tdstretch.h

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/*****************************************************************************
 * 
 * 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 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 @ iki.fi
 * File created  : 13-Jan-2002
 *
 * Last changed  : $Date: 2004/10/26 19:09:38 $
 * File revision : $Revision: 1.2 $
 *
 * $Id: TDStretch.h,v 1.2 2004/10/26 19:09:38 vjohnson Exp $
 *
 * License :
 * 
 *  SoundTouch sound 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 "STTypes.h"
#include "RateTransposer.h"
#include "FIFOSamplePipe.h"

namespace soundtouch
{

// Default values for sound processing parameters:

/// 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     82

/// 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   14

/// 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      12


/// Class that does the time-stretch (tempo change) effect for the processed
/// sound.
class TDStretch : public FIFOProcessor
{
protected:
    uint channels;
    uint sampleReq;
    float tempo;

    SAMPLETYPE *pMidBuffer;
    SAMPLETYPE *pRefMidBuffer;
    SAMPLETYPE *pRefMidBufferUnaligned;
    uint overlapLength;
    uint overlapDividerBits;
    uint slopingDivider;
    uint seekLength;
    uint seekWindowLength;
    uint maxOffset;
    float nominalSkip;
    float skipFract;
    FIFOSampleBuffer outputBuffer;
    FIFOSampleBuffer inputBuffer;
    BOOL bQuickseek;
    BOOL bMidBufferDirty;

    uint sampleRate;
    uint sequenceMs;
    uint seekWindowMs;
    uint overlapMs;

    void acceptNewOverlapLength(uint newOverlapLength);

    virtual void clearCrossCorrState();
    void calculateOverlapLength(uint overlapMs);

    virtual LONG_SAMPLETYPE calcCrossCorrStereo(const SAMPLETYPE *mixingPos, const SAMPLETYPE *compare) const;
    virtual LONG_SAMPLETYPE calcCrossCorrMono(const SAMPLETYPE *mixingPos, const SAMPLETYPE *compare) const;

    virtual uint seekBestOverlapPositionStereo(const SAMPLETYPE *refPos);
    virtual uint seekBestOverlapPositionStereoQuick(const SAMPLETYPE *refPos);
    virtual uint seekBestOverlapPositionMono(const SAMPLETYPE *refPos);
    virtual uint seekBestOverlapPositionMonoQuick(const SAMPLETYPE *refPos);
    uint seekBestOverlapPosition(const SAMPLETYPE *refPos);

    virtual void overlapStereo(SAMPLETYPE *output, const SAMPLETYPE *input) const;
    virtual void overlapMono(SAMPLETYPE *output, const SAMPLETYPE *input) const;

    void clearMidBuffer();
    void overlap(SAMPLETYPE *output, const SAMPLETYPE *input, uint ovlPos) const;

    void precalcCorrReferenceMono();
    void precalcCorrReferenceStereo();

    void processNominalTempo();

    /// 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.
    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(float 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(uint 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(uint sampleRate,                             ///< Samplerate of sound being processed (Hz)
                       uint sequenceMS = DEFAULT_SEQUENCE_MS,       ///< Single processing sequence length (ms)
                       uint seekwindowMS = DEFAULT_SEEKWINDOW_MS,   ///< Offset seeking window length (ms)
                       uint overlapMS = DEFAULT_OVERLAP_MS          ///< 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(uint *pSampleRate, uint *pSequenceMs, uint *pSeekWindowMs, uint *pOverlapMs);

    /// 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
            );
};



// Implementation-specific class declarations:

#ifdef ALLOW_MMX
    /// Class that implements MMX optimized routines for 16bit integer samples type.
    class TDStretchMMX : public TDStretch
    {
    protected:
        long calcCrossCorrStereo(const short *mixingPos, const short *compare) const;
        virtual void overlapStereo(short *output, const short *input) const;
        virtual void clearCrossCorrState();
    };
#endif /// ALLOW_MMX


#ifdef ALLOW_3DNOW
    /// Class that implements 3DNow! optimized routines for floating point samples type.
    class TDStretch3DNow : public TDStretch
    {
    protected:
        double calcCrossCorrStereo(const float *mixingPos, const float *compare) const;
    };
#endif /// ALLOW_3DNOW


#ifdef ALLOW_SSE
    /// Class that implements SSE optimized routines for floating point samples type.
    class TDStretchSSE : public TDStretch
    {
    protected:
        double calcCrossCorrStereo(const float *mixingPos, const float *compare) const;
    };

#endif /// ALLOW_SSE

}
#endif  /// TDStretch_H