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diff --git a/noatun/library/noatunarts/fft.h b/noatun/library/noatunarts/fft.h
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+++ b/noatun/library/noatunarts/fft.h
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+#ifndef FFT_H
+#define FFT_H
+
+
+
+/* this is from ddcmath.h */
+
+#define  DDC_PI  (3.14159265358979323846)
+
+/*============================================================================
+
+       fourier.h  -  Don Cross <dcross@intersrv.com>
+
+       http://www.intersrv.com/~dcross/fft.html
+
+       Contains definitions for doing Fourier transforms
+       and inverse Fourier transforms.
+
+============================================================================*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+**   If you change anything here, make sure to check if
+**   the offsets used in the asm version of BandPass() are affected
+*/
+struct BandPassInfo
+{
+	float center;
+	float bandwidth;
+
+	float C, D;
+	float a[3], b[2];
+
+	float bufferX[2];
+	float bufferY[2];
+
+};
+
+void BandPassInit(struct BandPassInfo *i, float center, float bw);
+void BandPassSSE(struct BandPassInfo *ip, float *inbuffer, float *outbuffer, unsigned long samples);
+void BandPass(struct BandPassInfo *ip, float *inbuffer, float *outbuffer, unsigned long samples);
+
+/*
+**   fft() computes the Fourier transform or inverse transform
+**   of the complex inputs to produce the complex outputs.
+**   The number of samples must be a power of two to do the
+**   recursive decomposition of the FFT algorithm.
+**   See Chapter 12 of "Numerical Recipes in FORTRAN" by
+**   Press, Teukolsky, Vetterling, and Flannery,
+**   Cambridge University Press.
+**
+**   Notes:  If you pass ImaginaryIn = NULL, this function will "pretend"
+**           that it is an array of all zeroes.  This is convenient for
+**           transforming digital samples of real number data without
+**           wasting memory.
+*/
+
+void fft_float (
+    unsigned  NumSamples,          /* must be a power of 2 */
+    int       InverseTransform,    /* 0=forward FFT, 1=inverse FFT */
+    float    *RealIn,              /* array of input's real samples */
+    float    *ImaginaryIn,         /* array of input's imag samples */
+    float    *RealOut,             /* array of output's reals */
+    float    *ImaginaryOut );      /* array of output's imaginaries */
+
+
+/*
+int IsPowerOfTwo ( unsigned x );
+unsigned NumberOfBitsNeeded ( unsigned PowerOfTwo );
+unsigned ReverseBits ( unsigned index, unsigned NumBits );
+*/
+
+/*
+**   The following function returns an "abstract frequency" of a
+**   given index into a buffer with a given number of frequency samples.
+**   Multiply return value by sampling rate to get frequency expressed in Hz.
+*/
+/*
+double Index_to_frequency ( unsigned NumSamples, unsigned Index );
+*/
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* FFT_H */