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+/*
+ * Rational Sample Rate Conversion
+ * Copyright (C) 2012, 2013  Thomas Tsou <tom@tsou.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _RESAMPLER_H_
+#define _RESAMPLER_H_
+
+class Resampler {
+public:
+	/* Constructor for rational sample rate conversion
+	 *   @param p numerator of resampling ratio
+	 *   @param q denominator of resampling ratio
+	 *   @param filt_len length of each polyphase subfilter 
+	 */
+	Resampler(size_t p, size_t q, size_t filt_len = 16);
+	~Resampler();
+
+	/* Initilize resampler filterbank.
+	 *   @param bw bandwidth factor on filter generation (pre-window)
+	 *   @return false on error, zero otherwise
+	 *
+	 * Automatic setting is to compute the filter to prevent aliasing with
+	 * a Blackman-Harris window. Adjustment is made through a bandwith
+	 * factor to shift the cutoff and/or the constituent filter lengths.
+	 * Calculation of specific rolloff factors or 3-dB cutoff points is
+	 * left as an excersize for the reader.
+	 */
+	bool init(float bw = 1.0f);
+
+	/* Rotate "commutator" and drive samples through filterbank
+	 *   @param in continuous buffer of input complex float values
+	 *   @param in_len input buffer length
+	 *   @param out continuous buffer of output complex float values
+	 *   @param out_len output buffer length
+	 *   @return number of samples outputted, negative on error
+         *
+	 * Input and output vector lengths must of be equal multiples of the
+	 * rational conversion rate denominator and numerator respectively.
+	 */
+	int rotate(float *in, size_t in_len, float *out, size_t out_len);
+
+	/* Get filter length
+	 *   @return number of taps in each filter partition 
+	 */
+	size_t len();
+
+private:
+	size_t p;
+	size_t q;
+	size_t filt_len;
+	size_t *in_index;
+	size_t *out_path;
+
+	float **partitions;
+	float *history;
+
+	bool initFilters(float bw);
+	void releaseFilters();
+	void computePath();
+};
+
+#endif /* _RESAMPLER_H_ */