mgcp_codec: refactor payload type converstion

in mgcp_codec.c we have a function mgcp_codec_pt_translate that is used
to find the equivalent payload type number on an opposite connection.
This is quite specific and the resulting payload type number may still
belong to a codec that might require some form of conversion.

Lets refactor this so that the function just finds a convertible codec
for a given connection. This also opens up other usecases. The payload
type conversion like we did it before can then be done with a few lines
in mgcp_network.c

Related: OS#5461
Change-Id: I085260a2ca8cfecdb58656b7a046c536189e238d

include/osmocom/mgcp/mgcp_codec.h

@@ -14,8 +14,9 @@ void mgcp_codec_summary(struct mgcp_conn_rtp *conn);
 void mgcp_codec_reset_all(struct mgcp_conn_rtp *conn);
 int mgcp_codec_add(struct mgcp_conn_rtp *conn, int payload_type, const char *audio_name, const struct mgcp_codec_param *param);
 int mgcp_codec_decide(struct mgcp_conn_rtp *conn);
-int mgcp_codec_pt_translate(struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp *conn_dst, int payload_type);
+struct mgcp_rtp_codec *mgcp_codec_find_convertible(struct mgcp_conn_rtp *conn, struct mgcp_rtp_codec *codec);
 const struct mgcp_rtp_codec *mgcp_codec_pt_find_by_subtype_name(struct mgcp_conn_rtp *conn,
 								const char *subtype_name, unsigned int match_nr);
 bool mgcp_codec_amr_align_mode_is_indicated(const struct mgcp_rtp_codec *codec);
 bool mgcp_codec_amr_is_octet_aligned(const struct mgcp_rtp_codec *codec);
+struct mgcp_rtp_codec *mgcp_codec_from_pt(struct mgcp_conn_rtp *conn, int payload_type);

src/libosmo-mgcp/mgcp_codec.c

@@ -425,63 +425,42 @@ static bool codecs_convertible(struct mgcp_rtp_codec *codec_a, struct mgcp_rtp_c
 	return true;
 }
 
-/*! Translate a given payload type number that belongs to the packet of a
- *  source connection to the equivalent payload type number that matches the
- *  configuration of a destination connection.
- *  \param[in] conn_src related source rtp-connection.
- *  \param[in] conn_dst related destination rtp-connection.
- *  \param[in] payload_type number from the source packet or source connection.
- *  \returns translated payload type number on success, -EINVAL on failure. */
-int mgcp_codec_pt_translate(struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp *conn_dst, int payload_type)
+/*! For a given codec, find a convertible codec in the given connection.
+ *  \param[in] conn connection to search for a convertible codec
+ *  \param[in] codec for which a convertible codec shall be found.
+ *  \returns codec on success, -NULL on failure. */
+struct mgcp_rtp_codec *mgcp_codec_find_convertible(struct mgcp_conn_rtp *conn, struct mgcp_rtp_codec *codec)
 {
-	struct mgcp_rtp_end *rtp_src;
-	struct mgcp_rtp_end *rtp_dst;
-	struct mgcp_rtp_codec *codec_src = NULL;
-	struct mgcp_rtp_codec *codec_dst = NULL;
+	struct mgcp_rtp_end *rtp_end;
 	unsigned int i;
 	unsigned int codecs_assigned;
+	struct mgcp_rtp_codec *codec_convertible = NULL;
 
-	rtp_src = &conn_src->end;
-	rtp_dst = &conn_dst->end;
-
-	/* Find the codec information that is used on the source side */
-	codecs_assigned = rtp_src->codecs_assigned;
-	OSMO_ASSERT(codecs_assigned <= MGCP_MAX_CODECS);
-	for (i = 0; i < codecs_assigned; i++) {
-		if (payload_type == rtp_src->codecs[i].payload_type) {
-			codec_src = &rtp_src->codecs[i];
-			break;
-		}
-	}
-	if (!codec_src)
-		return -EINVAL;
+	rtp_end = &conn->end;
 
 	/* Use the codec information from the source and try to find the equivalent of it on the destination side. In
 	 * the first run we will look for an exact match. */
-	codecs_assigned = rtp_dst->codecs_assigned;
+	codecs_assigned = rtp_end->codecs_assigned;
 	OSMO_ASSERT(codecs_assigned <= MGCP_MAX_CODECS);
 	for (i = 0; i < codecs_assigned; i++) {
-		if (codecs_same(codec_src, &rtp_dst->codecs[i])) {
-			codec_dst = &rtp_dst->codecs[i];
+		if (codecs_same(codec, &rtp_end->codecs[i])) {
+			codec_convertible = &rtp_end->codecs[i];
 			break;
 		}
 	}
 
 	/* In case we weren't able to find an exact match, we will try to find a match that is the same codec, but the
 	 * payload format may be different. This alternative will require a frame format conversion (i.e. AMR bwe->oe) */
-	if (!codec_dst) {
+	if (!codec_convertible) {
 		for (i = 0; i < codecs_assigned; i++) {
-			if (codecs_convertible(codec_src, &rtp_dst->codecs[i])) {
-				codec_dst = &rtp_dst->codecs[i];
+			if (codecs_convertible(codec, &rtp_end->codecs[i])) {
+				codec_convertible = &rtp_end->codecs[i];
 				break;
 			}
 		}
 	}
 
-	if (!codec_dst)
-		return -EINVAL;
-
-	return codec_dst->payload_type;
+	return codec_convertible;
 }
 
 /* Find the payload type number configured for a specific codec by SDP.
@@ -508,3 +487,26 @@ const struct mgcp_rtp_codec *mgcp_codec_pt_find_by_subtype_name(struct mgcp_conn
 	}
 	return NULL;
 }
+
+/*! Lookup a codec that is assigned to a connection by its payload type number.
+ *  \param[in] conn related rtp-connection.
+ *  \param[in] payload_type number of the codec to look up.
+ *  \returns pointer to codec struct on success, NULL on failure. */
+struct mgcp_rtp_codec *mgcp_codec_from_pt(struct mgcp_conn_rtp *conn, int payload_type)
+{
+	struct mgcp_rtp_end *rtp_end = &conn->end;
+	unsigned int codecs_assigned = rtp_end->codecs_assigned;
+	struct mgcp_rtp_codec *codec = NULL;
+	size_t i;
+
+	OSMO_ASSERT(codecs_assigned <= MGCP_MAX_CODECS);
+
+	for (i = 0; i < codecs_assigned; i++) {
+		if (payload_type == rtp_end->codecs[i].payload_type) {
+			codec = &rtp_end->codecs[i];
+			break;
+		}
+	}
+
+	return codec;
+}

src/libosmo-mgcp/mgcp_network.c

@@ -493,27 +493,31 @@ void mgcp_rtp_annex_count(const struct mgcp_endpoint *endp,
 /* There may be different payload type numbers negotiated for two connections.
  * Patch the payload type of an RTP packet so that it uses the payload type
  * that is valid for the destination connection (conn_dst) */
-static int mgcp_patch_pt(struct mgcp_conn_rtp *conn_src,
-			 struct mgcp_conn_rtp *conn_dst, struct msgb *msg)
+static int mgcp_patch_pt(struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp *conn_dst, struct msgb *msg)
 {
 	struct rtp_hdr *rtp_hdr;
-	uint8_t pt_in;
-	int pt_out;
+	struct mgcp_rtp_codec *codec_src;
+	struct mgcp_rtp_codec *codec_dst;
 
 	if (msgb_length(msg) < sizeof(struct rtp_hdr)) {
 		LOG_CONN_RTP(conn_src, LOGL_ERROR, "RTP packet too short (%u < %zu)\n",
 			     msgb_length(msg), sizeof(struct rtp_hdr));
 		return -EINVAL;
 	}
-
 	rtp_hdr = (struct rtp_hdr *)msgb_data(msg);
 
-	pt_in = rtp_hdr->payload_type;
-	pt_out = mgcp_codec_pt_translate(conn_src, conn_dst, pt_in);
-	if (pt_out < 0)
+	/* Find the codec information that is used on the source side */
+	codec_src = mgcp_codec_from_pt(conn_src, rtp_hdr->payload_type);
+	if (!codec_src)
+		return -EINVAL;
+
+	/* Lookup a suitable codec in the destination connection. (The codec must be of the same type or at least
+	 * convertible) */
+	codec_dst = mgcp_codec_find_convertible(conn_dst, codec_src);
+	if (!codec_dst)
 		return -EINVAL;
 
-	rtp_hdr->payload_type = (uint8_t) pt_out;
+	rtp_hdr->payload_type = (uint8_t) codec_dst->payload_type;
 	return 0;
 }
 

tests/mgcp/mgcp_test.c

@@ -1769,26 +1769,26 @@ static const struct mgcp_codec_param amr_param_octet_aligned_unset = {
 	.amr_octet_aligned_present = false,
 };
 
-struct testcase_mgcp_codec_pt_translate_codec {
+struct testcase_mgcp_codec_find_convertible_codec {
 	int payload_type;
 	const char *audio_name;
 	const struct mgcp_codec_param *param;
 	int expect_rc;
 };
 
-struct testcase_mgcp_codec_pt_translate_expect {
+struct testcase_mgcp_codec_find_convertible_expect {
 	bool end;
 	int payload_type_map[2];
 };
 
-struct testcase_mgcp_codec_pt_translate {
+struct testcase_mgcp_codec_find_convertible {
 	const char *descr;
 	/* two conns on an endpoint, each with N configured codecs */
-	struct testcase_mgcp_codec_pt_translate_codec codecs[2][10];
-	struct testcase_mgcp_codec_pt_translate_expect expect[32];
+	struct testcase_mgcp_codec_find_convertible_codec codecs[2][10];
+	struct testcase_mgcp_codec_find_convertible_expect expect[32];
 };
 
-static const struct testcase_mgcp_codec_pt_translate test_mgcp_codec_pt_translate_cases[] = {
+static const struct testcase_mgcp_codec_find_convertible test_mgcp_codec_find_convertible_cases[] = {
 	{
 		.descr = "same order, but differing payload type numbers",
 		.codecs = {
@@ -2044,14 +2044,39 @@ static const struct testcase_mgcp_codec_pt_translate test_mgcp_codec_pt_translat
 	},
 };
 
-static void test_mgcp_codec_pt_translate(void)
+static int pt_translate(struct mgcp_conn_rtp *conn, unsigned int index_src, unsigned int index_dst, int payload_type)
+{
+	struct mgcp_rtp_codec *codec_src = NULL;
+	struct mgcp_rtp_codec *codec_dst = NULL;
+	struct mgcp_conn_rtp *conn_src = &conn[index_src];
+	struct mgcp_conn_rtp *conn_dst = &conn[index_dst];
+
+	/* Find the codec information that is used on the source side */
+	codec_src = mgcp_codec_from_pt(conn_src, payload_type);
+	if (!codec_src) {
+		printf(" - mgcp_codec_from_pt(conn%u, %d) -> NO RESULT\n", index_src, payload_type);
+		return -EINVAL;
+	}
+	printf(" - mgcp_codec_from_pt(conn%u, %d) -> %s\n", index_src, payload_type, codec_src->subtype_name);
+
+	codec_dst = mgcp_codec_find_convertible(conn_dst, codec_src);
+	if (!codec_dst) {
+		printf(" - mgcp_codec_find_convertible(conn%u, %s) -> NO RESULT\n", index_dst, codec_src->subtype_name);
+		return -EINVAL;
+	}
+	printf(" - mgcp_codec_find_convertible(conn%u, %s) -> %s -> %u\n",
+	       index_dst, codec_src->subtype_name, codec_dst->subtype_name, codec_dst->payload_type);
+	return codec_dst->payload_type;
+}
+
+static void test_mgcp_codec_find_convertible(void)
 {
 	int i;
 	bool ok = true;
-	printf("\nTesting mgcp_codec_pt_translate()\n");
+	printf("\nTesting mgcp_codec_find_convertible()\n");
 
-	for (i = 0; i < ARRAY_SIZE(test_mgcp_codec_pt_translate_cases); i++) {
-		const struct testcase_mgcp_codec_pt_translate *t = &test_mgcp_codec_pt_translate_cases[i];
+	for (i = 0; i < ARRAY_SIZE(test_mgcp_codec_find_convertible_cases); i++) {
+		const struct testcase_mgcp_codec_find_convertible *t = &test_mgcp_codec_find_convertible_cases[i];
 		struct mgcp_conn_rtp conn[2] = {};
 		int rc;
 		int conn_i;
@@ -2062,7 +2087,7 @@ static void test_mgcp_codec_pt_translate(void)
 		for (conn_i = 0; conn_i < 2; conn_i++) {
 			printf(" - add codecs on conn%d:\n", conn_i);
 			for (c = 0; c < ARRAY_SIZE(t->codecs[conn_i]); c++) {
-				const struct testcase_mgcp_codec_pt_translate_codec *codec = &t->codecs[conn_i][c];
+				const struct testcase_mgcp_codec_find_convertible_codec *codec = &t->codecs[conn_i][c];
 				if (!codec->audio_name)
 					break;
 
@@ -2086,15 +2111,13 @@ static void test_mgcp_codec_pt_translate(void)
 		}
 
 		for (c = 0; c < ARRAY_SIZE(t->expect); c++) {
-			const struct testcase_mgcp_codec_pt_translate_expect *expect = &t->expect[c];
+			const struct testcase_mgcp_codec_find_convertible_expect *expect = &t->expect[c];
 			int result;
 
 			if (expect->end)
 				break;
 
-			result = mgcp_codec_pt_translate(&conn[0], &conn[1], expect->payload_type_map[0]);
-			printf(" - mgcp_codec_pt_translate(conn0, conn1, %d) -> %d\n",
-			       expect->payload_type_map[0], result);
+			result = pt_translate(conn, 0, 1, expect->payload_type_map[0]);
 			if (result != expect->payload_type_map[1]) {
 				printf("     ERROR: expected -> %d\n", expect->payload_type_map[1]);
 				ok = false;
@@ -2104,9 +2127,7 @@ static void test_mgcp_codec_pt_translate(void)
 			if (expect->payload_type_map[1] < 0)
 				continue;
 
-			result = mgcp_codec_pt_translate(&conn[1], &conn[0], expect->payload_type_map[1]);
-			printf(" - mgcp_codec_pt_translate(conn1, conn0, %d) -> %d\n",
-			       expect->payload_type_map[1], result);
+			result = pt_translate(conn, 1, 0, expect->payload_type_map[1]);
 			if (result != expect->payload_type_map[0]) {
 				printf("     ERROR: expected -> %d\n", expect->payload_type_map[0]);
 				ok = false;
@@ -2274,7 +2295,7 @@ int main(int argc, char **argv)
 	test_osmux_cid();
 	test_get_lco_identifier();
 	test_check_local_cx_options(ctx);
-	test_mgcp_codec_pt_translate();
+	test_mgcp_codec_find_convertible();
 	test_conn_id_matching();
 	test_e1_trunk_nr_from_epname();
 	test_mgcp_is_rtp_dummy_payload();

tests/mgcp/mgcp_test.ok

@@ -1276,7 +1276,7 @@ p:10, a:PCMU -> p:10, a:PCMU
 p10, aPCMU -> (null)
 '10,a :PCMU' -> '(null)'
 
-Testing mgcp_codec_pt_translate()
+Testing mgcp_codec_find_convertible()
 #0: same order, but differing payload type numbers
  - add codecs on conn0:
     0: 112 AMR/8000/1 octet-aligned=1  -> rc=0
@@ -1286,13 +1286,19 @@ Testing mgcp_codec_pt_translate()
     0:  96 AMR/8000/1 octet-aligned=1  -> rc=0
     1:   0 PCMU/8000/1  -> rc=0
     2:  97 GSM-HR-08/8000/1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
- - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
- - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
- - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 96
+ - mgcp_codec_from_pt(conn1, 96) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn1, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn1, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn0, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn0, 111) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> GSM-HR-08 -> 97
+ - mgcp_codec_from_pt(conn1, 97) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn0, GSM-HR-08) -> GSM-HR-08 -> 111
+ - mgcp_codec_from_pt(conn0, 123) -> NO RESULT
 #1: different order and different payload type numbers
  - add codecs on conn0:
     0:   0 PCMU/8000/1  -> rc=0
@@ -1302,13 +1308,19 @@ Testing mgcp_codec_pt_translate()
     0:  97 GSM-HR-08/8000/1  -> rc=0
     1:   0 PCMU/8000/1  -> rc=0
     2:  96 AMR/8000/1 octet-aligned=1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
- - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
- - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
- - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 96
+ - mgcp_codec_from_pt(conn1, 96) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn1, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn1, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn0, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn0, 111) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> GSM-HR-08 -> 97
+ - mgcp_codec_from_pt(conn1, 97) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn0, GSM-HR-08) -> GSM-HR-08 -> 111
+ - mgcp_codec_from_pt(conn0, 123) -> NO RESULT
 #2: both sides have the same payload_type numbers assigned to differing codecs
  - add codecs on conn0:
     0:   0 PCMU/8000/1  -> rc=0
@@ -1318,13 +1330,19 @@ Testing mgcp_codec_pt_translate()
     0:  97 GSM-HR-08/8000/1  -> rc=0
     1:   0 PCMU/8000/1  -> rc=0
     2:  96 AMR/8000/1 octet-aligned=1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 96) -> 97
- - mgcp_codec_pt_translate(conn1, conn0, 97) -> 96
- - mgcp_codec_pt_translate(conn0, conn1, 97) -> 96
- - mgcp_codec_pt_translate(conn1, conn0, 96) -> 97
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
- - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
- - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+ - mgcp_codec_from_pt(conn0, 96) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> GSM-HR-08 -> 97
+ - mgcp_codec_from_pt(conn1, 97) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn0, GSM-HR-08) -> GSM-HR-08 -> 96
+ - mgcp_codec_from_pt(conn0, 97) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 96
+ - mgcp_codec_from_pt(conn1, 96) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 97
+ - mgcp_codec_from_pt(conn0, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn1, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn1, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn0, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn0, 123) -> NO RESULT
 #3: conn0 has no codecs
  - add codecs on conn0:
     (none)
@@ -1332,9 +1350,9 @@ Testing mgcp_codec_pt_translate()
     0:  96 AMR/8000/1 octet-aligned=1  -> rc=0
     1:   0 PCMU/8000/1  -> rc=0
     2:  97 GSM-HR-08/8000/1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> -22
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> -22
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> NO RESULT
+ - mgcp_codec_from_pt(conn0, 0) -> NO RESULT
+ - mgcp_codec_from_pt(conn0, 111) -> NO RESULT
 #4: conn1 has no codecs
  - add codecs on conn0:
     0: 112 AMR/8000/1 octet-aligned=1  -> rc=0
@@ -1342,9 +1360,12 @@ Testing mgcp_codec_pt_translate()
     2: 111 GSM-HR-08/8000/1  -> rc=0
  - add codecs on conn1:
     (none)
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> -22
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> -22
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> NO RESULT
+ - mgcp_codec_from_pt(conn0, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn1, PCMU) -> NO RESULT
+ - mgcp_codec_from_pt(conn0, 111) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> NO RESULT
 #5: test AMR with differing octet-aligned settings
  - add codecs on conn0:
     0: 111 AMR/8000 octet-aligned=1  -> rc=0
@@ -1352,43 +1373,55 @@ Testing mgcp_codec_pt_translate()
  - add codecs on conn1:
     0: 122 AMR/8000 octet-aligned=0  -> rc=0
     1: 121 AMR/8000 octet-aligned=1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 121
- - mgcp_codec_pt_translate(conn1, conn0, 121) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 122
- - mgcp_codec_pt_translate(conn1, conn0, 122) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+ - mgcp_codec_from_pt(conn0, 111) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 121
+ - mgcp_codec_from_pt(conn1, 121) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 111
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 122
+ - mgcp_codec_from_pt(conn1, 122) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 123) -> NO RESULT
 #6: test AMR with missing octet-aligned settings (oa <-> unset)
  - add codecs on conn0:
     0: 111 AMR/8000 octet-aligned=1  -> rc=0
  - add codecs on conn1:
     0: 122 AMR/8000 octet-aligned=unset  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 122
- - mgcp_codec_pt_translate(conn1, conn0, 122) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 55) -> -22
+ - mgcp_codec_from_pt(conn0, 111) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 122
+ - mgcp_codec_from_pt(conn1, 122) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 111
+ - mgcp_codec_from_pt(conn0, 55) -> NO RESULT
 #7: test AMR with missing octet-aligned settings (bwe <-> unset)
  - add codecs on conn0:
     0: 111 AMR/8000 octet-aligned=0  -> rc=0
  - add codecs on conn1:
     0: 122 AMR/8000 octet-aligned=unset  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 122
- - mgcp_codec_pt_translate(conn1, conn0, 122) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 55) -> -22
+ - mgcp_codec_from_pt(conn0, 111) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 122
+ - mgcp_codec_from_pt(conn1, 122) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 111
+ - mgcp_codec_from_pt(conn0, 55) -> NO RESULT
 #8: test AMR with NULL param (oa <-> null)
  - add codecs on conn0:
     0: 112 AMR/8000 octet-aligned=1  -> rc=0
  - add codecs on conn1:
     0: 122 AMR/8000  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 122
- - mgcp_codec_pt_translate(conn1, conn0, 122) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 55) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 122
+ - mgcp_codec_from_pt(conn1, 122) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 55) -> NO RESULT
 #9: test AMR with NULL param (bwe <-> null)
  - add codecs on conn0:
     0: 112 AMR/8000 octet-aligned=0  -> rc=0
  - add codecs on conn1:
     0: 122 AMR/8000  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 122
- - mgcp_codec_pt_translate(conn1, conn0, 122) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 55) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 122
+ - mgcp_codec_from_pt(conn1, 122) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 55) -> NO RESULT
 #10: match FOO/8000/1 and FOO/8000 as identical, single channel is implicit
  - add codecs on conn0:
     0:   0 PCMU/8000/1  -> rc=0
@@ -1398,13 +1431,19 @@ Testing mgcp_codec_pt_translate()
     0:  97 GSM-HR-08/8000  -> rc=0
     1:   0 PCMU/8000  -> rc=0
     2:  96 AMR/8000 octet-aligned=1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
- - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
- - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
- - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 96
+ - mgcp_codec_from_pt(conn1, 96) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn1, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn1, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn0, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn0, 111) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> GSM-HR-08 -> 97
+ - mgcp_codec_from_pt(conn1, 97) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn0, GSM-HR-08) -> GSM-HR-08 -> 111
+ - mgcp_codec_from_pt(conn0, 123) -> NO RESULT
 #11: match FOO/8000/1 and FOO as identical, 8k and single channel are implicit
  - add codecs on conn0:
     0:   0 PCMU/8000/1  -> rc=0
@@ -1414,13 +1453,19 @@ Testing mgcp_codec_pt_translate()
     0:  97 GSM-HR-08  -> rc=0
     1:   0 PCMU  -> rc=0
     2:  96 AMR octet-aligned=1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
- - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
- - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
- - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
- - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+ - mgcp_codec_from_pt(conn0, 112) -> AMR
+ - mgcp_codec_find_convertible(conn1, AMR) -> AMR -> 96
+ - mgcp_codec_from_pt(conn1, 96) -> AMR
+ - mgcp_codec_find_convertible(conn0, AMR) -> AMR -> 112
+ - mgcp_codec_from_pt(conn0, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn1, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn1, 0) -> PCMU
+ - mgcp_codec_find_convertible(conn0, PCMU) -> PCMU -> 0
+ - mgcp_codec_from_pt(conn0, 111) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> GSM-HR-08 -> 97
+ - mgcp_codec_from_pt(conn1, 97) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn0, GSM-HR-08) -> GSM-HR-08 -> 111
+ - mgcp_codec_from_pt(conn0, 123) -> NO RESULT
 #12: test whether channel number matching is waterproof
  - add codecs on conn0:
     0: 111 GSM-HR-08/8000  -> rc=0
@@ -1429,10 +1474,12 @@ Testing mgcp_codec_pt_translate()
  - add codecs on conn1:
     0: 122 GSM-HR-08/8000/2  -> rc=-22
     1: 121 GSM-HR-08/8000/1  -> rc=0
- - mgcp_codec_pt_translate(conn0, conn1, 111) -> 121
- - mgcp_codec_pt_translate(conn1, conn0, 121) -> 111
- - mgcp_codec_pt_translate(conn0, conn1, 112) -> -22
- - mgcp_codec_pt_translate(conn0, conn1, 113) -> -22
+ - mgcp_codec_from_pt(conn0, 111) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn1, GSM-HR-08) -> GSM-HR-08 -> 121
+ - mgcp_codec_from_pt(conn1, 121) -> GSM-HR-08
+ - mgcp_codec_find_convertible(conn0, GSM-HR-08) -> GSM-HR-08 -> 111
+ - mgcp_codec_from_pt(conn0, 112) -> NO RESULT
+ - mgcp_codec_from_pt(conn0, 113) -> NO RESULT
 
 Testing test_conn_id_matching
 needle='23AB' found '000023AB'