rtpbin: added custom downstream sync event

rtpbin can now send a custom in-band downstream event which informs
downstream that the bin has received an RTCP SR packet. This is useful
for applications which want to drop the initial unsynchronized received
RTP packets.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=703560

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>

diff --git a/gst/rtpmanager/gstrtpbin.c b/gst/rtpmanager/gstrtpbin.c
index 0364880..0a0779f 100644 (file)
--- a/gst/rtpmanager/gstrtpbin.c
+++ b/gst/rtpmanager/gstrtpbin.c
@@ -253,6 +253,7 @@ enum
 #define DEFAULT_USE_PIPELINE_CLOCK   FALSE
 #define DEFAULT_RTCP_SYNC            GST_RTP_BIN_RTCP_SYNC_ALWAYS
 #define DEFAULT_RTCP_SYNC_INTERVAL   0
+#define DEFAULT_DO_SYNC_EVENT        FALSE
 
 enum
 {
@@ -268,6 +269,7 @@ enum
   PROP_AUTOREMOVE,
   PROP_BUFFER_MODE,
   PROP_USE_PIPELINE_CLOCK,
+  PROP_DO_SYNC_EVENT,
   PROP_LAST
 };
 
@@ -975,6 +977,25 @@ stream_set_ts_offset (GstRtpBin * bin, GstRtpBinStream * stream,
       stream->ssrc, ts_offset);
 }
 
+static void
+gst_rtp_bin_send_sync_event (GstRtpBinStream * stream)
+{
+  if (stream->bin->send_sync_event) {
+    GstEvent *event;
+    GstPad *srcpad;
+
+    GST_DEBUG_OBJECT (stream->bin,
+        "sending GstRTCPSRReceived event downstream");
+
+    event = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM,
+        gst_structure_new ("GstRTCPSRReceived", NULL));
+
+    srcpad = gst_element_get_static_pad (stream->buffer, "src");
+    gst_pad_push_event (srcpad, event);
+    gst_object_unref (srcpad);
+  }
+}
+
 /* associate a stream to the given CNAME. This will make sure all streams for
  * that CNAME are synchronized together.
  * Must be called with GST_RTP_BIN_LOCK */
@@ -1241,6 +1262,8 @@ gst_rtp_bin_associate (GstRtpBin * bin, GstRtpBinStream * stream, guint8 len,
       stream_set_ts_offset (bin, ostream, ts_offset, TRUE);
     }
   }
+  gst_rtp_bin_send_sync_event (stream);
+
   return;
 }
 
@@ -1840,6 +1863,11 @@ gst_rtp_bin_class_init (GstRtpBinClass * klass)
           0, G_MAXUINT, DEFAULT_RTCP_SYNC_INTERVAL,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
+  g_object_class_install_property (gobject_class, PROP_DO_SYNC_EVENT,
+      g_param_spec_boolean ("do-sync-event", "Do Sync Event",
+          "Send event downstream when a stream is synchronized to the sender",
+          DEFAULT_DO_SYNC_EVENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
   gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_rtp_bin_change_state);
   gstelement_class->request_new_pad =
       GST_DEBUG_FUNCPTR (gst_rtp_bin_request_new_pad);
@@ -1896,6 +1924,7 @@ gst_rtp_bin_init (GstRtpBin * rtpbin)
   rtpbin->priv->autoremove = DEFAULT_AUTOREMOVE;
   rtpbin->buffer_mode = DEFAULT_BUFFER_MODE;
   rtpbin->use_pipeline_clock = DEFAULT_USE_PIPELINE_CLOCK;
+  rtpbin->send_sync_event = DEFAULT_DO_SYNC_EVENT;
 
   /* some default SDES entries */
   cname = g_strdup_printf ("user%u@host-%x", g_random_int (), g_random_int ());
@@ -2039,6 +2068,9 @@ gst_rtp_bin_set_property (GObject * object, guint prop_id,
       GST_RTP_BIN_UNLOCK (rtpbin);
     }
       break;
+    case PROP_DO_SYNC_EVENT:
+      rtpbin->send_sync_event = g_value_get_boolean (value);
+      break;
     case PROP_BUFFER_MODE:
       GST_RTP_BIN_LOCK (rtpbin);
       rtpbin->buffer_mode = g_value_get_enum (value);
@@ -2100,6 +2132,9 @@ gst_rtp_bin_get_property (GObject * object, guint prop_id,
     case PROP_USE_PIPELINE_CLOCK:
       g_value_set_boolean (value, rtpbin->use_pipeline_clock);
       break;
+    case PROP_DO_SYNC_EVENT:
+      g_value_set_boolean (value, rtpbin->send_sync_event);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;

diff --git a/gst/rtpmanager/gstrtpbin.h b/gst/rtpmanager/gstrtpbin.h
index fd0a7cc..22d95f7 100644 (file)
--- a/gst/rtpmanager/gstrtpbin.h
+++ b/gst/rtpmanager/gstrtpbin.h
@@ -56,6 +56,7 @@ struct _GstRtpBin {
   RTPJitterBufferMode buffer_mode;
   gboolean        buffering;
   gboolean        use_pipeline_clock;
+  gboolean        send_sync_event;
   GstClockTime    buffer_start;
   /* a list of session */
   GSList         *sessions;