Disable anti-alias filter if SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER is defined

README.html

@@ -573,6 +573,13 @@ this corresponds to lowering the pitch by -0.318 semitones:</p>
 <hr>
 <h2>5. Change History</h2>
 <h3>5.1. SoundTouch library Change History </h3>
+    <p><b>2.0.1pre:</b></p>
+    <ul>
+        <li>Disable anti-alias filter when switch 
+		SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER defined because anti-alias 
+		filter cause slight click if the rate change crosses zero during 
+		processing</li>
+    </ul>
     <p><b>2.0:</b></p>
     <ul>
         <li>Added functions to get initial processing latency, duration ratio between the original input and processed output tracks, and clarified reporting of input/output batch sizes</li>
@@ -855,6 +862,7 @@ submitted bugfixes:</p>
   <li> Jason Garland</li>
   <li> Takashi Iwai</li>
   <li> Thomas Klausner</li>
+	<li> Lu Zhihe</li>
   <li> Tony Mechelynck </li>
   <li> Mathias M&ouml;hl</li>
   <li> Yuval Naveh</li>
@@ -872,6 +880,7 @@ submitted bugfixes:</p>
   <li> Tyson Smith</li>
   <li> John Stumpo</li>
   <li> Katja Vetter</li>
+	<li> Wu Q.</li>
 </ul>
 <p>Moral greetings to all other contributors and users also!</p>
 <hr>

source/SoundTouch/RateTransposer.cpp

@@ -57,7 +57,13 @@ TransposerBase::ALGORITHM TransposerBase::algorithm = TransposerBase::CUBIC;
 // Constructor
 RateTransposer::RateTransposer() : FIFOProcessor(&outputBuffer)
 {
-    bUseAAFilter = true;
+    bUseAAFilter = 
+#ifndef SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER
+        true;
+#else
+        // Disable Anti-alias filter if desirable to avoid click at rate change zero value crossover
+        false;
+#endif
 
     // Instantiates the anti-alias filter
     pAAFilter = new AAFilter(64);
@@ -77,7 +83,10 @@ RateTransposer::~RateTransposer()
 /// Enables/disables the anti-alias filter. Zero to disable, nonzero to enable
 void RateTransposer::enableAAFilter(bool newMode)
 {
+#ifndef SOUNDTOUCH_PREVENT_CLICK_AT_RATE_CROSSOVER
+    // Disable Anti-alias filter if desirable to avoid click at rate change zero value crossover
     bUseAAFilter = newMode;
+#endif
 }