Update from personal repository.

* Added an initial "formant preservation" option when pitch shifting
 * Real-time pitch shifting now uses a faster method by default, with
   less variation in CPU usage
 * The code is more amenable to compiler auto-vectorization (through
   e.g. gcc --ftree-vectorize).

src/StretcherImpl.h

@@ -3,7 +3,7 @@
 /*
     Rubber Band
     An audio time-stretching and pitch-shifting library.
-    Copyright 2007 Chris Cannam.
+    Copyright 2007-2008 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
@@ -50,6 +50,8 @@ public:
 
     void setTransientsOption(Options);
     void setPhaseOption(Options);
+    void setFormantOption(Options);
+    void setPitchOption(Options);
 
     void setExpectedInputDuration(size_t samples);
     void setMaxProcessSize(size_t samples);
@@ -86,7 +88,8 @@ protected:
     RubberBandStretcher *m_stretcher;
     size_t m_channels;
 
-    size_t consumeChannel(size_t channel, const float *input, size_t samples);
+    size_t consumeChannel(size_t channel, const float *input,
+                          size_t samples, bool final);
     void processChunks(size_t channel, bool &any, bool &last);
     bool processOneChunk(); // across all channels, for real time use
     bool processChunkForChannel(size_t channel, size_t phaseIncrement,
@@ -98,6 +101,7 @@ protected:
                        size_t &shiftIncrement, bool &phaseReset);
     void analyseChunk(size_t channel);
     void modifyChunk(size_t channel, size_t outputIncrement, bool phaseReset);
+    void formantShiftChunk(size_t channel);
     void synthesiseChunk(size_t channel);
     void writeChunk(size_t channel, size_t shiftIncrement, bool last);
 
@@ -109,6 +113,8 @@ protected:
     
     size_t roundUp(size_t value); // to next power of two
 
+    bool resampleBeforeStretching() const;
+    
     double m_timeRatio;
     double m_pitchScale;