patch: add optional SDP media encode handler

include/re_sdp.h

@@ -32,6 +32,7 @@ enum sdp_bandwidth {
 
 struct sdp_format;
 
+typedef int(sdp_media_enc_h)(struct mbuf *mb, bool offer, void *arg);
 typedef int(sdp_fmtp_enc_h)(struct mbuf *mb, const struct sdp_format *fmt,
 			    bool offer, void *data);
 typedef bool(sdp_fmtp_cmp_h)(const char *params1, const char *params2,
@@ -84,6 +85,8 @@ struct sdp_media;
 
 int  sdp_media_add(struct sdp_media **mp, struct sdp_session *sess,
 		   const char *name, uint16_t port, const char *proto);
+void sdp_media_set_encode_handler(struct sdp_media *m, sdp_media_enc_h *ench,
+				  void *arg);
 void sdp_media_set_disabled(struct sdp_media *m, bool disabled);
 void sdp_media_set_lport(struct sdp_media *m, uint16_t port);
 void sdp_media_set_laddr(struct sdp_media *m, const struct sa *laddr);

src/sdp/media.c

@@ -289,6 +289,24 @@ void sdp_media_align_formats(struct sdp_media *m, bool offer)
 }
 
 
+/**
+ * Set SDP Media line encode handler
+ *
+ * @param m    SDP Media line
+ * @param ench Encode handler
+ * @param arg  Encode handler argument
+ */
+void sdp_media_set_encode_handler(struct sdp_media *m, sdp_media_enc_h *ench,
+				  void *arg)
+{
+	if (!m)
+		return;
+
+	m->ench = ench;
+	m->arg  = arg;
+}
+
+
 /**
  * Set an SDP Media line to enabled/disabled
  *

src/sdp/msg.c

@@ -435,6 +435,9 @@ static int media_encode(const struct sdp_media *m, struct mbuf *mb, bool offer)
 	for (le = m->lattrl.head; le; le = le->next)
 		err |= mbuf_printf(mb, "%H", sdp_attr_print, le->data);
 
+	if (m->ench)
+		err |= m->ench(mb, offer, m->arg);
+
 	return err;
 }
 

src/sdp/sdp.h

@@ -39,6 +39,8 @@ struct sdp_media {
 	int32_t rbwv[SDP_BANDWIDTH_MAX];
 	char *name;
 	char *proto;
+	sdp_media_enc_h *ench;
+	void *arg;
 	enum sdp_dir ldir;
 	enum sdp_dir rdir;
 	bool disabled;