float2bits migrated to tetra-rx

- compatible to old mode
- new streaming mode (option -s)
- buffer size adjusted

src/tetra-rx.c

@@ -34,23 +34,79 @@
 #include <phy/tetra_burst_sync.h>
 #include "tetra_gsmtap.h"
 
+// size of IO buffers (number of elements)
+#define BUF_SIZE 256
+
 void *tetra_tall_ctx;
 
+
+static int process_sym_fl(float fl)
+{
+	int ret;
+
+	/* very simplistic scheme */
+	if (fl > 2)
+		ret = 3;
+	else if (fl > 0)
+		ret = 1;
+	else if (fl < -2)
+		ret = -3;
+	else
+		ret = -1;
+
+	return ret;
+}
+
+static void sym_int2bits(int sym, uint8_t *ret)
+{
+	switch (sym) {
+	case -3:
+		ret[0] = 1;
+		ret[1] = 1;
+		break;
+	case 1:
+		ret[0] = 0;
+		ret[1] = 0;
+		break;
+	case 3:
+		ret[0] = 0;
+		ret[1] = 1;
+		break;
+	case -1:
+		ret[0] = 1;
+		ret[1] = 0;
+		break;
+	}
+}
+
 int main(int argc, char **argv)
 {
 	int fd;
+	int opt;
+	int streaming   = 0;
+	int opt_verbose = 0;
+	
 	struct tetra_rx_state *trs;
 	struct tetra_mac_state *tms;
 
-	if (argc < 2) {
-		fprintf(stderr, "Usage: %s <file_with_1_byte_per_bit>\n", argv[0]);
-		exit(1);
+	while ((opt = getopt(argc, argv, "sv")) != -1) {
+		switch (opt) {
+		case 's':
+			streaming = 1;
+			break;
+		case 'v':
+			opt_verbose = 1;
+			break;
+
+		default:
+			exit(2);
+		}
 	}
 
-	fd = open(argv[1], O_RDONLY);
-	if (fd < 0) {
-		perror("open");
-		exit(2);
+	if (argc <= optind) {
+		fprintf(stderr, "Usage: %s -s [-v] <filestream>\n", argv[0]);
+		fprintf(stderr, "Usage: %s <file_with_1_byte_per_bit>\n", argv[0]);
+		exit(1);
 	}
 
 	tetra_gsmtap_init("localhost", 0);
@@ -61,19 +117,52 @@ int main(int argc, char **argv)
 	trs = talloc_zero(tetra_tall_ctx, struct tetra_rx_state);
 	trs->burst_cb_priv = tms;
 	
-	while (1) {
-		uint8_t buf[64];
-		int len;
+	fd = open(argv[optind], O_RDONLY);
+	if (fd < 0) {
+		perror("open");
+		exit(2);
+	}
 
-		len = read(fd, buf, sizeof(buf));
-		if (len < 0) {
-			perror("read");
-			exit(1);
-		} else if (len == 0) {
-			printf("EOF");
-			break;
+	// use old mode which uses files with 1 byte per bit
+	if(streaming == 0) {
+		while (1) {
+			uint8_t buf[64];
+			int len;
+
+			len = read(fd, buf, sizeof(buf));
+			if (len < 0) {
+				perror("read");
+				exit(1);
+			} else if (len == 0) {
+				printf("EOF");
+				break;
+			}
+			tetra_burst_sync_in(trs, buf, len);
+		}
+	}
+	else { // new fast mode - we will decode the incoming file ourself
+		while (1) {
+			int rc;
+			float fl[BUF_SIZE];
+			uint8_t bits[2*BUF_SIZE];
+			rc = read(fd, fl, sizeof(*fl) * BUF_SIZE);
+			if (rc < 0) {
+				perror("read");
+				exit(1);
+			} else if (rc == 0) {
+				break;
+			}
+			rc /= sizeof(*fl);
+			int i;
+			for (i = 0; i < rc; ++i) {
+				int sym = process_sym_fl(fl[i]);
+				sym_int2bits(sym, bits + i*2);
+				if (opt_verbose) {
+					printf("%1u%1u", bits[2*i + 0], bits[2*i + 1]);
+				}
+			}
+			tetra_burst_sync_in(trs, bits, rc * 2);
 		}
-		tetra_burst_sync_in(trs, buf, len);
 	}
 	
 	talloc_free(trs);