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changeset 110:597640501626

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trau-decode HR guts: prepare for integration with AMR8 A new investigation program is being developed that needs to decode both classic HR and AMR8 frame types on 8 kbit/s channels. Each side needs to be prepared for coexistence.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 22 Dec 2025 06:30:43 +0000
parents 382a80f91149
children b3ebfbeee32b
files trau-decode/hr-guts.c
diffstat 1 files changed, 66 insertions(+), 6 deletions(-) [+]
line wrap: on
line diff
--- a/trau-decode/hr-guts.c	Mon Dec 22 05:25:15 2025 +0000
+++ b/trau-decode/hr-guts.c	Mon Dec 22 06:30:43 2025 +0000
@@ -24,6 +24,24 @@
 	.remainder = 0x7,
 };
 
+static unsigned
+bits_to_num(bits, nbits)
+	ubit_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 int
 bit_parity(bits, nbits)
 	ubit_t *bits;
@@ -55,8 +73,8 @@
 	}
 }
 
-void
-print_gsmhr_frame(frame)
+static void
+print_hr1_speech(frame)
 	ubit_t *frame;
 {
 	ubit_t xc_bits[6], dbits[112];
@@ -64,12 +82,10 @@
 	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],
+	printf("  XC1-XC6: %u%u%u%u%u%u OP %s\n", xc_bits[0], xc_bits[1],
+		xc_bits[2], xc_bits[3], xc_bits[4], xc_bits[5],
 		bit_parity(xc_bits, 6) ? "good" : "bad");
 	bcopy(frame + 22, dbits, 2);
 	bcopy(frame + 25, dbits + 2, 7);
@@ -108,3 +124,47 @@
 		frame[157]);
 	printf("  T1=%u T2=%u\n", frame[158], frame[159]);
 }
+
+print_gsmhr_frame(frame)
+	ubit_t *frame;
+{
+	unsigned c1_3 = bits_to_num(frame + 9, 3);
+	char *desc;
+
+	switch (c1_3) {
+	case 0:
+		desc = "speech";
+		break;
+	case 1:
+		desc = "data";
+		break;
+	case 2:
+		desc = "O&M";
+		break;
+	case 7:
+		desc = "GCF";
+		break;
+	default:
+		desc = "unknown";
+	}
+	printf("  HR C1-C5: %u%u%u%u%u (%s) OP %s\n", frame[9], frame[10],
+		frame[11], frame[12], frame[13], desc,
+		bit_parity(frame + 9, 5) ? "good" : "bad");
+	/* return number of T bits */
+	switch (c1_3) {
+	case 0:
+		print_hr1_speech(frame);
+		return 2;
+	case 1:
+		/* TODO: print data frame */
+		return 0;
+	case 2:
+		/* TODO: print O&M frame */
+		return 0;
+	case 7:
+		/* TODO: print GCF */
+		return 2;
+	default:
+		return 0;
+	}
+}