coding: add gsm0503_detect_a[fh]s_dtx_frame2()

The new functions accept an additional mode_id poiner, which is
currently set for the following frames: AFS_ONSET, AHS_ONSET,
AHS_SID_FIRST_P2 with N * 16 - M bit pattern.

Also, the new API accepts soft-bits instead of hard-bits.
Converting bits from soft to hard is now performed internally.

Change-Id: Ibcac395f800bb64150c97fcdaca3523ecfc5fcee
Related: OS#5570

3 files changed, 122 insertions, 85 deletions

diff --git a/src/coding/gsm0503_amr_dtx.c b/src/coding/gsm0503_amr_dtx.c
index b1493300..7de3b281 100644
--- a/src/coding/gsm0503_amr_dtx.c
+++ b/src/coding/gsm0503_amr_dtx.c
@@ -1,5 +1,5 @@
 /*
- * (C) 2020 by sysmocom - s.f.m.c. GmbH, Author: Philipp Maier
+ * (C) 2020-2022 by sysmocom - s.f.m.c. GmbH, Author: Philipp Maier
  * All Rights Reserved
  *
  * SPDX-License-Identifier: GPL-2.0+
@@ -32,6 +32,8 @@
 #include <osmocom/coding/gsm0503_parity.h>
 #include <osmocom/gsm/gsm0503.h>
 
+#define S2U(b)	((b) < 0)
+
 /* See also: 3GPP TS 05.03, chapter 3.10.1.3, 3.10.5.2 Identification marker */
 static const ubit_t id_marker_1[] = { 1, 0, 1, 1, 0, 0, 0, 0, 1 };
 
@@ -60,7 +62,7 @@ const struct value_string gsm0503_amr_dtx_frame_names[] = {
 	{ 0, NULL }
 };
 
-static bool detect_afs_id_marker(int *n_errors, int *n_bits_total, const ubit_t * ubits, uint8_t offset, uint8_t count,
+static bool detect_afs_id_marker(int *n_errors, int *n_bits_total, const sbit_t *sbits, uint8_t offset, uint8_t count,
 				 const ubit_t * id_marker, uint8_t id_marker_len)
 {
 	unsigned int i, k;
@@ -69,20 +71,20 @@ static bool detect_afs_id_marker(int *n_errors, int *n_bits_total, const ubit_t
 	int bits = 0;
 
 	/* Override coded in-band data */
-	ubits += offset;
+	sbits += offset;
 
 	/* Check for identification marker bits */
 	for (i = 0; i < count; i++) {
 		for (k = 0; k < 4; k++) {
-			if (id_marker[id_bit_nr % id_marker_len] != *ubits)
+			if (*sbits == 0 || id_marker[id_bit_nr % id_marker_len] != S2U(*sbits))
 				errors++;
 			id_bit_nr++;
-			ubits++;
+			sbits++;
 			bits++;
 		}
 
 		/* Jump to the next block of 4 bits */
-		ubits += 4;
+		sbits += 4;
 	}
 
 	*n_errors = errors;
@@ -92,30 +94,30 @@ static bool detect_afs_id_marker(int *n_errors, int *n_bits_total, const ubit_t
 	return *n_errors < *n_bits_total / 8;
 }
 
-static bool detect_ahs_id_marker(int *n_errors, int *n_bits_total, const ubit_t * ubits, const ubit_t * id_marker)
+static bool detect_ahs_id_marker(int *n_errors, int *n_bits_total, const sbit_t *sbits, const ubit_t *id_marker)
 {
 	unsigned int i, k;
 	int errors = 0;
 	int bits = 0;
 
 	/* Override coded in-band data */
-	ubits += 16;
+	sbits += 16;
 
 	/* Check first identification marker bits (23*9 bits) */
 	for (i = 0; i < 23; i++) {
 		for (k = 0; k < 9; k++) {
-			if (id_marker[k] != *ubits)
+			if (*sbits == 0 || id_marker[k] != S2U(*sbits))
 				errors++;
-			ubits++;
+			sbits++;
 			bits++;
 		}
 	}
 
 	/* Check remaining identification marker bits (5 bits) */
 	for (k = 0; k < 5; k++) {
-		if (id_marker[k] != *ubits)
+		if (*sbits == 0 || id_marker[k] != S2U(*sbits))
 			errors++;
-		ubits++;
+		sbits++;
 		bits++;
 	}
 
@@ -126,7 +128,7 @@ static bool detect_ahs_id_marker(int *n_errors, int *n_bits_total, const ubit_t
 	return *n_errors < *n_bits_total / 8;
 }
 
-static bool detect_interleaved_ahs_id_marker(int *n_errors, int *n_bits_total, const ubit_t * ubits, uint8_t offset,
+static bool detect_interleaved_ahs_id_marker(int *n_errors, int *n_bits_total, const sbit_t *sbits, uint8_t offset,
 					     uint8_t n_bits, const ubit_t * id_marker, uint8_t id_marker_len)
 {
 	unsigned int i, k;
@@ -136,23 +138,23 @@ static bool detect_interleaved_ahs_id_marker(int *n_errors, int *n_bits_total, c
 	uint8_t remainder = n_bits % id_marker_len;
 
 	/* Override coded in-band data */
-	ubits += offset;
+	sbits += offset;
 
 	/* Check first identification marker bits (23*9 bits) */
 	for (i = 0; i < full_rounds; i++) {
 		for (k = 0; k < id_marker_len; k++) {
-			if (id_marker[k] != *ubits)
+			if (*sbits == 0 || id_marker[k] != S2U(*sbits))
 				errors++;
-			ubits += 2;
+			sbits += 2;
 			bits++;
 		}
 	}
 
 	/* Check remaining identification marker bits (5 bits) */
 	for (k = 0; k < remainder; k++) {
-		if (id_marker[k] != *ubits)
+		if (*sbits == 0 || id_marker[k] != S2U(*sbits))
 			errors++;
-		ubits += 2;
+		sbits += 2;
 		bits++;
 	}
 
@@ -164,125 +166,127 @@ static bool detect_interleaved_ahs_id_marker(int *n_errors, int *n_bits_total, c
 }
 
 /* Detect an FR AMR SID_FIRST frame by its identifcation marker */
-static bool detect_afs_sid_first(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static bool detect_afs_sid_first(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
-	return detect_afs_id_marker(n_errors, n_bits_total, ubits, 32, 53, id_marker_0, 9);
+	return detect_afs_id_marker(n_errors, n_bits_total, sbits, 32, 53, id_marker_0, 9);
 }
 
 /* Detect an FR AMR SID_UPDATE frame by its identification marker */
-static bool detect_afs_sid_update(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static bool detect_afs_sid_update(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
-	return detect_afs_id_marker(n_errors, n_bits_total, ubits, 36, 53, id_marker_0, 9);
+	return detect_afs_id_marker(n_errors, n_bits_total, sbits, 36, 53, id_marker_0, 9);
 }
 
 /* Detect an FR AMR ONSET frame by its repeating coded inband data */
-static bool detect_afs_onset(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static int detect_afs_onset(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
 	bool rc;
 
-	rc = detect_afs_id_marker(n_errors, n_bits_total, ubits, 4, 57, codec_mode_1_sid, 16);
+	rc = detect_afs_id_marker(n_errors, n_bits_total, sbits, 4, 57, codec_mode_1_sid, 16);
 	if (rc)
-		return true;
+		return 0;
 
-	rc = detect_afs_id_marker(n_errors, n_bits_total, ubits, 4, 57, codec_mode_2_sid, 16);
+	rc = detect_afs_id_marker(n_errors, n_bits_total, sbits, 4, 57, codec_mode_2_sid, 16);
 	if (rc)
-		return true;
+		return 1;
 
-	rc = detect_afs_id_marker(n_errors, n_bits_total, ubits, 4, 57, codec_mode_3_sid, 16);
+	rc = detect_afs_id_marker(n_errors, n_bits_total, sbits, 4, 57, codec_mode_3_sid, 16);
 	if (rc)
-		return true;
+		return 2;
 
-	rc = detect_afs_id_marker(n_errors, n_bits_total, ubits, 4, 57, codec_mode_4_sid, 16);
+	rc = detect_afs_id_marker(n_errors, n_bits_total, sbits, 4, 57, codec_mode_4_sid, 16);
 	if (rc)
-		return true;
+		return 3;
 
-	return false;
+	return -1;
 }
 
 /* Detect an HR AMR SID UPDATE frame by its identification marker */
-static bool detect_ahs_sid_update(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static bool detect_ahs_sid_update(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
-	return detect_ahs_id_marker(n_errors, n_bits_total, ubits, id_marker_1);
+	return detect_ahs_id_marker(n_errors, n_bits_total, sbits, id_marker_1);
 }
 
 /* Detect an HR AMR SID FIRST (part 1) frame by its identification marker */
-static bool detect_ahs_sid_first_p1(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static bool detect_ahs_sid_first_p1(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
-	return detect_ahs_id_marker(n_errors, n_bits_total, ubits, id_marker_0);
+	return detect_ahs_id_marker(n_errors, n_bits_total, sbits, id_marker_0);
 }
 
 /* Detect an HR AMR SID FIRST (part 2) frame by its repeating coded inband data */
-static bool detect_ahs_sid_first_p2(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static int detect_ahs_sid_first_p2(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
 	bool rc;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 0, 114, codec_mode_1_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 0, 114, codec_mode_1_sid, 16);
 	if (rc)
-		return true;
+		return 0;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 0, 114, codec_mode_2_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 0, 114, codec_mode_2_sid, 16);
 	if (rc)
-		return true;
+		return 1;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 0, 114, codec_mode_3_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 0, 114, codec_mode_3_sid, 16);
 	if (rc)
-		return true;
+		return 2;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 0, 114, codec_mode_4_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 0, 114, codec_mode_4_sid, 16);
 	if (rc)
-		return true;
+		return 3;
 
-	return false;
+	return -1;
 }
 
 /* Detect an HR AMR ONSET frame by its repeating coded inband data */
-static bool detect_ahs_onset(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static int detect_ahs_onset(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
 	bool rc;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 1, 114, codec_mode_1_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 1, 114, codec_mode_1_sid, 16);
 	if (rc)
-		return true;
+		return 0;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 1, 114, codec_mode_2_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 1, 114, codec_mode_2_sid, 16);
 	if (rc)
-		return true;
+		return 1;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 1, 114, codec_mode_3_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 1, 114, codec_mode_3_sid, 16);
 	if (rc)
-		return true;
+		return 2;
 
-	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 1, 114, codec_mode_4_sid, 16);
+	rc = detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 1, 114, codec_mode_4_sid, 16);
 	if (rc)
-		return true;
+		return 3;
 
-	return false;
+	return -1;
 }
 
 /* Detect an HR AMR SID FIRST INHIBIT frame by its identification marker */
-static bool detect_ahs_sid_first_inh(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static bool detect_ahs_sid_first_inh(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
-	return detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 33, 212, id_marker_1, 9);
+	return detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 33, 212, id_marker_1, 9);
 }
 
 /* Detect an HR AMR SID UPDATE INHIBIT frame by its identification marker */
-static bool detect_ahs_sid_update_inh(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+static bool detect_ahs_sid_update_inh(int *n_errors, int *n_bits_total, const sbit_t *sbits)
 {
-	return detect_interleaved_ahs_id_marker(n_errors, n_bits_total, ubits, 33, 212, id_marker_0, 9);
+	return detect_interleaved_ahs_id_marker(n_errors, n_bits_total, sbits, 33, 212, id_marker_0, 9);
 }
 
 /*! Detect FR AMR DTX frame in unmapped, deinterleaved frame bits.
- *  \param[in] ubits input bits (456 bit).
  *  \param[out] n_errors number of errornous bits.
  *  \param[out] n_bits_total number of checked bits.
+ *  \param[out] mode_id codec mode ID (0..3 or -1).
+ *  \param[in] sbits input soft-bits (456 bit).
  *  \returns dtx frame type. */
-enum gsm0503_amr_dtx_frames gsm0503_detect_afs_dtx_frame(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+enum gsm0503_amr_dtx_frames gsm0503_detect_afs_dtx_frame2(int *n_errors, int *n_bits_total,
+							  int *mode_id, const sbit_t *sbits)
 {
-	if (detect_afs_sid_first(n_errors, n_bits_total, ubits))
+	if (detect_afs_sid_first(n_errors, n_bits_total, sbits))
 		return AFS_SID_FIRST;
-	if (detect_afs_sid_update(n_errors, n_bits_total, ubits))
+	if (detect_afs_sid_update(n_errors, n_bits_total, sbits))
 		return AFS_SID_UPDATE;
-	if (detect_afs_onset(n_errors, n_bits_total, ubits))
+	if ((*mode_id = detect_afs_onset(n_errors, n_bits_total, sbits)) != -1)
 		return AFS_ONSET;
 
 	*n_errors = 0;
@@ -290,27 +294,62 @@ enum gsm0503_amr_dtx_frames gsm0503_detect_afs_dtx_frame(int *n_errors, int *n_b
 	return AMR_OTHER;
 }
 
-/*! Detect HR AMR DTX frame in unmapped, deinterleaved frame bits.
+/*! Detect FR AMR DTX frame in unmapped, deinterleaved frame bits.
+ *  DEPRECATED: use gsm0503_detect_afs_dtx_frame2() instead.
+ *  \param[out] n_errors number of errornous bits.
+ *  \param[out] n_bits_total number of checked bits.
  *  \param[in] ubits input bits (456 bit).
+ *  \returns dtx frame type. */
+enum gsm0503_amr_dtx_frames gsm0503_detect_afs_dtx_frame(int *n_errors, int *n_bits_total,
+							 const ubit_t *ubits)
+{
+	int mode_id; /* unused */
+	sbit_t sbits[456];
+
+	osmo_ubit2sbit(&sbits[0], &ubits[0], sizeof(sbits));
+	return gsm0503_detect_afs_dtx_frame2(n_errors, n_bits_total, &mode_id, &sbits[0]);
+}
+
+/*! Detect HR AMR DTX frame in unmapped, deinterleaved frame bits.
  *  \param[out] n_errors number of errornous bits.
  *  \param[out] n_bits_total number of checked bits.
+ *  \param[out] mode_id codec ID (CMI or CMC/CMR).
+ *  \param[out] mode_id codec mode ID (0..3 or -1).
+ *  \param[in] sbits input soft-bits (456 bit).
  *  \returns dtx frame type, */
-enum gsm0503_amr_dtx_frames gsm0503_detect_ahs_dtx_frame(int *n_errors, int *n_bits_total, const ubit_t * ubits)
+enum gsm0503_amr_dtx_frames gsm0503_detect_ahs_dtx_frame2(int *n_errors, int *n_bits_total,
+							  int *mode_id, const sbit_t *sbits)
 {
-	if (detect_ahs_sid_update(n_errors, n_bits_total, ubits))
+	if (detect_ahs_sid_update(n_errors, n_bits_total, sbits))
 		return AHS_SID_UPDATE;
-	if (detect_ahs_sid_first_inh(n_errors, n_bits_total, ubits))
+	if (detect_ahs_sid_first_inh(n_errors, n_bits_total, sbits))
 		return AHS_SID_FIRST_INH;
-	if (detect_ahs_sid_update_inh(n_errors, n_bits_total, ubits))
+	if (detect_ahs_sid_update_inh(n_errors, n_bits_total, sbits))
 		return AHS_SID_UPDATE_INH;
-	if (detect_ahs_sid_first_p1(n_errors, n_bits_total, ubits))
+	if (detect_ahs_sid_first_p1(n_errors, n_bits_total, sbits))
 		return AHS_SID_FIRST_P1;
-	if (detect_ahs_sid_first_p2(n_errors, n_bits_total, ubits))
+	if ((*mode_id = detect_ahs_sid_first_p2(n_errors, n_bits_total, sbits)) != -1)
 		return AHS_SID_FIRST_P2;
-	if (detect_ahs_onset(n_errors, n_bits_total, ubits))
+	if ((*mode_id = detect_ahs_onset(n_errors, n_bits_total, sbits)) != -1)
 		return AHS_ONSET;
 
 	*n_errors = 0;
 	*n_bits_total = 0;
 	return AMR_OTHER;
 }
+
+/*! Detect HR AMR DTX frame in unmapped, deinterleaved frame bits.
+ *  DEPRECATED: use gsm0503_detect_ahs_dtx_frame2() instead.
+ *  \param[out] n_errors number of errornous bits.
+ *  \param[out] n_bits_total number of checked bits.
+ *  \param[in] ubits input bits (456 bit).
+ *  \returns dtx frame type, */
+enum gsm0503_amr_dtx_frames gsm0503_detect_ahs_dtx_frame(int *n_errors, int *n_bits_total,
+							 const ubit_t *ubits)
+{
+	int mode_id; /* unused */
+	sbit_t sbits[456];
+
+	osmo_ubit2sbit(&sbits[0], &ubits[0], sizeof(sbits));
+	return gsm0503_detect_ahs_dtx_frame2(n_errors, n_bits_total, &mode_id, &sbits[0]);
+}
diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c
index 2b59b7b0..168e1207 100644
--- a/src/coding/gsm0503_coding.c
+++ b/src/coding/gsm0503_coding.c
@@ -2158,7 +2158,6 @@ int gsm0503_tch_afs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts,
 	sbit_t iB[912], cB[456], h;
 	ubit_t d[244], p[6], conv[250];
 	int i, j, k, best = 0, rv, len, steal = 0, id = -1;
-	ubit_t cBd[456];
 	*n_errors = 0; *n_bits_total = 0;
 	static ubit_t sid_first_dummy[64] = { 0 };
 	sbit_t sid_update_enc[256];
@@ -2172,7 +2171,7 @@ int gsm0503_tch_afs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts,
 
 	if (steal > 0) {
 		/* If not NULL, dtx indicates type of previously decoded TCH/AFS frame.
-		 * It's normally updated by gsm0503_detect_afs_dtx_frame(), which is not
+		 * It's normally updated by gsm0503_detect_afs_dtx_frame2(), which is not
 		 * reached in case of FACCH.  Reset it here to avoid FACCH/F frames being
 		 * misinterpreted as AMR's special DTX frames. */
 		if (dtx != NULL)
@@ -2190,8 +2189,7 @@ int gsm0503_tch_afs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts,
 	if (dtx) {
 		const enum gsm0503_amr_dtx_frames dtx_prev = *dtx;
 
-		osmo_sbit2ubit(cBd, cB, 456);
-		*dtx = gsm0503_detect_afs_dtx_frame(n_errors, n_bits_total, cBd);
+		*dtx = gsm0503_detect_afs_dtx_frame2(n_errors, n_bits_total, &id, cB);
 
 		switch (*dtx) {
 		case AMR_OTHER:
@@ -2230,7 +2228,7 @@ int gsm0503_tch_afs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts,
 			len = 5;
 			goto out;
 		case AFS_SID_UPDATE: /* TODO: parse CMI _and_ CMC/CMR (16 + 16 bit) */
-		case AFS_ONSET: /* TODO: parse CMI or CMC/CMR (N * 16 - M bit) */
+		case AFS_ONSET:
 			len = 0;
 			goto out;
 		default:
@@ -2625,7 +2623,6 @@ int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd,
 	sbit_t iB[912], cB[456], h;
 	ubit_t d[244], p[6], conv[135];
 	int i, j, k, best = 0, rv, len, steal = 0, id = -1;
-	ubit_t cBd[456];
 	static ubit_t sid_first_dummy[64] = { 0 };
 
 	/* only unmap the stealing bits */
@@ -2643,7 +2640,7 @@ int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd,
 	/* if we found a stole FACCH, but only at correct alignment */
 	if (steal > 0) {
 		/* If not NULL, dtx indicates type of previously decoded TCH/AHS frame.
-		 * It's normally updated by gsm0503_detect_ahs_dtx_frame(), which is not
+		 * It's normally updated by gsm0503_detect_ahs_dtx_frame2(), which is not
 		 * reached in case of FACCH.  Reset it here to avoid FACCH/H frames being
 		 * misinterpreted as AMR's special DTX frames. */
 		if (dtx != NULL)
@@ -2682,8 +2679,7 @@ int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd,
 		int n_bits_total_sid;
 		int n_errors_sid;
 
-		osmo_sbit2ubit(cBd, cB, 456);
-		*dtx = gsm0503_detect_ahs_dtx_frame(n_errors, n_bits_total, cBd);
+		*dtx = gsm0503_detect_ahs_dtx_frame2(n_errors, n_bits_total, &id, cB);
 		/* TODO: detect and handle AHS_SID_UPDATE + AHS_SID_UPDATE_INH */
 
 		switch (*dtx) {
@@ -2705,7 +2701,7 @@ int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd,
 			osmo_conv_decode_ber(&gsm0503_tch_axs_sid_update,
 					     cB + 16, conv, &n_errors_sid,
 					     &n_bits_total_sid);
-			/* gsm0503_detect_ahs_dtx_frame() calculates BER for the marker,
+			/* gsm0503_detect_ahs_dtx_frame2() calculates BER for the marker,
 			 * osmo_conv_decode_ber() calculates BER for the coded data. */
 			if (n_errors != NULL)
 				*n_errors += n_errors_sid;
@@ -2724,14 +2720,14 @@ int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd,
 			tch_amr_reassemble(tch_data, conv, 39);
 			len = 5;
 			goto out;
-		case AHS_SID_FIRST_P2: /* TODO: parse CMI or CMC/CMR (N * 16 - M bit) */
+		case AHS_SID_FIRST_P2:
 			tch_amr_sid_update_append(sid_first_dummy, 0,
 						  (codec_mode_req) ? codec[*ft]
 						  : codec[id > 0 ? id : 0]);
 			tch_amr_reassemble(tch_data, sid_first_dummy, 39);
 			len = 5;
 			goto out;
-		case AHS_ONSET: /* TODO: parse CMI or CMC/CMR (N * 16 - M bit) */
+		case AHS_ONSET:
 		case AHS_SID_FIRST_INH: /* TODO: parse CMI or CMC/CMR (16 bit) */
 		case AHS_SID_UPDATE_INH: /* TODO: parse CMI or CMC/CMR (16 bit) */
 		case AHS_SID_FIRST_P1: /* TODO: parse CMI or CMC/CMR (16 bit) */
diff --git a/src/coding/libosmocoding.map b/src/coding/libosmocoding.map
index 325b6d80..b083564a 100644
--- a/src/coding/libosmocoding.map
+++ b/src/coding/libosmocoding.map
@@ -123,6 +123,8 @@ gsm0503_amr_dtx_frame_names;
 gsm0503_amr_dtx_frame_name;
 gsm0503_detect_afs_dtx_frame;
 gsm0503_detect_ahs_dtx_frame;
+gsm0503_detect_afs_dtx_frame2;
+gsm0503_detect_ahs_dtx_frame2;
 
 local: *;
 };