transient_detector.cc

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/*
    Copyright (C) 2012 Paul Davis 

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <cmath>

#include "ardour/readable.h"
#include "ardour/transient_detector.h"

#include "i18n.h"

using namespace Vamp;
using namespace ARDOUR;
using namespace std;

/* need a static initializer function for this */

string TransientDetector::_op_id = X_("libardourvampplugins:qm-onsetdetector:2");

TransientDetector::TransientDetector (float sr)
        : AudioAnalyser (sr, X_("libardourvampplugins:qm-onsetdetector"))
{
        /* update the op_id */

        _op_id = X_("libardourvampplugins:qm-onsetdetector");

        // XXX this should load the above-named plugin and get the current version

        _op_id += ":2";

        threshold = 0.00;
}

TransientDetector::~TransientDetector()
{
}

string
TransientDetector::operational_identifier()
{
        return _op_id;
}

int
TransientDetector::run (const std::string& path, Readable* src, uint32_t channel, AnalysisFeatureList& results)
{
        current_results = &results;
        int ret = analyse (path, src, channel);

        current_results = 0;

        return ret;
}

int
TransientDetector::use_features (Plugin::FeatureSet& features, ostream* out)
{
        const Plugin::FeatureList& fl (features[0]);

        for (Plugin::FeatureList::const_iterator f = fl.begin(); f != fl.end(); ++f) {

                if (f->hasTimestamp) {

                        if (out) {
                                (*out) << (*f).timestamp.toString() << endl;
                        }

                        current_results->push_back (RealTime::realTime2Frame (f->timestamp, (framecnt_t) floor(sample_rate)));
                }
        }

        return 0;
}

void
TransientDetector::set_threshold (float val)
{
        threshold = val;
}

void
TransientDetector::set_sensitivity (float val)
{
        if (plugin) {
                plugin->selectProgram ("Percussive onsets");
                plugin->setParameter ("sensitivity", val);
        }
}

void
TransientDetector::cleanup_transients (AnalysisFeatureList& t, float sr, float gap_msecs)
{
        if (t.empty()) {
                return;
        }

        t.sort ();

        /* remove duplicates or other things that are too close */

        AnalysisFeatureList::iterator i = t.begin();
        AnalysisFeatureList::iterator f, b;
        const framecnt_t gap_frames = (framecnt_t) floor (gap_msecs * (sr / 1000.0));

        while (i != t.end()) {

                // move front iterator to just past i, and back iterator the same place

                f = i;
                ++f;
                b = f;

                // move f until we find a new value that is far enough away

                while ((f != t.end()) && (((*f) - (*i)) < gap_frames)) {
                        ++f;
                }

                i = f;

                // if f moved forward from b, we had duplicates/too-close points: get rid of them

                if (b != f) {
                        t.erase (b, f);
                }
        }
}

void
TransientDetector::update_positions (Readable* src, uint32_t channel, AnalysisFeatureList& positions)
{
        int const buff_size = 1024;
        int const step_size = 64;

        Sample* data = new Sample[buff_size];

        AnalysisFeatureList::iterator i = positions.begin();

        while (i != positions.end()) {

                /* read from source */
                framecnt_t const to_read = buff_size;

                if (src->read (data, (*i) - buff_size, to_read, channel) != to_read) {
                        break;
                }

                // Simple heuristic for locating approx correct cut position.

                for (int j = 0; j < (buff_size - step_size); ) {

                        Sample const s = abs (data[j]);
                        Sample const s2 = abs (data[j + step_size]);

                        if ((s2 - s) > threshold) {
                                //cerr << "Thresh exceeded. Moving pos from: " << (*i) << " to: " << (*i) - buff_size + (j + 16) << endl;
                                (*i) = (*i) - buff_size + (j + 24);
                                break;
                        }

                        j += step_size;
                }

                ++i;
        }

        delete [] data;
}