--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/v110/v110-dump16.c	Thu Sep 12 21:55:32 2024 +0000
@@ -0,0 +1,137 @@
+/*
+ * This program reads a 64 kbit/s timeslot recording file, examines it
+ * as V.110 with 16 kbit/s intermediate rate, locates 80-bit V.110 frames
+ * and dumps them in a mostly raw form.
+ */
+
+#include <sys/types.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+static const uint8_t *filebuf;
+static unsigned total_size;
+
+static void
+read_ts_file(filename)
+	char *filename;
+{
+	int fd;
+	struct stat st;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		perror(filename);
+		exit(1);
+	}
+	fstat(fd, &st);
+	if (!S_ISREG(st.st_mode)) {
+		fprintf(stderr, "error: %s is not a regular file\n", filename);
+		exit(1);
+	}
+	total_size = st.st_size;
+	if (total_size < 40) {
+		fprintf(stderr, "error: %s is too short\n", filename);
+		exit(1);
+	}
+	filebuf = mmap(NULL, total_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	if (filebuf == MAP_FAILED) {
+		perror("mmap");
+		exit(1);
+	}
+	close(fd);
+}
+
+static int
+check_sync(pos)
+	unsigned pos;
+{
+	const uint8_t *cand = filebuf + pos;
+	unsigned n;
+
+	for (n = 0; n < 4; n++) {
+		if (cand[n] & 0xC0)
+			return 0;
+	}
+	for (n = 1; n < 10; n++) {
+		if (!(cand[n * 4] & 0x80))
+			return 0;
+	}
+	return 1;
+}
+
+static unsigned
+extract_data_byte(pos)
+	unsigned pos;
+{
+	const uint8_t *src = filebuf + pos;
+	unsigned accum;
+	unsigned n;
+
+	accum = 0;
+	for (n = 0; n < 4; n++) {
+		accum <<= 1;
+		if (*src & 0x80)
+			accum |= 1;
+		accum <<= 1;
+		if (*src & 0x40)
+			accum |= 1;
+		src++;
+	}
+	return accum;
+}
+
+static void
+process_frame(pos)
+	unsigned pos;
+{
+	unsigned nb;
+
+	printf("Frame at 0x%x:", pos);
+	pos += 4;
+	for (nb = 0; nb < 9; nb++) {
+		printf(" %02X", extract_data_byte(pos));
+		pos += 4;
+	}
+	putchar('\n');
+}
+
+static void
+process_filebuf()
+{
+	unsigned p, endp;
+	int sync = 0, match;
+
+	endp = total_size - 40;
+	for (p = 0; p <= endp; ) {
+		match = check_sync(p);
+		if (match != sync) {
+			printf("# %s frame sync at file offset 0x%x\n",
+				match ? "Acquired" : "Lost", p);
+		}
+		if (match) {
+			process_frame(p);
+			p += 40;
+		} else
+			p++;
+		sync = match;
+	}
+}
+
+main(argc, argv)
+	char **argv;
+{
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s binfile\n", argv[0]);
+		exit(1);
+	}
+	read_ts_file(argv[1]);
+	process_filebuf();
+	exit(0);
+}