From a2704c86955830fda9ef4c8de9dca5ae95eb7f2a Mon Sep 17 00:00:00 2001
From: John Glover <john@john-glovers-macbook.local>
Date: Fri, 17 Dec 2010 15:59:42 +0000
Subject: Added an option in SMS_AnalParams/SMS_SynthParams to enable/disable
 pre-emphasis (still enabled by default).

---
 sms/filters.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

(limited to 'sms/filters.c')

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
-- 
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