shallow zip-file copy from codec2 e9d726bf20

1 files changed, 53 insertions, 0 deletions

diff --git a/src/codec2_fm.h b/src/codec2_fm.h
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--- /dev/null
+++ b/src/codec2_fm.h
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+/*---------------------------------------------------------------------------*\
+
+  FILE........: codec2_fm.h
+  AUTHOR......: David Rowe
+  DATE CREATED: February 2015
+
+  Functions that implement analog FM, see also octave/fm.m.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2015 David Rowe
+
+  All rights reserved.
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License version 2.1, as
+  published by the Free Software Foundation.  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 Lesser General Public License
+  along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CODEC2_FM__
+#define __CODEC2_FM__
+
+#include "comp.h"
+
+struct FM {
+    float  Fs;               /* setme: sample rate                  */
+    float  fm_max;           /* setme: maximum modulation frequency */
+    float  fd;               /* setme: maximum deviation            */
+    float  fc;               /* setme: carrier frequency            */
+    COMP  *rx_bb;
+    COMP   rx_bb_filt_prev;
+    float *rx_dem_mem;
+    float  tx_phase;
+    int    nsam;
+    COMP   lo_phase;
+};
+
+struct FM *fm_create(int nsam);
+void fm_destroy(struct FM *fm_states);
+void fm_demod(struct FM *fm, float rx_out[], float rx[]);
+void fm_mod(struct FM *fm, float tx_in[], float tx_out[]);
+void fm_mod_comp(struct FM *fm_states, float tx_in[], COMP tx_out[]);
+
+#endif
+