st_stretch.cc

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/*
    Copyright (C) 2004-2007 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 <algorithm>
#include <cmath>

#include "pbd/error.h"

#include "ardour/types.h"
#include "ardour/stretch.h"
#include "ardour/audiofilesource.h"
#include "ardour/session.h"
#include "ardour/audioregion.h"

#include "i18n.h"

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

STStretch::STStretch (Session& s, TimeFXRequest& req)
        : Filter (s)
        , tsr (req)
{
        float percentage;

        /* the soundtouch code wants a *tempo* change percentage, which is
           of opposite sign to the length change.
        */

        percentage = -tsr.time_fraction;

        st.setSampleRate (s.frame_rate());
        st.setChannels (1);
        st.setTempoChange (percentage);
        st.setPitchSemiTones (0);
        st.setRateChange (0);

        st.setSetting(SETTING_USE_QUICKSEEK, tsr.quick_seek);
        st.setSetting(SETTING_USE_AA_FILTER, tsr.antialias);

}

STStretch::~STStretch ()
{
}

int
STStretch::run (boost::shared_ptr<Region> a_region, Progress* progress)
{
        SourceList nsrcs;
        framecnt_t total_frames;
        framecnt_t done;
        int ret = -1;
        const framecnt_t bufsize = 16384;
        gain_t *gain_buffer = 0;
        Sample *buffer = 0;
        char suffix[32];
        string new_name;
        string::size_type at;

        progress->set_progress (0);
        tsr.done = false;

        boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion>(a_region);

        total_frames = region->length() * region->n_channels();
        done = 0;

        /* 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 (tsr.time_fraction * 100.0f));

        /* create new sources */

        if (make_new_sources (region, nsrcs, suffix)) {
                goto out;
        }

        gain_buffer = new gain_t[bufsize];
        buffer = new Sample[bufsize];

        // soundtouch throws runtime_error on error

        try {
                for (uint32_t i = 0; i < nsrcs.size(); ++i) {

                        boost::shared_ptr<AudioSource> asrc
                                = boost::dynamic_pointer_cast<AudioSource>(nsrcs[i]);

                        framepos_t pos = 0;
                        framecnt_t this_read = 0;

                        st.clear();

                        while (!tsr.cancel && pos < region->length()) {
                                framecnt_t this_time;

                                this_time = min (bufsize, region->length() - pos);

                                /* read from the master (original) sources for the region,
                                   not the ones currently in use, in case it's already been
                                   subject to timefx.
                                */

                                if ((this_read = region->master_read_at (buffer, buffer, gain_buffer, pos + region->position(), this_time)) != this_time) {
                                        error << string_compose (_("tempoize: error reading data from %1"), asrc->name()) << endmsg;
                                        goto out;
                                }

                                pos += this_read;
                                done += this_read;

                                progress->set_progress ((float) done / total_frames);

                                st.putSamples (buffer, this_read);

                                while ((this_read = st.receiveSamples (buffer, bufsize)) > 0 && !tsr.cancel) {
                                        if (asrc->write (buffer, this_read) != this_read) {
                                                error << string_compose (_("error writing tempo-adjusted data to %1"), asrc->name()) << endmsg;
                                                goto out;
                                        }
                                }
                        }

                        if (!tsr.cancel) {
                                st.flush ();
                        }

                        while (!tsr.cancel && (this_read = st.receiveSamples (buffer, bufsize)) > 0) {
                                if (asrc->write (buffer, this_read) != this_read) {
                                        error << string_compose (_("error writing tempo-adjusted data to %1"), asrc->name()) << endmsg;
                                        goto out;
                                }
                        }
                }

        } catch (runtime_error& err) {
                error << _("timefx code failure. please notify ardour-developers.") << endmsg;
                error << err.what() << endmsg;
                goto out;
        }

        new_name = region->name();
        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;

        ret = finish (region, nsrcs, new_name);

        /* now reset ancestral data for each new region */

        for (vector<boost::shared_ptr<Region> >::iterator x = results.begin(); x != results.end(); ++x) {
                framepos_t astart = (*x)->ancestral_start();
                framepos_t alength = (*x)->ancestral_length();
                framepos_t start;
                framecnt_t length;

                // note: tsr.fraction is a percentage of original length. 100 = no change,
                // 50 is half as long, 200 is twice as long, etc.

                float stretch = (*x)->stretch() * (tsr.time_fraction/100.0);

                start = (framepos_t) floor (astart + ((astart - (*x)->start()) / stretch));
                length = (framecnt_t) floor (alength / stretch);

                (*x)->set_ancestral_data (start, length, stretch, (*x)->shift());
        }

  out:

        delete [] gain_buffer;
        delete [] buffer;

        if (ret || tsr.cancel) {
                for (SourceList::iterator si = nsrcs.begin(); si != nsrcs.end(); ++si) {
                        (*si)->mark_for_remove ();
                }
        }

        return ret;
}