tdstretch.cpp

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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 19:09:37 $
 * File revision : $Revision: 1.4 $
 *
 * $Id: TDStretch.cpp,v 1.4 2004/10/26 19:09:37 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
 *
 *****************************************************************************/


#include <string.h>
#include <stdlib.h>
#include <memory.h>
#include <limits.h>
#include <math.h>
#include <assert.h>

#include "STTypes.h"
#include "cpu_detect.h"
#include "TDStretch.h"

using namespace soundtouch;

#ifndef min
#define min(a,b) ((a > b) ? b : a)
#define max(a,b) ((a < b) ? b : a)
#endif



/*****************************************************************************
 *
 * Constant definitions
 *
 *****************************************************************************/


#define MAX_SCAN_DELTA      124

// Table for the hierarchical mixing position seeking algorithm
int scanOffsets[4][24]={
    { 124,  186,  248,  310,  372,  434,  496,  558,  620,  682,  744, 806, 
      868,  930,  992, 1054, 1116, 1178, 1240, 1302, 1364, 1426, 1488,   0}, 
    {-100,  -75,  -50,  -25,   25,   50,   75,  100,    0,    0,    0,   0,
        0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,   0},
    { -20,  -15,  -10,   -5,    5,   10,   15,   20,    0,    0,    0,   0,
        0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,   0},
    {  -4,   -3,   -2,   -1,    1,    2,    3,    4,    0,    0,    0,   0,
        0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,   0}};

/*****************************************************************************
 *
 * Implementation of the class 'TDStretch'
 *
 *****************************************************************************/


TDStretch::TDStretch() : FIFOProcessor(&outputBuffer)
{
    bQuickseek = FALSE;
    channels = 2;
    bMidBufferDirty = FALSE;

    pMidBuffer = NULL;
    pRefMidBufferUnaligned = NULL;
    overlapLength = 0;

    setParameters(44100, DEFAULT_SEQUENCE_MS, DEFAULT_SEEKWINDOW_MS, DEFAULT_OVERLAP_MS);

    setTempo(1.0f);
}




TDStretch::~TDStretch()
{
    delete[] pMidBuffer;
    delete[] pRefMidBufferUnaligned;
}


    
// Calculates the x having the closest 2^x value for the given value
static int _getClosest2Power(double value)
{
    return (int)(log(value) / log(2.0) + 0.5);
}



// 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 (default = 82 ms)
// 'seekwindowMS' = seeking window length for scanning the best overlapping 
//      position (default = 28 ms)
// 'overlapMS' = overlapping length (default = 12 ms)

void TDStretch::setParameters(uint aSampleRate, uint aSequenceMS, 
                              uint aSeekWindowMS, uint aOverlapMS)
{
    this->sampleRate = aSampleRate;
    this->sequenceMs = aSequenceMS;
    this->seekWindowMs = aSeekWindowMS;
    this->overlapMs = aOverlapMS;

    seekLength = (sampleRate * seekWindowMs) / 1000;
    seekWindowLength = (sampleRate * sequenceMs) / 1000;

    maxOffset = seekLength;

    calculateOverlapLength(overlapMs);

    // set tempo to recalculate 'sampleReq'
    setTempo(tempo);

}



/// 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 TDStretch::getParameters(uint *pSampleRate, uint *pSequenceMs, uint *pSeekWindowMs, uint *pOverlapMs)
{
    if (pSampleRate)
    {
        *pSampleRate = sampleRate;
    }

    if (pSequenceMs)
    {
        *pSequenceMs = sequenceMs;
    }

    if (pSeekWindowMs)
    {
        *pSeekWindowMs = seekWindowMs;
    }

    if (pOverlapMs)
    {
        *pOverlapMs = overlapMs;
    }
}


// Overlaps samples in 'midBuffer' with the samples in 'input'
void TDStretch::overlapMono(SAMPLETYPE *output, const SAMPLETYPE *input) const
{
    int i, itemp;

    for (i = 0; i < (int)overlapLength ; i ++) 
    {
        itemp = overlapLength - i;
        output[i] = (input[i] * i + pMidBuffer[i] * itemp ) / overlapLength;    // >> overlapDividerBits;
    }
}



void TDStretch::clearMidBuffer()
{
    if (bMidBufferDirty) 
    {
        memset(pMidBuffer, 0, 2 * sizeof(SAMPLETYPE) * overlapLength);
        bMidBufferDirty = FALSE;
    }
}


void TDStretch::clearInput()
{
    inputBuffer.clear();
    clearMidBuffer();
}


// Clears the sample buffers
void TDStretch::clear()
{
    outputBuffer.clear();
    inputBuffer.clear();
    clearMidBuffer();
}



// Enables/disables the quick position seeking algorithm. Zero to disable, nonzero
// to enable
void TDStretch::enableQuickSeek(BOOL enable)
{
    bQuickseek = enable;
}


// Returns nonzero if the quick seeking algorithm is enabled.
BOOL TDStretch::isQuickSeekEnabled() const
{
    return bQuickseek;
}


// Seeks for the optimal overlap-mixing position.
uint TDStretch::seekBestOverlapPosition(const SAMPLETYPE *refPos)
{
    if (channels == 2) 
    {
        // stereo sound
        if (bQuickseek) 
        {
            return seekBestOverlapPositionStereoQuick(refPos);
        } 
        else 
        {
            return seekBestOverlapPositionStereo(refPos);
        }
    } 
    else 
    {
        // mono sound
        if (bQuickseek) 
        {
            return seekBestOverlapPositionMonoQuick(refPos);
        } 
        else 
        {
            return seekBestOverlapPositionMono(refPos);
        }
    }
}




// Overlaps samples in 'midBuffer' with the samples in 'inputBuffer' at position
// of 'ovlPos'.
inline void TDStretch::overlap(SAMPLETYPE *output, const SAMPLETYPE *input, uint ovlPos) const
{
    if (channels == 2) 
    {
        // stereo sound
        overlapStereo(output, input + 2 * ovlPos);
    } else {
        // mono sound.
        overlapMono(output, input + ovlPos);
    }
}




// Seeks for the optimal overlap-mixing position. The 'stereo' version of the
// routine
//
// The best position is determined as the position where the two overlapped
// sample sequences are 'most alike', in terms of the highest cross-correlation
// value over the overlapping period
uint TDStretch::seekBestOverlapPositionStereo(const SAMPLETYPE *refPos) 
{
    uint bestOffs;
    LONG_SAMPLETYPE bestCorr, corr;
    uint i;

    // Slopes the amplitudes of the 'midBuffer' samples
    precalcCorrReferenceStereo();

    bestCorr = INT_MIN;
    bestOffs = 0;

    // Scans for the best correlation value by testing each possible position
    // over the permitted range.
    for (i = 0; i < seekLength; i ++) 
    {
        // Calculates correlation value for the mixing position corresponding
        // to 'i'
        corr = calcCrossCorrStereo(refPos + 2 * i, pRefMidBuffer);

        // Checks for the highest correlation value
        if (corr > bestCorr) 
        {
            bestCorr = corr;
            bestOffs = i;
        }
    }
    // clear cross correlation routine state if necessary (is so e.g. in MMX routines).
    clearCrossCorrState();

    return bestOffs;
}


// Seeks for the optimal overlap-mixing position. The 'stereo' version of the
// routine
//
// The best position is determined as the position where the two overlapped
// sample sequences are 'most alike', in terms of the highest cross-correlation
// value over the overlapping period
uint TDStretch::seekBestOverlapPositionStereoQuick(const SAMPLETYPE *refPos) 
{
    uint j;
    uint bestOffs;
    LONG_SAMPLETYPE bestCorr, corr;
    uint scanCount, corrOffset, tempOffset;

    // Slopes the amplitude of the 'midBuffer' samples
    precalcCorrReferenceStereo();

    bestCorr = INT_MIN;
    bestOffs = 0;
    corrOffset = 0;
    tempOffset = 0;

    // Scans for the best correlation value using four-pass hierarchical search.
    //
    // The look-up table 'scans' has hierarchical position adjusting steps.
    // In first pass the routine searhes for the highest correlation with 
    // relatively coarse steps, then rescans the neighbourhood of the highest
    // correlation with better resolution and so on.
    for (scanCount = 0;scanCount < 4; scanCount ++) 
    {
        j = 0;
        while (scanOffsets[scanCount][j]) 
        {
            tempOffset = corrOffset + scanOffsets[scanCount][j];
            if (tempOffset >= seekLength) break;

            // Calculates correlation value for the mixing position corresponding
            // to 'tempOffset'
            corr = calcCrossCorrStereo(refPos + 2 * tempOffset, pRefMidBuffer);

            // Checks for the highest correlation value
            if (corr > bestCorr) 
            {
                bestCorr = corr;
                bestOffs = tempOffset;
            }
            j ++;
        }
        corrOffset = bestOffs;
    }
    // clear cross correlation routine state if necessary (is so e.g. in MMX routines).
    clearCrossCorrState();

    return bestOffs;
}



// Seeks for the optimal overlap-mixing position. The 'mono' version of the
// routine
//
// The best position is determined as the position where the two overlapped
// sample sequences are 'most alike', in terms of the highest cross-correlation
// value over the overlapping period
uint TDStretch::seekBestOverlapPositionMono(const SAMPLETYPE *refPos) 
{
    uint bestOffs;
    LONG_SAMPLETYPE bestCorr, corr;
    uint tempOffset;
    const SAMPLETYPE *compare;

    // Slopes the amplitude of the 'midBuffer' samples
    precalcCorrReferenceMono();

    bestCorr = INT_MIN;
    bestOffs = 0;

    // Scans for the best correlation value by testing each possible position
    // over the permitted range.
    for (tempOffset = 0; tempOffset < seekLength; tempOffset ++) 
    {
        compare = refPos + tempOffset;

        // Calculates correlation value for the mixing position corresponding
        // to 'tempOffset'
        corr = calcCrossCorrMono(pRefMidBuffer, compare);

        // Checks for the highest correlation value
        if (corr > bestCorr) 
        {
            bestCorr = corr;
            bestOffs = tempOffset;
        }
    }
    // clear cross correlation routine state if necessary (is so e.g. in MMX routines).
    clearCrossCorrState();

    return bestOffs;
}


// Seeks for the optimal overlap-mixing position. The 'mono' version of the
// routine
//
// The best position is determined as the position where the two overlapped
// sample sequences are 'most alike', in terms of the highest cross-correlation
// value over the overlapping period
uint TDStretch::seekBestOverlapPositionMonoQuick(const SAMPLETYPE *refPos) 
{
    uint j;
    uint bestOffs;
    LONG_SAMPLETYPE bestCorr, corr;
    uint scanCount, corrOffset, tempOffset;

    // Slopes the amplitude of the 'midBuffer' samples
    precalcCorrReferenceMono();

    bestCorr = INT_MIN;
    bestOffs = 0;
    corrOffset = 0;
    tempOffset = 0;

    // Scans for the best correlation value using four-pass hierarchical search.
    //
    // The look-up table 'scans' has hierarchical position adjusting steps.
    // In first pass the routine searhes for the highest correlation with 
    // relatively coarse steps, then rescans the neighbourhood of the highest
    // correlation with better resolution and so on.
    for (scanCount = 0;scanCount < 4; scanCount ++) 
    {
        j = 0;
        while (scanOffsets[scanCount][j]) 
        {
            tempOffset = corrOffset + scanOffsets[scanCount][j];
            if (tempOffset >= seekLength) break;

            // Calculates correlation value for the mixing position corresponding
            // to 'tempOffset'
            corr = calcCrossCorrMono(refPos + tempOffset, pRefMidBuffer);

            // Checks for the highest correlation value
            if (corr > bestCorr) 
            {