Initial code import from debian snapshot

https://snapshot.debian.org/package/codeine/1.0.1-3.dfsg-3.1/

Signed-off-by: Michele Calgaro <[email protected]>

1 files changed, 126 insertions, 0 deletions

diff --git a/src/app/fht.h b/src/app/fht.h
new file mode 100644
index 0000000..3dc5387
--- /dev/null
+++ b/src/app/fht.h
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+// FHT - Fast Hartley Transform Class
+//
+// Copyright (C) 2004  Melchior FRANZ - [email protected]
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
+//
+// $Id: fht.h,v 1.3 2004/06/05 20:20:36 mfranz Exp $
+
+#ifndef FHT_H
+#define FHT_H
+
+/**
+ * Implementation of the Hartley Transform after Bracewell's discrete
+ * algorithm. The algorithm is subject to US patent No. 4,646,256 (1987)
+ * but was put into public domain by the Board of Trustees of Stanford
+ * University in 1994 and is now freely available[1].
+ *
+ * [1] Computer in Physics, Vol. 9, No. 4, Jul/Aug 1995 pp 373-379
+ */
+class FHT
+{
+	int	m_exp2;
+	int	m_num;
+	float	*m_buf;
+	float	*m_tab;
+	int	*m_log;
+
+	/**
+	 * Create a table of CAS (cosine and sine) values.
+	 * Has only to be done in the constructor and saves from
+	 * calculating the same values over and over while transforming.
+	 */
+	void	makeCasTable();
+
+	/**
+	 * Recursive in-place Hartley transform. For internal use only!
+	 */
+	void	_transform(float *, int, int);
+
+   public:
+	/**
+	* Prepare transform for data sets with @f$2^n@f$ numbers, whereby @f$n@f$
+	* should be at least 3. Values of more than 3 need a trigonometry table.
+	* @see makeCasTable()
+	*/
+	FHT(int);
+
+	~FHT();
+	inline int sizeExp() const { return m_exp2; }
+	inline int size() const { return m_num; }
+	float	*copy(float *, float *);
+	float	*clear(float *);
+	void	scale(float *, float);
+
+	/**
+	 * Exponentially Weighted Moving Average (EWMA) filter.
+	 * @param d is the filtered data.
+	 * @param s is fresh input.
+	 * @param w is the weighting factor.
+	 */
+	void	ewma(float *d, float *s, float w);
+
+	/**
+	 * Test routine to create wobbling sine or rectangle wave.
+	 * @param d destination vector.
+	 * @param rect rectangle if true, sine otherwise.
+	 */
+	void	pattern(float *d, bool rect);
+
+	/**
+	 * Logarithmic audio spectrum. Maps semi-logarithmic spectrum
+	 * to logarithmic frequency scale, interpolates missing values.
+	 * A logarithmic index map is calculated at the first run only.
+	 * @param p is the input array.
+	 * @param out is the spectrum.
+	 */
+	void	logSpectrum(float *out, float *p);
+
+	/**
+	 * Semi-logarithmic audio spectrum.
+	 */
+	void	semiLogSpectrum(float *);
+
+	/**
+	 * Fourier spectrum.
+	 */
+	void	spectrum(float *);
+
+	/**
+	 * Calculates a mathematically correct FFT power spectrum.
+	 * If further scaling is applied later, use power2 instead
+	 * and factor the 0.5 in the final scaling factor.
+	 * @see FHT::power2()
+	 */
+	void	power(float *);
+
+	/**
+	 * Calculates an FFT power spectrum with doubled values as a
+	 * result. The values need to be multiplied by 0.5 to be exact.
+	 * Note that you only get @f$2^{n-1}@f$ power values for a data set
+	 * of @f$2^n@f$ input values.
+	 * @see FHT::power()
+	 */
+	void	power2(float *);
+
+	/**
+	 * Discrete Hartley transform of data sets with 8 values.
+	 */
+	void	transform8(float *);
+
+	void	transform(float *);
+};
+
+#endif