ardour/libs/ardour/ardour/interpolation.h

83 lines
2.6 KiB
C++

/*
* Copyright (C) 2009-2010 Carl Hetherington <carl@carlh.net>
* Copyright (C) 2009-2011 David Robillard <d@drobilla.net>
* Copyright (C) 2009-2017 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2009 Hans Baier <hansfbaier@googlemail.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 <math.h>
#include <samplerate.h>
#include "ardour/libardour_visibility.h"
#include "ardour/types.h"
#ifndef __interpolation_h__
#define __interpolation_h__
namespace ARDOUR {
class LIBARDOUR_API Interpolation {
protected:
double _speed;
double _target_speed;
// the idea is that when the speed is not 1.0, we have to
// interpolate between samples and then we have to store where we thought we were.
// rather than being at sample N or N+1, we were at N+0.8792922
std::vector<double> phase;
public:
Interpolation () { _speed = 1.0; _target_speed = 1.0; }
virtual ~Interpolation() {}
void set_speed (double new_speed) { _speed = new_speed; _target_speed = new_speed; }
void set_target_speed (double new_speed) { _target_speed = new_speed; }
double target_speed() const { return _target_speed; }
double speed() const { return _speed; }
void add_channel () { phase.push_back (0.0); }
void remove_channel () { phase.pop_back (); }
virtual void reset () {
for (size_t i = 0; i < phase.size(); i++) {
phase[i] = 0.0;
}
}
};
class LIBARDOUR_API CubicInterpolation : public Interpolation {
public:
CubicInterpolation ();
samplecnt_t interpolate (int channel, samplecnt_t input_samples, Sample* input, samplecnt_t & output_samples, Sample* output);
samplecnt_t distance (samplecnt_t nframes);
void reset ();
private:
Sample z[4];
char valid_z_bits;
bool is_valid (int n) const { return valid_z_bits & (1<<n); }
bool invalid (int n) const { return !is_valid (n); }
void validate (int n) { valid_z_bits |= (1<<n); }
void invalidate (int n) { valid_z_bits &= (1<<n); }
};
} // namespace ARDOUR
#endif