midi_stretch.cc

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/*
    Copyright (C) 2008 Paul Davis
    Author: David Robillard

    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 "pbd/error.h"

#include "ardour/midi_model.h"
#include "ardour/midi_region.h"
#include "ardour/midi_source.h"
#include "ardour/midi_stretch.h"
#include "ardour/types.h"

#include "i18n.h"

using namespace std;
using namespace ARDOUR;
using namespace PBD;

MidiStretch::MidiStretch (Session& s, const TimeFXRequest& req)
        : Filter (s)
        , _request (req)
{
}

MidiStretch::~MidiStretch ()
{
}

int
MidiStretch::run (boost::shared_ptr<Region> r, Progress*)
{
        SourceList nsrcs;
        char suffix[32];

        boost::shared_ptr<MidiRegion> region = boost::dynamic_pointer_cast<MidiRegion>(r);
        if (!region) {
                return -1;
        }

        /* the name doesn't need to be super-precise, but allow for 2 fractional
           digits just to disambiguate close but not identical stretches.
        */

        snprintf (suffix, sizeof (suffix), "@%d", (int) floor (_request.time_fraction * 100.0f));

        string new_name = region->name();
        string::size_type at = new_name.find ('@');

        // remove any existing stretch indicator

        if (at != string::npos && at > 2) {
                new_name = new_name.substr (0, at - 1);
        }

        new_name += suffix;

        /* create new sources */

        if (make_new_sources (region, nsrcs, suffix))
                return -1;

        boost::shared_ptr<MidiSource> src = region->midi_source(0);
        {
                Source::Lock lock(src->mutex());
                src->load_model(lock);
        }

        boost::shared_ptr<MidiModel> old_model = src->model();

        boost::shared_ptr<MidiSource> new_src = boost::dynamic_pointer_cast<MidiSource>(nsrcs[0]);
        if (!new_src) {
                error << _("MIDI stretch created non-MIDI source") << endmsg;
                return -1;
        }

        Glib::Threads::Mutex::Lock sl (new_src->mutex ());

        new_src->load_model(sl, true);
        boost::shared_ptr<MidiModel> new_model = new_src->model();
        new_model->start_write();

        /* Note: pass true into force_discrete for the begin() iterator so that the model doesn't
         * do interpolation of controller data when we stretch.
         */
        for (Evoral::Sequence<MidiModel::TimeType>::const_iterator i = old_model->begin (MidiModel::TimeType(), true);
                        i != old_model->end(); ++i) {
                const MidiModel::TimeType new_time = i->time() * (double)_request.time_fraction;

                // FIXME: double copy
                Evoral::Event<MidiModel::TimeType> ev(*i, true);
                ev.set_time(new_time);
                new_model->append(ev, Evoral::next_event_id());
        }

        new_model->end_write (Evoral::Sequence<Evoral::Beats>::DeleteStuckNotes);
        new_model->set_edited (true);

        new_src->copy_interpolation_from (src);

        const int ret = finish (region, nsrcs, new_name);

        results[0]->set_length((framecnt_t) floor (r->length() * _request.time_fraction));

        return ret;
}