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/*
* Copyright (c) 2008 MUSIC TECHNOLOGY GROUP (MTG)
* UNIVERSITAT POMPEU FABRA
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, M 02111-1307 USA
*
*/
/*! \file stocAnalysis.c
* \brief stochastic analysis using spectral analysis and approximation
*/
#include "sms.h"
#define ENV_THRESHOLD .01 /* \todo was this value for type shorts?? */
/*! \brief main function for the stochastic analysis
* \param sizeWindow size of buffer
* \param pResidual pointer to residual signal
* \param pWindow pointer to windowing array
* \param pSmsData pointer to output SMS data
* \return 0 on success, -1 on error
*/
int sms_stocAnalysis ( int sizeWindow, sfloat *pResidual, sfloat *pWindow, SMS_Data *pSmsData)
{
int i;
sfloat fMag = 0.0;
sfloat fStocNorm;
static sfloat *pMagSpectrum;
static int sizeWindowStatic = 0;
static int sizeFft = 0;
static int sizeMag = 0;
/* update array sizes if sizeWindow is new */
if (sizeWindowStatic != sizeWindow)
{
if(sizeWindowStatic != 0) free(pMagSpectrum);
sizeWindowStatic = sizeWindow;
sizeFft = sms_power2(sizeWindow);
sizeMag = sizeFft >> 1;
if((pMagSpectrum = (sfloat *) calloc(sizeMag, sizeof(sfloat))) == NULL)
{
sms_error("sms_stocAnalysis: error allocating memory for pMagSpectrum");
return -1;
}
}
sms_spectrumMag (sizeWindow, pResidual, pWindow, sizeMag, pMagSpectrum);
sms_spectralApprox (pMagSpectrum, sizeMag, sizeMag, pSmsData->pFStocCoeff,
pSmsData->nCoeff, pSmsData->nCoeff);
/* get energy of spectrum */
for (i = 0; i < sizeMag; i++)
fMag += (pMagSpectrum[i] * pMagSpectrum[i]);
*pSmsData->pFStocGain = fMag / sizeMag;
fStocNorm = 1. / *pSmsData->pFStocGain;
/* normalize envelope */
/* \todo what good is this scaling, it is only being undone in resynthesis */
/* for (i = 0; i < pSmsData->nCoeff; i++) */
/* pSmsData->pFStocCoeff[i] *= fStocNorm; */
// *pSmsData->pFStocGain = sms_magToDB(*pSmsData->pFStocGain);
return(0);
}
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