diff options
Diffstat (limited to 'src/sms/synthesis.c')
| -rw-r--r-- | src/sms/synthesis.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/src/sms/synthesis.c b/src/sms/synthesis.c new file mode 100644 index 0000000..bc739d0 --- /dev/null +++ b/src/sms/synthesis.c @@ -0,0 +1,260 @@ +/* + * 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); +} |