Index: NuppelVideoPlayer.cpp
===================================================================
--- NuppelVideoPlayer.cpp	(revision 17338)
+++ NuppelVideoPlayer.cpp	(working copy)
@@ -3782,6 +3782,96 @@
 #endif
 }
 
+/** \fn agc(T, float)
+ * \brief Auto Gain Control (AGC) for audio samples 
+ *
+ * Implements a simple Auto Gain Control (AGC) for audio.
+ * it detects when it's output is too large 
+ * (caused by large periods of silence) and scales back the gain
+ * appropriately.  In normal operation there will be 2 floating point
+ * multiplicatioons and 2 floating point add/subtracks.
+ * Implemented as a template to avoid indencial code for 8 and 16 bit
+ * versions.
+ *
+ */
+template <class T> 
+inline
+T agc(const T yin, float NUM_MAX)
+{
+	const static float spoint = 0.05f * NUM_MAX;
+	const static float gain = 1e-9;
+	float yout;
+	static float iout=4;
+	float err;
+	float abs_yout;
+	
+	/* Voltage controlled amplifier is just a multiplier here */
+	yout=yin*iout;
+
+	/* error */
+	abs_yout = fabsf(yout);
+	err=spoint-abs_yout;
+
+	// make sure the gain doesn't over drive the maximum value
+	if (abs_yout> NUM_MAX)
+	{
+		iout = 0.95f*NUM_MAX/fabsf(yin); 	
+		yout = yin*iout; // do multiplication to keep the sign
+
+	//	printf("yin %d, err %f, iout %f, spoint %f, abs_yout %f, yout %f\n", 
+	//		(int)yin, err, iout, spoint, abs_yout, yout);
+	}
+	else
+	{
+		/* Integrate */
+		iout += gain*err ;
+	}
+		
+	/* round and return */
+	yout = rintf(yout);
+
+	return (T) yout;
+}
+
+/** \fn ManageAGC(T, int int int);
+ * \brief Runs AGC on all samples in a buffer
+ *
+ * Calculates the number of individual samples in the audio
+ * buffer and then runs Auto Gain Control (AGC) on each sample
+ * to equalise the audio.  It is coded as a template to reduce
+ * the amount of identical code where only the the buffer pointer
+ * varies.
+ */
+template<class T>
+void ManageAGC(T *buffer, int audio_bits, int audio_channels, int samples)
+{
+	int s, sc;
+	sc = samples * audio_channels;
+
+	if (audio_bits == 16 ) 
+	{
+		short *p = (short *) buffer;
+
+		for (s=0; s<sc; s++)
+		{
+			*p = agc(*p, SHRT_MAX);
+			p++;
+		}
+	}
+	else
+	{
+		char *p = (char *) buffer;
+
+		for (s=0; s<sc; s++)
+		{
+			*p = agc(*p, SCHAR_MAX);
+			p++;
+		}
+
+	}
+
+}
+
 /** \fn NuppelVideoPlayer::AddAudioData(char*,int,long long)
  *  \brief Sends audio to AudioOuput::AddSamples(char*,int,long long)
  *
@@ -3807,6 +3897,8 @@
         audioOutput->Drain();
     }
 
+    ManageAGC(buffer, audio_bits, audio_channels, samples);
+
     // If there is no warping, just send it to the audioOutput.
     if (!usevideotimebase)
     {
@@ -3866,6 +3958,9 @@
     if (!audioOutput)
         return;
 
+    ManageAGC(lbuffer, audio_bits, audio_channels, samples);
+    ManageAGC(rbuffer, audio_bits, audio_channels, samples);
+
     // If there is no warping, just send it to the audioOutput.
     if (!usevideotimebase)
     {