--- a/trau-decode/amr8-common.c	Thu Nov 20 16:52:21 2025 +0000
+++ b/trau-decode/amr8-common.c	Thu Nov 20 19:18:26 2025 +0000
@@ -179,10 +179,81 @@
 }
 
 static void
+decode_speech_frame(c_bits, d_bits)
+	ubit_t *c_bits, *d_bits;
+{
+	unsigned c1_3 = bits_to_num(c_bits, 3);
+	unsigned rif = (c1_3 >= 3);
+	unsigned c4_5 = bits_to_num(c_bits + 3, 2);
+
+	printf("  Speech: RIF=%u, %s\n", rif, fclass_names[c4_5]);
+	/* to be continued */
+}
+
+static void
+decode_nospeech_frame(c_bits, d_bits)
+	ubit_t *c_bits, *d_bits;
+{
+	ubit_t crc_collect[5 + 51];
+	int crc_stat;
+
+	printf("  No_Speech: RIF=%u TA=%u UFE/DFE=%u\n", c_bits[2],
+		bits_to_num(d_bits, 6), d_bits[6]);
+	printf("  No_Spch_Class=%u%u%u (%s) CMI=%u CMR=%u\n",
+		d_bits[7], d_bits[8], d_bits[9],
+		nospch_class_names[bits_to_num(d_bits + 7, 3)],
+		bits_to_num(d_bits + 10, 3), bits_to_num(d_bits + 13, 3));
+	saved_mode = bits_to_num(d_bits + 7, 3);
+	saved_mode_valid = 1;
+	bcopy(c_bits, crc_collect, 5);
+	bcopy(d_bits, crc_collect + 5, 51);
+	crc_stat = osmo_crc8gen_check_bits(&gsm0860_amr_crc3, crc_collect,
+					   5 + 51, d_bits + 51);
+	printf("  CRC %s\n", crc_stat ? "bad" : "good");
+	fputs("    SID", stdout);
+	print_generic_params(d_bits + 16, params_sid);
+	putchar('\n');
+	printf("  PAB=%u TAE=%u%u DTXd=%u TFOE=%u\n", d_bits[59], d_bits[60],
+		d_bits[61], d_bits[62], d_bits[63]);
+	check_spare_bits(d_bits + 64, 61, "D65..D125");
+}
+
+static void
 handle_amr8_low(frame_bits)
 	ubit_t *frame_bits;
 {
-	puts("  TRAU-AMR-8k Low format, decoding to be implemented");
+	ubit_t *c_bits = frame_bits + 17;
+	ubit_t d_bits[126];
+
+	bcopy(frame_bits + 9, d_bits, 7);
+	bcopy(frame_bits + 22, d_bits + 7, 2);
+	bcopy(frame_bits + 26, d_bits + 9, 6);
+	bcopy(frame_bits + 33, d_bits + 15, 7);
+	bcopy(frame_bits + 41, d_bits + 22, 7);
+	bcopy(frame_bits + 49, d_bits + 29, 7);
+	bcopy(frame_bits + 57, d_bits + 36, 7);
+	bcopy(frame_bits + 65, d_bits + 43, 7);
+	bcopy(frame_bits + 73, d_bits + 50, 7);
+	bcopy(frame_bits + 81, d_bits + 57, 7);
+	bcopy(frame_bits + 89, d_bits + 64, 7);
+	bcopy(frame_bits + 97, d_bits + 71, 7);
+	bcopy(frame_bits + 105, d_bits + 78, 7);
+	bcopy(frame_bits + 113, d_bits + 85, 7);
+	bcopy(frame_bits + 121, d_bits + 92, 7);
+	bcopy(frame_bits + 129, d_bits + 99, 7);
+	bcopy(frame_bits + 137, d_bits + 106, 7);
+	bcopy(frame_bits + 145, d_bits + 113, 7);
+	bcopy(frame_bits + 153, d_bits + 120, 6);
+
+	printf("  C1-C5: %u%u%u %u%u\n", c_bits[0], c_bits[1], c_bits[2],
+		c_bits[3], c_bits[4]);
+	printf("  Config_Prot=%u%u%u Msg_No=%u%u\n", d_bits[54], d_bits[55],
+		d_bits[56], d_bits[57], d_bits[58]);
+	if (c_bits[3] || c_bits[4])
+		decode_speech_frame(c_bits, d_bits);
+	else
+		decode_nospeech_frame(c_bits, d_bits);
+	printf("  T=%u\n", frame_bits[159]);
 }
 
 static void
@@ -190,6 +261,8 @@
 	ubit_t *frame_bits;
 {
 	puts("  TRAU-AMR-8k MR67 format, decoding to be implemented");
+	saved_mode = 3;
+	saved_mode_valid = 1;
 }
 
 static void
@@ -197,6 +270,8 @@
 	ubit_t *frame_bits;
 {
 	puts("  TRAU-AMR-8k MR74 format, decoding to be implemented");
+	saved_mode = 4;
+	saved_mode_valid = 1;
 }
 
 void