targetRate < m_sourceRate) {
- // antialiasing filter, should be slightly below nyquist
- m_peakToPole = m_peakToPole / (1.0 - bandwidth/2.0);
- }
-
- KaiserWindow::Parameters params =
- KaiserWindow::parametersForBandwidth(snr, bandwidth, higher / m_gcd);
-
- params.length =
- (params.length % 2 == 0 ? params.length + 1 : params.length);
-
- params.length =
- (params.length > 200001 ? 200001 : params.length);
-
- m_filterLength = params.length;
-
- vector<double> filter;
- knownFilterMutex.lock();
-
- if (knownFilters[m_peakToPole][m_filterLength].find(params.beta) ==
- knownFilters[m_peakToPole][m_filterLength].end()) {
-
- KaiserWindow kw(params);
- SincWindow sw(m_filterLength, m_peakToPole * 2);
-
- filter = vector<double>(m_filterLength, 0.0);
- for (int i = 0; i < m_filterLength; ++i) filter[i] = 1.0;
- sw.cut(filter.data());
- kw.cut(filter.data());
-
- knownFilters[m_peakToPole][m_filterLength][params.beta] = filter;
- }
-
- filter = knownFilters[m_peakToPole][m_filterLength][params.beta];
- knownFilterMutex.unlock();
-
- int inputSpacing = m_targetRate / m_gcd;
- int outputSpacing = m_sourceRate / m_gcd;
-
-#ifdef DEBUG_RESAMPLER
- cerr << "resample " << m_sourceRate << " -> " << m_targetRate
- << ": inputSpacing " << inputSpacing << ", outputSpacing "
- << outputSpacing << ": filter length " << m_filterLength
- << endl;
-#endif
-
- // Now we have a filter of (odd) length flen in which the lower
- // sample rate corresponds to every n'th point and the higher rate
- // to every m'th where n and m are higher and lower rates divided
- // by their gcd respectively. So if x coordinates are on the same
- // scale as our filter resolution, then source sample i is at i *
- // (targetRate / gcd) and target sample j is at j * (sourceRate /
- // gcd).
-
- // To reconstruct a single target sample, we want a buffer (real
- // or virtual) of flen values formed of source samples spaced at
- // intervals of (targetRate / gcd), in our example case 3. This
- // is initially formed with the first sample at the filter peak.
- //
- // 0 0 0 0 a 0 0 b 0
- //
- // and of course we have our filter
- //
- // f1 f2 f3 f4 f5 f6 f7 f8 f9
- //
- // We take the sum of products of non-zero values from this buffer
- // with corresponding values in the filter
- //
- // a * f5 + b * f8
- //
- // Then we drop (sourceRate / gcd) values, in our example case 4,
- // from the start of the buffer and fill until it has flen values
- // again
- //
- // a 0 0 b 0 0 c 0 0
- //
- // repeat to reconstruct the next target sample
- //
- // a * f1 + b * f4 + c * f7
- //
- // and so on.
- //
- // Above I said the buffer could be "real or virtual" -- ours is
- // virtual. We don't actually store all the zero spacing values,
- // except for padding at the start; normally we store only the
- // values that actually came from the source stream, along with a
- // phase value that tells us how many virtual zeroes there are at
- // the start of the virtual buffer. So the two examples above are
- //
- // 0 a b [ with phase 1 ]
- // a b c [ with phase 0 ]
- //
- // Having thus broken down the buffer so that only the elements we
- // need to multiply are present, we can also unzip the filter into
- // every-nth-element subsets at each phase, allowing us to do the
- // filter multiplication as a simply vector multiply. That is, rather
- // than store
- //
- // f1 f2 f3 f4 f5 f6 f7 f8 f9
- //
- // we store separately
- //
- // f1 f4 f7
- // f2 f5 f8
- // f3 f6 f9
- //
- // Each time we complete a multiply-and-sum, we need to work out
- // how many (real) samples to drop from the start of our buffer,
- // and how many to add at the end of it for the next multiply. We
- // know we want to drop enough real samples to move along by one
- // computed output sample, which is our outputSpacing number of
- // virtual buffer samples. Depending on the relationship between
- // input and output spacings, this may mean dropping several real
- // samples, one real sample, or none at all (and simply moving to
- // a different "phase").
-
- m_phaseData = new Phase[inputSpacing];
-
- for (int phase = 0; phase < inputSpacing; ++phase) {
-
- Phase p;
-
- p.nextPhase = phase - outputSpacing;
- while (p.nextPhase < 0) p.nextPhase += inputSpacing;
- p.nextPhase %= inputSpacing;
-
- p.drop = int(ceil(std::max(0.0, double(outputSpacing - phase))
- / inputSpacing));
-
- int filtZipLength = int(ceil(double(m_filterLength - phase)
- / inputSpacing));
-
- for (int i = 0; i < filtZipLength; ++i) {
- p.filter.push_back(filter[i * inputSpacing + phase]);
- }
-
- m_phaseData[phase] = p;
- }
-
-#ifdef DEBUG_RESAMPLER
- int cp = 0;
- int totDrop = 0;
- for (int i = 0; i < inputSpacing; ++i) {
- cerr << "phase = " << cp << ", drop = " << m_phaseData[cp].drop
- << ", filter length = " << m_phaseData[cp].filter.size()
- << ", next phase = " << m_phaseData[cp].nextPhase << endl;
- totDrop += m_phaseData[cp].drop;
- cp = m_phaseData[cp].nextPhase;
- }
- cerr << "total drop = " << totDrop << endl;
-#endif
-
- // The May implementation of this uses a pull model -- we ask the
- // resampler for a certain number of output samples, and it asks
- // its source stream for as many as it needs to calculate
- // those. This means (among other things) that the source stream
- // can be asked for enough samples up-front to fill the buffer
- // before the first output sample is generated.
- //
- // In this implementation we're using a push model in which a
- // certain number of source samples is provided and we're asked
- // for as many output samples as that makes available. But we
- // can't return any samples from the beginning until half the
- // filter length has been provided as input. This means we must
- // either return a very variable number of samples (none at all
- // until the filter fills, then half the filter length at once) or
- // else have a lengthy declared latency on the output. We do the
- // latter. (What do other implementations do?)
- //
- // We want to make sure the first "real" sample will eventually be
- // aligned with the centre sample in the filter (it's tidier, and
- // easier to do diagnostic calculations that way). So we need to
- // pick the initial phase and buffer fill accordingly.
- //
- // Example: if the inputSpacing is 2, outputSpacing is 3, and
- // filter length is 7,
- //
- // x x x x a b c ... input samples
- // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
- // i j k l ... output samples
- // [--------|--------] <- filter with centre mark
- //
- // Let h be the index of the centre mark, here 3 (generally
- // int(filterLength/2) for odd-length filters).
- //
- // The smallest n such that h + n * outputSpacing > filterLength
- // is 2 (that is, ceil((filterLength - h) / outputSpacing)), and
- // (h + 2 * outputSpacing) % inputSpacing == 1, so the initial
- // phase is 1.
- //
- // To achieve our n, we need to pre-fill the "virtual" buffer with
- // 4 zero samples: the x's above. This is int((h + n *
- // outputSpacing) / inputSpacing). It's the phase that makes this
- // buffer get dealt with in such a way as to give us an effective
- // index for sample a of 9 rather than 8 or 10 or whatever.
- //
- // This gives us output latency of 2 (== n), i.e. output samples i
- // and j will appear before the one in which input sample a is at
- // the centre of the filter.
-
- int h = int(m_filterLength / 2);
- int n = ceil(double(m_filterLength - h) / outputSpacing);
-
- m_phase = (h + n * outputSpacing) % inputSpacing;
-
- int fill = (h + n * outputSpacing) / inputSpacing;
-
- m_latency = n;
-
- m_buffer = vector<double>(fill, 0);
- m_bufferOrigin = 0;
-
-#ifdef DEBUG_RESAMPLER
- cerr << "initial phase " << m_phase << " (as " << (m_filterLength/2) << " % " << inputSpacing << ")"
- << ", latency " << m_latency << endl;
-#endif
-}
-
-double
-Resampler::reconstructOne()
-{
- Phase &pd = m_phaseData[m_phase];
- double v = 0.0;
- int n = pd.filter.size();
-
- assert(n + m_bufferOrigin <= (int)m_buffer.size());
-
- const double *const __restrict__ buf = m_buffer.data() + m_bufferOrigin;
- const double *const __restrict__ filt = pd.filter.data();
-
- for (int i = 0; i < n; ++i) {
- // NB gcc can only vectorize this with -ffast-math
- v += buf[i] * filt[i];
- }
-
- m_bufferOrigin += pd.drop;
- m_phase = pd.nextPhase;
- return v;
-}
-
-int
-Resampler::process(const double *src, double *dst, int n)
-{
- for (int i = 0; i < n; ++i) {
- m_buffer.push_back(src[i]);
- }
-
- int maxout = int(ceil(double(n) * m_targetRate / m_sourceRate));
- int outidx = 0;
-
-#ifdef DEBUG_RESAMPLER
- cerr << "process: buf siz " << m_buffer.size() << " filt siz for phase " << m_phase << " " << m_phaseData[m_phase].filter.size() << endl;
-#endif
-
- double scaleFactor = (double(m_targetRate) / m_gcd) / m_peakToPole;
-
- while (outidx < maxout &&
- m_buffer.size() >= m_phaseData[m_phase].filter.size() + m_bufferOrigin) {
- dst[outidx] = scaleFactor * reconstructOne();
- outidx++;
- }
-
- m_buffer = vector<double>(m_buffer.begin() + m_bufferOrigin, m_buffer.end());
- m_bufferOrigin = 0;
-
- return outidx;
-}
-
-vector<double>
-Resampler::process(const double *src, int n)
-{
- int maxout = int(ceil(double(n) * m_targetRate / m_sourceRate));
- vector<double> out(maxout, 0.0);
- int got = process(src, out.data(), n);
- assert(got <= maxout);
- if (got < maxout) out.resize(got);
- return out;
-}
-
-vector<double>
-Resampler::resample(int sourceRate, int targetRate, const double *data, int n)
-{
- Resampler r(sourceRate, targetRate);
-
- int latency = r.getLatency();
-
- // latency is the output latency. We need to provide enough
- // padding input samples at the end of input to guarantee at
- // *least* the latency's worth of output samples. that is,
-
- int inputPad = int(ceil((double(latency) * sourceRate) / targetRate));
-
- // that means we are providing this much input in total:
-
- int n1 = n + inputPad;
-
- // and obtaining this much output in total:
-
- int m1 = int(ceil((double(n1) * targetRate) / sourceRate));
-
- // in order to return this much output to the user:
-
- int m = int(ceil((double(n) * targetRate) / sourceRate));
-
-#ifdef DEBUG_RESAMPLER
- cerr << "n = " << n << ", sourceRate = " << sourceRate << ", targetRate = " << targetRate << ", m = " << m << ", latency = " << latency << ", inputPad = " << inputPad << ", m1 = " << m1 << ", n1 = " << n1 << ", n1 - n = " << n1 - n << endl;
-#endif
-
- vector<double> pad(n1 - n, 0.0);
- vector<double> out(m1 + 1, 0.0);
-
- int gotData = r.process(data, out.data(), n);
- int gotPad = r.process(pad.data(), out.data() + gotData, pad.size());
- int got = gotData + gotPad;
-
-#ifdef DEBUG_RESAMPLER
- cerr << "resample: " << n << " in, " << pad.size() << " padding, " << got << " out (" << gotData << " data, " << gotPad << " padding, latency = " << latency << ")" << endl;
-#endif
-#ifdef DEBUG_RESAMPLER_VERBOSE
- int printN = 50;
- cerr << "first " << printN << " in:" << endl;
- for (int i = 0; i < printN && i < n; ++i) {
- if (i % 5 == 0) cerr << endl << i << "... ";
- cerr << data[i] << " ";
- }
- cerr << endl;
-#endif
-
- int toReturn = got - latency;
- if (toReturn > m) toReturn = m;
-
- vector<double> sliced(out.begin() + latency,
- out.begin() + latency + toReturn);
-
-#ifdef DEBUG_RESAMPLER_VERBOSE
- cerr << "first " << printN << " out (after latency compensation), length " << sliced.size() << ":";
- for (int i = 0; i < printN && i < sliced.size(); ++i) {
- if (i % 5 == 0) cerr << endl << i << "... ";
- cerr << sliced[i] << " ";
- }
- cerr << endl;
-#endif
-
- return sliced;
-}
-
diff --git a/libs/qm-dsp/dsp/rateconversion/Resampler.h b/libs/qm-dsp/dsp/rateconversion/Resampler.h
deleted file mode 100644
index 92c0169ba0..0000000000
--- a/libs/qm-dsp/dsp/rateconversion/Resampler.h
+++ /dev/null
@@ -1,102 +0,0 @@
-/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
-/*
- QM DSP Library
-
- Centre for Digital Music, Queen Mary, University of London.
- This file by Chris Cannam.
-
- 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. See the file
- COPYING included with this distribution for more information.
-*/
-
-#ifndef RESAMPLER_H
-#define RESAMPLER_H
-
-#include <vector>
-
-/**
- * Resampler resamples a stream from one integer sample rate to
- * another (arbitrary) rate, using a kaiser-windowed sinc filter. The
- * results and performance are pretty similar to libraries such as
- * libsamplerate, though this implementation does not support
- * time-varying ratios (the ratio is fixed on construction).
- *
- * See also Decimator, which is faster and rougher but supports only
- * power-of-two downsampling factors.
- */
-class Resampler
-{
-public:
- /**
- * Construct a Resampler to resample from sourceRate to
- * targetRate.
- */
- Resampler(int sourceRate, int targetRate);
-
- /**
- * Construct a Resampler to resample from sourceRate to
- * targetRate, using the given filter parameters.
- */
- Resampler(int sourceRate, int targetRate,
- double snr, double bandwidth);
-
- virtual ~Resampler();
-
- /**
- * Read n input samples from src and write resampled data to
- * dst. The return value is the number of samples written, which
- * will be no more than ceil((n * targetRate) / sourceRate). The
- * caller must ensure the dst buffer has enough space for the
- * samples returned.
- */
- int process(const double *src, double *dst, int n);
-
- /**
- * Read n input samples from src and return resampled data by
- * value.
- */
- std::vector<double> process(const double *src, int n);
-
- /**
- * Return the number of samples of latency at the output due by
- * the filter. (That is, the output will be delayed by this number
- * of samples relative to the input.)
- */
- int getLatency() const { return m_latency; }
-
- /**
- * Carry out a one-off resample of a single block of n
- * samples. The output is latency-compensated.
- */
- static std::vector<double> resample
- (int sourceRate, int targetRate, const double *data, int n);
-
-private:
- int m_sourceRate;
- int m_targetRate;
- int m_gcd;
- int m_filterLength;
- int m_bufferLength;
- int m_latency;
- double m_peakToPole;
-
- struct Phase {
- int nextPhase;
- std::vector<double> filter;
- int drop;
- };
-
- Phase *m_phaseData;
- int m_phase;
- std::vector<double> m_buffer;
- int m_bufferOrigin;
-
- void initialise(double, double);
- double reconstructOne();
-};
-
-#endif
-