--- /dev/null
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio 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 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gr_fmdet_cf.h>
+#include <gr_io_signature.h>
+#include <math.h>
+#include <gr_math.h>
+
+#define M_TWOPI (2*M_PI)
+
+gr_fmdet_cf_sptr
+gr_make_fmdet_cf (float samplerate, float freq_low, float freq_high, float scl)
+{
+ return gr_fmdet_cf_sptr (new gr_fmdet_cf (samplerate, freq_low, freq_high, scl));
+}
+
+gr_fmdet_cf::gr_fmdet_cf (float samplerate, float freq_low, float freq_high, float scl)
+ : gr_sync_block ("fmdet_cf",
+ gr_make_io_signature (1, 1, sizeof (gr_complex)),
+ gr_make_io_signature (1, 1, sizeof (float))),
+ d_S1(0.1),d_S2(0.1),
+ d_S3(0.1),d_S4(0.1)
+{
+ #include <stdio.h>
+ float delta;
+ d_freqhi = freq_high;
+ d_freqlo = freq_low;
+ delta = (d_freqhi - d_freqlo);
+ d_scl = scl;
+ d_bias = 0.5*scl*(d_freqhi+d_freqlo)/delta;
+ fprintf(stderr,"delta = %f d_scl=%f d_bias=%f\n",delta,d_scl,d_bias),fflush(stderr);
+}
+
+int
+gr_fmdet_cf::work (int noutput_items,
+ gr_vector_const_void_star &input_items,
+ gr_vector_void_star &output_items)
+{
+ const gr_complex *iptr = (gr_complex *) input_items[0];
+ float *optr = (float *) output_items[0];
+
+ int size = noutput_items;
+
+ gr_complex Sdot,S0,S1=d_S1,S2=d_S2,S3=d_S3,S4=d_S4;
+
+ while (size-- > 0) {
+ S0=*iptr++;
+
+ Sdot = gr_complex(d_scl*
+ (-S0.real() + 8.0*S1.real() - 8.0*S3.real() + S4.real()),
+ d_scl*
+ (-S0.imag() + 8.0*S1.imag() - 8.0*S3.imag() + S4.imag()));
+ d_freq = (S2.real()*Sdot.imag()-S2.imag()*Sdot.real())/
+ (S2.real()*S2.real()+S2.imag()*S2.imag());
+
+ S4=S3;
+ S3=S2;
+ S2=S1;
+ S1=S0;
+
+
+ *optr++ = d_freq-d_bias;
+ }
+ d_S1=S1;
+ d_S2=S2;
+ d_S3=S3;
+ d_S4=S4;
+ return noutput_items;
+}