X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fardour%2Finterpolation.h;h=488a5fe5b40c7a1c287131d546c2547e8435e349;hb=7a524285385d4581ad3f1e085629379e32f82fda;hp=09ae2424906c3b923f66df563caa15fce356ee1b;hpb=f284d28d5306114e9badc9077835683e541420e0;p=ardour.git

diff --git a/libs/ardour/ardour/interpolation.h b/libs/ardour/ardour/interpolation.h
index 09ae242490..488a5fe5b4 100644
--- a/libs/ardour/ardour/interpolation.h
+++ b/libs/ardour/ardour/interpolation.h
@@ -1,49 +1,80 @@
+/*
+    Copyright (C) 1999-2010 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 <math.h>
-//#include "ardour/types.h"
-
-typedef float Sample;
-#define nframes_t uint32_t
-
-// 40.24 fixpoint math
-#define FIXPOINT_ONE 0x1000000
-
-class Interpolation {
-    protected:
-    /// speed in fixed point math
-    uint64_t      phi;
-    
-    /// target speed in fixed point math
-    uint64_t      target_phi;
-    
-    uint64_t      last_phase;
-
-	// 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:
-        Interpolation () : phi (FIXPOINT_ONE), target_phi (FIXPOINT_ONE), last_phase (0) {}
-    
-        void set_speed (double new_speed) {
-            target_phi = (uint64_t) (FIXPOINT_ONE * fabs(new_speed));
-            phi = target_phi;
-        }
-        
-        uint64_t get_phi () const { return phi; }
-        uint64_t get_target_phi () const { return target_phi; }
-        uint64_t get_last_phase () const { return last_phase; }
- 
-        virtual nframes_t interpolate (nframes_t nframes, Sample* input, Sample* output) = 0;
+#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 LinearInterpolation : public Interpolation {
-    public:
-        nframes_t interpolate (nframes_t nframes, Sample* input, Sample* output);
+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