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authortoma <toma@283d02a7-25f6-0310-bc7c-ecb5cbfe19da>2009-11-25 17:56:58 +0000
committertoma <toma@283d02a7-25f6-0310-bc7c-ecb5cbfe19da>2009-11-25 17:56:58 +0000
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tree9047cf9e6b5c43878d5bf82660adae77ceee097a /noatun/library/noatunarts/fft.h
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Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.
BUG:215923 git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdemultimedia@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
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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 */