1 files changed, 122 insertions, 0 deletions
diff --git a/src/cohpsk_mod.c b/src/cohpsk_mod.c
new file mode 100644
index 0000000..b6e0fb4
--- /dev/null
+++ b/src/cohpsk_mod.c
@@ -0,0 +1,122 @@
+/*---------------------------------------------------------------------------*\
+
+  FILE........: cohpsk_mod.c
+  AUTHOR......: David Rowe
+  DATE CREATED: April 5 2015
+
+  Given an input file of bits (note one bit per float, soft decision format),
+  outputs a raw file (8kHz, 16 bit shorts) of COHPSK modem samples
+  ready to send over a HF radio channel.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  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/>.
+*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <errno.h>
+
+#include "codec2_cohpsk.h"
+#include "codec2_fdmdv.h"
+
+int opt_exists(char *argv[], int argc, char opt[]) {
+    int i;
+    for (i=0; i<argc; i++) {
+        if (strcmp(argv[i], opt) == 0) {
+            return i;
+        }
+    }
+    return 0;
+}
+
+int main(int argc, char *argv[])
+{
+    FILE          *fin, *fout;
+    struct COHPSK *cohpsk;
+    char          tx_bits_char[2*COHPSK_BITS_PER_FRAME];
+    int           tx_bits[2*COHPSK_BITS_PER_FRAME];
+    COMP          tx_fdm[COHPSK_NOM_SAMPLES_PER_FRAME];
+    short         tx_fdm_scaled[COHPSK_NOM_SAMPLES_PER_FRAME];
+    int           frames, diversity;
+    int           i;
+
+    if (argc < 3) {
+        fprintf(stderr, "\n");
+	fprintf(stderr, "usage: %s InputOneCharPerBitFile OutputModemRawFile [-nd]\n", argv[0]);
+        fprintf(stderr, "\n");
+        fprintf(stderr, "  --nd        non-diversity mode, input frames of %d bits\n", 2*COHPSK_BITS_PER_FRAME);
+        fprintf(stderr, "\n");
+	exit(1);
+    }
+
+    if (strcmp(argv[1], "-")  == 0) fin = stdin;
+    else if ( (fin = fopen(argv[1],"rb")) == NULL ) {
+	fprintf(stderr, "Error opening input file: %s: %s.\n",
+         argv[1], strerror(errno));
+	exit(1);
+    }
+
+    if (strcmp(argv[2], "-") == 0) fout = stdout;
+    else if ( (fout = fopen(argv[2],"wb")) == NULL ) {
+	fprintf(stderr, "Error opening output modem sample file: %s: %s.\n",
+         argv[2], strerror(errno));
+	exit(1);
+    }
+
+    cohpsk = cohpsk_create();
+
+    if (opt_exists(argv, argc, "--nd")) {
+        diversity = 2;
+    }
+    else {
+        diversity = 1;
+    }
+    fprintf(stderr, "diversity: %d\n", diversity);
+
+    frames = 0;
+
+    while(fread(tx_bits_char, sizeof(char), COHPSK_BITS_PER_FRAME*diversity, fin) == COHPSK_BITS_PER_FRAME*diversity) {
+        frames++;
+
+        for(i=0; i<COHPSK_BITS_PER_FRAME*diversity; i++)
+            tx_bits[i] = tx_bits_char[i];
+        cohpsk_mod(cohpsk, tx_fdm, tx_bits, COHPSK_BITS_PER_FRAME*diversity);
+        cohpsk_clip(tx_fdm, COHPSK_CLIP, COHPSK_NOM_SAMPLES_PER_FRAME);
+
+        /* scale and save to disk as shorts */
+
+        for(i=0; i<COHPSK_NOM_SAMPLES_PER_FRAME; i++)
+            tx_fdm_scaled[i] = COHPSK_SCALE * tx_fdm[i].real;
+
+        fwrite(tx_fdm_scaled, sizeof(short), COHPSK_NOM_SAMPLES_PER_FRAME, fout);
+
+        /* if this is in a pipeline, we probably don't want the usual
+           buffering to occur */
+
+        if (fout == stdout) fflush(stdout);
+    }
+
+    fclose(fin);
+    fclose(fout);
+    cohpsk_destroy(cohpsk);
+
+    return 0;
+}