class Interpolation {
protected:
- double _speed, _target_speed;
-
+ double _speed, _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; }
-
- void set_speed (double new_speed) { _speed = new_speed; _target_speed = new_speed; }
- void set_target_speed (double new_speed) { _target_speed = new_speed; }
+ Interpolation () { _speed = 1.0; _target_speed = 1.0; }
+ ~Interpolation () { phase.clear(); }
- double target_speed() const { return _target_speed; }
- double speed() const { return _speed; }
-
- void add_channel_to (int input_buffer_size, int output_buffer_size) {}
- void remove_channel_from () {}
-
- void reset () {}
-};
+ void set_speed (double new_speed) { _speed = new_speed; _target_speed = new_speed; }
+ void set_target_speed (double new_speed) { _target_speed = new_speed; }
-// 40.24 fixpoint math
-#define FIXPOINT_ONE 0x1000000
+ double target_speed() const { return _target_speed; }
+ double speed() const { return _speed; }
-class FixedPointLinearInterpolation : public Interpolation {
- protected:
- /// speed in fixed point math
- uint64_t phi;
-
- /// target speed in fixed point math
- uint64_t target_phi;
-
- std::vector<uint64_t> last_phase;
+ void add_channel_to (int /*input_buffer_size*/, int /*output_buffer_size*/) { phase.push_back (0.0); }
+ void remove_channel_from () { phase.pop_back (); }
- // Fixed point is just an integer with an implied scaling factor.
- // In 40.24 the scaling factor is 2^24 = 16777216,
- // so a value of 10*2^24 (in integer space) is equivalent to 10.0.
- //
- // The advantage is that addition and modulus [like x = (x + y) % 2^40]
- // have no rounding errors and no drift, and just require a single integer add.
- // (swh)
-
- static const int64_t fractional_part_mask = 0xFFFFFF;
- static const Sample binary_scaling_factor = 16777216.0f;
-
- public:
-
- FixedPointLinearInterpolation () : phi (FIXPOINT_ONE), target_phi (FIXPOINT_ONE) {}
-
- void set_speed (double new_speed) {
- target_phi = (uint64_t) (FIXPOINT_ONE * fabs(new_speed));
- phi = target_phi;
- }
-
- uint64_t get_phi() { return phi; }
- uint64_t get_target_phi() { return target_phi; }
- uint64_t get_last_phase() { assert(last_phase.size()); return last_phase[0]; }
- void set_last_phase(uint64_t phase) { assert(last_phase.size()); last_phase[0] = phase; }
-
- void add_channel_to (int input_buffer_size, int output_buffer_size);
- void remove_channel_from ();
-
- nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
- void reset ();
+ void reset () {
+ for (size_t i = 0; i < phase.size(); i++) {
+ phase[i] = 0.0;
+ }
+ }
};
- class LinearInterpolation : public Interpolation {
- protected:
- // 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;
-
+class LinearInterpolation : public Interpolation {
public:
- void add_channel_to (int input_buffer_size, int output_buffer_size);
- void remove_channel_from ();
-
- nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
- void reset ();
- };
+ nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
+};
-class LibSamplerateInterpolation : public Interpolation {
- protected:
- std::vector<SRC_STATE*> state;
- std::vector<SRC_DATA*> data;
-
- int error;
-
- void reset_state ();
-
+class CubicInterpolation : public Interpolation {
public:
- LibSamplerateInterpolation ();
- ~LibSamplerateInterpolation ();
-
- void set_speed (double new_speed);
- void set_target_speed (double new_speed) {}
- double speed () const { return _speed; }
-
- void add_channel_to (int input_buffer_size, int output_buffer_size);
- void remove_channel_from ();
-
- nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
- void reset() { reset_state (); }
+ nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output);
};
} // namespace ARDOUR