shallow zip-file copy from codec2 e9d726bf20

1 files changed, 235 insertions, 0 deletions

diff --git a/src/freedv_data_rx.c b/src/freedv_data_rx.c
new file mode 100644
index 0000000..0e028e3
--- /dev/null
+++ b/src/freedv_data_rx.c
@@ -0,0 +1,235 @@
+/*---------------------------------------------------------------------------*\
+
+  FILE........: freedv_data_rx.c
+  AUTHOR......: Jeroen Vreeken
+  DATE CREATED: May 2020
+
+  Demo receive program for FreeDV API functions ignores everything but
+  VHF packet data.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2020 Jeroen Vreeken
+
+  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 <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "freedv_api.h"
+
+/**********************************************************
+	Encoding an ITU callsign (and 4 bit secondary station ID to a valid MAC address.
+	http://dmlinking.net/eth_ar.html
+ */
+
+// Lookup table for valid callsign characters
+static char alnum2code[37] = {
+	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+	'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 
+	0
+};
+
+// Decode the callsign in a MAC address
+static int eth_ar_mac2call(char *callsign, int *ssid, bool *multicast, uint8_t mac[6])
+{
+	uint64_t add;
+	int i;
+
+	if (!memcmp(mac, (uint8_t[6]){ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, 6)) {
+		*ssid = 0;
+		*multicast = true;
+		strcpy(callsign, "*");
+		return 0;
+	}
+	*multicast = mac[0] & 0x01;
+	*ssid = (mac[0] & 0x3c) >> 2;
+	add = (uint64_t)(mac[0] & 0xc0) << (40 - 6);
+	add |= (uint64_t)mac[1] << 32;
+	add |= (uint64_t)mac[2] << 24;
+	add |= (uint64_t)mac[3] << 16;
+	add |= (uint64_t)mac[4] << 8;
+	add |= (uint64_t)mac[5];
+
+	for (i = 0; i < 8; i++) {
+		int c = add % 37;
+		callsign[i] = alnum2code[c];
+		add /= 37;
+	}
+	callsign[i] = 0;
+
+	return 0;
+}
+
+
+
+/**********************************************************
+	Data channel callback functions
+ */
+
+
+struct my_callback_state {
+    FILE *fdataout;
+    int calls;
+};
+
+/* Called when a packet has been received */
+void my_datarx(void *callback_state, unsigned char *packet, size_t size) 
+{
+    struct my_callback_state* pstate = (struct my_callback_state*)callback_state;
+    pstate->calls++;
+    fprintf(pstate->fdataout, "%-4d", pstate->calls);
+
+    if (pstate->fdataout != NULL) {
+        size_t i;
+	
+	char callsign_to[9], callsign_from[9];
+	int ssid_to, ssid_from;
+	bool multicast_to, multicast_from;
+	eth_ar_mac2call(callsign_to, &ssid_to, &multicast_to, packet);
+	eth_ar_mac2call(callsign_from, &ssid_from, &multicast_from, packet + 6);
+	
+	if (multicast_from)
+	    fprintf(pstate->fdataout, "Multicast");
+	else
+	    fprintf(pstate->fdataout, "%s-%d", callsign_from, ssid_from);
+
+        printf(" -> ");
+
+	if (multicast_to)
+	    fprintf(pstate->fdataout, "Multicast");
+	else
+	    fprintf(pstate->fdataout, "%s-%d", callsign_to, ssid_to);
+	
+	printf(" (%zd bytes)", size);
+	
+	/* It could be just an identification frame */
+	if (size < 14) {
+	    fprintf(pstate->fdataout, " Identification");
+	} else {
+	    unsigned short ethertype = packet[12] << 8 | packet[13];
+	    fprintf(pstate->fdataout, " EtherType 0x%04x", ethertype);
+	    
+	    if (ethertype == 0x7370)
+	        fprintf(pstate->fdataout, " (FPRS)");
+        }
+        
+	fprintf(pstate->fdataout, ":");
+
+	for (i = 0; i < size; i++) {
+	    if (i % 0x10 == 0)
+	        fprintf(pstate->fdataout, "\n0x%04zx: ", i);
+	    fprintf(pstate->fdataout, "0x%02x ", packet[i]);
+	}
+       	fprintf(pstate->fdataout, "\n");
+    }
+}
+
+/* Called when a new packet can be send */
+void my_datatx(void *callback_state, unsigned char *packet, size_t *size) {
+    /* This should not happen while receiving.. */
+    fprintf(stderr, "datarx callback called, this should not happen!\n");    
+    *size = 0;
+}
+
+
+int main(int argc, char *argv[]) {
+    FILE                      *fin;
+    struct freedv             *freedv;
+    int                        nin, frame = 0;
+    struct my_callback_state   my_cb_state = {0};
+    int                        mode;
+    int                        verbose;
+    int                        i;
+
+    
+    if (argc < 3) {
+	printf("usage: %s 2400A|2400B|800XA InputModemSpeechFile\n"
+               " \n", argv[0]);
+	printf("e.g    %s 2400A data_fdmdv.raw\n", argv[0]);
+	exit(1);
+    }
+
+    my_cb_state.fdataout = stdout;
+
+    mode = -1;
+    if (!strcmp(argv[1],"2400A"))
+        mode = FREEDV_MODE_2400A;
+    if (!strcmp(argv[1],"2400B"))
+        mode = FREEDV_MODE_2400B;
+    if (!strcmp(argv[1],"800XA"))
+        mode = FREEDV_MODE_800XA;
+    assert(mode != -1);
+
+    if (strcmp(argv[2], "-")  == 0) fin = stdin;
+    else if ( (fin = fopen(argv[2],"rb")) == NULL ) {
+	fprintf(stderr, "Error opening input raw modem sample file: %s: %s.\n",
+         argv[2], strerror(errno));
+	exit(1);
+    }
+
+    verbose = 0;
+    
+    if (argc > 3) {
+        for (i = 3; i < argc; i++) {
+            if (strcmp(argv[i], "-v") == 0) {
+                verbose = 1;
+            }
+            if (strcmp(argv[i], "-vv") == 0) {
+                verbose = 2;
+            }
+        }
+    }
+
+    freedv = freedv_open(mode);
+    assert(freedv != NULL);
+
+    freedv_set_verbose(freedv, verbose);
+
+    short speech_out[freedv_get_n_max_speech_samples(freedv)];
+    short demod_in[freedv_get_n_max_modem_samples(freedv)];
+
+    freedv_set_callback_data(freedv, my_datarx, my_datatx, &my_cb_state);
+
+    /* Note we need to work out how many samples demod needs on each
+       call (nin).  This is used to adjust for differences in the tx and rx
+       sample clock frequencies.  Note also the number of output
+       speech samples is time varying. */
+
+    nin = freedv_nin(freedv);
+    while(fread(demod_in, sizeof(short), nin, fin) == nin) {
+        frame++;
+        
+        /* usual case: use the freedv_api to do everything: speech decoding, demodulating */
+        // most common interface - real shorts in, real shorts out
+        freedv_rx(freedv, speech_out, demod_in);
+
+        nin = freedv_nin(freedv);
+    }
+
+    fclose(fin);
+    fprintf(stderr, "frames decoded: %d\n", frame);
+
+    freedv_close(freedv);
+    return 0;
+}
+