From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Tue, 20 Mar 2018 08:54:01 +0000 (+0000)
Subject: first pass at ofdm_mod, command line OFDM modulator program
X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=d6cb56204952da92a943fa3ecb2373d84e674858;p=freetel-svn-tracking.git

first pass at ofdm_mod, command line OFDM modulator program

git-svn-id: https://svn.code.sf.net/p/freetel/code@3419 01035d8c-6547-0410-b346-abe4f91aad63
---

diff --git a/codec2-dev/src/CMakeLists.txt b/codec2-dev/src/CMakeLists.txt
index 3822b816..f7f15666 100644
--- a/codec2-dev/src/CMakeLists.txt
+++ b/codec2-dev/src/CMakeLists.txt
@@ -318,7 +318,7 @@ add_executable(fsk_demod fsk_demod.c modem_probe.c octave.c)
 target_link_libraries(fsk_demod ${CMAKE_REQUIRED_LIBRARIES} codec2)
 
 add_executable(fsk_get_test_bits fsk_get_test_bits.c)
-target_link_libraries(fsk_get_test_bits ${CMAKE_REQUIRED_LIBRARIES} codec2)
+target_link_libraries(fsk_get_test_bits)
 
 add_executable(fsk_put_test_bits fsk_put_test_bits.c)
 target_link_libraries(fsk_put_test_bits ${CMAKE_REQUIRED_LIBRARIES} codec2)
@@ -329,6 +329,9 @@ target_link_libraries(fm_demod ${CMAKE_REQUIRED_LIBRARIES})
 add_executable(cohpsk_mod cohpsk_mod.c)
 target_link_libraries(cohpsk_mod ${CMAKE_REQUIRED_LIBRARIES} codec2)
 
+add_executable(ofdm_mod ofdm_mod.c  ../src/ofdm.c)
+target_link_libraries(ofdm_mod ${CMAKE_REQUIRED_LIBRARIES} codec2)
+
 add_executable(fmfsk_mod fmfsk_mod.c)
 target_link_libraries(fmfsk_mod ${CMAKE_REQUIRED_LIBRARIES} codec2)
 
diff --git a/codec2-dev/src/ofdm_mod.c b/codec2-dev/src/ofdm_mod.c
new file mode 100644
index 00000000..67735c98
--- /dev/null
+++ b/codec2-dev/src/ofdm_mod.c
@@ -0,0 +1,117 @@
+/*---------------------------------------------------------------------------*\
+
+  FILE........: ofdm_mod.c
+  AUTHOR......: David Rowe
+  DATE CREATED: March 2018
+
+  Given an input file of bits (note one bit per char format), outputs
+  a raw file (8kHz, 16 bit shorts) of OFDM modem samples ready to send
+  over a HF radio channel.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2018 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, 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_ofdm.h"
+
+#define ASCALE (2E5*1.1491)
+
+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 OFDM   *ofdm;
+    int           frames;
+    int           i;
+
+    if (argc < 3) {
+        fprintf(stderr, "\n");
+	fprintf(stderr, "usage: %s InputOneCharPerBitFile OutputModemRawFile\n", argv[0]);
+        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);
+    }
+
+    ofdm = ofdm_create(OFDM_CONFIG_700D);
+    assert(ofdm != NULL);
+    int Nbitsperframe = ofdm_get_bits_per_frame(ofdm);
+    int Nsamperframe = ofdm_get_samples_per_frame();
+
+    char  tx_bits_char[Nbitsperframe];
+    int   tx_bits[Nbitsperframe];
+    COMP  tx_sams[Nsamperframe];
+    short tx_scaled[Nsamperframe];
+    
+    frames = 0;
+
+    while(fread(tx_bits_char, sizeof(char), Nbitsperframe, fin) == Nbitsperframe) {
+	frames++;
+        
+        for(i=0; i<Nbitsperframe; i++)
+            tx_bits[i] = tx_bits_char[i];
+	ofdm_mod(ofdm, tx_sams, tx_bits);
+
+	/* scale and save to disk as shorts */
+
+	for(i=0; i<Nsamperframe; i++)
+	    tx_scaled[i] = ASCALE * tx_sams[i].real;
+
+ 	fwrite(tx_scaled, sizeof(short), Nsamperframe, fout);
+
+	/* if this is in a pipeline, we probably don't want the usual
+	   buffering to occur */
+
+        if (fout == stdout) fflush(stdout);
+        if (fin == stdin) fflush(stdin);
+    }
+
+    fclose(fin);
+    fclose(fout);
+    ofdm_destroy(ofdm);
+
+    return 0;
+}