--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/trau-decode/hr-guts.c	Sat Feb 08 03:00:31 2025 +0000
@@ -0,0 +1,110 @@
+/*
+ * This module contains the guts of trau-hr-dump program in terms of
+ * HRv1 frame decoding.  It has been factored out to facilitate creation
+ * of trau-hr-dump-hex version.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include "gsmhr_unpack.h"
+#include "osmo_bits.h"
+
+/*
+ * EFR TRAU parity (also used for HR)
+ *
+ * g(x) = x^3 + x^1 + 1
+ */
+static const struct osmo_crc8gen_code gsm0860_efr_crc3 = {
+	.bits = 3,
+	.poly = 0x3,
+	.init = 0x0,
+	.remainder = 0x7,
+};
+
+static int
+bit_parity(bits, nbits)
+	ubit_t *bits;
+	unsigned nbits;
+{
+	unsigned n, sum;
+
+	sum = 0;
+	for (n = 0; n < nbits; n++)
+		sum += bits[n];
+	return sum & 1;
+}
+
+static void
+bits2bytes(bits, bytes, nbytes)
+	ubit_t *bits;
+	uint8_t *bytes;
+	unsigned nbytes;
+{
+	unsigned n, m, acc;
+
+	for (n = 0; n < nbytes; n++) {
+		acc = 0;
+		for (m = 0; m < 8; m++) {
+			acc <<= 1;
+			acc |= *bits++;
+		}
+		*bytes++ = acc;
+	}
+}
+
+void
+print_gsmhr_frame(frame)
+	ubit_t *frame;
+{
+	ubit_t xc_bits[6], dbits[112];
+	uint8_t hr_bytes[14];
+	int16_t params[18];
+	int crc_stat;
+
+	printf("  C1-C4: %u%u%u%u OP %s\n", frame[9], frame[10], frame[11],
+		frame[12], bit_parity(frame + 9, 5) ? "good" : "bad");
+	bcopy(frame + 14, xc_bits, 2);
+	bcopy(frame + 18, xc_bits + 2, 4);
+	printf("  XC1-XC5: %u%u%u%u%u OP %s\n", xc_bits[0], xc_bits[1],
+		xc_bits[2], xc_bits[3], xc_bits[4],
+		bit_parity(xc_bits, 6) ? "good" : "bad");
+	bcopy(frame + 22, dbits, 2);
+	bcopy(frame + 25, dbits + 2, 7);
+	bcopy(frame + 33, dbits + 9, 7);
+	bcopy(frame + 41, dbits + 16, 7);
+	bcopy(frame + 49, dbits + 23, 7);
+	bcopy(frame + 57, dbits + 30, 7);
+	bcopy(frame + 65, dbits + 37, 7);
+	bcopy(frame + 76, dbits + 44, 4);
+	bcopy(frame + 81, dbits + 48, 7);
+	bcopy(frame + 89, dbits + 55, 7);
+	bcopy(frame + 97, dbits + 62, 7);
+	bcopy(frame + 105, dbits + 69, 7);
+	bcopy(frame + 113, dbits + 76, 7);
+	bcopy(frame + 121, dbits + 83, 7);
+	bcopy(frame + 129, dbits + 90, 7);
+	bcopy(frame + 137, dbits + 97, 7);
+	bcopy(frame + 145, dbits + 104, 7);
+	dbits[111] = frame[153];
+	crc_stat = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, dbits, 44,
+					   frame + 73);
+	printf("  CRC %s\n", crc_stat ? "bad" : "good");
+	bits2bytes(dbits, hr_bytes, 14);
+	gsmhr_unpack_ts101318(hr_bytes, params);
+	printf("  R0=%02x LPC=%03x,%03x,%02x Int=%x Mode=%x\n", params[0],
+		params[1], params[2], params[3], params[4], params[5]);
+	printf(params[5] ? "  s1=%02x,%03x,%02x" : "  s1=%02x,%02x,%02x",
+		params[6], params[7], params[8]);
+	printf(params[5] ? " s2=%x,%03x,%02x" : " s2=%02x,%02x,%02x",
+		params[9], params[10], params[11]);
+	printf(params[5] ? " s3=%x,%03x,%02x" : " s3=%02x,%02x,%02x",
+		params[12], params[13], params[14]);
+	printf(params[5] ? " s4=%x,%03x,%02x\n" : " s4=%02x,%02x,%02x\n",
+		params[15], params[16], params[17]);
+	printf("  C6-C9: %u%u%u%u\n", frame[154], frame[155], frame[156],
+		frame[157]);
+	printf("  T1=%u T2=%u\n", frame[158], frame[159]);
+}