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livetrax/libs/ardour/reverse.cc

132 lines
2.8 KiB
C++

/*
* Copyright (C) 2006-2012 David Robillard <d@drobilla.net>
* Copyright (C) 2008-2010 Carl Hetherington <carl@carlh.net>
* Copyright (C) 2008-2017 Paul Davis <paul@linuxaudiosystems.com>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <algorithm>
#include "ardour/audioregion.h"
#include "ardour/audiosource.h"
#include "ardour/reverse.h"
#include "ardour/types.h"
using namespace std;
using namespace ARDOUR;
namespace ARDOUR {
class Session;
}
Reverse::Reverse (Session& s)
: Filter (s)
{
}
Reverse::~Reverse ()
{
}
int
Reverse::run (std::shared_ptr<Region> r, PBD::Progress*)
{
SourceList nsrcs;
SourceList::iterator si;
samplecnt_t blocksize = 256 * 1024;
Sample* buf = 0;
samplepos_t fpos;
samplepos_t fstart;
samplecnt_t to_read;
int ret = -1;
std::shared_ptr<AudioRegion> region = std::dynamic_pointer_cast<AudioRegion>(r);
if (!region) {
return ret;
}
/* create new sources */
if (make_new_sources (region, nsrcs, "", false)) {
goto out;
}
fstart = region->start_sample();
if (blocksize > region->length_samples()) {
blocksize = region->length_samples();
}
fpos = max (fstart, (fstart + region->length_samples() - blocksize));
buf = new Sample[blocksize];
to_read = blocksize;
/* now read it backwards */
while (to_read) {
uint32_t n;
for (n = 0, si = nsrcs.begin(); n < region->n_channels(); ++n, ++si) {
/* read it in directly from the source */
if (region->audio_source (n)->read (buf, fpos, to_read) != to_read) {
goto out;
}
/* swap memory order */
for (samplecnt_t i = 0; i < to_read/2; ++i) {
swap (buf[i],buf[to_read-1-i]);
}
/* write it out */
std::shared_ptr<AudioSource> asrc(std::dynamic_pointer_cast<AudioSource>(*si));
if (asrc && asrc->write (buf, to_read) != to_read) {
goto out;
}
}
if (fpos > fstart + blocksize) {
fpos -= to_read;
to_read = blocksize;
} else {
to_read = fpos - fstart;
fpos = fstart;
}
};
ret = finish (region, nsrcs);
out:
delete [] buf;
if (ret) {
for (si = nsrcs.begin(); si != nsrcs.end(); ++si) {
std::shared_ptr<AudioSource> asrc(std::dynamic_pointer_cast<AudioSource>(*si));
asrc->mark_for_remove ();
}
}
return ret;
}