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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, MA 02111-1307 USA
*
*/
/*! \file sineSynth.c
* \brief functions for synthesizing evolving sinusoids
*/
#include "sms.h"
/*! \brief generate a sinusoid given two peaks, current and last
*
* it interpolation between phase values and magnitudes
*
* \param fFreq current frequency
* \param fMag current magnitude
* \param fPhase current phase
* \param pLastFrame stucture with values from last frame
* \param pFWaveform pointer to output waveform
* \param sizeBuffer size of the synthesis buffer
* \param iTrack current track
*/
static void SinePhaSynth(sfloat fFreq, sfloat fMag, sfloat fPhase,
SMS_Data *pLastFrame, sfloat *pFWaveform,
int sizeBuffer, int iTrack)
{
sfloat fMagIncr, fInstMag, fInstPhase, fTmp;
int iM, i;
sfloat fAlpha, fBeta, fTmp1, fTmp2;
/* if no mag in last frame copy freq from current and make phase */
if(pLastFrame->pFSinAmp[iTrack] <= 0)
{
pLastFrame->pFSinFreq[iTrack] = fFreq;
fTmp = fPhase - (fFreq * sizeBuffer);
pLastFrame->pFSinPha[iTrack] = fTmp - floor(fTmp / TWO_PI) * TWO_PI;
}
/* and the other way */
else if(fMag <= 0)
{
fFreq = pLastFrame->pFSinFreq[iTrack];
fTmp = pLastFrame->pFSinPha[iTrack] +
(pLastFrame->pFSinFreq[iTrack] * sizeBuffer);
fPhase = fTmp - floor(fTmp / TWO_PI) * TWO_PI;
}
/* caculate the instantaneous amplitude */
fMagIncr = (fMag - pLastFrame->pFSinAmp[iTrack]) / sizeBuffer;
fInstMag = pLastFrame->pFSinAmp[iTrack];
/* create instantaneous phase from freq. and phase values */
fTmp1 = fFreq - pLastFrame->pFSinFreq[iTrack];
fTmp2 = ((pLastFrame->pFSinPha[iTrack] +
pLastFrame->pFSinFreq[iTrack] * sizeBuffer - fPhase) +
fTmp1 * sizeBuffer / 2.0) / TWO_PI;
iM = (int)(fTmp2 + .5);
fTmp2 = fPhase - pLastFrame->pFSinPha[iTrack] -
pLastFrame->pFSinFreq[iTrack] * sizeBuffer + TWO_PI * iM;
fAlpha = (3.0 / (sfloat)(sizeBuffer * sizeBuffer)) *
fTmp2 - fTmp1 / sizeBuffer;
fBeta = (-2.0 / ((sfloat) (sizeBuffer * sizeBuffer * sizeBuffer))) *
fTmp2 + fTmp1 / ((sfloat) (sizeBuffer * sizeBuffer));
for(i=0; i<sizeBuffer; i++)
{
fInstMag += fMagIncr;
fInstPhase = pLastFrame->pFSinPha[iTrack] +
pLastFrame->pFSinFreq[iTrack] * i +
fAlpha * i * i + fBeta * i * i * i;
/*pFWaveform[i] += sms_dBToMag(fInstMag) * sms_sine(fInstPhase + PI_2);*/
pFWaveform[i] += sms_dBToMag(fInstMag) * sinf(fInstPhase + PI_2);
}
/* save current values into buffer */
pLastFrame->pFSinFreq[iTrack] = fFreq;
pLastFrame->pFSinAmp[iTrack] = fMag;
pLastFrame->pFSinPha[iTrack] = fPhase;
}
/*! \brief generate a sinusoid given two frames, current and last
*
* \param fFreq current frequency
* \param fMag current magnitude
* \param pLastFrame stucture with values from last frame
* \param pFBuffer pointer to output waveform
* \param sizeBuffer size of the synthesis buffer
* \param iTrack current track
*/
static void SineSynth(sfloat fFreq, sfloat fMag, SMS_Data *pLastFrame,
sfloat *pFBuffer, int sizeBuffer, int iTrack)
{
sfloat fMagIncr, fInstMag, fFreqIncr, fInstPhase, fInstFreq;
int i;
/* if no mag in last frame copy freq from current */
if(pLastFrame->pFSinAmp[iTrack] <= 0)
{
pLastFrame->pFSinFreq[iTrack] = fFreq;
pLastFrame->pFSinPha[iTrack] = TWO_PI * sms_random();
}
/* and the other way */
else if(fMag <= 0)
fFreq = pLastFrame->pFSinFreq[iTrack];
/* calculate the instantaneous amplitude */
fMagIncr = (fMag - pLastFrame->pFSinAmp[iTrack]) / sizeBuffer;
fInstMag = pLastFrame->pFSinAmp[iTrack];
/* calculate instantaneous frequency */
fFreqIncr = (fFreq - pLastFrame->pFSinFreq[iTrack]) / sizeBuffer;
fInstFreq = pLastFrame->pFSinFreq[iTrack];
fInstPhase = pLastFrame->pFSinPha[iTrack];
/* generate all the samples */
for(i = 0; i < sizeBuffer; i++)
{
fInstMag += fMagIncr;
fInstFreq += fFreqIncr;
fInstPhase += fInstFreq;
pFBuffer[i] += sms_dBToMag(fInstMag) * sms_sine(fInstPhase);
}
/* save current values into last values */
pLastFrame->pFSinFreq[iTrack] = fFreq;
pLastFrame->pFSinAmp[iTrack] = fMag;
pLastFrame->pFSinPha[iTrack] = fInstPhase - floor(fInstPhase / TWO_PI) * TWO_PI;
}
/*! \brief generate all the sinusoids for a given frame
*
* \param pSmsData SMS data for current frame
* \param pFBuffer pointer to output waveform
* \param sizeBuffer size of the synthesis buffer
* \param pLastFrame SMS data from last frame
* \param iSamplingRate sampling rate to synthesize for
*/
void sms_sineSynthFrame(SMS_Data *pSmsData, sfloat *pFBuffer,
int sizeBuffer, SMS_Data *pLastFrame,
int iSamplingRate)
{
sfloat fMag, fFreq;
int i;
int nTracks = pSmsData->nTracks;
int iHalfSamplingRate = iSamplingRate >> 1;
/* go through all the tracks */
for(i = 0; i < nTracks; i++)
{
fMag = pSmsData->pFSinAmp[i];
fFreq = pSmsData->pFSinFreq[i];
/* make that sure transposed frequencies don't alias */
if(fFreq > iHalfSamplingRate || fFreq < 0)
fMag = 0;
/* generate sines if there are magnitude values */
if((fMag > 0) || (pLastFrame->pFSinAmp[i] > 0))
{
/* frequency from Hz to radians */
fFreq = (fFreq == 0) ? 0 : TWO_PI * fFreq / iSamplingRate;
/* \todo make seperate function for SineSynth /wo phase */
if(pSmsData->pFSinPha == NULL)
{
SineSynth(fFreq, fMag, pLastFrame, pFBuffer, sizeBuffer, i);
}
else
{
SinePhaSynth(fFreq, fMag, pSmsData->pFSinPha[i], pLastFrame,
pFBuffer, sizeBuffer, i);
}
}
}
}
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