/*
* 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, MA 02111-1307 USA
*
*/
/*! \file synthesis.c
* \brief main synthesis routines
*/
#include "sms.h"
/*! \brief synthesis of one frame of the deterministic component using the IFFT
*
* \param pSmsData pointer to SMS data structure frame
* \param pSynthParams pointer to structure of synthesis parameters
*/
static void SineSynthIFFT(SMS_Data *pSmsData, SMS_SynthParams *pSynthParams)
{
int sizeFft = pSynthParams->sizeHop << 1;
int iHalfSamplingRate = pSynthParams->iSamplingRate >> 1;
int sizeMag = pSynthParams->sizeHop;
int nBins = 8;
int nTracks = pSmsData->nTracks;
int iFirstBin, k, i, l, b;
sfloat fMag=0.0, fFreq=0.0, fPhase=0.0, fLoc, fSin, fCos, fBinRemainder,
fTmp, fNewMag, fIndex;
sfloat fSamplingPeriod = 1.0 / pSynthParams->iSamplingRate;
memset(pSynthParams->pSpectra, 0, sizeFft * sizeof(sfloat));
for(i = 0; i < nTracks; i++)
{
if(((fMag = pSmsData->pFSinAmp[i]) > 0) &&
((fFreq = (pSmsData->pFSinFreq[i])) < iHalfSamplingRate))
{
/* \todo maybe this check can be removed if the SynthParams->prevFrame gets random
phases in sms_initSynth? */
if(pSynthParams->prevFrame.pFSinAmp[i] <= 0)
pSynthParams->prevFrame.pFSinPha[i] = TWO_PI * sms_random();
fMag = sms_dBToMag(fMag);
fTmp = pSynthParams->prevFrame.pFSinPha[i] +
TWO_PI * fFreq * fSamplingPeriod * sizeMag;
fPhase = fTmp - floor(fTmp * INV_TWO_PI) * TWO_PI;
fLoc = sizeFft * fFreq * fSamplingPeriod;
iFirstBin = (int) fLoc - 3;
fBinRemainder = fLoc - floor (fLoc);
fSin = sms_sine(fPhase);
fCos = sms_sine(fPhase + PI_2);
for (k = 1, l = iFirstBin; k <= nBins; k++, l++)
{
fIndex = (k - fBinRemainder);
if (fIndex > 7.999) fIndex = 0;
fNewMag = fMag * sms_sinc (fIndex);
if(l > 0 && l < sizeMag)
{
pSynthParams->pSpectra[l*2+1] += fNewMag * fCos;
pSynthParams->pSpectra[l*2] += fNewMag * fSin;
}
else if(l == 0)
{
pSynthParams->pSpectra[0] += 2 * fNewMag * fSin;
}
else if(l < 0)
{
b = abs(l);
pSynthParams->pSpectra[b*2+1] -= fNewMag * fCos;
pSynthParams->pSpectra[b*2] += fNewMag * fSin;
}
else if(l > sizeMag)
{
b = sizeMag - (l - sizeMag);
pSynthParams->pSpectra[b*2+1] -= fNewMag * fCos;
pSynthParams->pSpectra[b*2] += fNewMag * fSin;
}
else if(l == sizeMag)
{
pSynthParams->pSpectra[1] += 2 * fNewMag * fSin;
}
}
}
pSynthParams->prevFrame.pFSinAmp[i] = fMag;
pSynthParams->prevFrame.pFSinPha[i] = fPhase;
pSynthParams->prevFrame.pFSinFreq[i] = fFreq;
}
sms_ifft(sizeFft, pSynthParams->pSpectra);
for(i = 0, k = sizeMag; i < sizeMag; i++, k++)
pSynthParams->pSynthBuff[i] += pSynthParams->pSpectra[k] * pSynthParams->pFDetWindow[i];
for(i= sizeMag, k = 0; i < sizeFft; i++, k++)
pSynthParams->pSynthBuff[i] += pSynthParams->pSpectra[k] * pSynthParams->pFDetWindow[i];
}
/*! \brief synthesis of one frame of the stochastic component by apprimating phases
*
* computes a linearly interpolated spectral envelope to fit the correct number of output
* audio samples. Phases are generated randomly.
*
* \param pSmsData pointer to the current SMS frame
* \param pSynthParams pointer to a strucure of synthesis parameters
* \return
* \todo cleanup returns and various constant multipliers. check that approximation is ok
*/
static int StocSynthApprox(SMS_Data *pSmsData, SMS_SynthParams *pSynthParams)
{
int i, sizeSpec1Used;
int sizeSpec1 = pSmsData->nCoeff;
int sizeSpec2 = pSynthParams->sizeHop;
int sizeFft = pSynthParams->sizeHop << 1; /* 50% overlap, so sizeFft is 2x sizeHop */
/* if no gain or no coefficients return */
if(*(pSmsData->pFStocGain) <= 0)
return 0;
sizeSpec1Used = sizeSpec1 * pSynthParams->iSamplingRate / pSynthParams->iOriginalSRate;
/* sizeSpec1Used cannot be more than what is available \todo check by graph */
if(sizeSpec1Used > sizeSpec1) sizeSpec1Used = sizeSpec1;
sms_spectralApprox(pSmsData->pFStocCoeff, sizeSpec1, sizeSpec1Used,
pSynthParams->pMagBuff, sizeSpec2, sizeSpec1Used,
pSynthParams->approxEnvelope);
/* generate random phases */
for(i = 0; i < sizeSpec2; i++)
pSynthParams->pPhaseBuff[i] = TWO_PI * sms_random();
sms_invQuickSpectrumW(pSynthParams->pMagBuff, pSynthParams->pPhaseBuff,
sizeFft, pSynthParams->pSynthBuff, sizeFft,
pSynthParams->pFStocWindow, pSynthParams->pSpectra);
return 1;
}
/*! \brief synthesizes one frame of the residual signal
*
* \param residualParams Parameters and memory for residual synthesis
*/
void sms_approxResidual(int sizeResidual, sfloat* residual,
int sizeApprox, sfloat* approx,
SMS_ResidualParams *residualParams)
{
int i;
/* shift buffers */
memcpy(residualParams->residual,
residualParams->residual + residualParams->hopSize,
sizeof(sfloat) * residualParams->hopSize);
memcpy(residualParams->residual + residualParams->hopSize, residual,
sizeof(sfloat) * residualParams->hopSize);
memcpy(residualParams->approx,
residualParams->approx + residualParams->hopSize,
sizeof(sfloat) * residualParams->hopSize);
memset(residualParams->approx + residualParams->hopSize, 0,
sizeof(sfloat) * residualParams->hopSize);
sms_spectrumMag(residualParams->residualSize,
residualParams->residual,
residualParams->fftWindow,
residualParams->sizeStocMagSpectrum,
residualParams->stocMagSpectrum,
residualParams->fftBuffer);
if(residualParams->sizeStocMagSpectrum != residualParams->nCoeffs)
{
sms_spectralApprox(residualParams->stocMagSpectrum,
residualParams->sizeStocMagSpectrum,
residualParams->sizeStocMagSpectrum,
residualParams->stocCoeffs,
residualParams->nCoeffs,
residualParams->nCoeffs,
residualParams->approxEnvelope);
sms_spectralApprox(residualParams->stocCoeffs,
residualParams->nCoeffs,
residualParams->nCoeffs,
residualParams->stocMagSpectrum,
residualParams->sizeStocMagSpectrum,
residualParams->sizeStocMagSpectrum,
residualParams->approxEnvelope);
}
/* generate random phases */
for(i = 0; i < residualParams->sizeStocMagSpectrum; i++)
{
residualParams->stocPhaseSpectrum[i] = TWO_PI * sms_random();
}
/* IFFT with 50% overlap */
sms_invQuickSpectrumW(residualParams->stocMagSpectrum,
residualParams->stocPhaseSpectrum,
residualParams->sizeStocMagSpectrum*2,
residualParams->approx,
residualParams->residualSize,
residualParams->ifftWindow,
residualParams->fftBuffer);
/* output */
for(i = 0; i < sizeApprox; i++)
{
approx[i] = residualParams->approx[i] * residualParams->windowScale;
}
}
/*! \brief synthesizes one frame of SMS data
*
* \param pSmsData input SMS data
* \param pFSynthesis output sound buffer
* \param pSynthParams synthesis parameters
*/
void sms_synthesize(SMS_Data *pSmsData, sfloat *pFSynthesis, SMS_SynthParams *pSynthParams)
{
int i;
int sizeHop = pSynthParams->sizeHop;
memcpy(pSynthParams->pSynthBuff, (sfloat *)(pSynthParams->pSynthBuff+sizeHop),
sizeof(sfloat) * sizeHop);
memset(pSynthParams->pSynthBuff+sizeHop, 0, sizeof(sfloat) * sizeHop);
/* convert mags from linear to db */
sms_arrayMagToDB(pSmsData->nTracks, pSmsData->pFSinAmp);
/* decide which combo of synthesis methods to use */
if(pSynthParams->iSynthesisType == SMS_STYPE_ALL)
{
if(pSynthParams->iDetSynthType == SMS_DET_IFFT)
{
SineSynthIFFT(pSmsData, pSynthParams);
}
else /*pSynthParams->iDetSynthType == SMS_DET_SIN*/
{
sms_sineSynthFrame(pSmsData, pSynthParams->pSynthBuff, pSynthParams->sizeHop,
&(pSynthParams->prevFrame), pSynthParams->iSamplingRate);
}
StocSynthApprox(pSmsData, pSynthParams);
}
else if(pSynthParams->iSynthesisType == SMS_STYPE_DET)
{
if(pSynthParams->iDetSynthType == SMS_DET_IFFT)
{
SineSynthIFFT(pSmsData, pSynthParams);
}
else /*pSynthParams->iDetSynthType == SMS_DET_SIN*/
{
sms_sineSynthFrame(pSmsData, pSynthParams->pSynthBuff, pSynthParams->sizeHop,
&(pSynthParams->prevFrame), pSynthParams->iSamplingRate);
}
}
else /* pSynthParams->iSynthesisType == SMS_STYPE_STOC */
{
StocSynthApprox(pSmsData, pSynthParams);
}
/* de-emphasize the sound and normalize*/
for(i = 0; i < sizeHop; i++)
{
pFSynthesis[i] = sms_deEmphasis(pSynthParams->pSynthBuff[i], pSynthParams);
}
}