annotate libmain.cpp @ 40:08d9660e57e8 tip

Or better, this

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Vamp feature extraction plugins using Jamie Bullock's
    libxtract audio feature extraction library.

    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Queen Mary, University of London.
    
    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 <vamp/vamp.h>
#include <vamp-sdk/PluginAdapter.h>

#include "plugins/XTractPlugin.h"

#include <xtract/libxtract.h>

#include <map>
#include <cassert>

class XTractPluginAdapter : public Vamp::PluginAdapterBase
{
public:
    XTractPluginAdapter(unsigned int feature) :
        PluginAdapterBase(),
        m_xtFeature(feature) 
    { }

    virtual ~XTractPluginAdapter() { }

protected:
    Vamp::Plugin *createPlugin(float inputSampleRate) {
        XTractPlugin *xtp = new XTractPlugin(m_xtFeature, inputSampleRate);
        return xtp;
    }

    unsigned int m_xtFeature;
};

static std::map<unsigned int, XTractPluginAdapter *> pluginAdapterMap;

// Note: libxtract must have been compiled with XTRACT_FFT and
// linked with fftw3

const VampPluginDescriptor *vampGetPluginDescriptor(unsigned int vampApiVersion,
                                                    unsigned int index)
{
    if (vampApiVersion < 1) return 0;

    // The missingFeatures array contains the libxtract enum values
    // for features that we are not providing in this plugin, either
    // because they aren't very meaningful in isolation or because the
    // version of libxtract we're using doesn't support them yet.
    // 
    // These must appear in this array in the same order as in the
    // original enum in libxtract.h.

    const unsigned int missingFeatures[] = {

	XTRACT_SPECTRAL_MEAN,   // Just a wrapper for XTRACT_SPECTRAL_CENTROID
        XTRACT_FLATNESS_DB,     // appears to implement only the db part
	XTRACT_POWER,		// not implemented
        XTRACT_HPS,             // "this function doesn't work properly"
        XTRACT_LNORM,           // not quite sure what it is or its parameters
        XTRACT_FLUX,            // not implemented
        XTRACT_ATTACK_TIME,     // not implemented
        XTRACT_DECAY_TIME,      // not implemented
        XTRACT_DIFFERENCE_VECTOR,   // not meaningful (this used to be XTRACT_DELTA_FEATURE)
        XTRACT_AUTOCORRELATION_FFT, // apparently erroneous
        XTRACT_LPC,             // not meaningful and/or not implemented here
        XTRACT_LPCC,            // not meaningful and/or not implemented here
        XTRACT_SUBBANDS,        // not meaningful in isolation
        XTRACT_WINDOWED         // not meaningful
    };

    for (unsigned int i = 0;
         i < sizeof(missingFeatures)/sizeof(missingFeatures[0]);
         ++i) {
        if (i > 0) assert(missingFeatures[i] > missingFeatures[i-1]);
        if (index >= missingFeatures[i]) ++index;
    }

    if (index >= XTRACT_FEATURES) return 0;

    if (pluginAdapterMap.find(index) == pluginAdapterMap.end()) {
        pluginAdapterMap[index] = new XTractPluginAdapter(index);
    }

    return pluginAdapterMap[index]->getDescriptor();
}