--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/trau-decode/parse-hex16.c	Tue Feb 25 05:36:25 2025 +0000
@@ -0,0 +1,215 @@
+/*
+ * This program reads a line-based text file in an ad hoc hex format
+ * where each line represents a TRAU-16k frame.  These TRAU-16k frames
+ * are then decoded.
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+static int
+decode_hex_digit(c)
+{
+	if (isdigit(c))
+		return c - '0';
+	else if (isupper(c))
+		return c - 'A' + 10;
+	else
+		return c - 'a' + 10;
+}
+
+static void
+hex2bits(hex, bits)
+	char *hex;
+	uint8_t *bits;
+{
+	unsigned n, m, x;
+
+	for (n = 0; n < 80; n++) {
+		x = decode_hex_digit(hex[n]);
+		for (m = 8; m; m >>= 1) {
+			if (x & m)
+				*bits++ = 1;
+			else
+				*bits++ = 0;
+		}
+	}
+}
+
+static unsigned
+bits_to_num(bits, nbits)
+	uint8_t *bits;
+	unsigned nbits;
+{
+	unsigned accum;
+	unsigned n;
+
+	accum = 0;
+	for (n = 0; n < nbits; n++) {
+		accum <<= 1;
+		if (*bits)
+			accum |= 1;
+		bits++;
+	}
+	return accum;
+}
+
+static void
+process_frame(frame_bits)
+	uint8_t *frame_bits;
+{
+	unsigned c1_5, c6_11;
+
+	printf("  C1-C5: %u%u%u%u%u", frame_bits[17], frame_bits[18],
+		frame_bits[19], frame_bits[20], frame_bits[21]);
+	c1_5 = bits_to_num(frame_bits + 17, 5);
+	switch (c1_5) {
+	case 0x02:
+		fputs(" (FR UL)", stdout);
+		break;
+	case 0x1C:
+		fputs(" (FR DL)", stdout);
+		break;
+	case 0x1A:
+		fputs(" (EFR)", stdout);
+		break;
+	case 0x10:
+		fputs(" (idle UL)", stdout);
+		break;
+	case 0x0E:
+		fputs(" (idle DL)", stdout);
+		break;
+	case 0x08:
+		fputs(" (data UL)", stdout);
+		break;
+	case 0x16:
+		fputs(" (data DL)", stdout);
+		break;
+	case 0x09:
+		fputs(" (HR data UL)", stdout);
+		break;
+	case 0x17:
+		fputs(" (HR data DL)", stdout);
+		break;
+	case 0x14:
+		fputs(" (D144 sync)", stdout);
+		break;
+	case 0x1F:
+		fputs(" (E-TRAU)", stdout);
+		break;
+	case 0x06:
+		fputs(" (AMR)", stdout);
+		break;
+	}
+	putchar('\n');
+	switch (c1_5) {
+	case 0x02:
+	case 0x1C:
+	case 0x1A:
+	case 0x10:
+	case 0x0E:
+		c6_11 = bits_to_num(frame_bits + 22, 6);
+		printf("  C6-C11: %u\n", c6_11);
+		printf("  C12=%u C13=%u C14=%u C15=%u\n", frame_bits[28],
+			frame_bits[29], frame_bits[30], frame_bits[31]);
+		print_fr_efr_frame(frame_bits, c1_5);
+		printf("  C16=%u C17=%u C18=%u C19=%u C20=%u C21=%u\n",
+			frame_bits[310], frame_bits[311], frame_bits[312],
+			frame_bits[313], frame_bits[314], frame_bits[315]);
+		printf("  T1=%u T2=%u T3=%u T4=%u\n", frame_bits[316],
+			frame_bits[317], frame_bits[318], frame_bits[319]);
+		break;
+	case 0x08:
+	case 0x09:
+	case 0x16:
+	case 0x17:
+	case 0x14:
+		print_data_frame(frame_bits);
+		break;
+	case 0x1F:
+		print_edata_frame(frame_bits);
+		break;
+	case 0x06:
+		print_amr_frame(frame_bits);
+		break;
+	default:
+		printf("  C6-C15: %u%u%u%u%u%u%u%u%u%u\n", frame_bits[22],
+			frame_bits[23], frame_bits[24], frame_bits[25],
+			frame_bits[26], frame_bits[27], frame_bits[28],
+			frame_bits[29], frame_bits[30], frame_bits[31]);
+		printf("  C16=%u C17=%u C18=%u C19=%u C20=%u C21=%u\n",
+			frame_bits[310], frame_bits[311], frame_bits[312],
+			frame_bits[313], frame_bits[314], frame_bits[315]);
+		printf("  T1=%u T2=%u T3=%u T4=%u\n", frame_bits[316],
+			frame_bits[317], frame_bits[318], frame_bits[319]);
+	}
+}
+
+static void
+process_record(hex_frame, lineno)
+	char *hex_frame;
+{
+	uint8_t frame_bits[320];
+
+	printf("line %d:\n%s\n", lineno, hex_frame);
+	hex2bits(hex_frame, frame_bits);
+	process_frame(frame_bits);
+}
+
+static void
+process_line(linebuf, filename, lineno)
+	char *linebuf, *filename;
+{
+	char *cp, *np;
+	unsigned n;
+
+	for (cp = linebuf; isspace(*cp); cp++)
+		;
+	if (*cp == '\0' || *cp == '#')
+		return;
+	np = cp;
+	for (n = 0; n < 80; n++) {
+		if (!isxdigit(*cp))
+			goto inv;
+		cp++;
+	}
+	if (*cp) {
+		if (!isspace(*cp))
+			goto inv;
+		*cp++ = '\0';
+	}
+	while (isspace(*cp))
+		cp++;
+	if (*cp != '\0' && *cp != '#')
+		goto inv;
+	process_record(np, lineno);
+	return;
+
+inv:	fprintf(stderr, "%s line %d: invalid syntax\n", filename, lineno);
+	exit(1);
+}
+
+main(argc, argv)
+	char **argv;
+{
+	FILE *inf;
+	char linebuf[128];
+	int lineno;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s hex-file\n", argv[0]);
+		exit(1);
+	}
+	inf = fopen(argv[1], "r");
+	if (!inf) {
+		perror(argv[1]);
+		exit(1);
+	}
+	for (lineno = 1; fgets(linebuf, sizeof linebuf, inf); lineno++)
+		process_line(linebuf, argv[1], lineno);
+	exit(0);
+}