2 #include <samplerate.h>
4 #include "ardour/types.h"
6 #ifndef __interpolation_h__
7 #define __interpolation_h__
13 double _speed, _target_speed;
15 // the idea is that when the speed is not 1.0, we have to
16 // interpolate between samples and then we have to store where we thought we were.
17 // rather than being at sample N or N+1, we were at N+0.8792922
18 std::vector<double> phase;
22 Interpolation () { _speed = 1.0; _target_speed = 1.0; }
23 ~Interpolation () { phase.clear(); }
25 void set_speed (double new_speed) { _speed = new_speed; _target_speed = new_speed; }
26 void set_target_speed (double new_speed) { _target_speed = new_speed; }
28 double target_speed() const { return _target_speed; }
29 double speed() const { return _speed; }
31 void add_channel_to (int input_buffer_size, int output_buffer_size) { phase.push_back (0.0); }
32 void remove_channel_from () { phase.pop_back (); }
35 for (size_t i = 0; i < phase.size(); i++) {
41 class LinearInterpolation : public Interpolation {
45 nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
48 class CubicInterpolation : public Interpolation {
50 // shamelessly ripped from Steve Harris' swh-plugins (ladspa-util.h)
51 static inline float cube_interp(const float fr, const float inm1, const float
52 in, const float inp1, const float inp2)
54 return in + 0.5f * fr * (inp1 - inm1 +
55 fr * (4.0f * inp1 + 2.0f * inm1 - 5.0f * in - inp2 +
56 fr * (3.0f * (in - inp1) - inm1 + inp2)));
60 nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);