webrtcbin: fix blocking of receive bin

The receive bin should block buffers from reaching dtlsdec before
the dtls connection has started.

While there was code to block its sinkpads until receive_state
was different from BLOCK, nothing was ever setting it to BLOCK
in the first place. This commit corrects this by setting the
initial state to BLOCK, directly in the constructor.

In addition, now that blocking is effective, we want to only
block buffers and buffer lists, as that's what might trigger
errors, we want to still let events and queries go through,
not doing so causes immediate deadlocks when linking the
bin.

diff --git a/ext/webrtc/transportreceivebin.c b/ext/webrtc/transportreceivebin.c
index 667fae6344a9407b8c289b14cb2463fd9b7dea7e..16a0452828d643c5a51c87df1dbad63e6077418a 100644 (file)
--- a/ext/webrtc/transportreceivebin.c
+++ b/ext/webrtc/transportreceivebin.c
@@ -215,13 +215,14 @@ transport_receive_bin_change_state (GstElement * element,
       receive->rtp_block =
           _create_pad_block (GST_ELEMENT (receive), pad, 0, NULL, NULL);
       receive->rtp_block->block_id =
-          gst_pad_add_probe (pad, GST_PAD_PROBE_TYPE_ALL_BOTH,
+          gst_pad_add_probe (pad,
+          GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST,
           (GstPadProbeCallback) pad_block, receive, NULL);
       gst_object_unref (pad);
 
       receive->rtp_src_probe_id = gst_pad_add_probe (receive->rtp_src,
-          GST_PAD_PROBE_TYPE_ALL_BOTH, (GstPadProbeCallback) src_probe_cb,
-          receive, NULL);
+          GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST,
+          (GstPadProbeCallback) src_probe_cb, receive, NULL);
 
       transport = receive->stream->rtcp_transport;
       dtlssrtpdec = transport->dtlssrtpdec;
@@ -229,13 +230,14 @@ transport_receive_bin_change_state (GstElement * element,
       receive->rtcp_block =
           _create_pad_block (GST_ELEMENT (receive), pad, 0, NULL, NULL);
       receive->rtcp_block->block_id =
-          gst_pad_add_probe (pad, GST_PAD_PROBE_TYPE_ALL_BOTH,
+          gst_pad_add_probe (pad,
+          GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST,
           (GstPadProbeCallback) pad_block, receive, NULL);
       gst_object_unref (pad);
 
       receive->rtcp_src_probe_id = gst_pad_add_probe (receive->rtcp_src,
-          GST_PAD_PROBE_TYPE_ALL_BOTH, (GstPadProbeCallback) src_probe_cb,
-          receive, NULL);
+          GST_PAD_PROBE_TYPE_BUFFER | GST_PAD_PROBE_TYPE_BUFFER_LIST,
+          (GstPadProbeCallback) src_probe_cb, receive, NULL);
 
       /* XXX: because nice needs the nicesrc internal main loop running in order
        * correctly STUN... */
@@ -448,6 +450,7 @@ transport_receive_bin_class_init (TransportReceiveBinClass * klass)
 static void
 transport_receive_bin_init (TransportReceiveBin * receive)
 {
+  receive->receive_state = RECEIVE_STATE_BLOCK;
   g_mutex_init (&receive->pad_block_lock);
   g_cond_init (&receive->pad_block_cond);
 }