Fix video stall on playback resume.

Allocation query can stall the straming thread when sent with sink
waiting in pre-roll. Effectively blocking the processing of
data.

This change implements dropping of the query in source pad, since we
don't use proposed allocation anywhay. And also removes the extra
buffering target for video (reducing the time to resume the playback).

Change-Id: I32b4a303763e958ef8fcadebd9f2e4820594be24
Signed-off-by: Eugene Mutavchi <Ievgen_Mutavchi@comcast.com>

src/third_party/starboard/rdk/shared/player/player_internal.cc

diff --git a/src/third_party/starboard/rdk/shared/player/player_internal.cc b/src/third_party/starboard/rdk/shared/player/player_internal.cc
index 2b7b8a7..0e3b448 100644
--- a/src/third_party/starboard/rdk/shared/player/player_internal.cc
+++ b/src/third_party/starboard/rdk/shared/player/player_internal.cc
@@ -542,6 +542,19 @@
     }, gst_segment_new(), reinterpret_cast<GDestroyNotify>(gst_segment_free));
 #endif
 
+  // Allocation query can stall streaming thread if sent during pre-roll.
+  // Drop the query since we don't use proposed allocation anyway.
+  gst_pad_add_probe (
+    pad, GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM,
+    [](GstPad * pad, GstPadProbeInfo * info, gpointer data) -> GstPadProbeReturn {
+      GstQuery* query = GST_PAD_PROBE_INFO_QUERY(info);
+      if (GST_QUERY_TYPE (query) == GST_QUERY_ALLOCATION) {
+        GST_DEBUG_OBJECT(pad, "Drop allocation query");
+        return GST_PAD_PROBE_DROP;
+      }
+      return GST_PAD_PROBE_OK;
+    }, nullptr, nullptr);
+
   auto proxypad = GST_PAD(gst_proxy_pad_get_internal(GST_PROXY_PAD(pad)));
   gst_flow_combiner_add_pad(src->priv->flow_combiner, proxypad);
   gst_pad_set_chain_function(proxypad, static_cast<GstPadChainFunction>(gst_cobalt_src_chain_with_parent));
@@ -2945,7 +2958,6 @@
   }
 
   if (video_appsrc_) {
-    target +=  10 * 16 * GST_MSECOND;
     if (add_probe(video_appsrc_, target, ticket, buffering_probe_callback) != 0u)
       buffering_state_ |= static_cast<int>(MediaType::kVideo);
   }