* Initial import

src/StretchCalculator.h

@@ -0,0 +1,89 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Rubber Band
+    An audio time-stretching and pitch-shifting library.
+    Copyright 2007 Chris Cannam.
+    
+    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.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#ifndef _RUBBERBAND_STRETCH_CALCULATOR_H_
+#define _RUBBERBAND_STRETCH_CALCULATOR_H_
+
+#include <sys/types.h>
+
+#include <vector>
+
+namespace RubberBand
+{
+
+class StretchCalculator
+{
+public:
+    StretchCalculator(size_t sampleRate, size_t inputIncrement, bool useHardPeaks);
+    virtual ~StretchCalculator();
+
+    /**
+     * Calculate phase increments for a region of audio, given the
+     * overall target stretch ratio, input duration in audio samples,
+     * and the audio curves to use for identifying phase lock points
+     * (lockAudioCurve) and for allocating stretches to relatively
+     * less prominent points (stretchAudioCurve).
+     */
+    virtual std::vector<int> calculate(double ratio, size_t inputDuration,
+                                       const std::vector<float> &lockAudioCurve,
+                                       const std::vector<float> &stretchAudioCurve);
+
+    /**
+     * Calculate the phase increment for a single audio block, given
+     * the overall target stretch ratio and the block's value on the
+     * phase-lock audio curve.  State is retained between calls in the
+     * StretchCalculator object; call reset() to reset it.  This uses
+     * a less sophisticated method than the offline calculate().
+     */
+    virtual int calculateSingle(double ratio, size_t inputDurationSoFar,
+                                float curveValue);
+
+    void reset();
+  
+    void setDebugLevel(int level) { m_debugLevel = level; }
+
+    std::vector<float> smoothDF(const std::vector<float> &df);
+
+protected:
+    struct Peak {
+        size_t frame;
+        bool hard;
+    };
+    std::vector<Peak> findPeaks(const std::vector<float> &audioCurve);
+
+    std::vector<int> distributeRegion(const std::vector<float> &regionCurve,
+                                      size_t outputDuration, float ratio,
+                                      bool lock);
+
+    void calculateDisplacements(const std::vector<float> &df,
+                                float &maxDf,
+                                double &totalDisplacement,
+                                double &maxDisplacement,
+                                float adj) const;
+
+    size_t m_sampleRate;
+    size_t m_blockSize;
+    size_t m_increment;
+    float m_prevDf;
+    double m_divergence;
+    float m_recovery;
+    float m_prevRatio;
+    bool m_wasTransient;
+    int m_debugLevel;
+    bool m_useHardPeaks;
+};
+
+}
+
+#endif