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-rw-r--r--sms/peakDetection.c202
1 files changed, 99 insertions, 103 deletions
diff --git a/sms/peakDetection.c b/sms/peakDetection.c
index ad94332..1bbe713 100644
--- a/sms/peakDetection.c
+++ b/sms/peakDetection.c
@@ -38,12 +38,12 @@
static sfloat PeakInterpolation (sfloat fMaxVal, sfloat fLeftBinVal,
sfloat fRightBinVal, sfloat *pFDiffFromMax)
{
- /* get the location of the tip of the parabola */
- *pFDiffFromMax = (.5 * (fLeftBinVal - fRightBinVal) /
- (fLeftBinVal - (2*fMaxVal) + fRightBinVal));
- /* return the value at the tip */
- return(fMaxVal - (.25 * (fLeftBinVal - fRightBinVal) *
- *pFDiffFromMax));
+ /* get the location of the tip of the parabola */
+ *pFDiffFromMax = (.5 * (fLeftBinVal - fRightBinVal) /
+ (fLeftBinVal - (2*fMaxVal) + fRightBinVal));
+ /* return the value at the tip */
+ return(fMaxVal - (.25 * (fLeftBinVal - fRightBinVal) *
+ *pFDiffFromMax));
}
/*! \brief detect the next local maximum in the spectrum
@@ -62,29 +62,29 @@ static sfloat PeakInterpolation (sfloat fMaxVal, sfloat fLeftBinVal,
static int FindNextMax ( sfloat *pFMagSpectrum, int iHighBinBound,
int *pICurrentLoc, sfloat *pFMaxVal, sfloat fMinPeakMag)
{
- int iCurrentBin = *pICurrentLoc;
- sfloat fPrevVal = pFMagSpectrum[iCurrentBin - 1];
+ int iCurrentBin = *pICurrentLoc;
+ sfloat fPrevVal = pFMagSpectrum[iCurrentBin - 1];
sfloat fCurrentVal = pFMagSpectrum[iCurrentBin];
sfloat fNextVal = (iCurrentBin >= iHighBinBound)
? 0 : pFMagSpectrum[iCurrentBin + 1];
- /* try to find a local maximum */
- while (iCurrentBin <= iHighBinBound)
- {
- if (fCurrentVal > fMinPeakMag &&
- fCurrentVal >= fPrevVal &&
- fCurrentVal >= fNextVal)
- break;
- iCurrentBin++;
- fPrevVal = fCurrentVal;
- fCurrentVal = fNextVal;
- fNextVal = pFMagSpectrum[1+iCurrentBin];
- }
- /* save the current location, value of maximum and return */
- /* location of max */
- *pICurrentLoc = iCurrentBin + 1;
- *pFMaxVal = fCurrentVal;
- return(iCurrentBin);
+ /* try to find a local maximum */
+ while (iCurrentBin <= iHighBinBound)
+ {
+ if (fCurrentVal > fMinPeakMag &&
+ fCurrentVal >= fPrevVal &&
+ fCurrentVal >= fNextVal)
+ break;
+ iCurrentBin++;
+ fPrevVal = fCurrentVal;
+ fCurrentVal = fNextVal;
+ fNextVal = pFMagSpectrum[1+iCurrentBin];
+ }
+ /* save the current location, value of maximum and return */
+ /* location of max */
+ *pICurrentLoc = iCurrentBin + 1;
+ *pFMaxVal = fCurrentVal;
+ return(iCurrentBin);
}
/*! \brief function to detect the next spectral peak
@@ -101,29 +101,29 @@ static int FindNextPeak (sfloat *pFMagSpectrum, int iHighestBin,
int *pICurrentLoc, sfloat *pFPeakMag, sfloat *pFPeakLoc,
sfloat fMinPeakMag)
{
- int iPeakBin = 0; /* location of the local peak */
- sfloat fPeakMag = 0; /* value of local peak */
+ int iPeakBin = 0; /* location of the local peak */
+ sfloat fPeakMag = 0; /* value of local peak */
- /* keep trying to find a good peak while inside the freq range */
- while ((iPeakBin = FindNextMax(pFMagSpectrum, iHighestBin,
- pICurrentLoc, &fPeakMag, fMinPeakMag))
- <= iHighestBin)
- {
- /* get the neighboring samples */
- sfloat fDiffFromMax = 0;
- sfloat fLeftBinVal = pFMagSpectrum[iPeakBin - 1];
- sfloat fRightBinVal = pFMagSpectrum[iPeakBin + 1];
- if (fLeftBinVal <= 0 || fRightBinVal <= 0) //ahah! there you are!
- continue;
- /* interpolate the spectral samples to obtain
- a more accurate magnitude and freq */
- *pFPeakMag = PeakInterpolation (fPeakMag, fLeftBinVal,
- fRightBinVal, &fDiffFromMax);
- *pFPeakLoc = iPeakBin + fDiffFromMax;
- return (1);
- }
- /* if it does not find a peak return 0 */
- return (0);
+ /* keep trying to find a good peak while inside the freq range */
+ while ((iPeakBin = FindNextMax(pFMagSpectrum, iHighestBin,
+ pICurrentLoc, &fPeakMag, fMinPeakMag))
+ <= iHighestBin)
+ {
+ /* get the neighboring samples */
+ sfloat fDiffFromMax = 0;
+ sfloat fLeftBinVal = pFMagSpectrum[iPeakBin - 1];
+ sfloat fRightBinVal = pFMagSpectrum[iPeakBin + 1];
+ if (fLeftBinVal <= 0 || fRightBinVal <= 0) //ahah! there you are!
+ continue;
+ /* interpolate the spectral samples to obtain
+ a more accurate magnitude and freq */
+ *pFPeakMag = PeakInterpolation (fPeakMag, fLeftBinVal,
+ fRightBinVal, &fDiffFromMax);
+ *pFPeakLoc = iPeakBin + fDiffFromMax;
+ return (1);
+ }
+ /* if it does not find a peak return 0 */
+ return (0);
}
/*! \brief get the corresponding phase value for a given peak
@@ -136,76 +136,72 @@ static int FindNextPeak (sfloat *pFMagSpectrum, int iHighestBin,
*/
static sfloat GetPhaseVal (sfloat *pPhaseSpectrum, sfloat fPeakLoc)
{
- int bin = (int) fPeakLoc;
- sfloat fFraction = fPeakLoc - bin,
- fLeftPha = pPhaseSpectrum[bin],
- fRightPha = pPhaseSpectrum[bin+1];
+ int bin = (int) fPeakLoc;
+ sfloat fFraction = fPeakLoc - bin,
+ fLeftPha = pPhaseSpectrum[bin],
+ fRightPha = pPhaseSpectrum[bin+1];
- /* check for phase wrapping */
- if (fLeftPha - fRightPha > 1.5 * PI)
- fRightPha += TWO_PI;
- else if (fRightPha - fLeftPha > 1.5 * PI)
- fLeftPha += TWO_PI;
+ /* check for phase wrapping */
+ if (fLeftPha - fRightPha > 1.5 * PI)
+ fRightPha += TWO_PI;
+ else if (fRightPha - fLeftPha > 1.5 * PI)
+ fLeftPha += TWO_PI;
- /* return interpolated phase */
- return (fLeftPha + fFraction * (fRightPha - fLeftPha));
+ /* return interpolated phase */
+ return (fLeftPha + fFraction * (fRightPha - fLeftPha));
}
/*! \brief find the prominent spectral peaks
*
* uses a dB spectrum
*
- * \param sizeSpec size of magnitude spectrum
- * \param pMag pointer to power spectrum
- * \param pPhase pointer to phase spectrum
- * \param pSpectralPeaks pointer to array of peaks
- * \param pPeakParams peak detection parameters
+ * \param sizeSpec size of magnitude spectrum
+ * \param pMag pointer to power spectrum
+ * \param pPhase pointer to phase spectrum
+ * \param pSpectralPeaks pointer to array of peaks
+ * \param pAnalParams peak detection parameters
* \return the number of peaks found
*/
-int sms_detectPeaks (int sizeSpec, sfloat *pMag, sfloat *pPhase,
- SMS_Peak *pSpectralPeaks, SMS_PeakParams *pPeakParams)
+int sms_detectPeaks(int sizeSpec, sfloat *pMag, sfloat *pPhase,
+ SMS_Peak *pSpectralPeaks, SMS_AnalParams *pAnalParams)
{
- static int iFirstBin, iHighestBin, sizeFft;
- static sfloat fInvSizeFft;
- static int sizeSpecStatic = 0;
+ static int iFirstBin, iHighestBin, sizeFft;
+ static sfloat fInvSizeFft;
+ static int sizeSpecStatic = 0;
- /* allocate memory if sizeSpec has changed or this is the first run */
- if(sizeSpecStatic != sizeSpec)
- {
- sizeSpecStatic = sizeSpec;
- //printf("sizeSpecStatic: %d \n", sizeSpecStatic);
- sizeFft = sizeSpec << 1;
- fInvSizeFft = 1.0 / sizeFft;
- /* make sure to start on the 2nd bin so interpolation is possible QUESTION: why not allow a peak in bin 1 or 0? */
- /* rte: changed the first argument of MAX from 2 to 1 */
- iFirstBin = MAX (1, sizeFft * pPeakParams->fLowestFreq /
- pPeakParams->iSamplingRate);
- iHighestBin = MIN (sizeSpec-1,
- sizeFft * pPeakParams->fHighestFreq /
- pPeakParams->iSamplingRate);
- }
+ /* allocate memory if sizeSpec has changed or this is the first run */
+ if(sizeSpecStatic != sizeSpec)
+ {
+ sizeSpecStatic = sizeSpec;
+ sizeFft = sizeSpec << 1;
+ fInvSizeFft = 1.0 / sizeFft;
+ /* make sure to start on the 2nd bin so interpolation is possible QUESTION: why not allow a peak in bin 1 or 0? */
+ /* rte: changed the first argument of MAX from 2 to 1 */
+ iFirstBin = MAX(1, sizeFft * pAnalParams->fLowestFreq / pAnalParams->iSamplingRate);
+ iHighestBin = MIN(sizeSpec-1, sizeFft * pAnalParams->fHighestFreq / pAnalParams->iSamplingRate);
+ }
- /* clear peak structure */
- memset (pSpectralPeaks, 0, pPeakParams->iMaxPeaks * sizeof(SMS_Peak));
+ /* clear peak structure */
+ memset(pSpectralPeaks, 0, pAnalParams->maxPeaks * sizeof(SMS_Peak));
- /* set starting search values */
- int iCurrentLoc = iFirstBin;
- int iPeak = 0; /* index for spectral search */
- sfloat fPeakMag = 0.0; /* magnitude of peak */
- sfloat fPeakLoc = 0.0; /* location of peak */
+ /* set starting search values */
+ int iCurrentLoc = iFirstBin;
+ int iPeak = 0; /* index for spectral search */
+ sfloat fPeakMag = 0.0; /* magnitude of peak */
+ sfloat fPeakLoc = 0.0; /* location of peak */
- /* find peaks */
- while ((iPeak < pPeakParams->iMaxPeaks) &&
- (FindNextPeak(pMag, iHighestBin,
- &iCurrentLoc, &fPeakMag, &fPeakLoc, pPeakParams->fMinPeakMag) == 1))
- {
- /* store peak values */
- pSpectralPeaks[iPeak].fFreq = pPeakParams->iSamplingRate * fPeakLoc * fInvSizeFft;
- pSpectralPeaks[iPeak].fMag = fPeakMag;
- pSpectralPeaks[iPeak].fPhase = GetPhaseVal(pPhase, fPeakLoc);
- iPeak++;
- }
+ /* find peaks */
+ while((iPeak < pAnalParams->maxPeaks) &&
+ (FindNextPeak(pMag, iHighestBin, &iCurrentLoc, &fPeakMag,
+ &fPeakLoc, pAnalParams->fMinPeakMag) == 1))
+ {
+ /* store peak values */
+ pSpectralPeaks[iPeak].fFreq = pAnalParams->iSamplingRate * fPeakLoc * fInvSizeFft;
+ pSpectralPeaks[iPeak].fMag = fPeakMag;
+ pSpectralPeaks[iPeak].fPhase = GetPhaseVal(pPhase, fPeakLoc);
+ iPeak++;
+ }
- /* return the number of peaks found */
- return (iPeak);
+ /* return the number of peaks found */
+ return iPeak;
}
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