rtsp-stream: Listen on the multicast group for RTP/RTCP packets

When a UDP multicast transport is used it is expected that the server listens
for RTP and RTCP packets on the multicast group with the corresponding port.
Without this we will never get RTCP packets from clients in multicast mode.

https://bugzilla.gnome.org/show_bug.cgi?id=732238

1 files changed, 89 insertions, 1 deletions

diff --git a/gst/rtsp-server/rtsp-stream.c b/gst/rtsp-server/rtsp-stream.c
index 942b837..9ed194f 100644
--- a/gst/rtsp-server/rtsp-stream.c
+++ b/gst/rtsp-server/rtsp-stream.c
@@ -58,6 +58,15 @@
 #define GST_RTSP_STREAM_GET_PRIVATE(obj)  \
      (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_RTSP_STREAM, GstRTSPStreamPrivate))
 
+typedef struct
+{
+  GstRTSPStreamTransport *transport;
+
+  /* RTP and RTCP source */
+  GstElement *udpsrc[2];
+  GstPad *selpad[2];
+} GstRTSPMulticastTransportSource;
+
 struct _GstRTSPStreamPrivate
 {
   GMutex lock;
@@ -128,6 +137,9 @@ struct _GstRTSPStreamPrivate
   GList *tr_cache;
   guint tr_cache_cookie;
 
+  /* UDP sources for UDP multicast transports */
+  GList *transport_sources;
+
   gint dscp_qos;
 
   /* stream blocking */
@@ -1137,6 +1149,7 @@ again:
   udpsrc_out[1] = udpsrc1;
   udpsink_out[0] = udpsink0;
   udpsink_out[1] = udpsink1;
+
   server_port_out->min = rtpport;
   server_port_out->max = rtcpport;
 
@@ -2236,9 +2249,84 @@ update_transport (GstRTSPStream * stream, GstRTSPStreamTransport * trans,
   tr = gst_rtsp_stream_transport_get_transport (trans);
 
   switch (tr->lower_transport) {
-    case GST_RTSP_LOWER_TRANS_UDP:
     case GST_RTSP_LOWER_TRANS_UDP_MCAST:
     {
+      GstRTSPMulticastTransportSource *source;
+      GstBin *bin;
+
+      bin = GST_BIN (gst_object_get_parent (GST_OBJECT (priv->funnel[0])));
+
+      if (add) {
+        gchar *host;
+        gint i;
+        GstPad *selpad, *pad;
+
+        source = g_slice_new0 (GstRTSPMulticastTransportSource);
+        source->transport = trans;
+
+        for (i = 0; i < 2; i++) {
+          host =
+              g_strdup_printf ("udp://%s:%d", tr->destination,
+              (i == 0) ? tr->port.min : tr->port.max);
+          source->udpsrc[i] =
+              gst_element_make_from_uri (GST_URI_SRC, host, NULL, NULL);
+          g_free (host);
+
+          /* we set and keep these to playing so that they don't cause NO_PREROLL return
+           * values */
+          gst_element_set_state (source->udpsrc[i], GST_STATE_PLAYING);
+          gst_element_set_locked_state (source->udpsrc[i], TRUE);
+          /* add udpsrc */
+          gst_bin_add (bin, source->udpsrc[i]);
+
+          /* and link to the funnel v4 */
+          source->selpad[i] = selpad =
+              gst_element_get_request_pad (priv->funnel[i], "sink_%u");
+          pad = gst_element_get_static_pad (source->udpsrc[i], "src");
+          gst_pad_link (pad, selpad);
+          gst_object_unref (pad);
+          gst_object_unref (selpad);
+        }
+        gst_object_unref (bin);
+
+        priv->transport_sources =
+            g_list_prepend (priv->transport_sources, source);
+      } else {
+        GList *l;
+
+        for (l = priv->transport_sources; l; l = l->next) {
+          source = l->data;
+
+          if (source->transport == trans) {
+            priv->transport_sources =
+                g_list_delete_link (priv->transport_sources, l);
+            break;
+          }
+        }
+
+        if (l != NULL) {
+          gint i;
+
+          for (i = 0; i < 2; i++) {
+            /* Will automatically unlink everything */
+            gst_bin_remove (bin,
+                GST_ELEMENT (gst_object_ref (source->udpsrc[i])));
+
+            gst_element_set_state (source->udpsrc[i], GST_STATE_NULL);
+            gst_object_unref (source->udpsrc[i]);
+
+            gst_element_release_request_pad (priv->funnel[i],
+                source->selpad[i]);
+          }
+
+          g_slice_free (GstRTSPMulticastTransportSource, source);
+        }
+      }
+
+      /* fall through for the generic case */
+    }
+    case GST_RTSP_LOWER_TRANS_UDP:
+    {
       gchar *dest;
       gint min, max;
       guint ttl = 0;