Added an option in SMS_AnalParams/SMS_SynthParams to enable/disable pre-emphasis (still enabled by default).

3 files changed, 18 insertions, 6 deletions

diff --git a/sms/filters.c b/sms/filters.c
index 9c13ad5..7f31317 100644
--- a/sms/filters.c
+++ b/sms/filters.c
@@ -33,9 +33,13 @@
  */
 sfloat sms_preEmphasis(sfloat fInput, SMS_AnalParams *pAnalParams)
 {
-    sfloat fOutput = fInput - SMS_EMPH_COEF * pAnalParams->preEmphasisLastValue;
-    pAnalParams->preEmphasisLastValue = fOutput;
-    return fOutput;
+    if(pAnalParams->preEmphasis)
+    {
+        sfloat fOutput = fInput - SMS_EMPH_COEF * pAnalParams->preEmphasisLastValue;
+        pAnalParams->preEmphasisLastValue = fOutput;
+        return fOutput;
+    }
+    return fInput;
 }
 
 /* de-emphasis filter function, it returns the filtered value 
@@ -44,9 +48,13 @@ sfloat sms_preEmphasis(sfloat fInput, SMS_AnalParams *pAnalParams)
  */
 sfloat sms_deEmphasis(sfloat fInput, SMS_SynthParams *pSynthParams)
 {
-    sfloat fOutput = fInput + SMS_EMPH_COEF * pSynthParams->deEmphasisLastValue;
-    pSynthParams->deEmphasisLastValue = fInput;
-    return fOutput;
+    if(pSynthParams->deEmphasis)
+    {
+        sfloat fOutput = fInput + SMS_EMPH_COEF * pSynthParams->deEmphasisLastValue;
+        pSynthParams->deEmphasisLastValue = fInput;
+        return fOutput;
+    }
+    return fInput;
 }
 
 /*! \brief  function to implement a zero-pole filter
diff --git a/sms/sms.c b/sms/sms.c
index 89bfa9f..8294224 100644
--- a/sms/sms.c
+++ b/sms/sms.c
@@ -139,6 +139,7 @@ void sms_initAnalParams(SMS_AnalParams *pAnalParams)
     pAnalParams->iMaxDelayFrames = MAX(pAnalParams->iMinTrackLength, pAnalParams->iMaxSleepingTime) + 2 +
         (pAnalParams->minGoodFrames + pAnalParams->analDelay);
     pAnalParams->fResidualAccumPerc = 0.;
+    pAnalParams->preEmphasis = 1; /*!< perform pre-emphasis by default */
     pAnalParams->preEmphasisLastValue = 0.;
     /* spectral envelope params */
     pAnalParams->specEnvParams.iType = SMS_ENV_NONE; /* turn off enveloping */
@@ -412,6 +413,7 @@ void sms_initSynthParams(SMS_SynthParams *synthParams)
     synthParams->pPhaseBuff = NULL;
     synthParams->pSpectra = NULL;
     synthParams->approxEnvelope = NULL;
+    synthParams->deEmphasis = 1; /*!< perform de-emphasis by default */
     synthParams->deEmphasisLastValue = 0;
 }
 
diff --git a/sms/sms.h b/sms/sms.h
index 6e5e407..f998145 100644
--- a/sms/sms.h
+++ b/sms/sms.h
@@ -242,6 +242,7 @@ typedef struct
     int analDelay;                   /*! number of frames in the past to be looked in possible re-analyze */
     sfloat fResidualAccumPerc;       /*!< accumalitive residual percentage */
     int sizeNextRead;                /*!< size of samples to read from sound file next analysis */
+    int preEmphasis;                 /*!< whether or not to perform pre-emphasis */
     sfloat preEmphasisLastValue;
     SMS_Data prevFrame;              /*!< the previous analysis frame  */
     SMS_SEnvParams specEnvParams;    /*!< all data for spectral enveloping */
@@ -306,6 +307,7 @@ typedef struct
     int origSizeHop;            /*!< original number of samples used to create each analysis frame */
     int nTracks;
     int nStochasticCoeff;
+    int deEmphasis;             /*!< whether or not to perform de-emphasis */
     sfloat deEmphasisLastValue;
     sfloat *pFDetWindow;        /*!< array to hold the window used for deterministic synthesis  \see SMS_WIN_IFFT */
     sfloat *pFStocWindow;       /*!< array to hold the window used for stochastic synthesis (Hanning) */