1 files changed, 37 insertions, 0 deletions
diff --git a/dfx-library/FIRfilter.h b/dfx-library/FIRfilter.h
new file mode 100755
index 0000000..d0f763b
--- /dev/null
+++ b/dfx-library/FIRfilter.h
@@ -0,0 +1,37 @@
+#ifndef __FIRfilter
+#define __FIRfilter
+
+#include <math.h>
+
+
+#define PI   3.1415926535897932384626433832795f
+#define SHELF_START_FIR   0.333f
+
+
+//----------------------------------------------------------------------------- 
+void calculateFIRidealLowpassCoefficients(float cutoff, float samplerate, 
+											int numTaps, float *coefficients);
+void applyKaiserWindow(int numTaps, float *coefficients, float attenuation);
+float besselIzero(float in);
+float besselIzero2(float in);
+
+//----------------------------------------------------------------------------- 
+inline float processFIRfilter(float *in, int numTaps, float *coefficients, 
+								long inPos, long arraySize)
+{
+	float out = 0.0f;
+	if ( (inPos+numTaps) > arraySize )
+	{
+		for (long i=0; i < numTaps; i++)
+			out += in[(inPos+i)%arraySize] * coefficients[i];
+	}
+	else
+	{
+		for (long i=0; i < numTaps; i++)
+			out += in[inPos+i] * coefficients[i];
+	}
+	return out;
+} 
+
+
+#endif
+\ No newline at end of file