Set direction in offer

src/main.c

@@ -54,6 +54,7 @@ on_offer_created (GstPromise *promise, GstElement *webrtcbin)
   GstWebRTCSessionDescription *offer = NULL;
   gchar *sdp;
   GstSDPMedia *media;
+  guint i;
 
   gst_structure_get (gst_promise_get_reply (promise),
       "offer", GST_TYPE_WEBRTC_SESSION_DESCRIPTION, &offer, NULL);
@@ -61,6 +62,18 @@ on_offer_created (GstPromise *promise, GstElement *webrtcbin)
 
   media = (GstSDPMedia *) gst_sdp_message_get_media (offer->sdp, 0);
 
+  for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
+    const GstSDPAttribute *a = gst_sdp_media_get_attribute (media, i);
+
+    if (!strcmp (a->key, "sendrecv")) {
+      GstSDPAttribute newa;
+
+      newa.key = g_strdup ("sendonly");
+      newa.value = g_strdup ("");
+      gst_sdp_media_replace_attribute (media, i, &newa);
+      break;
+    }
+  }
   gst_sdp_media_add_attribute (media, "fmtp",
       "96 packetization-mode=1;profile-level-id=42e01f");