comparison vamp-sdk/hostext/PluginInputDomainAdapter.cpp @ 64:9d3272c7db60

* Merge from host-factory-stuff branch: this adds several helper classes in
  the hostext directory that should make a host's life much easier.  This
  will become version 1.1 of the SDK, eventually.

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Vamp
+
+    An API for audio analysis and feature extraction plugins.
+
+    Centre for Digital Music, Queen Mary, University of London.
+    Copyright 2006 Chris Cannam.
+  
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
+    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+    Except as contained in this notice, the names of the Centre for
+    Digital Music; Queen Mary, University of London; and Chris Cannam
+    shall not be used in advertising or otherwise to promote the sale,
+    use or other dealings in this Software without prior written
+    authorization.
+*/
+
+#include "PluginInputDomainAdapter.h"
+
+#include <cmath>
+
+namespace Vamp {
+
+namespace HostExt {
+
+PluginInputDomainAdapter::PluginInputDomainAdapter(Plugin *plugin) :
+    PluginWrapper(plugin),
+    m_channels(0),
+    m_blockSize(0),
+    m_freqbuf(0)
+{
+}
+
+PluginInputDomainAdapter::~PluginInputDomainAdapter()
+{
+}
+    
+bool
+PluginInputDomainAdapter::initialise(size_t channels, size_t stepSize, size_t blockSize)
+{
+    if (m_plugin->getInputDomain() == TimeDomain) {
+
+        m_blockSize = blockSize;
+        m_channels = channels;
+
+        return m_plugin->initialise(channels, stepSize, blockSize);
+    }
+
+    if (blockSize < 2) {
+        std::cerr << "ERROR: Vamp::HostExt::PluginInputDomainAdapter::initialise: blocksize < 2 not supported" << std::endl;
+        return false;
+    }                
+        
+    if (blockSize & (blockSize-1)) {
+        std::cerr << "ERROR: Vamp::HostExt::PluginInputDomainAdapter::initialise: non-power-of-two\nblocksize " << blockSize << " not supported" << std::endl;
+        return false;
+    }
+
+    if (m_channels > 0) {
+        for (size_t c = 0; c < m_channels; ++c) {
+            delete[] m_freqbuf[c];
+        }
+        delete[] m_freqbuf;
+        delete[] m_ri;
+        delete[] m_ro;
+        delete[] m_io;
+    }
+
+    m_blockSize = blockSize;
+    m_channels = channels;
+
+    m_freqbuf = new float *[m_channels];
+    for (size_t c = 0; c < m_channels; ++c) {
+        m_freqbuf[c] = new float[m_blockSize + 2];
+    }
+    m_ri = new double[m_blockSize];
+    m_ro = new double[m_blockSize];
+    m_io = new double[m_blockSize];
+
+    return m_plugin->initialise(channels, stepSize, blockSize);
+}
+
+Plugin::InputDomain
+PluginInputDomainAdapter::getInputDomain() const
+{
+    return TimeDomain;
+}
+
+size_t
+PluginInputDomainAdapter::getPreferredStepSize() const
+{
+    size_t step = m_plugin->getPreferredStepSize();
+
+    if (step == 0 && (m_plugin->getInputDomain() == FrequencyDomain)) {
+        step = getPreferredBlockSize() / 2;
+    }
+
+    return step;
+}
+
+size_t
+PluginInputDomainAdapter::getPreferredBlockSize() const
+{
+    size_t block = m_plugin->getPreferredBlockSize();
+
+    if (m_plugin->getInputDomain() == FrequencyDomain) {
+        if (block == 0) {
+            block = 1024;
+        } else {
+            block = makeBlockSizeAcceptable(block);
+        }
+    }
+
+    return block;
+}
+
+size_t
+PluginInputDomainAdapter::makeBlockSizeAcceptable(size_t blockSize) const
+{
+    if (blockSize < 2) {
+
+        std::cerr << "WARNING: Vamp::HostExt::PluginInputDomainAdapter::initialise: blocksize < 2 not" << std::endl
+                  << "supported, increasing from " << blockSize << " to 2" << std::endl;
+        blockSize = 2;
+        
+    } else if (blockSize & (blockSize-1)) {
+            
+        // not a power of two, can't handle that with our current fft
+        // implementation
+
+        size_t nearest = blockSize;
+        size_t power = 0;
+        while (nearest > 1) {
+            nearest >>= 1;
+            ++power;
+        }
+        nearest = 1;
+        while (power) {
+            nearest <<= 1;
+            --power;
+        }
+        
+        if (blockSize - nearest > (nearest*2) - blockSize) {
+            nearest = nearest*2;
+        }
+        
+        std::cerr << "WARNING: Vamp::HostExt::PluginInputDomainAdapter::initialise: non-power-of-two\nblocksize " << blockSize << " not supported, using blocksize " << nearest << " instead" << std::endl;
+        blockSize = nearest;
+    }
+
+    return blockSize;
+}
+
+Plugin::FeatureSet
+PluginInputDomainAdapter::process(const float *const *inputBuffers, RealTime timestamp)
+{
+    if (m_plugin->getInputDomain() == TimeDomain) {
+        return m_plugin->process(inputBuffers, timestamp);
+    }
+
+    // The timestamp supplied should be (according to the Vamp::Plugin
+    // spec) the time of the start of the time-domain input block.
+    // However, we want to pass to the plugin an FFT output calculated
+    // from the block of samples _centred_ on that timestamp.
+    // 
+    // We have two options:
+    // 
+    // 1. Buffer the input, calculating the fft of the values at the
+    // passed-in block minus blockSize/2 rather than starting at the
+    // passed-in block.  So each time we call process on the plugin,
+    // we are passing in the same timestamp as was passed to our own
+    // process plugin, but not (the frequency domain representation
+    // of) the same set of samples.  Advantages: avoids confusion in
+    // the host by ensuring the returned values have timestamps
+    // comparable with that passed in to this function (in fact this
+    // is pretty much essential for one-value-per-block outputs);
+    // consistent with hosts such as SV that deal with the
+    // frequency-domain transform themselves.  Disadvantages: means
+    // making the not necessarily correct assumption that the samples
+    // preceding the first official block are all zero (or some other
+    // known value).
+    //
+    // 2. Increase the passed-in timestamps by half the blocksize.  So
+    // when we call process, we are passing in the frequency domain
+    // representation of the same set of samples as passed to us, but
+    // with a different timestamp.  Advantages: simplicity; avoids
+    // iffy assumption mentioned above.  Disadvantages: inconsistency
+    // with SV in cases where stepSize != blockSize/2; potential
+    // confusion arising from returned timestamps being calculated
+    // from the adjusted input timestamps rather than the original
+    // ones (and inaccuracy where the returned timestamp is implied,
+    // as in one-value-per-block).
+    //
+    // Neither way is ideal, but I don't think either is strictly
+    // incorrect either.  I think this is just a case where the same
+    // plugin can legitimately produce differing results from the same
+    // input data, depending on how that data is packaged.
+    // 
+    // We'll go for option 2, adjusting the timestamps.  Note in
+    // particular that this means some results can differ from those
+    // produced by SV.
+
+    std::cerr << "PluginInputDomainAdapter: sampleRate " << m_inputSampleRate << ", blocksize " << m_blockSize << ", adjusting time from " << timestamp;
+
+    timestamp = timestamp + RealTime::frame2RealTime(m_blockSize/2,
+                                                     m_inputSampleRate);
+
+    std::cerr << " to " << timestamp << std::endl;
+
+    for (size_t c = 0; c < m_channels; ++c) {
+
+        for (size_t i = 0; i < m_blockSize; ++i) {
+            // Hanning window
+            m_ri[i] = double(inputBuffers[c][i])
+                * (0.50 - 0.50 * cos((2 * M_PI * i)
+                                     / m_blockSize));
+        }
+
+        for (size_t i = 0; i < m_blockSize/2; ++i) {
+            // FFT shift
+            double value = m_ri[i];
+            m_ri[i] = m_ri[i + m_blockSize/2];
+            m_ri[i + m_blockSize/2] = value;
+        }
+
+        fft(m_blockSize, false, m_ri, 0, m_ro, m_io);
+
+        for (size_t i = 0; i <= m_blockSize/2; ++i) {
+            m_freqbuf[c][i * 2] = m_ro[i];
+            m_freqbuf[c][i * 2 + 1] = m_io[i];
+        }
+    }
+
+    return m_plugin->process(m_freqbuf, timestamp);
+}
+
+void
+PluginInputDomainAdapter::fft(unsigned int n, bool inverse,
+                              double *ri, double *ii, double *ro, double *io)
+{
+    if (!ri || !ro || !io) return;
+
+    unsigned int bits;
+    unsigned int i, j, k, m;
+    unsigned int blockSize, blockEnd;
+
+    double tr, ti;
+
+    if (n < 2) return;
+    if (n & (n-1)) return;
+
+    double angle = 2.0 * M_PI;
+    if (inverse) angle = -angle;
+
+    for (i = 0; ; ++i) {
+	if (n & (1 << i)) {
+	    bits = i;
+	    break;
+	}
+    }
+
+    static unsigned int tableSize = 0;
+    static int *table = 0;
+
+    if (tableSize != n) {
+
+	delete[] table;
+
+	table = new int[n];
+
+	for (i = 0; i < n; ++i) {
+	
+	    m = i;
+
+	    for (j = k = 0; j < bits; ++j) {
+		k = (k << 1) | (m & 1);
+		m >>= 1;
+	    }
+
+	    table[i] = k;
+	}
+
+	tableSize = n;
+    }
+
+    if (ii) {
+	for (i = 0; i < n; ++i) {
+	    ro[table[i]] = ri[i];
+	    io[table[i]] = ii[i];
+	}
+    } else {
+	for (i = 0; i < n; ++i) {
+	    ro[table[i]] = ri[i];
+	    io[table[i]] = 0.0;
+	}
+    }
+
+    blockEnd = 1;
+
+    for (blockSize = 2; blockSize <= n; blockSize <<= 1) {
+
+	double delta = angle / (double)blockSize;
+	double sm2 = -sin(-2 * delta);
+	double sm1 = -sin(-delta);
+	double cm2 = cos(-2 * delta);
+	double cm1 = cos(-delta);
+	double w = 2 * cm1;
+	double ar[3], ai[3];
+
+	for (i = 0; i < n; i += blockSize) {
+
+	    ar[2] = cm2;
+	    ar[1] = cm1;
+
+	    ai[2] = sm2;
+	    ai[1] = sm1;
+
+	    for (j = i, m = 0; m < blockEnd; j++, m++) {
+
+		ar[0] = w * ar[1] - ar[2];
+		ar[2] = ar[1];
+		ar[1] = ar[0];
+
+		ai[0] = w * ai[1] - ai[2];
+		ai[2] = ai[1];
+		ai[1] = ai[0];
+
+		k = j + blockEnd;
+		tr = ar[0] * ro[k] - ai[0] * io[k];
+		ti = ar[0] * io[k] + ai[0] * ro[k];
+
+		ro[k] = ro[j] - tr;
+		io[k] = io[j] - ti;
+
+		ro[j] += tr;
+		io[j] += ti;
+	    }
+	}
+
+	blockEnd = blockSize;
+    }
+
+    if (inverse) {
+
+	double denom = (double)n;
+
+	for (i = 0; i < n; i++) {
+	    ro[i] /= denom;
+	    io[i] /= denom;
+	}
+    }
+}
+
+}
+        
+}
+