Added: Support for independent filter sets per channel. The new command "Channel" allows to specify the channel(s) to which the following "Filter" and "Preamp" commands should apply.

ParametricEQ.h

@@ -20,14 +20,62 @@
 #pragma once
 
 #include <string>
+#include <vector>
+
+#define IS_DENORMAL(f) (((*(unsigned int *)&(f))&0x7f800000) == 0)
 
 struct BiQuad
 {
-    BiQuad() {}
-    BiQuad(float dbGain, float freq, float srate, float bandwidthOrQ, bool isQ);
-        
-    __declspec(align(16)) float a[4];
+	BiQuad() {}
+	BiQuad(float dbGain, float freq, float srate, float bandwidthOrQ, bool isQ);
+
+	__forceinline
+	void removeDenormals()
+	{
+		if(IS_DENORMAL(x1))
+			x1 = 0.0f;
+		if(IS_DENORMAL(x2))
+			x2 = 0.0f;
+		if(IS_DENORMAL(y1))
+			y1 = 0.0f;
+		if(IS_DENORMAL(y2))
+			y2 = 0.0f;
+	}
+
+	__forceinline
+	float process(float sample)
+	{
+		float result = a0 * sample + a[0] * x1 + a[1] * x2 +
+			a[2] * y1 + a[3] * y2;
+
+		x2 = x1;
+		x1 = sample;
+
+		y2 = y1;
+		y1 = result;
+
+		//Input for next stage
+		return result;
+	}
+
+	__declspec(align(16)) float a[4];
 	float a0;
+
+	float x1, x2;
+	float y1, y2;
+};
+
+struct ChannelData
+{
+	ChannelData();
+
+	float preamp;
+	unsigned filterCount;
+	BiQuad filters[100];
+
+	// used while loading instead of overwriting immediately
+	float loadPreamp;
+	unsigned loadFilterCount;
 };
 
 class ParametricEQ
@@ -37,13 +85,14 @@ public:
 	~ParametricEQ();
 
 	void setDeviceInfo(const std::wstring& deviceName, const std::wstring& connectionName, const std::wstring& deviceGuid);
-	void initialize(float sampleRate, unsigned channelCount);
+	void initialize(float sampleRate, unsigned channelCount, unsigned channelMask);
 	void loadConfig();
 	void process(float *output, float *input, unsigned frameCount);
 
 private:
-	void loadConfig(std::wstring path, unsigned& loadFilterCount, float& loadPreamp);
+	void loadConfig(const std::wstring& path, std::vector<bool> selectedChannels);
 	float getFreq(const std::wstring& freqString);
+	unsigned getChannelNumber(unsigned position);
 	static unsigned long __stdcall notificationThread(void* parameter);
 
 	std::wstring deviceName;
@@ -52,10 +101,8 @@ private:
 	std::wstring configPath;
 	float sampleRate;
 	unsigned channelCount;
-	float preamp;
-    BiQuad filters[100];
-    unsigned filterCount;
-    float sampleData[2000];
+	unsigned channelMask;
+	ChannelData* channelData;
 	bool lastInputWasSilent;
 	void* threadHandle;
 	void* shutdownEvent;