Stripped down version of SoundTouch 1.9.2

CMakeLists.txt

@@ -0,0 +1,14 @@
+set(SRCS
+    src/AAFilter.cpp
+    src/cpu_detect_x86.cpp
+    src/FIFOSampleBuffer.cpp
+    src/FIRFilter.cpp
+    src/InterpolateLinear.cpp
+    src/RateTransposer.cpp
+    src/SoundTouch.cpp
+    src/TDStretch.cpp
+    )
+
+include_directories(src include)
+
+add_library(SoundTouch STATIC ${SRCS})

include/FIFOSampleBuffer.h

@@ -0,0 +1,184 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// A buffer class for temporarily storaging sound samples, operates as a 
+/// first-in-first-out pipe.
+///
+/// Samples are added to the end of the sample buffer with the 'putSamples' 
+/// function, and are received from the beginning of the buffer by calling
+/// the 'receiveSamples' function. The class automatically removes the 
+/// output samples from the buffer as well as grows the storage size 
+/// whenever necessary.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2014-01-05 23:40:22 +0200 (Sun, 05 Jan 2014) $
+// File revision : $Revision: 4 $
+//
+// $Id: FIFOSampleBuffer.h 177 2014-01-05 21:40:22Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef FIFOSampleBuffer_H
+#define FIFOSampleBuffer_H
+
+#include "FIFOSamplePipe.h"
+
+namespace soundtouch
+{
+
+/// Sample buffer working in FIFO (first-in-first-out) principle. The class takes
+/// care of storage size adjustment and data moving during input/output operations.
+///
+/// Notice that in case of stereo audio, one sample is considered to consist of 
+/// both channel data.
+class FIFOSampleBuffer : public FIFOSamplePipe
+{
+private:
+    /// Sample buffer.
+    SAMPLETYPE *buffer;
+
+    // Raw unaligned buffer memory. 'buffer' is made aligned by pointing it to first
+    // 16-byte aligned location of this buffer
+    SAMPLETYPE *bufferUnaligned;
+
+    /// Sample buffer size in bytes
+    uint sizeInBytes;
+
+    /// How many samples are currently in buffer.
+    uint samplesInBuffer;
+
+    /// Channels, 1=mono, 2=stereo.
+    uint channels;
+
+    /// Current position pointer to the buffer. This pointer is increased when samples are 
+    /// removed from the pipe so that it's necessary to actually rewind buffer (move data)
+    /// only new data when is put to the pipe.
+    uint bufferPos;
+
+    /// Rewind the buffer by moving data from position pointed by 'bufferPos' to real 
+    /// beginning of the buffer.
+    void rewind();
+
+    /// Ensures that the buffer has capacity for at least this many samples.
+    void ensureCapacity(uint capacityRequirement);
+
+    /// Returns current capacity.
+    uint getCapacity() const;
+
+public:
+
+    /// Constructor
+    FIFOSampleBuffer(int numChannels = 2     ///< Number of channels, 1=mono, 2=stereo.
+                                              ///< Default is stereo.
+                     );
+
+    /// destructor
+    ~FIFOSampleBuffer();
+
+    /// Returns a pointer to the beginning of the output samples. 
+    /// This function is provided for accessing the output samples directly. 
+    /// Please be careful for not to corrupt the book-keeping!
+    ///
+    /// When using this function to output samples, also remember to 'remove' the
+    /// output samples from the buffer by calling the 
+    /// 'receiveSamples(numSamples)' function
+    virtual SAMPLETYPE *ptrBegin();
+
+    /// Returns a pointer to the end of the used part of the sample buffer (i.e. 
+    /// where the new samples are to be inserted). This function may be used for 
+    /// inserting new samples into the sample buffer directly. Please be careful
+    /// not corrupt the book-keeping!
+    ///
+    /// When using this function as means for inserting new samples, also remember 
+    /// to increase the sample count afterwards, by calling  the 
+    /// 'putSamples(numSamples)' function.
+    SAMPLETYPE *ptrEnd(
+                uint slackCapacity   ///< How much free capacity (in samples) there _at least_ 
+                                     ///< should be so that the caller can succesfully insert the 
+                                     ///< desired samples to the buffer. If necessary, the function 
+                                     ///< grows the buffer size to comply with this requirement.
+                );
+
+    /// Adds 'numSamples' pcs of samples from the 'samples' memory position to
+    /// the sample buffer.
+    virtual void putSamples(const SAMPLETYPE *samples,  ///< Pointer to samples.
+                            uint numSamples                         ///< Number of samples to insert.
+                            );
+
+    /// Adjusts the book-keeping to increase number of samples in the buffer without 
+    /// copying any actual samples.
+    ///
+    /// This function is used to update the number of samples in the sample buffer
+    /// when accessing the buffer directly with 'ptrEnd' function. Please be 
+    /// careful though!
+    virtual void putSamples(uint numSamples   ///< Number of samples been inserted.
+                            );
+
+    /// Output samples from beginning of the sample buffer. Copies requested samples to 
+    /// output buffer and removes them from the sample buffer. If there are less than 
+    /// 'numsample' samples in the buffer, returns all that available.
+    ///
+    /// \return Number of samples returned.
+    virtual uint receiveSamples(SAMPLETYPE *output, ///< Buffer where to copy output samples.
+                                uint maxSamples                 ///< How many samples to receive at max.
+                                );
+
+    /// Adjusts book-keeping so that given number of samples are removed from beginning of the 
+    /// sample buffer without copying them anywhere. 
+    ///
+    /// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
+    /// with 'ptrBegin' function.
+    virtual uint receiveSamples(uint maxSamples   ///< Remove this many samples from the beginning of pipe.
+                                );
+
+    /// Returns number of samples currently available.
+    virtual uint numSamples() const;
+
+    /// Sets number of channels, 1 = mono, 2 = stereo.
+    void setChannels(int numChannels);
+
+    /// Get number of channels
+    int getChannels() 
+    {
+        return channels;
+    }
+
+    /// Returns nonzero if there aren't any samples available for outputting.
+    virtual int isEmpty() const;
+
+    /// Clears all the samples.
+    virtual void clear();
+
+    /// allow trimming (downwards) amount of samples in pipeline.
+    /// Returns adjusted amount of samples
+    uint adjustAmountOfSamples(uint numSamples);
+};
+
+}
+
+#endif

include/FIFOSamplePipe.h

@@ -0,0 +1,234 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// 'FIFOSamplePipe' : An abstract base class for classes that manipulate sound
+/// samples by operating like a first-in-first-out pipe: New samples are fed
+/// into one end of the pipe with the 'putSamples' function, and the processed
+/// samples are received from the other end with the 'receiveSamples' function.
+///
+/// 'FIFOProcessor' : A base class for classes the do signal processing with 
+/// the samples while operating like a first-in-first-out pipe. When samples
+/// are input with the 'putSamples' function, the class processes them
+/// and moves the processed samples to the given 'output' pipe object, which
+/// may be either another processing stage, or a fifo sample buffer object.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2012-06-13 22:29:53 +0300 (Wed, 13 Jun 2012) $
+// File revision : $Revision: 4 $
+//
+// $Id: FIFOSamplePipe.h 143 2012-06-13 19:29:53Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef FIFOSamplePipe_H
+#define FIFOSamplePipe_H
+
+#include <assert.h>
+#include <stdlib.h>
+#include "STTypes.h"
+
+namespace soundtouch
+{
+
+/// Abstract base class for FIFO (first-in-first-out) sample processing classes.
+class FIFOSamplePipe
+{
+public:
+    // virtual default destructor
+    virtual ~FIFOSamplePipe() {}
+
+
+    /// Returns a pointer to the beginning of the output samples. 
+    /// This function is provided for accessing the output samples directly. 
+    /// Please be careful for not to corrupt the book-keeping!
+    ///
+    /// When using this function to output samples, also remember to 'remove' the
+    /// output samples from the buffer by calling the 
+    /// 'receiveSamples(numSamples)' function
+    virtual SAMPLETYPE *ptrBegin() = 0;
+
+    /// Adds 'numSamples' pcs of samples from the 'samples' memory position to
+    /// the sample buffer.
+    virtual void putSamples(const SAMPLETYPE *samples,  ///< Pointer to samples.
+                            uint numSamples             ///< Number of samples to insert.
+                            ) = 0;
+
+
+    // Moves samples from the 'other' pipe instance to this instance.
+    void moveSamples(FIFOSamplePipe &other  ///< Other pipe instance where from the receive the data.
+         )
+    {
+        int oNumSamples = other.numSamples();
+
+        putSamples(other.ptrBegin(), oNumSamples);
+        other.receiveSamples(oNumSamples);
+    };
+
+    /// Output samples from beginning of the sample buffer. Copies requested samples to 
+    /// output buffer and removes them from the sample buffer. If there are less than 
+    /// 'numsample' samples in the buffer, returns all that available.
+    ///
+    /// \return Number of samples returned.
+    virtual uint receiveSamples(SAMPLETYPE *output, ///< Buffer where to copy output samples.
+                                uint maxSamples                 ///< How many samples to receive at max.
+                                ) = 0;
+
+    /// Adjusts book-keeping so that given number of samples are removed from beginning of the 
+    /// sample buffer without copying them anywhere. 
+    ///
+    /// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
+    /// with 'ptrBegin' function.
+    virtual uint receiveSamples(uint maxSamples   ///< Remove this many samples from the beginning of pipe.
+                                ) = 0;
+
+    /// Returns number of samples currently available.
+    virtual uint numSamples() const = 0;
+
+    // Returns nonzero if there aren't any samples available for outputting.
+    virtual int isEmpty() const = 0;
+
+    /// Clears all the samples.
+    virtual void clear() = 0;
+
+    /// allow trimming (downwards) amount of samples in pipeline.
+    /// Returns adjusted amount of samples
+    virtual uint adjustAmountOfSamples(uint numSamples) = 0;
+
+};
+
+
+
+/// Base-class for sound processing routines working in FIFO principle. With this base 
+/// class it's easy to implement sound processing stages that can be chained together,
+/// so that samples that are fed into beginning of the pipe automatically go through 
+/// all the processing stages.
+///
+/// When samples are input to this class, they're first processed and then put to 
+/// the FIFO pipe that's defined as output of this class. This output pipe can be
+/// either other processing stage or a FIFO sample buffer.
+class FIFOProcessor :public FIFOSamplePipe
+{
+protected:
+    /// Internal pipe where processed samples are put.
+    FIFOSamplePipe *output;
+
+    /// Sets output pipe.
+    void setOutPipe(FIFOSamplePipe *pOutput)
+    {
+        assert(output == NULL);
+        assert(pOutput != NULL);
+        output = pOutput;
+    }
+
+
+    /// Constructor. Doesn't define output pipe; it has to be set be 
+    /// 'setOutPipe' function.
+    FIFOProcessor()
+    {
+        output = NULL;
+    }
+
+
+    /// Constructor. Configures output pipe.
+    FIFOProcessor(FIFOSamplePipe *pOutput   ///< Output pipe.
+                 )
+    {
+        output = pOutput;
+    }
+
+
+    /// Destructor.
+    virtual ~FIFOProcessor()
+    {
+    }
+
+
+    /// Returns a pointer to the beginning of the output samples. 
+    /// This function is provided for accessing the output samples directly. 
+    /// Please be careful for not to corrupt the book-keeping!
+    ///
+    /// When using this function to output samples, also remember to 'remove' the
+    /// output samples from the buffer by calling the 
+    /// 'receiveSamples(numSamples)' function
+    virtual SAMPLETYPE *ptrBegin()
+    {
+        return output->ptrBegin();
+    }
+
+public:
+
+    /// Output samples from beginning of the sample buffer. Copies requested samples to 
+    /// output buffer and removes them from the sample buffer. If there are less than 
+    /// 'numsample' samples in the buffer, returns all that available.
+    ///
+    /// \return Number of samples returned.
+    virtual uint receiveSamples(SAMPLETYPE *outBuffer, ///< Buffer where to copy output samples.
+                                uint maxSamples                    ///< How many samples to receive at max.
+                                )
+    {
+        return output->receiveSamples(outBuffer, maxSamples);
+    }
+
+
+    /// Adjusts book-keeping so that given number of samples are removed from beginning of the 
+    /// sample buffer without copying them anywhere. 
+    ///
+    /// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
+    /// with 'ptrBegin' function.
+    virtual uint receiveSamples(uint maxSamples   ///< Remove this many samples from the beginning of pipe.
+                                )
+    {
+        return output->receiveSamples(maxSamples);
+    }
+
+
+    /// Returns number of samples currently available.
+    virtual uint numSamples() const
+    {
+        return output->numSamples();
+    }
+
+
+    /// Returns nonzero if there aren't any samples available for outputting.
+    virtual int isEmpty() const
+    {
+        return output->isEmpty();
+    }
+
+    /// allow trimming (downwards) amount of samples in pipeline.
+    /// Returns adjusted amount of samples
+    virtual uint adjustAmountOfSamples(uint numSamples)
+    {
+        return output->adjustAmountOfSamples(numSamples);
+    }
+
+};
+
+}
+
+#endif

include/STTypes.h

@@ -0,0 +1,177 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// Common type definitions for SoundTouch audio processing library.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-05-18 18:25:07 +0300 (Mon, 18 May 2015) $
+// File revision : $Revision: 3 $
+//
+// $Id: STTypes.h 215 2015-05-18 15:25:07Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef STTypes_H
+#define STTypes_H
+
+typedef unsigned int    uint;
+typedef unsigned long   ulong;
+
+// Patch for MinGW: on Win64 long is 32-bit
+#ifdef _WIN64
+    typedef unsigned long long ulongptr;
+#else
+    typedef ulong ulongptr;
+#endif
+
+
+// Helper macro for aligning pointer up to next 16-byte boundary
+#define SOUNDTOUCH_ALIGN_POINTER_16(x)      ( ( (ulongptr)(x) + 15 ) & ~(ulongptr)15 )
+
+namespace soundtouch
+{
+    /// Activate these undef's to overrule the possible sampletype 
+    /// setting inherited from some other header file:
+    //#undef SOUNDTOUCH_INTEGER_SAMPLES
+    //#undef SOUNDTOUCH_FLOAT_SAMPLES
+
+    /// If following flag is defined, always uses multichannel processing 
+    /// routines also for mono and stero sound. This is for routine testing 
+    /// purposes; output should be same with either routines, yet disabling 
+    /// the dedicated mono/stereo processing routines will result in slower 
+    /// runtime performance so recommendation is to keep this off.
+    // #define USE_MULTICH_ALWAYS
+
+    #if (defined(__SOFTFP__) && defined(ANDROID))
+        // For Android compilation: Force use of Integer samples in case that
+        // compilation uses soft-floating point emulation - soft-fp is way too slow
+        #undef  SOUNDTOUCH_FLOAT_SAMPLES
+        #define SOUNDTOUCH_INTEGER_SAMPLES      1
+    #endif
+
+    #if !(SOUNDTOUCH_INTEGER_SAMPLES || SOUNDTOUCH_FLOAT_SAMPLES)
+       
+        /// Choose either 32bit floating point or 16bit integer sampletype
+        /// by choosing one of the following defines, unless this selection 
+        /// has already been done in some other file.
+        ////
+        /// Notes:
+        /// - In Windows environment, choose the sample format with the
+        ///   following defines.
+        /// - In GNU environment, the floating point samples are used by 
+        ///   default, but integer samples can be chosen by giving the 
+        ///   following switch to the configure script:
+        ///       ./configure --enable-integer-samples
+        ///   However, if you still prefer to select the sample format here 
+        ///   also in GNU environment, then please #undef the INTEGER_SAMPLE
+        ///   and FLOAT_SAMPLE defines first as in comments above.
+        #define SOUNDTOUCH_INTEGER_SAMPLES     1    //< 16bit integer samples
+        //#define SOUNDTOUCH_FLOAT_SAMPLES       1    //< 32bit float samples
+     
+    #endif
+
+    #if (_M_IX86 || __i386__ || __x86_64__ || _M_X64)
+        /// Define this to allow X86-specific assembler/intrinsic optimizations. 
+        /// Notice that library contains also usual C++ versions of each of these
+        /// these routines, so if you're having difficulties getting the optimized 
+        /// routines compiled for whatever reason, you may disable these optimizations 
+        /// to make the library compile.
+
+        //#define SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS     1
+
+        /// In GNU environment, allow the user to override this setting by
+        /// giving the following switch to the configure script:
+        /// ./configure --disable-x86-optimizations
+        /// ./configure --enable-x86-optimizations=no
+        #ifdef SOUNDTOUCH_DISABLE_X86_OPTIMIZATIONS
+            #undef SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS
+        #endif
+    #else
+        /// Always disable optimizations when not using a x86 systems.
+        #undef SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS
+
+    #endif
+
+    // If defined, allows the SIMD-optimized routines to take minor shortcuts 
+    // for improved performance. Undefine to require faithfully similar SIMD 
+    // calculations as in normal C implementation.
+    #define SOUNDTOUCH_ALLOW_NONEXACT_SIMD_OPTIMIZATION    1
+
+
+    #ifdef SOUNDTOUCH_INTEGER_SAMPLES
+        // 16bit integer sample type
+        typedef short SAMPLETYPE;
+        // data type for sample accumulation: Use 32bit integer to prevent overflows
+        typedef long  LONG_SAMPLETYPE;
+
+        #ifdef SOUNDTOUCH_FLOAT_SAMPLES
+            // check that only one sample type is defined
+            #error "conflicting sample types defined"
+        #endif // SOUNDTOUCH_FLOAT_SAMPLES
+
+        #ifdef SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS
+            // Allow MMX optimizations
+            #define SOUNDTOUCH_ALLOW_MMX   1
+        #endif
+
+    #else
+
+        // floating point samples
+        typedef float  SAMPLETYPE;
+        // data type for sample accumulation: Use double to utilize full precision.
+        typedef double LONG_SAMPLETYPE;
+
+        #ifdef SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS
+            // Allow SSE optimizations
+            #define SOUNDTOUCH_ALLOW_SSE       1
+        #endif
+
+    #endif  // SOUNDTOUCH_INTEGER_SAMPLES
+
+};
+
+// define ST_NO_EXCEPTION_HANDLING switch to disable throwing std exceptions:
+// #define ST_NO_EXCEPTION_HANDLING    1
+#ifdef ST_NO_EXCEPTION_HANDLING
+    // Exceptions disabled. Throw asserts instead if enabled.
+    #include <assert.h>
+    #define ST_THROW_RT_ERROR(x)    {assert((const char *)x);}
+#else
+    // use c++ standard exceptions
+    #include <stdexcept>
+    #include <string>
+    #define ST_THROW_RT_ERROR(x)    {throw std::runtime_error(x);}
+#endif
+
+// When this #define is active, eliminates a clicking sound when the "rate" or "pitch" 
+// parameter setting crosses from value <1 to >=1 or vice versa during processing. 
+// Default is off as such crossover is untypical case and involves a slight sound 
+// quality compromise.
+//#define SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER   1
+
+#endif

include/SoundTouch.h

@@ -0,0 +1,301 @@
+//////////////////////////////////////////////////////////////////////////////
+///
+/// SoundTouch - main class for tempo/pitch/rate adjusting routines. 
+///
+/// Notes:
+/// - Initialize the SoundTouch object instance by setting up the sound stream 
+///   parameters with functions 'setSampleRate' and 'setChannels', then set 
+///   desired tempo/pitch/rate settings with the corresponding functions.
+///
+/// - The SoundTouch class behaves like a first-in-first-out pipeline: The 
+///   samples that are to be processed are fed into one of the pipe by calling
+///   function 'putSamples', while the ready processed samples can be read 
+///   from the other end of the pipeline with function 'receiveSamples'.
+/// 
+/// - The SoundTouch processing classes require certain sized 'batches' of 
+///   samples in order to process the sound. For this reason the classes buffer 
+///   incoming samples until there are enough of samples available for 
+///   processing, then they carry out the processing step and consequently
+///   make the processed samples available for outputting.
+/// 
+/// - For the above reason, the processing routines introduce a certain 
+///   'latency' between the input and output, so that the samples input to
+///   SoundTouch may not be immediately available in the output, and neither 
+///   the amount of outputtable samples may not immediately be in direct 
+///   relationship with the amount of previously input samples.
+///
+/// - The tempo/pitch/rate control parameters can be altered during processing.
+///   Please notice though that they aren't currently protected by semaphores,
+///   so in multi-thread application external semaphore protection may be
+///   required.
+///
+/// - This class utilizes classes 'TDStretch' for tempo change (without modifying
+///   pitch) and 'RateTransposer' for changing the playback rate (that is, both 
+///   tempo and pitch in the same ratio) of the sound. The third available control 
+///   'pitch' (change pitch but maintain tempo) is produced by a combination of
+///   combining the two other controls.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-09-20 10:38:32 +0300 (Sun, 20 Sep 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: SoundTouch.h 230 2015-09-20 07:38:32Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SoundTouch_H
+#define SoundTouch_H
+
+#include "FIFOSamplePipe.h"
+#include "STTypes.h"
+
+namespace soundtouch
+{
+
+/// Soundtouch library version string
+#define SOUNDTOUCH_VERSION          "1.9.2"
+
+/// SoundTouch library version id
+#define SOUNDTOUCH_VERSION_ID       (10902)
+
+//
+// Available setting IDs for the 'setSetting' & 'get_setting' functions:
+
+/// Enable/disable anti-alias filter in pitch transposer (0 = disable)
+#define SETTING_USE_AA_FILTER       0
+
+/// Pitch transposer anti-alias filter length (8 .. 128 taps, default = 32)
+#define SETTING_AA_FILTER_LENGTH    1
+
+/// Enable/disable quick seeking algorithm in tempo changer routine
+/// (enabling quick seeking lowers CPU utilization but causes a minor sound
+///  quality compromising)
+#define SETTING_USE_QUICKSEEK       2
+
+/// Time-stretch algorithm single processing sequence length in milliseconds. This determines 
+/// to how long sequences the original sound is chopped in the time-stretch algorithm. 
+/// See "STTypes.h" or README for more information.
+#define SETTING_SEQUENCE_MS         3
+
+/// Time-stretch algorithm seeking window length in milliseconds for algorithm that finds the 
+/// best possible overlapping location. This determines from how wide window the algorithm 
+/// may look for an optimal joining location when mixing the sound sequences back together. 
+/// See "STTypes.h" or README for more information.
+#define SETTING_SEEKWINDOW_MS       4
+
+/// Time-stretch algorithm overlap length in milliseconds. When the chopped sound sequences 
+/// are mixed back together, to form a continuous sound stream, this parameter defines over 
+/// how long period the two consecutive sequences are let to overlap each other. 
+/// See "STTypes.h" or README for more information.
+#define SETTING_OVERLAP_MS          5
+
+
+/// Call "getSetting" with this ID to query nominal average processing sequence
+/// size in samples. This value tells approcimate value how many input samples 
+/// SoundTouch needs to gather before it does DSP processing run for the sample batch.
+///
+/// Notices: 
+/// - This is read-only parameter, i.e. setSetting ignores this parameter
+/// - Returned value is approximate average value, exact processing batch
+///   size may wary from time to time
+/// - This parameter value is not constant but may change depending on 
+///   tempo/pitch/rate/samplerate settings.
+#define SETTING_NOMINAL_INPUT_SEQUENCE		6
+
+
+/// Call "getSetting" with this ID to query nominal average processing output 
+/// size in samples. This value tells approcimate value how many output samples 
+/// SoundTouch outputs once it does DSP processing run for a batch of input samples.
+///	
+/// Notices: 
+/// - This is read-only parameter, i.e. setSetting ignores this parameter
+/// - Returned value is approximate average value, exact processing batch
+///   size may wary from time to time
+/// - This parameter value is not constant but may change depending on 
+///   tempo/pitch/rate/samplerate settings.
+#define SETTING_NOMINAL_OUTPUT_SEQUENCE		7
+
+class SoundTouch : public FIFOProcessor
+{
+private:
+    /// Rate transposer class instance
+    class RateTransposer *pRateTransposer;
+
+    /// Time-stretch class instance
+    class TDStretch *pTDStretch;
+
+    /// Virtual pitch parameter. Effective rate & tempo are calculated from these parameters.
+    double virtualRate;
+
+    /// Virtual pitch parameter. Effective rate & tempo are calculated from these parameters.
+    double virtualTempo;
+
+    /// Virtual pitch parameter. Effective rate & tempo are calculated from these parameters.
+    double virtualPitch;
+
+    /// Flag: Has sample rate been set?
+    bool  bSrateSet;
+
+    /// Accumulator for how many samples in total will be expected as output vs. samples put in,
+    /// considering current processing settings.
+    double samplesExpectedOut;
+
+    /// Accumulator for how many samples in total have been read out from the processing so far
+    long   samplesOutput;
+
+    /// Calculates effective rate & tempo valuescfrom 'virtualRate', 'virtualTempo' and 
+    /// 'virtualPitch' parameters.
+    void calcEffectiveRateAndTempo();
+
+protected :
+    /// Number of channels
+    uint  channels;
+
+    /// Effective 'rate' value calculated from 'virtualRate', 'virtualTempo' and 'virtualPitch'
+    double rate;
+
+    /// Effective 'tempo' value calculated from 'virtualRate', 'virtualTempo' and 'virtualPitch'
+    double tempo;
+
+public:
+    SoundTouch();
+    virtual ~SoundTouch();
+
+    /// Get SoundTouch library version string
+    static const char *getVersionString();
+
+    /// Get SoundTouch library version Id
+    static uint getVersionId();
+
+    /// Sets new rate control value. Normal rate = 1.0, smaller values
+    /// represent slower rate, larger faster rates.
+    void setRate(double newRate);
+
+    /// Sets new tempo control value. Normal tempo = 1.0, smaller values
+    /// represent slower tempo, larger faster tempo.
+    void setTempo(double newTempo);
+
+    /// Sets new rate control value as a difference in percents compared
+    /// to the original rate (-50 .. +100 %)
+    void setRateChange(double newRate);
+
+    /// Sets new tempo control value as a difference in percents compared
+    /// to the original tempo (-50 .. +100 %)
+    void setTempoChange(double newTempo);
+
+    /// Sets new pitch control value. Original pitch = 1.0, smaller values
+    /// represent lower pitches, larger values higher pitch.
+    void setPitch(double newPitch);
+
+    /// Sets pitch change in octaves compared to the original pitch  
+    /// (-1.00 .. +1.00)
+    void setPitchOctaves(double newPitch);
+
+    /// Sets pitch change in semi-tones compared to the original pitch
+    /// (-12 .. +12)
+    void setPitchSemiTones(int newPitch);
+    void setPitchSemiTones(double newPitch);
+
+    /// Sets the number of channels, 1 = mono, 2 = stereo
+    void setChannels(uint numChannels);
+
+    /// Sets sample rate.
+    void setSampleRate(uint srate);
+
+    /// Flushes the last samples from the processing pipeline to the output.
+    /// Clears also the internal processing buffers.
+    //
+    /// Note: This function is meant for extracting the last samples of a sound
+    /// stream. This function may introduce additional blank samples in the end
+    /// of the sound stream, and thus it's not recommended to call this function
+    /// in the middle of a sound stream.
+    void flush();
+
+    /// Adds 'numSamples' pcs of samples from the 'samples' memory position into
+    /// the input of the object. Notice that sample rate _has_to_ be set before
+    /// calling this function, otherwise throws a runtime_error exception.
+    virtual void putSamples(
+            const SAMPLETYPE *samples,  ///< Pointer to sample buffer.
+            uint numSamples                         ///< Number of samples in buffer. Notice
+                                                    ///< that in case of stereo-sound a single sample
+                                                    ///< contains data for both channels.
+            );
+
+    /// Output samples from beginning of the sample buffer. Copies requested samples to 
+    /// output buffer and removes them from the sample buffer. If there are less than 
+    /// 'numsample' samples in the buffer, returns all that available.
+    ///
+    /// \return Number of samples returned.
+    virtual uint receiveSamples(SAMPLETYPE *output, ///< Buffer where to copy output samples.
+        uint maxSamples                 ///< How many samples to receive at max.
+        );
+
+    /// Adjusts book-keeping so that given number of samples are removed from beginning of the 
+    /// sample buffer without copying them anywhere. 
+    ///
+    /// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
+    /// with 'ptrBegin' function.
+    virtual uint receiveSamples(uint maxSamples   ///< Remove this many samples from the beginning of pipe.
+        );
+
+    /// Clears all the samples in the object's output and internal processing
+    /// buffers.
+    virtual void clear();
+
+    /// Changes a setting controlling the processing system behaviour. See the
+    /// 'SETTING_...' defines for available setting ID's.
+    /// 
+    /// \return 'true' if the setting was succesfully changed
+    bool setSetting(int settingId,   ///< Setting ID number. see SETTING_... defines.
+                    int value        ///< New setting value.
+                    );
+
+    /// Reads a setting controlling the processing system behaviour. See the
+    /// 'SETTING_...' defines for available setting ID's.
+    ///
+    /// \return the setting value.
+    int getSetting(int settingId    ///< Setting ID number, see SETTING_... defines.
+                   ) const;
+
+    /// Returns number of samples currently unprocessed.
+    virtual uint numUnprocessedSamples() const;
+
+
+    /// Other handy functions that are implemented in the ancestor classes (see
+    /// classes 'FIFOProcessor' and 'FIFOSamplePipe')
+    ///
+    /// - receiveSamples() : Use this function to receive 'ready' processed samples from SoundTouch.
+    /// - numSamples()     : Get number of 'ready' samples that can be received with 
+    ///                      function 'receiveSamples()'
+    /// - isEmpty()        : Returns nonzero if there aren't any 'ready' samples.
+    /// - clear()          : Clears all samples from ready/processing buffers.
+};
+
+}
+#endif

src/AAFilter.cpp

@@ -0,0 +1,236 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// FIR low-pass (anti-alias) filter with filter coefficient design routine and
+/// MMX optimization. 
+/// 
+/// Anti-alias filter is used to prevent folding of high frequencies when 
+/// transposing the sample rate with interpolation.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2014-01-05 23:40:22 +0200 (Sun, 05 Jan 2014) $
+// File revision : $Revision: 4 $
+//
+// $Id: AAFilter.cpp 177 2014-01-05 21:40:22Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <memory.h>
+#include <assert.h>
+#include <math.h>
+#include <stdlib.h>
+#include "AAFilter.h"
+#include "FIRFilter.h"
+
+using namespace soundtouch;
+
+#define PI        3.141592655357989
+#define TWOPI    (2 * PI)
+
+// define this to save AA filter coefficients to a file
+// #define _DEBUG_SAVE_AAFILTER_COEFFICIENTS   1
+
+#ifdef _DEBUG_SAVE_AAFILTER_COEFFICIENTS
+    #include <stdio.h>
+
+    static void _DEBUG_SAVE_AAFIR_COEFFS(SAMPLETYPE *coeffs, int len)
+    {
+        FILE *fptr = fopen("aa_filter_coeffs.txt", "wt");
+        if (fptr == NULL) return;
+
+        for (int i = 0; i < len; i ++)
+        {
+            double temp = coeffs[i];
+            fprintf(fptr, "%lf\n", temp);
+        }
+        fclose(fptr);
+    }
+
+#else
+    #define _DEBUG_SAVE_AAFIR_COEFFS(x, y)
+#endif
+
+
+/*****************************************************************************
+ *
+ * Implementation of the class 'AAFilter'
+ *
+ *****************************************************************************/
+
+AAFilter::AAFilter(uint len)
+{
+    pFIR = FIRFilter::newInstance();
+    cutoffFreq = 0.5;
+    setLength(len);
+}
+
+
+
+AAFilter::~AAFilter()
+{
+    delete pFIR;
+}
+
+
+
+// Sets new anti-alias filter cut-off edge frequency, scaled to
+// sampling frequency (nyquist frequency = 0.5).
+// The filter will cut frequencies higher than the given frequency.
+void AAFilter::setCutoffFreq(double newCutoffFreq)
+{
+    cutoffFreq = newCutoffFreq;
+    calculateCoeffs();
+}
+
+
+
+// Sets number of FIR filter taps
+void AAFilter::setLength(uint newLength)
+{
+    length = newLength;
+    calculateCoeffs();
+}
+
+
+
+// Calculates coefficients for a low-pass FIR filter using Hamming window
+void AAFilter::calculateCoeffs()
+{
+    uint i;
+    double cntTemp, temp, tempCoeff,h, w;
+    double wc;
+    double scaleCoeff, sum;
+    double *work;
+    SAMPLETYPE *coeffs;
+
+    assert(length >= 2);
+    assert(length % 4 == 0);
+    assert(cutoffFreq >= 0);
+    assert(cutoffFreq <= 0.5);
+
+    work = new double[length];
+    coeffs = new SAMPLETYPE[length];
+
+    wc = 2.0 * PI * cutoffFreq;
+    tempCoeff = TWOPI / (double)length;
+
+    sum = 0;
+    for (i = 0; i < length; i ++) 
+    {
+        cntTemp = (double)i - (double)(length / 2);
+
+        temp = cntTemp * wc;
+        if (temp != 0) 
+        {
+            h = sin(temp) / temp;                     // sinc function
+        } 
+        else 
+        {
+            h = 1.0;
+        }
+        w = 0.54 + 0.46 * cos(tempCoeff * cntTemp);       // hamming window
+
+        temp = w * h;
+        work[i] = temp;
+
+        // calc net sum of coefficients 
+        sum += temp;
+    }
+
+    // ensure the sum of coefficients is larger than zero
+    assert(sum > 0);
+
+    // ensure we've really designed a lowpass filter...
+    assert(work[length/2] > 0);
+    assert(work[length/2 + 1] > -1e-6);
+    assert(work[length/2 - 1] > -1e-6);
+
+    // Calculate a scaling coefficient in such a way that the result can be
+    // divided by 16384
+    scaleCoeff = 16384.0f / sum;
+
+    for (i = 0; i < length; i ++) 
+    {
+        temp = work[i] * scaleCoeff;
+//#if SOUNDTOUCH_INTEGER_SAMPLES
+        // scale & round to nearest integer
+        temp += (temp >= 0) ? 0.5 : -0.5;
+        // ensure no overfloods
+        assert(temp >= -32768 && temp <= 32767);
+//#endif
+        coeffs[i] = (SAMPLETYPE)temp;
+    }
+
+    // Set coefficients. Use divide factor 14 => divide result by 2^14 = 16384
+    pFIR->setCoefficients(coeffs, length, 14);
+
+    _DEBUG_SAVE_AAFIR_COEFFS(coeffs, length);
+
+    delete[] work;
+    delete[] coeffs;
+}
+
+
+// Applies the filter to the given sequence of samples. 
+// Note : The amount of outputted samples is by value of 'filter length' 
+// smaller than the amount of input samples.
+uint AAFilter::evaluate(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples, uint numChannels) const
+{
+    return pFIR->evaluate(dest, src, numSamples, numChannels);
+}
+
+
+/// Applies the filter to the given src & dest pipes, so that processed amount of
+/// samples get removed from src, and produced amount added to dest 
+/// Note : The amount of outputted samples is by value of 'filter length' 
+/// smaller than the amount of input samples.
+uint AAFilter::evaluate(FIFOSampleBuffer &dest, FIFOSampleBuffer &src) const
+{
+    SAMPLETYPE *pdest;
+    const SAMPLETYPE *psrc;
+    uint numSrcSamples;
+    uint result;
+    int numChannels = src.getChannels();
+
+    assert(numChannels == dest.getChannels());
+
+    numSrcSamples = src.numSamples();
+    psrc = src.ptrBegin();
+    pdest = dest.ptrEnd(numSrcSamples);
+    result = pFIR->evaluate(pdest, psrc, numSrcSamples, numChannels);
+    src.receiveSamples(result);
+    dest.putSamples(result);
+
+    return result;
+}
+
+
+uint AAFilter::getLength() const
+{
+    return pFIR->getLength();
+}

src/AAFilter.h

@@ -0,0 +1,100 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// Sampled sound tempo changer/time stretch algorithm. Changes the sound tempo 
+/// while maintaining the original pitch by using a time domain WSOLA-like method 
+/// with several performance-increasing tweaks.
+///
+/// Anti-alias filter is used to prevent folding of high frequencies when 
+/// transposing the sample rate with interpolation.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2014-01-07 21:41:23 +0200 (Tue, 07 Jan 2014) $
+// File revision : $Revision: 4 $
+//
+// $Id: AAFilter.h 187 2014-01-07 19:41:23Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef AAFilter_H
+#define AAFilter_H
+
+#include "STTypes.h"
+#include "FIFOSampleBuffer.h"
+
+namespace soundtouch
+{
+
+class AAFilter
+{
+protected:
+    class FIRFilter *pFIR;
+
+    /// Low-pass filter cut-off frequency, negative = invalid
+    double cutoffFreq;
+
+    /// num of filter taps
+    uint length;
+
+    /// Calculate the FIR coefficients realizing the given cutoff-frequency
+    void calculateCoeffs();
+public:
+    AAFilter(uint length);
+
+    ~AAFilter();
+
+    /// Sets new anti-alias filter cut-off edge frequency, scaled to sampling 
+    /// frequency (nyquist frequency = 0.5). The filter will cut off the 
+    /// frequencies than that.
+    void setCutoffFreq(double newCutoffFreq);
+
+    /// Sets number of FIR filter taps, i.e. ~filter complexity
+    void setLength(uint newLength);
+
+    uint getLength() const;
+
+    /// Applies the filter to the given sequence of samples. 
+    /// Note : The amount of outputted samples is by value of 'filter length' 
+    /// smaller than the amount of input samples.
+    uint evaluate(SAMPLETYPE *dest, 
+                  const SAMPLETYPE *src, 
+                  uint numSamples, 
+                  uint numChannels) const;
+
+    /// Applies the filter to the given src & dest pipes, so that processed amount of
+    /// samples get removed from src, and produced amount added to dest 
+    /// Note : The amount of outputted samples is by value of 'filter length' 
+    /// smaller than the amount of input samples.
+    uint evaluate(FIFOSampleBuffer &dest, 
+                  FIFOSampleBuffer &src) const;
+
+};
+
+}
+
+#endif

src/FIFOSampleBuffer.cpp

@@ -0,0 +1,274 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// A buffer class for temporarily storaging sound samples, operates as a 
+/// first-in-first-out pipe.
+///
+/// Samples are added to the end of the sample buffer with the 'putSamples' 
+/// function, and are received from the beginning of the buffer by calling
+/// the 'receiveSamples' function. The class automatically removes the 
+/// outputted samples from the buffer, as well as grows the buffer size 
+/// whenever necessary.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2012-11-08 20:53:01 +0200 (Thu, 08 Nov 2012) $
+// File revision : $Revision: 4 $
+//
+// $Id: FIFOSampleBuffer.cpp 160 2012-11-08 18:53:01Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <stdlib.h>
+#include <memory.h>
+#include <string.h>
+#include <assert.h>
+
+#include "FIFOSampleBuffer.h"
+
+using namespace soundtouch;
+
+// Constructor
+FIFOSampleBuffer::FIFOSampleBuffer(int numChannels)
+{
+    assert(numChannels > 0);
+    sizeInBytes = 0; // reasonable initial value
+    buffer = NULL;
+    bufferUnaligned = NULL;
+    samplesInBuffer = 0;
+    bufferPos = 0;
+    channels = (uint)numChannels;
+    ensureCapacity(32);     // allocate initial capacity 
+}
+
+
+// destructor
+FIFOSampleBuffer::~FIFOSampleBuffer()
+{
+    delete[] bufferUnaligned;
+    bufferUnaligned = NULL;
+    buffer = NULL;
+}
+
+
+// Sets number of channels, 1 = mono, 2 = stereo
+void FIFOSampleBuffer::setChannels(int numChannels)
+{
+    uint usedBytes;
+
+    assert(numChannels > 0);
+    usedBytes = channels * samplesInBuffer;
+    channels = (uint)numChannels;
+    samplesInBuffer = usedBytes / channels;
+}
+
+
+// if output location pointer 'bufferPos' isn't zero, 'rewinds' the buffer and
+// zeroes this pointer by copying samples from the 'bufferPos' pointer 
+// location on to the beginning of the buffer.
+void FIFOSampleBuffer::rewind()
+{
+    if (buffer && bufferPos) 
+    {
+        memmove(buffer, ptrBegin(), sizeof(SAMPLETYPE) * channels * samplesInBuffer);
+        bufferPos = 0;
+    }
+}
+
+
+// Adds 'numSamples' pcs of samples from the 'samples' memory position to 
+// the sample buffer.
+void FIFOSampleBuffer::putSamples(const SAMPLETYPE *samples, uint nSamples)
+{
+    memcpy(ptrEnd(nSamples), samples, sizeof(SAMPLETYPE) * nSamples * channels);
+    samplesInBuffer += nSamples;
+}
+
+
+// Increases the number of samples in the buffer without copying any actual
+// samples.
+//
+// This function is used to update the number of samples in the sample buffer
+// when accessing the buffer directly with 'ptrEnd' function. Please be 
+// careful though!
+void FIFOSampleBuffer::putSamples(uint nSamples)
+{
+    uint req;
+
+    req = samplesInBuffer + nSamples;
+    ensureCapacity(req);
+    samplesInBuffer += nSamples;
+}
+
+
+// Returns a pointer to the end of the used part of the sample buffer (i.e. 
+// where the new samples are to be inserted). This function may be used for 
+// inserting new samples into the sample buffer directly. Please be careful! 
+//
+// Parameter 'slackCapacity' tells the function how much free capacity (in
+// terms of samples) there _at least_ should be, in order to the caller to
+// succesfully insert all the required samples to the buffer. When necessary, 
+// the function grows the buffer size to comply with this requirement.
+//
+// When using this function as means for inserting new samples, also remember 
+// to increase the sample count afterwards, by calling  the 
+// 'putSamples(numSamples)' function.
+SAMPLETYPE *FIFOSampleBuffer::ptrEnd(uint slackCapacity) 
+{
+    ensureCapacity(samplesInBuffer + slackCapacity);
+    return buffer + samplesInBuffer * channels;
+}
+
+
+// Returns a pointer to the beginning of the currently non-outputted samples. 
+// This function is provided for accessing the output samples directly. 
+// Please be careful!
+//
+// When using this function to output samples, also remember to 'remove' the
+// outputted samples from the buffer by calling the 
+// 'receiveSamples(numSamples)' function
+SAMPLETYPE *FIFOSampleBuffer::ptrBegin()
+{
+    assert(buffer);
+    return buffer + bufferPos * channels;
+}
+
+
+// Ensures that the buffer has enought capacity, i.e. space for _at least_
+// 'capacityRequirement' number of samples. The buffer is grown in steps of
+// 4 kilobytes to eliminate the need for frequently growing up the buffer,
+// as well as to round the buffer size up to the virtual memory page size.
+void FIFOSampleBuffer::ensureCapacity(uint capacityRequirement)
+{
+    SAMPLETYPE *tempUnaligned, *temp;
+
+    if (capacityRequirement > getCapacity()) 
+    {
+        // enlarge the buffer in 4kbyte steps (round up to next 4k boundary)
+        sizeInBytes = (capacityRequirement * channels * sizeof(SAMPLETYPE) + 4095) & (uint)-4096;
+        assert(sizeInBytes % 2 == 0);
+        tempUnaligned = new SAMPLETYPE[sizeInBytes / sizeof(SAMPLETYPE) + 16 / sizeof(SAMPLETYPE)];
+        if (tempUnaligned == NULL)
+        {
+            ST_THROW_RT_ERROR("Couldn't allocate memory!\n");
+        }
+        // Align the buffer to begin at 16byte cache line boundary for optimal performance
+        temp = (SAMPLETYPE *)SOUNDTOUCH_ALIGN_POINTER_16(tempUnaligned);
+        if (samplesInBuffer)
+        {
+            memcpy(temp, ptrBegin(), samplesInBuffer * channels * sizeof(SAMPLETYPE));
+        }
+        delete[] bufferUnaligned;
+        buffer = temp;
+        bufferUnaligned = tempUnaligned;
+        bufferPos = 0;
+    } 
+    else 
+    {
+        // simply rewind the buffer (if necessary)
+        rewind();
+    }
+}
+
+
+// Returns the current buffer capacity in terms of samples
+uint FIFOSampleBuffer::getCapacity() const
+{
+    return sizeInBytes / (channels * sizeof(SAMPLETYPE));
+}
+
+
+// Returns the number of samples currently in the buffer
+uint FIFOSampleBuffer::numSamples() const
+{
+    return samplesInBuffer;
+}
+
+
+// Output samples from beginning of the sample buffer. Copies demanded number
+// of samples to output and removes them from the sample buffer. If there
+// are less than 'numsample' samples in the buffer, returns all available.
+//
+// Returns number of samples copied.
+uint FIFOSampleBuffer::receiveSamples(SAMPLETYPE *output, uint maxSamples)
+{
+    uint num;
+
+    num = (maxSamples > samplesInBuffer) ? samplesInBuffer : maxSamples;
+
+    memcpy(output, ptrBegin(), channels * sizeof(SAMPLETYPE) * num);
+    return receiveSamples(num);
+}
+
+
+// Removes samples from the beginning of the sample buffer without copying them
+// anywhere. Used to reduce the number of samples in the buffer, when accessing
+// the sample buffer with the 'ptrBegin' function.
+uint FIFOSampleBuffer::receiveSamples(uint maxSamples)
+{
+    if (maxSamples >= samplesInBuffer)
+    {
+        uint temp;
+
+        temp = samplesInBuffer;
+        samplesInBuffer = 0;
+        return temp;
+    }
+
+    samplesInBuffer -= maxSamples;
+    bufferPos += maxSamples;
+
+    return maxSamples;
+}
+
+
+// Returns nonzero if the sample buffer is empty
+int FIFOSampleBuffer::isEmpty() const
+{
+    return (samplesInBuffer == 0) ? 1 : 0;
+}
+
+
+// Clears the sample buffer
+void FIFOSampleBuffer::clear()
+{
+    samplesInBuffer = 0;
+    bufferPos = 0;
+}
+
+
+/// allow trimming (downwards) amount of samples in pipeline.
+/// Returns adjusted amount of samples
+uint FIFOSampleBuffer::adjustAmountOfSamples(uint numSamples)
+{
+    if (numSamples < samplesInBuffer)
+    {
+        samplesInBuffer = numSamples;
+    }
+    return samplesInBuffer;
+}
+

src/FIRFilter.cpp

@@ -0,0 +1,328 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// General FIR digital filter routines with MMX optimization. 
+///
+/// Note : MMX optimized functions reside in a separate, platform-specific file, 
+/// e.g. 'mmx_win.cpp' or 'mmx_gcc.cpp'
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-02-21 23:24:29 +0200 (Sat, 21 Feb 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: FIRFilter.cpp 202 2015-02-21 21:24:29Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <memory.h>
+#include <assert.h>
+#include <math.h>
+#include <stdlib.h>
+#include "FIRFilter.h"
+#include "cpu_detect.h"
+
+using namespace soundtouch;
+
+/*****************************************************************************
+ *
+ * Implementation of the class 'FIRFilter'
+ *
+ *****************************************************************************/
+
+FIRFilter::FIRFilter()
+{
+    resultDivFactor = 0;
+    resultDivider = 0;
+    length = 0;
+    lengthDiv8 = 0;
+    filterCoeffs = NULL;
+}
+
+
+FIRFilter::~FIRFilter()
+{
+    delete[] filterCoeffs;
+}
+
+// Usual C-version of the filter routine for stereo sound
+uint FIRFilter::evaluateFilterStereo(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples) const
+{
+    int j, end;
+#ifdef SOUNDTOUCH_FLOAT_SAMPLES
+    // when using floating point samples, use a scaler instead of a divider
+    // because division is much slower operation than multiplying.
+    double dScaler = 1.0 / (double)resultDivider;
+#endif
+
+    assert(length != 0);
+    assert(src != NULL);
+    assert(dest != NULL);
+    assert(filterCoeffs != NULL);
+
+    end = 2 * (numSamples - length);
+
+    #pragma omp parallel for
+    for (j = 0; j < end; j += 2) 
+    {
+        const SAMPLETYPE *ptr;
+        LONG_SAMPLETYPE suml, sumr;
+        uint i;
+
+        suml = sumr = 0;
+        ptr = src + j;
+
+        for (i = 0; i < length; i += 4) 
+        {
+            // loop is unrolled by factor of 4 here for efficiency
+            suml += ptr[2 * i + 0] * filterCoeffs[i + 0] +
+                    ptr[2 * i + 2] * filterCoeffs[i + 1] +
+                    ptr[2 * i + 4] * filterCoeffs[i + 2] +
+                    ptr[2 * i + 6] * filterCoeffs[i + 3];
+            sumr += ptr[2 * i + 1] * filterCoeffs[i + 0] +
+                    ptr[2 * i + 3] * filterCoeffs[i + 1] +
+                    ptr[2 * i + 5] * filterCoeffs[i + 2] +
+                    ptr[2 * i + 7] * filterCoeffs[i + 3];
+        }
+
+#ifdef SOUNDTOUCH_INTEGER_SAMPLES
+        suml >>= resultDivFactor;
+        sumr >>= resultDivFactor;
+        // saturate to 16 bit integer limits
+        suml = (suml < -32768) ? -32768 : (suml > 32767) ? 32767 : suml;
+        // saturate to 16 bit integer limits
+        sumr = (sumr < -32768) ? -32768 : (sumr > 32767) ? 32767 : sumr;
+#else
+        suml *= dScaler;
+        sumr *= dScaler;
+#endif // SOUNDTOUCH_INTEGER_SAMPLES
+        dest[j] = (SAMPLETYPE)suml;
+        dest[j + 1] = (SAMPLETYPE)sumr;
+    }
+    return numSamples - length;
+}
+
+
+
+
+// Usual C-version of the filter routine for mono sound
+uint FIRFilter::evaluateFilterMono(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples) const
+{
+    int j, end;
+#ifdef SOUNDTOUCH_FLOAT_SAMPLES
+    // when using floating point samples, use a scaler instead of a divider
+    // because division is much slower operation than multiplying.
+    double dScaler = 1.0 / (double)resultDivider;
+#endif
+
+    assert(length != 0);
+
+    end = numSamples - length;
+    #pragma omp parallel for
+    for (j = 0; j < end; j ++) 
+    {
+        const SAMPLETYPE *pSrc = src + j;
+        LONG_SAMPLETYPE sum;
+        uint i;
+
+        sum = 0;
+        for (i = 0; i < length; i += 4) 
+        {
+            // loop is unrolled by factor of 4 here for efficiency
+            sum += pSrc[i + 0] * filterCoeffs[i + 0] + 
+                   pSrc[i + 1] * filterCoeffs[i + 1] + 
+                   pSrc[i + 2] * filterCoeffs[i + 2] + 
+                   pSrc[i + 3] * filterCoeffs[i + 3];
+        }
+#ifdef SOUNDTOUCH_INTEGER_SAMPLES
+        sum >>= resultDivFactor;
+        // saturate to 16 bit integer limits
+        sum = (sum < -32768) ? -32768 : (sum > 32767) ? 32767 : sum;
+#else
+        sum *= dScaler;
+#endif // SOUNDTOUCH_INTEGER_SAMPLES
+        dest[j] = (SAMPLETYPE)sum;
+    }
+    return end;
+}
+
+
+uint FIRFilter::evaluateFilterMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples, uint numChannels)
+{
+    int j, end;
+
+#ifdef SOUNDTOUCH_FLOAT_SAMPLES
+    // when using floating point samples, use a scaler instead of a divider
+    // because division is much slower operation than multiplying.
+    double dScaler = 1.0 / (double)resultDivider;
+#endif
+
+    assert(length != 0);
+    assert(src != NULL);
+    assert(dest != NULL);
+    assert(filterCoeffs != NULL);
+    assert(numChannels < 16);
+
+    end = numChannels * (numSamples - length);
+
+    #pragma omp parallel for
+    for (j = 0; j < end; j += numChannels)
+    {
+        const SAMPLETYPE *ptr;
+        LONG_SAMPLETYPE sums[16];
+        uint c, i;
+
+        for (c = 0; c < numChannels; c ++)
+        {
+            sums[c] = 0;
+        }
+
+        ptr = src + j;
+
+        for (i = 0; i < length; i ++)
+        {
+            SAMPLETYPE coef=filterCoeffs[i];
+            for (c = 0; c < numChannels; c ++)
+            {
+                sums[c] += ptr[0] * coef;
+                ptr ++;
+            }
+        }
+        
+        for (c = 0; c < numChannels; c ++)
+        {
+#ifdef SOUNDTOUCH_INTEGER_SAMPLES
+            sums[c] >>= resultDivFactor;
+#else
+            sums[c] *= dScaler;
+#endif // SOUNDTOUCH_INTEGER_SAMPLES
+            dest[j+c] = (SAMPLETYPE)sums[c];
+        }
+    }
+    return numSamples - length;
+}
+
+
+// Set filter coeffiecients and length.
+//
+// Throws an exception if filter length isn't divisible by 8
+void FIRFilter::setCoefficients(const SAMPLETYPE *coeffs, uint newLength, uint uResultDivFactor)
+{
+    assert(newLength > 0);
+    if (newLength % 8) ST_THROW_RT_ERROR("FIR filter length not divisible by 8");
+
+    lengthDiv8 = newLength / 8;
+    length = lengthDiv8 * 8;
+    assert(length == newLength);
+
+    resultDivFactor = uResultDivFactor;
+    resultDivider = (SAMPLETYPE)::pow(2.0, (int)resultDivFactor);
+
+    delete[] filterCoeffs;
+    filterCoeffs = new SAMPLETYPE[length];
+    memcpy(filterCoeffs, coeffs, length * sizeof(SAMPLETYPE));
+}
+
+
+uint FIRFilter::getLength() const
+{
+    return length;
+}
+
+
+
+// Applies the filter to the given sequence of samples. 
+//
+// Note : The amount of outputted samples is by value of 'filter_length' 
+// smaller than the amount of input samples.
+uint FIRFilter::evaluate(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples, uint numChannels) 
+{
+    assert(length > 0);
+    assert(lengthDiv8 * 8 == length);
+
+    if (numSamples < length) return 0;
+
+#ifndef USE_MULTICH_ALWAYS
+    if (numChannels == 1)
+    {
+        return evaluateFilterMono(dest, src, numSamples);
+    } 
+    else if (numChannels == 2)
+    {
+        return evaluateFilterStereo(dest, src, numSamples);
+    }
+    else
+#endif // USE_MULTICH_ALWAYS
+    {
+        assert(numChannels > 0);
+        return evaluateFilterMulti(dest, src, numSamples, numChannels);
+    }
+}
+
+
+
+// Operator 'new' is overloaded so that it automatically creates a suitable instance 
+// depending on if we've a MMX-capable CPU available or not.
+void * FIRFilter::operator new(size_t s)
+{
+    // Notice! don't use "new FIRFilter" directly, use "newInstance" to create a new instance instead!
+    ST_THROW_RT_ERROR("Error in FIRFilter::new: Don't use 'new FIRFilter', use 'newInstance' member instead!");
+    return newInstance();
+}
+
+
+FIRFilter * FIRFilter::newInstance()
+{
+    uint uExtensions;
+
+    uExtensions = detectCPUextensions();
+
+    // Check if MMX/SSE instruction set extensions supported by CPU
+
+#ifdef SOUNDTOUCH_ALLOW_MMX
+    // MMX routines available only with integer sample types
+    if (uExtensions & SUPPORT_MMX)
+    {
+        return ::new FIRFilterMMX;
+    }
+    else
+#endif // SOUNDTOUCH_ALLOW_MMX
+
+#ifdef SOUNDTOUCH_ALLOW_SSE
+    if (uExtensions & SUPPORT_SSE)
+    {
+        // SSE support
+        return ::new FIRFilterSSE;
+    }
+    else
+#endif // SOUNDTOUCH_ALLOW_SSE
+
+    {
+        // ISA optimizations not supported, use plain C version
+        return ::new FIRFilter;
+    }
+}

src/FIRFilter.h

@@ -0,0 +1,146 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// General FIR digital filter routines with MMX optimization. 
+///
+/// Note : MMX optimized functions reside in a separate, platform-specific file, 
+/// e.g. 'mmx_win.cpp' or 'mmx_gcc.cpp'
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-02-21 23:24:29 +0200 (Sat, 21 Feb 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: FIRFilter.h 202 2015-02-21 21:24:29Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef FIRFilter_H
+#define FIRFilter_H
+
+#include <stddef.h>
+#include "STTypes.h"
+
+namespace soundtouch
+{
+
+class FIRFilter 
+{
+protected:
+    // Number of FIR filter taps
+    uint length;    
+    // Number of FIR filter taps divided by 8
+    uint lengthDiv8;
+
+    // Result divider factor in 2^k format
+    uint resultDivFactor;
+
+    // Result divider value.
+    SAMPLETYPE resultDivider;
+
+    // Memory for filter coefficients
+    SAMPLETYPE *filterCoeffs;
+
+    virtual uint evaluateFilterStereo(SAMPLETYPE *dest, 
+                                      const SAMPLETYPE *src, 
+                                      uint numSamples) const;
+    virtual uint evaluateFilterMono(SAMPLETYPE *dest, 
+                                    const SAMPLETYPE *src, 
+                                    uint numSamples) const;
+    virtual uint evaluateFilterMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples, uint numChannels);
+
+public:
+    FIRFilter();
+    virtual ~FIRFilter();
+
+    /// Operator 'new' is overloaded so that it automatically creates a suitable instance 
+    /// depending on if we've a MMX-capable CPU available or not.
+    static void * operator new(size_t s);
+
+    static FIRFilter *newInstance();
+
+    /// Applies the filter to the given sequence of samples. 
+    /// Note : The amount of outputted samples is by value of 'filter_length' 
+    /// smaller than the amount of input samples.
+    ///
+    /// \return Number of samples copied to 'dest'.
+    uint evaluate(SAMPLETYPE *dest, 
+                  const SAMPLETYPE *src, 
+                  uint numSamples, 
+                  uint numChannels);
+
+    uint getLength() const;
+
+    virtual void setCoefficients(const SAMPLETYPE *coeffs, 
+                                 uint newLength, 
+                                 uint uResultDivFactor);
+};
+
+
+// Optional subclasses that implement CPU-specific optimizations:
+
+#ifdef SOUNDTOUCH_ALLOW_MMX
+
+/// Class that implements MMX optimized functions exclusive for 16bit integer samples type.
+    class FIRFilterMMX : public FIRFilter
+    {
+    protected:
+        short *filterCoeffsUnalign;
+        short *filterCoeffsAlign;
+
+        virtual uint evaluateFilterStereo(short *dest, const short *src, uint numSamples) const;
+    public:
+        FIRFilterMMX();
+        ~FIRFilterMMX();
+
+        virtual void setCoefficients(const short *coeffs, uint newLength, uint uResultDivFactor);
+    };
+
+#endif // SOUNDTOUCH_ALLOW_MMX
+
+
+#ifdef SOUNDTOUCH_ALLOW_SSE
+    /// Class that implements SSE optimized functions exclusive for floating point samples type.
+    class FIRFilterSSE : public FIRFilter
+    {
+    protected:
+        float *filterCoeffsUnalign;
+        float *filterCoeffsAlign;
+
+        virtual uint evaluateFilterStereo(float *dest, const float *src, uint numSamples) const;
+    public:
+        FIRFilterSSE();
+        ~FIRFilterSSE();
+
+        virtual void setCoefficients(const float *coeffs, uint newLength, uint uResultDivFactor);
+    };
+
+#endif // SOUNDTOUCH_ALLOW_SSE
+
+}
+
+#endif  // FIRFilter_H

src/InterpolateLinear.cpp

@@ -0,0 +1,300 @@
+////////////////////////////////////////////////////////////////////////////////
+/// 
+/// Linear interpolation algorithm.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// $Id: InterpolateLinear.cpp 225 2015-07-26 14:45:48Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <assert.h>
+#include <stdlib.h>
+#include "InterpolateLinear.h"
+
+using namespace soundtouch;
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// InterpolateLinearInteger - integer arithmetic implementation
+// 
+
+/// fixed-point interpolation routine precision
+#define SCALE    65536
+
+
+// Constructor
+InterpolateLinearInteger::InterpolateLinearInteger() : TransposerBase()
+{
+    // Notice: use local function calling syntax for sake of clarity, 
+    // to indicate the fact that C++ constructor can't call virtual functions.
+    resetRegisters();
+    setRate(1.0f);
+}
+
+
+void InterpolateLinearInteger::resetRegisters()
+{
+    iFract = 0;
+}
+
+
+// Transposes the sample rate of the given samples using linear interpolation. 
+// 'Mono' version of the routine. Returns the number of samples returned in 
+// the "dest" buffer
+int InterpolateLinearInteger::transposeMono(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)
+{
+    int i;
+    int srcSampleEnd = srcSamples - 1;
+    int srcCount = 0;
+
+    i = 0;
+    while (srcCount < srcSampleEnd)
+    {
+        LONG_SAMPLETYPE temp;
+    
+        assert(iFract < SCALE);
+
+        temp = (SCALE - iFract) * src[0] + iFract * src[1];
+        dest[i] = (SAMPLETYPE)(temp / SCALE);
+        i++;
+
+        iFract += iRate;
+
+        int iWhole = iFract / SCALE;
+        iFract -= iWhole * SCALE;
+        srcCount += iWhole;
+        src += iWhole;
+    }
+    srcSamples = srcCount;
+
+    return i;
+}
+
+
+// Transposes the sample rate of the given samples using linear interpolation. 
+// 'Stereo' version of the routine. Returns the number of samples returned in 
+// the "dest" buffer
+int InterpolateLinearInteger::transposeStereo(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)
+{
+    int i;
+    int srcSampleEnd = srcSamples - 1;
+    int srcCount = 0;
+
+    i = 0;
+    while (srcCount < srcSampleEnd)
+    {
+        LONG_SAMPLETYPE temp0;
+        LONG_SAMPLETYPE temp1;
+    
+        assert(iFract < SCALE);
+
+        temp0 = (SCALE - iFract) * src[0] + iFract * src[2];
+        temp1 = (SCALE - iFract) * src[1] + iFract * src[3];
+        dest[0] = (SAMPLETYPE)(temp0 / SCALE);
+        dest[1] = (SAMPLETYPE)(temp1 / SCALE);
+        dest += 2;
+        i++;
+
+        iFract += iRate;
+
+        int iWhole = iFract / SCALE;
+        iFract -= iWhole * SCALE;
+        srcCount += iWhole;
+        src += 2*iWhole;
+    }
+    srcSamples = srcCount;
+
+    return i;
+}
+
+
+int InterpolateLinearInteger::transposeMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)
+{
+    int i;
+    int srcSampleEnd = srcSamples - 1;
+    int srcCount = 0;
+
+    i = 0;
+    while (srcCount < srcSampleEnd)
+    {
+        LONG_SAMPLETYPE temp, vol1;
+    
+        assert(iFract < SCALE);
+        vol1 = (SCALE - iFract);
+        for (int c = 0; c < numChannels; c ++)
+        {
+            temp = vol1 * src[c] + iFract * src[c + numChannels];
+            dest[0] = (SAMPLETYPE)(temp / SCALE);
+            dest ++;
+        }
+        i++;
+
+        iFract += iRate;
+
+        int iWhole = iFract / SCALE;
+        iFract -= iWhole * SCALE;
+        srcCount += iWhole;
+        src += iWhole * numChannels;
+    }
+    srcSamples = srcCount;
+
+    return i;
+}
+
+
+// Sets new target iRate. Normal iRate = 1.0, smaller values represent slower 
+// iRate, larger faster iRates.
+void InterpolateLinearInteger::setRate(double newRate)
+{
+    iRate = (int)(newRate * SCALE + 0.5);
+    TransposerBase::setRate(newRate);
+}
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// InterpolateLinearFloat - floating point arithmetic implementation
+// 
+//////////////////////////////////////////////////////////////////////////////
+
+
+// Constructor
+InterpolateLinearFloat::InterpolateLinearFloat() : TransposerBase()
+{
+    // Notice: use local function calling syntax for sake of clarity, 
+    // to indicate the fact that C++ constructor can't call virtual functions.
+    resetRegisters();
+    setRate(1.0);
+}
+
+
+void InterpolateLinearFloat::resetRegisters()
+{
+    fract = 0;
+}
+
+
+// Transposes the sample rate of the given samples using linear interpolation. 
+// 'Mono' version of the routine. Returns the number of samples returned in 
+// the "dest" buffer
+int InterpolateLinearFloat::transposeMono(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)
+{
+    int i;
+    int srcSampleEnd = srcSamples - 1;
+    int srcCount = 0;
+
+    i = 0;
+    while (srcCount < srcSampleEnd)
+    {
+        double out;
+        assert(fract < 1.0);
+
+        out = (1.0 - fract) * src[0] + fract * src[1];
+        dest[i] = (SAMPLETYPE)out;
+        i ++;
+
+        // update position fraction
+        fract += rate;
+        // update whole positions
+        int whole = (int)fract;
+        fract -= whole;
+        src += whole;
+        srcCount += whole;
+    }
+    srcSamples = srcCount;
+    return i;
+}
+
+
+// Transposes the sample rate of the given samples using linear interpolation. 
+// 'Mono' version of the routine. Returns the number of samples returned in 
+// the "dest" buffer
+int InterpolateLinearFloat::transposeStereo(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)
+{
+    int i;
+    int srcSampleEnd = srcSamples - 1;
+    int srcCount = 0;
+
+    i = 0;
+    while (srcCount < srcSampleEnd)
+    {
+        double out0, out1;
+        assert(fract < 1.0);
+
+        out0 = (1.0 - fract) * src[0] + fract * src[2];
+        out1 = (1.0 - fract) * src[1] + fract * src[3];
+        dest[2*i]   = (SAMPLETYPE)out0;
+        dest[2*i+1] = (SAMPLETYPE)out1;
+        i ++;
+
+        // update position fraction
+        fract += rate;
+        // update whole positions
+        int whole = (int)fract;
+        fract -= whole;
+        src += 2*whole;
+        srcCount += whole;
+    }
+    srcSamples = srcCount;
+    return i;
+}
+
+
+int InterpolateLinearFloat::transposeMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)
+{
+    int i;
+    int srcSampleEnd = srcSamples - 1;
+    int srcCount = 0;
+
+    i = 0;
+    while (srcCount < srcSampleEnd)
+    {
+        float temp, vol1, fract_float;
+    
+        vol1 = (float)(1.0 - fract);
+		fract_float = (float)fract;
+        for (int c = 0; c < numChannels; c ++)
+        {
+			temp = vol1 * src[c] + fract_float * src[c + numChannels];
+            *dest = (SAMPLETYPE)temp;
+            dest ++;
+        }
+        i++;
+
+        fract += rate;
+
+        int iWhole = (int)fract;
+        fract -= iWhole;
+        srcCount += iWhole;
+        src += iWhole * numChannels;
+    }
+    srcSamples = srcCount;
+
+    return i;
+}

src/InterpolateLinear.h

@@ -0,0 +1,92 @@
+////////////////////////////////////////////////////////////////////////////////
+/// 
+/// Linear interpolation routine.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// $Id: InterpolateLinear.h 225 2015-07-26 14:45:48Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef _InterpolateLinear_H_
+#define _InterpolateLinear_H_
+
+#include "RateTransposer.h"
+#include "STTypes.h"
+
+namespace soundtouch
+{
+
+/// Linear transposer class that uses integer arithmetics
+class InterpolateLinearInteger : public TransposerBase
+{
+protected:
+    int iFract;
+    int iRate;
+
+    virtual void resetRegisters();
+
+    virtual int transposeMono(SAMPLETYPE *dest, 
+                       const SAMPLETYPE *src, 
+                       int &srcSamples);
+    virtual int transposeStereo(SAMPLETYPE *dest, 
+                         const SAMPLETYPE *src, 
+                         int &srcSamples);
+    virtual int transposeMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples);
+public:
+    InterpolateLinearInteger();
+
+    /// Sets new target rate. Normal rate = 1.0, smaller values represent slower 
+    /// rate, larger faster rates.
+    virtual void setRate(double newRate);
+};
+
+
+/// Linear transposer class that uses floating point arithmetics
+class InterpolateLinearFloat : public TransposerBase
+{
+protected:
+    double fract;
+
+    virtual void resetRegisters();
+
+    virtual int transposeMono(SAMPLETYPE *dest, 
+                       const SAMPLETYPE *src, 
+                       int &srcSamples);
+    virtual int transposeStereo(SAMPLETYPE *dest, 
+                         const SAMPLETYPE *src, 
+                         int &srcSamples);
+    virtual int transposeMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples);
+
+public:
+    InterpolateLinearFloat();
+};
+
+}
+
+#endif

src/RateTransposer.cpp

@@ -0,0 +1,300 @@
+////////////////////////////////////////////////////////////////////////////////
+/// 
+/// Sample rate transposer. Changes sample rate by using linear interpolation 
+/// together with anti-alias filtering (first order interpolation with anti-
+/// alias filtering should be quite adequate for this application)
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-07-26 17:45:48 +0300 (Sun, 26 Jul 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: RateTransposer.cpp 225 2015-07-26 14:45:48Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <memory.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "RateTransposer.h"
+#include "InterpolateLinear.h"
+#include "AAFilter.h"
+
+using namespace soundtouch;
+
+// Define default interpolation algorithm here
+TransposerBase::ALGORITHM TransposerBase::algorithm = TransposerBase::CUBIC;
+
+
+// Constructor
+RateTransposer::RateTransposer() : FIFOProcessor(&outputBuffer)
+{
+    bUseAAFilter = true;
+
+    // Instantiates the anti-alias filter
+    pAAFilter = new AAFilter(64);
+    pTransposer = TransposerBase::newInstance();
+}
+
+
+
+RateTransposer::~RateTransposer()
+{
+    delete pAAFilter;
+    delete pTransposer;
+}
+
+
+
+/// Enables/disables the anti-alias filter. Zero to disable, nonzero to enable
+void RateTransposer::enableAAFilter(bool newMode)
+{
+    bUseAAFilter = newMode;
+}
+
+
+/// Returns nonzero if anti-alias filter is enabled.
+bool RateTransposer::isAAFilterEnabled() const
+{
+    return bUseAAFilter;
+}
+
+
+AAFilter *RateTransposer::getAAFilter()
+{
+    return pAAFilter;
+}
+
+
+
+// Sets new target iRate. Normal iRate = 1.0, smaller values represent slower 
+// iRate, larger faster iRates.
+void RateTransposer::setRate(double newRate)
+{
+    double fCutoff;
+
+    pTransposer->setRate(newRate);
+
+    // design a new anti-alias filter
+    if (newRate > 1.0) 
+    {
+        fCutoff = 0.5 / newRate;
+    } 
+    else 
+    {
+        fCutoff = 0.5 * newRate;
+    }
+    pAAFilter->setCutoffFreq(fCutoff);
+}
+
+
+// Adds 'nSamples' pcs of samples from the 'samples' memory position into
+// the input of the object.
+void RateTransposer::putSamples(const SAMPLETYPE *samples, uint nSamples)
+{
+    processSamples(samples, nSamples);
+}
+
+
+// Transposes sample rate by applying anti-alias filter to prevent folding. 
+// Returns amount of samples returned in the "dest" buffer.
+// The maximum amount of samples that can be returned at a time is set by
+// the 'set_returnBuffer_size' function.
+void RateTransposer::processSamples(const SAMPLETYPE *src, uint nSamples)
+{
+    uint count;
+
+    if (nSamples == 0) return;
+
+    // Store samples to input buffer
+    inputBuffer.putSamples(src, nSamples);
+
+    // If anti-alias filter is turned off, simply transpose without applying
+    // the filter
+    if (bUseAAFilter == false) 
+    {
+        count = pTransposer->transpose(outputBuffer, inputBuffer);
+        return;
+    }
+
+    assert(pAAFilter);
+
+    // Transpose with anti-alias filter
+    if (pTransposer->rate < 1.0f) 
+    {
+        // If the parameter 'Rate' value is smaller than 1, first transpose
+        // the samples and then apply the anti-alias filter to remove aliasing.
+
+        // Transpose the samples, store the result to end of "midBuffer"
+        pTransposer->transpose(midBuffer, inputBuffer);
+
+        // Apply the anti-alias filter for transposed samples in midBuffer
+        pAAFilter->evaluate(outputBuffer, midBuffer);
+    } 
+    else  
+    {
+        // If the parameter 'Rate' value is larger than 1, first apply the
+        // anti-alias filter to remove high frequencies (prevent them from folding
+        // over the lover frequencies), then transpose.
+
+        // Apply the anti-alias filter for samples in inputBuffer
+        pAAFilter->evaluate(midBuffer, inputBuffer);
+
+        // Transpose the AA-filtered samples in "midBuffer"
+        pTransposer->transpose(outputBuffer, midBuffer);
+    }
+}
+
+
+// Sets the number of channels, 1 = mono, 2 = stereo
+void RateTransposer::setChannels(int nChannels)
+{
+    assert(nChannels > 0);
+
+    if (pTransposer->numChannels == nChannels) return;
+    pTransposer->setChannels(nChannels);
+
+    inputBuffer.setChannels(nChannels);
+    midBuffer.setChannels(nChannels);
+    outputBuffer.setChannels(nChannels);
+}
+
+
+// Clears all the samples in the object
+void RateTransposer::clear()
+{
+    outputBuffer.clear();
+    midBuffer.clear();
+    inputBuffer.clear();
+}
+
+
+// Returns nonzero if there aren't any samples available for outputting.
+int RateTransposer::isEmpty() const
+{
+    int res;
+
+    res = FIFOProcessor::isEmpty();
+    if (res == 0) return 0;
+    return inputBuffer.isEmpty();
+}
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// TransposerBase - Base class for interpolation
+// 
+
+// static function to set interpolation algorithm
+void TransposerBase::setAlgorithm(TransposerBase::ALGORITHM a)
+{
+    TransposerBase::algorithm = a;
+}
+
+
+// Transposes the sample rate of the given samples using linear interpolation. 
+// Returns the number of samples returned in the "dest" buffer
+int TransposerBase::transpose(FIFOSampleBuffer &dest, FIFOSampleBuffer &src)
+{
+    int numSrcSamples = src.numSamples();
+    int sizeDemand = (int)((double)numSrcSamples / rate) + 8;
+    int numOutput;
+    SAMPLETYPE *psrc = src.ptrBegin();
+    SAMPLETYPE *pdest = dest.ptrEnd(sizeDemand);
+
+#ifndef USE_MULTICH_ALWAYS
+    if (numChannels == 1)
+    {
+        numOutput = transposeMono(pdest, psrc, numSrcSamples);
+    }
+    else if (numChannels == 2) 
+    {
+        numOutput = transposeStereo(pdest, psrc, numSrcSamples);
+    } 
+    else 
+#endif // USE_MULTICH_ALWAYS
+    {
+        assert(numChannels > 0);
+        numOutput = transposeMulti(pdest, psrc, numSrcSamples);
+    }
+    dest.putSamples(numOutput);
+    src.receiveSamples(numSrcSamples);
+    return numOutput;
+}
+
+
+TransposerBase::TransposerBase()
+{
+    numChannels = 0;
+    rate = 1.0f;
+}
+
+
+TransposerBase::~TransposerBase()
+{
+}
+
+
+void TransposerBase::setChannels(int channels)
+{
+    numChannels = channels;
+    resetRegisters();
+}
+
+
+void TransposerBase::setRate(double newRate)
+{
+    rate = newRate;
+}
+
+
+// static factory function
+TransposerBase *TransposerBase::newInstance()
+{
+#ifdef SOUNDTOUCH_INTEGER_SAMPLES
+    // Notice: For integer arithmetics support only linear algorithm (due to simplest calculus)
+    return ::new InterpolateLinearInteger;
+#else
+    switch (algorithm)
+    {
+        case LINEAR:
+            return new InterpolateLinearFloat;
+
+        case CUBIC:
+            return new InterpolateCubic;
+
+        case SHANNON:
+            return new InterpolateShannon;
+
+        default:
+            assert(false);
+            return NULL;
+    }
+#endif
+}

src/RateTransposer.h

@@ -0,0 +1,179 @@
+////////////////////////////////////////////////////////////////////////////////
+/// 
+/// Sample rate transposer. Changes sample rate by using linear interpolation 
+/// together with anti-alias filtering (first order interpolation with anti-
+/// alias filtering should be quite adequate for this application).
+///
+/// Use either of the derived classes of 'RateTransposerInteger' or 
+/// 'RateTransposerFloat' for corresponding integer/floating point tranposing
+/// algorithm implementation.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-07-26 17:45:48 +0300 (Sun, 26 Jul 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: RateTransposer.h 225 2015-07-26 14:45:48Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef RateTransposer_H
+#define RateTransposer_H
+
+#include <stddef.h>
+#include "AAFilter.h"
+#include "FIFOSamplePipe.h"
+#include "FIFOSampleBuffer.h"
+
+#include "STTypes.h"
+
+namespace soundtouch
+{
+
+/// Abstract base class for transposer implementations (linear, advanced vs integer, float etc)
+class TransposerBase
+{
+public:
+        enum ALGORITHM {
+        LINEAR = 0,
+        CUBIC,
+        SHANNON
+    };
+
+protected:
+    virtual void resetRegisters() = 0;
+
+    virtual int transposeMono(SAMPLETYPE *dest, 
+                        const SAMPLETYPE *src, 
+                        int &srcSamples)  = 0;
+    virtual int transposeStereo(SAMPLETYPE *dest, 
+                        const SAMPLETYPE *src, 
+                        int &srcSamples) = 0;
+    virtual int transposeMulti(SAMPLETYPE *dest, 
+                        const SAMPLETYPE *src, 
+                        int &srcSamples) = 0;
+
+    static ALGORITHM algorithm;
+
+public:
+    double rate;
+    int numChannels;
+
+    TransposerBase();
+    virtual ~TransposerBase();
+
+    virtual int transpose(FIFOSampleBuffer &dest, FIFOSampleBuffer &src);
+    virtual void setRate(double newRate);
+    virtual void setChannels(int channels);
+
+    // static factory function
+    static TransposerBase *newInstance();
+
+    // static function to set interpolation algorithm
+    static void setAlgorithm(ALGORITHM a);
+};
+
+
+/// A common linear samplerate transposer class.
+///
+class RateTransposer : public FIFOProcessor
+{
+protected:
+    /// Anti-alias filter object
+    AAFilter *pAAFilter;
+    TransposerBase *pTransposer;
+
+    /// Buffer for collecting samples to feed the anti-alias filter between
+    /// two batches
+    FIFOSampleBuffer inputBuffer;
+
+    /// Buffer for keeping samples between transposing & anti-alias filter
+    FIFOSampleBuffer midBuffer;
+
+    /// Output sample buffer
+    FIFOSampleBuffer outputBuffer;
+
+    bool bUseAAFilter;
+
+
+    /// Transposes sample rate by applying anti-alias filter to prevent folding. 
+    /// Returns amount of samples returned in the "dest" buffer.
+    /// The maximum amount of samples that can be returned at a time is set by
+    /// the 'set_returnBuffer_size' function.
+    void processSamples(const SAMPLETYPE *src, 
+                        uint numSamples);
+
+public:
+    RateTransposer();
+    virtual ~RateTransposer();
+
+    /// Operator 'new' is overloaded so that it automatically creates a suitable instance 
+    /// depending on if we're to use integer or floating point arithmetics.
+//    static void *operator new(size_t s);
+
+    /// Use this function instead of "new" operator to create a new instance of this class. 
+    /// This function automatically chooses a correct implementation, depending on if 
+    /// integer ot floating point arithmetics are to be used.
+//    static RateTransposer *newInstance();
+
+    /// Returns the output buffer object
+    FIFOSamplePipe *getOutput() { return &outputBuffer; };
+
+    /// Returns the store buffer object
+//    FIFOSamplePipe *getStore() { return &storeBuffer; };
+
+    /// Return anti-alias filter object
+    AAFilter *getAAFilter();
+
+    /// Enables/disables the anti-alias filter. Zero to disable, nonzero to enable
+    void enableAAFilter(bool newMode);
+
+    /// Returns nonzero if anti-alias filter is enabled.
+    bool isAAFilterEnabled() const;
+
+    /// Sets new target rate. Normal rate = 1.0, smaller values represent slower 
+    /// rate, larger faster rates.
+    virtual void setRate(double newRate);
+
+    /// Sets the number of channels, 1 = mono, 2 = stereo
+    void setChannels(int channels);
+
+    /// Adds 'numSamples' pcs of samples from the 'samples' memory position into
+    /// the input of the object.
+    void putSamples(const SAMPLETYPE *samples, uint numSamples);
+
+    /// Clears all the samples in the object
+    void clear();
+
+    /// Returns nonzero if there aren't any samples available for outputting.
+    int isEmpty() const;
+};
+
+}
+
+#endif

src/SoundTouch.cpp

@@ -0,0 +1,526 @@
+//////////////////////////////////////////////////////////////////////////////
+///
+/// SoundTouch - main class for tempo/pitch/rate adjusting routines. 
+///
+/// Notes:
+/// - Initialize the SoundTouch object instance by setting up the sound stream 
+///   parameters with functions 'setSampleRate' and 'setChannels', then set 
+///   desired tempo/pitch/rate settings with the corresponding functions.
+///
+/// - The SoundTouch class behaves like a first-in-first-out pipeline: The 
+///   samples that are to be processed are fed into one of the pipe by calling
+///   function 'putSamples', while the ready processed samples can be read 
+///   from the other end of the pipeline with function 'receiveSamples'.
+/// 
+/// - The SoundTouch processing classes require certain sized 'batches' of 
+///   samples in order to process the sound. For this reason the classes buffer 
+///   incoming samples until there are enough of samples available for 
+///   processing, then they carry out the processing step and consequently
+///   make the processed samples available for outputting.
+/// 
+/// - For the above reason, the processing routines introduce a certain 
+///   'latency' between the input and output, so that the samples input to
+///   SoundTouch may not be immediately available in the output, and neither 
+///   the amount of outputtable samples may not immediately be in direct 
+///   relationship with the amount of previously input samples.
+///
+/// - The tempo/pitch/rate control parameters can be altered during processing.
+///   Please notice though that they aren't currently protected by semaphores,
+///   so in multi-thread application external semaphore protection may be
+///   required.
+///
+/// - This class utilizes classes 'TDStretch' for tempo change (without modifying
+///   pitch) and 'RateTransposer' for changing the playback rate (that is, both 
+///   tempo and pitch in the same ratio) of the sound. The third available control 
+///   'pitch' (change pitch but maintain tempo) is produced by a combination of
+///   combining the two other controls.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-07-26 17:45:48 +0300 (Sun, 26 Jul 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: SoundTouch.cpp 225 2015-07-26 14:45:48Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <assert.h>
+#include <stdlib.h>
+#include <memory.h>
+#include <math.h>
+#include <stdio.h>
+
+#include "SoundTouch.h"
+#include "TDStretch.h"
+#include "RateTransposer.h"
+#include "cpu_detect.h"
+
+using namespace soundtouch;
+    
+/// test if two floating point numbers are equal
+#define TEST_FLOAT_EQUAL(a, b)  (fabs(a - b) < 1e-10)
+
+
+/// Print library version string for autoconf
+extern "C" void soundtouch_ac_test()
+{
+    printf("SoundTouch Version: %s\n",SOUNDTOUCH_VERSION);
+} 
+
+
+SoundTouch::SoundTouch()
+{
+    // Initialize rate transposer and tempo changer instances
+
+    pRateTransposer = new RateTransposer();
+    pTDStretch = TDStretch::newInstance();
+
+    setOutPipe(pTDStretch);
+
+    rate = tempo = 0;
+
+    virtualPitch = 
+    virtualRate = 
+    virtualTempo = 1.0;
+
+    calcEffectiveRateAndTempo();
+
+	samplesExpectedOut = 0;
+	samplesOutput = 0;
+
+    channels = 0;
+    bSrateSet = false;
+}
+
+
+
+SoundTouch::~SoundTouch()
+{
+    delete pRateTransposer;
+    delete pTDStretch;
+}
+
+
+
+/// Get SoundTouch library version string
+const char *SoundTouch::getVersionString()
+{
+    static const char *_version = SOUNDTOUCH_VERSION;
+
+    return _version;
+}
+
+
+/// Get SoundTouch library version Id
+uint SoundTouch::getVersionId()
+{
+    return SOUNDTOUCH_VERSION_ID;
+}
+
+
+// Sets the number of channels, 1 = mono, 2 = stereo
+void SoundTouch::setChannels(uint numChannels)
+{
+    /*if (numChannels != 1 && numChannels != 2) 
+    {
+        //ST_THROW_RT_ERROR("Illegal number of channels");
+		return;
+    }*/
+    channels = numChannels;
+    pRateTransposer->setChannels((int)numChannels);
+    pTDStretch->setChannels((int)numChannels);
+}
+
+
+
+// Sets new rate control value. Normal rate = 1.0, smaller values
+// represent slower rate, larger faster rates.
+void SoundTouch::setRate(double newRate)
+{
+    virtualRate = newRate;
+    calcEffectiveRateAndTempo();
+}
+
+
+
+// Sets new rate control value as a difference in percents compared
+// to the original rate (-50 .. +100 %)
+void SoundTouch::setRateChange(double newRate)
+{
+    virtualRate = 1.0 + 0.01 * newRate;
+    calcEffectiveRateAndTempo();
+}
+
+
+
+// Sets new tempo control value. Normal tempo = 1.0, smaller values
+// represent slower tempo, larger faster tempo.
+void SoundTouch::setTempo(double newTempo)
+{
+    virtualTempo = newTempo;
+    calcEffectiveRateAndTempo();
+}
+
+
+
+// Sets new tempo control value as a difference in percents compared
+// to the original tempo (-50 .. +100 %)
+void SoundTouch::setTempoChange(double newTempo)
+{
+    virtualTempo = 1.0 + 0.01 * newTempo;
+    calcEffectiveRateAndTempo();
+}
+
+
+
+// Sets new pitch control value. Original pitch = 1.0, smaller values
+// represent lower pitches, larger values higher pitch.
+void SoundTouch::setPitch(double newPitch)
+{
+    virtualPitch = newPitch;
+    calcEffectiveRateAndTempo();
+}
+
+
+
+// Sets pitch change in octaves compared to the original pitch
+// (-1.00 .. +1.00)
+void SoundTouch::setPitchOctaves(double newPitch)
+{
+    virtualPitch = exp(0.69314718056 * newPitch);
+    calcEffectiveRateAndTempo();
+}
+
+
+
+// Sets pitch change in semi-tones compared to the original pitch
+// (-12 .. +12)
+void SoundTouch::setPitchSemiTones(int newPitch)
+{
+    setPitchOctaves((double)newPitch / 12.0);
+}
+
+
+
+void SoundTouch::setPitchSemiTones(double newPitch)
+{
+    setPitchOctaves(newPitch / 12.0);
+}
+
+
+// Calculates 'effective' rate and tempo values from the
+// nominal control values.
+void SoundTouch::calcEffectiveRateAndTempo()
+{
+    double oldTempo = tempo;
+    double oldRate = rate;
+
+	tempo = virtualTempo / virtualPitch;
+	rate = virtualPitch * virtualRate;
+
+    if (!TEST_FLOAT_EQUAL(rate,oldRate)) pRateTransposer->setRate(rate);
+	if (!TEST_FLOAT_EQUAL(tempo, oldTempo)) pTDStretch->setTempo(tempo);
+
+#ifndef SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER
+    if (rate <= 1.0f) 
+    {
+        if (output != pTDStretch) 
+        {
+            FIFOSamplePipe *tempoOut;
+
+            assert(output == pRateTransposer);
+            // move samples in the current output buffer to the output of pTDStretch
+            tempoOut = pTDStretch->getOutput();
+            tempoOut->moveSamples(*output);
+            // move samples in pitch transposer's store buffer to tempo changer's input
+            // deprecated : pTDStretch->moveSamples(*pRateTransposer->getStore());
+
+            output = pTDStretch;
+        }
+    }
+    else
+#endif
+    {
+        if (output != pRateTransposer) 
+        {
+            FIFOSamplePipe *transOut;
+
+            assert(output == pTDStretch);
+            // move samples in the current output buffer to the output of pRateTransposer
+            transOut = pRateTransposer->getOutput();
+            transOut->moveSamples(*output);
+            // move samples in tempo changer's input to pitch transposer's input
+            pRateTransposer->moveSamples(*pTDStretch->getInput());
+
+            output = pRateTransposer;
+        }
+    } 
+}
+
+
+// Sets sample rate.
+void SoundTouch::setSampleRate(uint srate)
+{
+    bSrateSet = true;
+    // set sample rate, leave other tempo changer parameters as they are.
+    pTDStretch->setParameters((int)srate);
+}
+
+
+// Adds 'numSamples' pcs of samples from the 'samples' memory position into
+// the input of the object.
+void SoundTouch::putSamples(const SAMPLETYPE *samples, uint nSamples)
+{
+    if (bSrateSet == false) 
+    {
+        ST_THROW_RT_ERROR("SoundTouch : Sample rate not defined");
+    } 
+    else if (channels == 0) 
+    {
+        ST_THROW_RT_ERROR("SoundTouch : Number of channels not defined");
+    }
+
+    // Transpose the rate of the new samples if necessary
+    /* Bypass the nominal setting - can introduce a click in sound when tempo/pitch control crosses the nominal value...
+    if (rate == 1.0f) 
+    {
+        // The rate value is same as the original, simply evaluate the tempo changer. 
+        assert(output == pTDStretch);
+        if (pRateTransposer->isEmpty() == 0) 
+        {
+            // yet flush the last samples in the pitch transposer buffer
+            // (may happen if 'rate' changes from a non-zero value to zero)
+            pTDStretch->moveSamples(*pRateTransposer);
+        }
+        pTDStretch->putSamples(samples, nSamples);
+    } 
+    */
+
+	// accumulate how many samples are expected out from processing, given the current 
+	// processing setting
+	samplesExpectedOut += (double)nSamples / ((double)rate * (double)tempo);
+
+#ifndef SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER
+    if (rate <= 1.0f) 
+    {
+        // transpose the rate down, output the transposed sound to tempo changer buffer
+        assert(output == pTDStretch);
+        pRateTransposer->putSamples(samples, nSamples);
+        pTDStretch->moveSamples(*pRateTransposer);
+    } 
+    else 
+#endif
+    {
+        // evaluate the tempo changer, then transpose the rate up, 
+        assert(output == pRateTransposer);
+        pTDStretch->putSamples(samples, nSamples);
+        pRateTransposer->moveSamples(*pTDStretch);
+    }
+}
+
+
+// Flushes the last samples from the processing pipeline to the output.
+// Clears also the internal processing buffers.
+//
+// Note: This function is meant for extracting the last samples of a sound
+// stream. This function may introduce additional blank samples in the end
+// of the sound stream, and thus it's not recommended to call this function
+// in the middle of a sound stream.
+void SoundTouch::flush()
+{
+    int i;
+	int numStillExpected;
+    SAMPLETYPE *buff = new SAMPLETYPE[128 * channels];
+
+	// how many samples are still expected to output
+	numStillExpected = (int)((long)(samplesExpectedOut + 0.5) - samplesOutput);
+
+    memset(buff, 0, 128 * channels * sizeof(SAMPLETYPE));
+    // "Push" the last active samples out from the processing pipeline by
+    // feeding blank samples into the processing pipeline until new, 
+    // processed samples appear in the output (not however, more than 
+    // 24ksamples in any case)
+	for (i = 0; (numStillExpected > (int)numSamples()) && (i < 200); i ++)
+	{
+		putSamples(buff, 128);
+	}
+
+	adjustAmountOfSamples(numStillExpected);
+
+    delete[] buff;
+
+    // Clear input buffers
+ //   pRateTransposer->clearInput();
+    pTDStretch->clearInput();
+    // yet leave the output intouched as that's where the
+    // flushed samples are!
+}
+
+
+// Changes a setting controlling the processing system behaviour. See the
+// 'SETTING_...' defines for available setting ID's.
+bool SoundTouch::setSetting(int settingId, int value)
+{
+    int sampleRate, sequenceMs, seekWindowMs, overlapMs;
+
+    // read current tdstretch routine parameters
+    pTDStretch->getParameters(&sampleRate, &sequenceMs, &seekWindowMs, &overlapMs);
+
+    switch (settingId) 
+    {
+        case SETTING_USE_AA_FILTER :
+            // enables / disabless anti-alias filter
+            pRateTransposer->enableAAFilter((value != 0) ? true : false);
+            return true;
+
+        case SETTING_AA_FILTER_LENGTH :
+            // sets anti-alias filter length
+            pRateTransposer->getAAFilter()->setLength(value);
+            return true;
+
+        case SETTING_USE_QUICKSEEK :
+            // enables / disables tempo routine quick seeking algorithm
+            pTDStretch->enableQuickSeek((value != 0) ? true : false);
+            return true;
+
+        case SETTING_SEQUENCE_MS:
+            // change time-stretch sequence duration parameter
+            pTDStretch->setParameters(sampleRate, value, seekWindowMs, overlapMs);
+            return true;
+
+        case SETTING_SEEKWINDOW_MS:
+            // change time-stretch seek window length parameter
+            pTDStretch->setParameters(sampleRate, sequenceMs, value, overlapMs);
+            return true;
+
+        case SETTING_OVERLAP_MS:
+            // change time-stretch overlap length parameter
+            pTDStretch->setParameters(sampleRate, sequenceMs, seekWindowMs, value);
+            return true;
+
+        default :
+            return false;
+    }
+}
+
+
+// Reads a setting controlling the processing system behaviour. See the
+// 'SETTING_...' defines for available setting ID's.
+//
+// Returns the setting value.
+int SoundTouch::getSetting(int settingId) const
+{
+    int temp;
+
+    switch (settingId) 
+    {
+        case SETTING_USE_AA_FILTER :
+            return (uint)pRateTransposer->isAAFilterEnabled();
+
+        case SETTING_AA_FILTER_LENGTH :
+            return pRateTransposer->getAAFilter()->getLength();
+
+        case SETTING_USE_QUICKSEEK :
+            return (uint)   pTDStretch->isQuickSeekEnabled();
+
+        case SETTING_SEQUENCE_MS:
+            pTDStretch->getParameters(NULL, &temp, NULL, NULL);
+            return temp;
+
+        case SETTING_SEEKWINDOW_MS:
+            pTDStretch->getParameters(NULL, NULL, &temp, NULL);
+            return temp;
+
+        case SETTING_OVERLAP_MS:
+            pTDStretch->getParameters(NULL, NULL, NULL, &temp);
+            return temp;
+
+		case SETTING_NOMINAL_INPUT_SEQUENCE :
+			return pTDStretch->getInputSampleReq();
+
+		case SETTING_NOMINAL_OUTPUT_SEQUENCE :
+			return pTDStretch->getOutputBatchSize();
+
+		default :
+            return 0;
+    }
+}
+
+
+// Clears all the samples in the object's output and internal processing
+// buffers.
+void SoundTouch::clear()
+{
+	samplesExpectedOut = 0;
+    pRateTransposer->clear();
+    pTDStretch->clear();
+}
+
+
+
+/// Returns number of samples currently unprocessed.
+uint SoundTouch::numUnprocessedSamples() const
+{
+    FIFOSamplePipe * psp;
+    if (pTDStretch)
+    {
+        psp = pTDStretch->getInput();
+        if (psp)
+        {
+            return psp->numSamples();
+        }
+    }
+    return 0;
+}
+
+
+
+/// Output samples from beginning of the sample buffer. Copies requested samples to 
+/// output buffer and removes them from the sample buffer. If there are less than 
+/// 'numsample' samples in the buffer, returns all that available.
+///
+/// \return Number of samples returned.
+uint SoundTouch::receiveSamples(SAMPLETYPE *output, uint maxSamples)
+{
+	uint ret = FIFOProcessor::receiveSamples(output, maxSamples);
+	samplesOutput += (long)ret;
+	return ret;
+}
+
+
+/// Adjusts book-keeping so that given number of samples are removed from beginning of the 
+/// sample buffer without copying them anywhere. 
+///
+/// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
+/// with 'ptrBegin' function.
+uint SoundTouch::receiveSamples(uint maxSamples)
+{
+	uint ret = FIFOProcessor::receiveSamples(maxSamples);
+	samplesOutput += (long)ret;
+	return ret;
+}

src/TDStretch.h

@@ -0,0 +1,281 @@
+////////////////////////////////////////////////////////////////////////////////
+/// 
+/// Sampled sound tempo changer/time stretch algorithm. Changes the sound tempo 
+/// while maintaining the original pitch by using a time domain WSOLA-like method 
+/// with several performance-increasing tweaks.
+///
+/// Note : MMX/SSE optimized functions reside in separate, platform-specific files 
+/// 'mmx_optimized.cpp' and 'sse_optimized.cpp'
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2015-08-09 00:00:15 +0300 (Sun, 09 Aug 2015) $
+// File revision : $Revision: 4 $
+//
+// $Id: TDStretch.h 226 2015-08-08 21:00:15Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef TDStretch_H
+#define TDStretch_H
+
+#include <stddef.h>
+#include "STTypes.h"
+#include "RateTransposer.h"
+#include "FIFOSamplePipe.h"
+
+namespace soundtouch
+{
+
+/// Default values for sound processing parameters:
+/// Notice that the default parameters are tuned for contemporary popular music 
+/// processing. For speech processing applications these parameters suit better:
+///     #define DEFAULT_SEQUENCE_MS     40
+///     #define DEFAULT_SEEKWINDOW_MS   15
+///     #define DEFAULT_OVERLAP_MS      8
+///
+
+/// Default length of a single processing sequence, in milliseconds. This determines to how 
+/// long sequences the original sound is chopped in the time-stretch algorithm.
+///
+/// The larger this value is, the lesser sequences are used in processing. In principle
+/// a bigger value sounds better when slowing down tempo, but worse when increasing tempo
+/// and vice versa.
+///
+/// Increasing this value reduces computational burden & vice versa.
+//#define DEFAULT_SEQUENCE_MS         40
+#define DEFAULT_SEQUENCE_MS         USE_AUTO_SEQUENCE_LEN
+
+/// Giving this value for the sequence length sets automatic parameter value
+/// according to tempo setting (recommended)
+#define USE_AUTO_SEQUENCE_LEN       0
+
+/// Seeking window default length in milliseconds for algorithm that finds the best possible 
+/// overlapping location. This determines from how wide window the algorithm may look for an 
+/// optimal joining location when mixing the sound sequences back together. 
+///
+/// The bigger this window setting is, the higher the possibility to find a better mixing
+/// position will become, but at the same time large values may cause a "drifting" artifact
+/// because consequent sequences will be taken at more uneven intervals.
+///
+/// If there's a disturbing artifact that sounds as if a constant frequency was drifting 
+/// around, try reducing this setting.
+///
+/// Increasing this value increases computational burden & vice versa.
+//#define DEFAULT_SEEKWINDOW_MS       15
+#define DEFAULT_SEEKWINDOW_MS       USE_AUTO_SEEKWINDOW_LEN
+
+/// Giving this value for the seek window length sets automatic parameter value
+/// according to tempo setting (recommended)
+#define USE_AUTO_SEEKWINDOW_LEN     0
+
+/// Overlap length in milliseconds. When the chopped sound sequences are mixed back together, 
+/// to form a continuous sound stream, this parameter defines over how long period the two 
+/// consecutive sequences are let to overlap each other. 
+///
+/// This shouldn't be that critical parameter. If you reduce the DEFAULT_SEQUENCE_MS setting 
+/// by a large amount, you might wish to try a smaller value on this.
+///
+/// Increasing this value increases computational burden & vice versa.
+#define DEFAULT_OVERLAP_MS      8
+
+
+/// Class that does the time-stretch (tempo change) effect for the processed
+/// sound.
+class TDStretch : public FIFOProcessor
+{
+protected:
+    int channels;
+    int sampleReq;
+
+    int overlapLength;
+    int seekLength;
+    int seekWindowLength;
+    int overlapDividerBitsNorm;
+    int overlapDividerBitsPure;
+    int slopingDivider;
+    int sampleRate;
+    int sequenceMs;
+    int seekWindowMs;
+    int overlapMs;
+
+    unsigned long maxnorm;
+    float maxnormf;
+
+    double tempo;
+    double nominalSkip;
+    double skipFract;
+
+    bool bQuickSeek;
+    bool bAutoSeqSetting;
+    bool bAutoSeekSetting;
+
+    SAMPLETYPE *pMidBuffer;
+    SAMPLETYPE *pMidBufferUnaligned;
+
+    FIFOSampleBuffer outputBuffer;
+    FIFOSampleBuffer inputBuffer;
+
+    void acceptNewOverlapLength(int newOverlapLength);
+
+    virtual void clearCrossCorrState();
+    void calculateOverlapLength(int overlapMs);
+
+    virtual double calcCrossCorr(const SAMPLETYPE *mixingPos, const SAMPLETYPE *compare, double &norm);
+    virtual double calcCrossCorrAccumulate(const SAMPLETYPE *mixingPos, const SAMPLETYPE *compare, double &norm);
+
+    virtual int seekBestOverlapPositionFull(const SAMPLETYPE *refPos);
+    virtual int seekBestOverlapPositionQuick(const SAMPLETYPE *refPos);
+    virtual int seekBestOverlapPosition(const SAMPLETYPE *refPos);
+
+    virtual void overlapStereo(SAMPLETYPE *output, const SAMPLETYPE *input) const;
+    virtual void overlapMono(SAMPLETYPE *output, const SAMPLETYPE *input) const;
+    virtual void overlapMulti(SAMPLETYPE *output, const SAMPLETYPE *input) const;
+
+    void clearMidBuffer();
+    void overlap(SAMPLETYPE *output, const SAMPLETYPE *input, uint ovlPos) const;
+
+    void calcSeqParameters();
+    void adaptNormalizer();
+
+
+    /// Changes the tempo of the given sound samples.
+    /// Returns amount of samples returned in the "output" buffer.
+    /// The maximum amount of samples that can be returned at a time is set by
+    /// the 'set_returnBuffer_size' function.
+    void processSamples();
+    
+public:
+    TDStretch();
+    virtual ~TDStretch();
+
+    /// Operator 'new' is overloaded so that it automatically creates a suitable instance 
+    /// depending on if we've a MMX/SSE/etc-capable CPU available or not.
+    static void *operator new(size_t s);
+
+    /// Use this function instead of "new" operator to create a new instance of this class. 
+    /// This function automatically chooses a correct feature set depending on if the CPU
+    /// supports MMX/SSE/etc extensions.
+    static TDStretch *newInstance();
+    
+    /// Returns the output buffer object
+    FIFOSamplePipe *getOutput() { return &outputBuffer; };
+
+    /// Returns the input buffer object
+    FIFOSamplePipe *getInput() { return &inputBuffer; };
+
+    /// Sets new target tempo. Normal tempo = 'SCALE', smaller values represent slower 
+    /// tempo, larger faster tempo.
+    void setTempo(double newTempo);
+
+    /// Returns nonzero if there aren't any samples available for outputting.
+    virtual void clear();
+
+    /// Clears the input buffer
+    void clearInput();
+
+    /// Sets the number of channels, 1 = mono, 2 = stereo
+    void setChannels(int numChannels);
+
+    /// Enables/disables the quick position seeking algorithm. Zero to disable, 
+    /// nonzero to enable
+    void enableQuickSeek(bool enable);
+
+    /// Returns nonzero if the quick seeking algorithm is enabled.
+    bool isQuickSeekEnabled() const;
+
+    /// Sets routine control parameters. These control are certain time constants
+    /// defining how the sound is stretched to the desired duration.
+    //
+    /// 'sampleRate' = sample rate of the sound
+    /// 'sequenceMS' = one processing sequence length in milliseconds
+    /// 'seekwindowMS' = seeking window length for scanning the best overlapping 
+    ///      position
+    /// 'overlapMS' = overlapping length
+    void setParameters(int sampleRate,          ///< Samplerate of sound being processed (Hz)
+                       int sequenceMS = -1,     ///< Single processing sequence length (ms)
+                       int seekwindowMS = -1,   ///< Offset seeking window length (ms)
+                       int overlapMS = -1       ///< Sequence overlapping length (ms)
+                       );
+
+    /// Get routine control parameters, see setParameters() function.
+    /// Any of the parameters to this function can be NULL, in such case corresponding parameter
+    /// value isn't returned.
+    void getParameters(int *pSampleRate, int *pSequenceMs, int *pSeekWindowMs, int *pOverlapMs) const;
+
+    /// Adds 'numsamples' pcs of samples from the 'samples' memory position into
+    /// the input of the object.
+    virtual void putSamples(
+            const SAMPLETYPE *samples,  ///< Input sample data
+            uint numSamples                         ///< Number of samples in 'samples' so that one sample
+                                                    ///< contains both channels if stereo
+            );
+
+    /// return nominal input sample requirement for triggering a processing batch
+    int getInputSampleReq() const
+    {
+        return (int)(nominalSkip + 0.5);
+    }
+
+    /// return nominal output sample amount when running a processing batch
+    int getOutputBatchSize() const
+    {
+        return seekWindowLength - overlapLength;
+    }
+};
+
+
+
+// Implementation-specific class declarations:
+
+#ifdef SOUNDTOUCH_ALLOW_MMX
+    /// Class that implements MMX optimized routines for 16bit integer samples type.
+    class TDStretchMMX : public TDStretch
+    {
+    protected:
+        double calcCrossCorr(const short *mixingPos, const short *compare, double &norm);
+        double calcCrossCorrAccumulate(const short *mixingPos, const short *compare, double &norm);
+        virtual void overlapStereo(short *output, const short *input) const;
+        virtual void clearCrossCorrState();
+    };
+#endif /// SOUNDTOUCH_ALLOW_MMX
+
+
+#ifdef SOUNDTOUCH_ALLOW_SSE
+    /// Class that implements SSE optimized routines for floating point samples type.
+    class TDStretchSSE : public TDStretch
+    {
+    protected:
+        double calcCrossCorr(const float *mixingPos, const float *compare, double &norm);
+        double calcCrossCorrAccumulate(const float *mixingPos, const float *compare, double &norm);
+    };
+
+#endif /// SOUNDTOUCH_ALLOW_SSE
+
+}
+#endif  /// TDStretch_H

src/cpu_detect.h

@@ -0,0 +1,62 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// A header file for detecting the Intel MMX instructions set extension.
+///
+/// Please see 'mmx_win.cpp', 'mmx_cpp.cpp' and 'mmx_non_x86.cpp' for the 
+/// routine implementations for x86 Windows, x86 gnu version and non-x86 
+/// platforms, respectively.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2008-02-10 18:26:55 +0200 (Sun, 10 Feb 2008) $
+// File revision : $Revision: 4 $
+//
+// $Id: cpu_detect.h 11 2008-02-10 16:26:55Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef _CPU_DETECT_H_
+#define _CPU_DETECT_H_
+
+#include "STTypes.h"
+
+#define SUPPORT_MMX         0x0001
+#define SUPPORT_3DNOW       0x0002
+#define SUPPORT_ALTIVEC     0x0004
+#define SUPPORT_SSE         0x0008
+#define SUPPORT_SSE2        0x0010
+
+/// Checks which instruction set extensions are supported by the CPU.
+///
+/// \return A bitmask of supported extensions, see SUPPORT_... defines.
+uint detectCPUextensions(void);
+
+/// Disables given set of instruction extensions. See SUPPORT_... defines.
+void disableExtensions(uint wDisableMask);
+
+#endif  // _CPU_DETECT_H_

src/cpu_detect_x86.cpp

@@ -0,0 +1,138 @@
+////////////////////////////////////////////////////////////////////////////////
+///
+/// Generic version of the x86 CPU extension detection routine.
+///
+/// This file is for GNU & other non-Windows compilers, see 'cpu_detect_x86_win.cpp' 
+/// for the Microsoft compiler version.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2014-01-07 20:24:28 +0200 (Tue, 07 Jan 2014) $
+// File revision : $Revision: 4 $
+//
+// $Id: cpu_detect_x86.cpp 183 2014-01-07 18:24:28Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include "cpu_detect.h"
+#include "STTypes.h"
+
+
+#if defined(SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS)
+
+   #if defined(__GNUC__) && defined(__i386__)
+       // gcc
+       #include "cpuid.h"
+   #elif defined(_M_IX86)
+       // windows non-gcc
+       #include <intrin.h>
+   #endif
+
+   #define bit_MMX     (1 << 23)
+   #define bit_SSE     (1 << 25)
+   #define bit_SSE2    (1 << 26)
+#endif
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// processor instructions extension detection routines
+//
+//////////////////////////////////////////////////////////////////////////////
+
+// Flag variable indicating whick ISA extensions are disabled (for debugging)
+static uint _dwDisabledISA = 0x00;      // 0xffffffff; //<- use this to disable all extensions
+
+// Disables given set of instruction extensions. See SUPPORT_... defines.
+void disableExtensions(uint dwDisableMask)
+{
+    _dwDisabledISA = dwDisableMask;
+}
+
+
+
+/// Checks which instruction set extensions are supported by the CPU.
+uint detectCPUextensions(void)
+{
+/// If building for a 64bit system (no Itanium) and the user wants optimizations.
+/// Return the OR of SUPPORT_{MMX,SSE,SSE2}. 11001 or 0x19.
+/// Keep the _dwDisabledISA test (2 more operations, could be eliminated).
+#if ((defined(__GNUC__) && defined(__x86_64__)) \
+    || defined(_M_X64))  \
+    && defined(SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS)
+    return 0x19 & ~_dwDisabledISA;
+
+/// If building for a 32bit system and the user wants optimizations.
+/// Keep the _dwDisabledISA test (2 more operations, could be eliminated).
+#elif ((defined(__GNUC__) && defined(__i386__)) \
+    || defined(_M_IX86))  \
+    && defined(SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS)
+
+    if (_dwDisabledISA == 0xffffffff) return 0;
+ 
+    uint res = 0;
+ 
+#if defined(__GNUC__)
+    // GCC version of cpuid. Requires GCC 4.3.0 or later for __cpuid intrinsic support.
+    uint eax, ebx, ecx, edx;  // unsigned int is the standard type. uint is defined by the compiler and not guaranteed to be portable.
+
+    // Check if no cpuid support.
+    if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx)) return 0; // always disable extensions.
+
+    if (edx & bit_MMX)  res = res | SUPPORT_MMX;
+    if (edx & bit_SSE)  res = res | SUPPORT_SSE;
+    if (edx & bit_SSE2) res = res | SUPPORT_SSE2;
+
+#else
+    // Window / VS version of cpuid. Notice that Visual Studio 2005 or later required 
+    // for __cpuid intrinsic support.
+    int reg[4] = {-1};
+
+    // Check if no cpuid support.
+    __cpuid(reg,0);
+    if ((unsigned int)reg[0] == 0) return 0; // always disable extensions.
+
+    __cpuid(reg,1);
+    if ((unsigned int)reg[3] & bit_MMX)  res = res | SUPPORT_MMX;
+    if ((unsigned int)reg[3] & bit_SSE)  res = res | SUPPORT_SSE;
+    if ((unsigned int)reg[3] & bit_SSE2) res = res | SUPPORT_SSE2;
+
+#endif
+
+    return res & ~_dwDisabledISA;
+
+#else
+
+/// One of these is true:
+/// 1) We don't want optimizations.
+/// 2) Using an unsupported compiler.
+/// 3) Running on a non-x86 platform.
+    return 0;
+
+#endif
+}