From 24754f0490b0f77fca4110402bbff08603a29360 Mon Sep 17 00:00:00 2001 From: Jacob Erlbeck Date: Tue, 10 Dec 2013 13:09:37 +0100 Subject: mgcp: Parse SDP to get rate and packet duration This patch parses the 'ptime' and 'maxptime' SDP attributes, and the SDP rate information and sets up packet_duration_ms accordingly. If the packet duration is unknown or allows for different values (e.g. because 'ptime' uses a range or 'maxptime' allows for more than one frame) the duration is set to 0. Sponsored-by: On-Waves ehf --- openbsc/src/libmgcp/mgcp_network.c | 9 +++++++ openbsc/src/libmgcp/mgcp_protocol.c | 53 ++++++++++++++++++++++++++++++++----- openbsc/tests/mgcp/mgcp_test.ok | 10 +++---- 3 files changed, 61 insertions(+), 11 deletions(-) diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c index 8bd8afba8..40227af01 100644 --- a/openbsc/src/libmgcp/mgcp_network.c +++ b/openbsc/src/libmgcp/mgcp_network.c @@ -300,6 +300,15 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *sta state->seq_offset, state->packet_duration, inet_ntoa(addr->sin_addr), ntohs(addr->sin_port), endp->conn_mode); + if (state->packet_duration == 0 && rtp_end->force_constant_timing) + LOGP(DMGCP, LOGL_ERROR, + "Cannot patch timestamps on 0x%x: " + "RTP packet duration is unknown, SSRC: %u, " + "from %s:%d in %d\n", + ENDPOINT_NUMBER(endp), state->in_stream.ssrc, + inet_ntoa(addr->sin_addr), ntohs(addr->sin_port), + endp->conn_mode); + } else if (state->in_stream.ssrc != ssrc) { LOGP(DMGCP, LOGL_NOTICE, "The SSRC changed on 0x%x: %u -> %u " diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c index c4ff757c3..b8d192043 100644 --- a/openbsc/src/libmgcp/mgcp_protocol.c +++ b/openbsc/src/libmgcp/mgcp_protocol.c @@ -562,25 +562,64 @@ static int parse_sdp_data(struct mgcp_rtp_end *rtp, struct mgcp_parse_data *p) { char *line; int found_media = 0; + int audio_payload = -1; for_each_line(line, p->save) { switch (line[0]) { - case 'a': case 'o': case 's': case 't': case 'v': /* skip these SDP attributes */ break; + case 'a': { + int payload; + int rate; + int channels = 1; + int ptime, ptime2 = 0; + char audio_name[64]; + char audio_codec[64]; + + if (audio_payload == -1) + break; + + if (sscanf(line, "a=rtpmap:%d %64s", + &payload, audio_name) == 2) { + if (payload != audio_payload) + break; + + if (sscanf(audio_name, "%[^/]/%d/%d", + audio_codec, &rate, &channels) < 2) + break; + + rtp->rate = rate; + if (channels != 1) + LOGP(DMGCP, LOGL_NOTICE, + "Channels != 1 in SDP: '%s' on 0x%x\n", + line, ENDPOINT_NUMBER(p->endp)); + } else if (sscanf(line, "a=ptime:%d-%d", + &ptime, &ptime2) >= 1) { + if (ptime2 > 0 && ptime2 != ptime) + rtp->packet_duration_ms = 0; + else + rtp->packet_duration_ms = ptime; + } else if (sscanf(line, "a=maxptime:%d", &ptime2) == 1) { + if (ptime2 * rtp->frame_duration_den > + rtp->frame_duration_num * 1500) + /* more than 1 frame */ + rtp->packet_duration_ms = 0; + } + break; + } case 'm': { int port; - int payload; + audio_payload = -1; if (sscanf(line, "m=audio %d RTP/AVP %d", - &port, &payload) == 2) { + &port, &audio_payload) == 2) { rtp->rtp_port = htons(port); rtp->rtcp_port = htons(port + 1); - rtp->payload_type = payload; + rtp->payload_type = audio_payload; found_media = 1; } break; @@ -608,8 +647,10 @@ static int parse_sdp_data(struct mgcp_rtp_end *rtp, struct mgcp_parse_data *p) if (found_media) LOGP(DMGCP, LOGL_NOTICE, - "Got media info via SDP: port %d, payload %d, addr %s\n", - ntohs(rtp->rtp_port), rtp->payload_type, inet_ntoa(rtp->addr)); + "Got media info via SDP: port %d, payload %d, " + "duration %d, addr %s\n", + ntohs(rtp->rtp_port), rtp->payload_type, + rtp->packet_duration_ms, inet_ntoa(rtp->addr)); return found_media; } diff --git a/openbsc/tests/mgcp/mgcp_test.ok b/openbsc/tests/mgcp/mgcp_test.ok index 24f9b336c..f9dd7cb62 100644 --- a/openbsc/tests/mgcp/mgcp_test.ok +++ b/openbsc/tests/mgcp/mgcp_test.ok @@ -16,22 +16,22 @@ Testing AUEP2 Testing MDCX1 Testing MDCX2 Testing CRCX -Packet duration not set +Detected packet duration: 40 Requested packetetization period: 20-20 Testing MDCX3 Packet duration not set Requested packetization period not set Testing MDCX4 -Packet duration not set +Detected packet duration: 40 Requested packetetization period: 20-20 Testing MDCX4_PT1 -Packet duration not set +Detected packet duration: 40 Requested packetetization period: 20-40 Testing MDCX4_PT2 -Packet duration not set +Detected packet duration: 40 Requested packetetization period: 20-20 Testing MDCX4_PT3 -Packet duration not set +Detected packet duration: 40 Requested packetization period not set Testing DLCX Detected packet duration: 20 -- cgit v1.2.3