mgcp: Add a function to get media info for MGCP responses
This patch adds the get_net_downlink_format_cb() callback to provide
payload_type, subtype_name, and fmtp_extra suitable for use in a MGCP
response sent to the network. Per default, the BTS side values are
returned since these must be honoured by the net peer when sending
audio to the media gateway (unless transcoding is done).
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index 393a9e5..05c3e77 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -353,6 +353,19 @@
return 0;
}
+void mgcp_get_net_downlink_format_default(struct mgcp_endpoint *endp,
+ int *payload_type,
+ const char**audio_name,
+ const char**fmtp_extra)
+{
+ /* Use the BTS side parameters when passing the SDP data (for
+ * downlink) to the net peer.
+ */
+ *payload_type = endp->bts_end.payload_type;
+ *audio_name = endp->bts_end.audio_name;
+ *fmtp_extra = endp->bts_end.fmtp_extra;
+}
+
/**
* The RFC 3550 Appendix A assumes there are multiple sources but
* some of the supported endpoints (e.g. the nanoBTS) can only handle
diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index 862bf17..7837378 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -245,12 +245,15 @@
const char *msg, const char *trans_id)
{
const char *addr = endp->cfg->local_ip;
- const char *fmtp_extra = endp->bts_end.fmtp_extra;
- const char *audio_name = endp->bts_end.audio_name;
- int payload_type = endp->bts_end.payload_type;
+ const char *fmtp_extra;
+ const char *audio_name;
+ int payload_type;
char sdp_record[4096];
int len;
+ endp->cfg->get_net_downlink_format_cb(endp, &payload_type,
+ &audio_name, &fmtp_extra);
+
if (!addr)
addr = endp->cfg->source_addr;
@@ -1268,6 +1271,8 @@
cfg->rtp_processing_cb = &mgcp_rtp_processing_default;
cfg->setup_rtp_processing_cb = &mgcp_setup_rtp_processing_default;
+ cfg->get_net_downlink_format_cb = &mgcp_get_net_downlink_format_default;
+
/* default trunk handling */
cfg->trunk.cfg = cfg;
cfg->trunk.trunk_nr = 0;
@@ -1424,8 +1429,12 @@
{
char buf[2096];
int len;
- const char *audio_name = endp->bts_end.audio_name;
- int payload_type = endp->bts_end.payload_type;
+ const char *fmtp_extra;
+ const char *audio_name;
+ int payload_type;
+
+ endp->cfg->get_net_downlink_format_cb(endp, &payload_type,
+ &audio_name, &fmtp_extra);
/* hardcoded to AMR right now, we do not know the real type at this point */
len = snprintf(buf, sizeof(buf),